WO2023018649A1

WO2023018649A1 - Liquid formulations comprising alginic acid, pectin, and carrageenan and methods of using thereof for gastric and gastroesophageal disorders

Info

Publication number: WO2023018649A1
Application number: PCT/US2022/039699
Authority: WO
Inventors: Reginald Bradley; Debanjan DAS; Gerard MEISEL
Original assignee: Bayer Healthcare Llc
Priority date: 2021-08-10
Filing date: 2022-08-08
Publication date: 2023-02-16

Abstract

The present disclosure relates generally to formulations for gastric and gastroesophageal disorders, such as gastroesophageal reflux disorder (GERD) acid reflux, peptic ulceration, acute and/or chronic gastritis, and other disorders, and more specifically to formulations comprising alginic acid or pharmaceutically acceptable salts thereof, pectin, and carrageenan. The liquid formulations described herein demonstrate long-lasting mucoadhesion and raft-forming ability. The present disclosure also provides methods of using the liquid formulations described herein for treatment of such gastric and gastroesophageal disorders.

Description

LIQUID FORMULATIONS COMPRISING ALGINIC ACID, PECTIN, AND CARRAGEENAN AND METHODS OF USING THEREOF FOR GASTRIC AND GASTROESOPHAGEAL DISORDERS

FIELD

[0001] The present disclosure relates generally to liquid formulations for gastric and gastroesophageal disorders, such as gastroesophageal reflux disorder (GERD), peptic ulceration, acute and/or chronic gastritis, and more specifically to oral antacid suspensions comprising alginic acid or pharmaceutically acceptable salts thereof in combination with pectin and/or carrageenan. The liquid formulations described herein possess raft-forming ability when introduced into the stomach and also demonstrate long-lasting adhesion to the mucous membranes of the esophagus and stomach. The formulations may offer immediate relief to inflamed or ulcerated mucosa associated with said disorders by coating gastric and esophageal surfaces, while also providing extended relief in the form of long-lasting protective barriers (raft and coating) against further irritation. The formulations described herein may further facilitate the recovery of damaged tissues caused by chronic exposure to stomach acid. The present disclosure also provides methods of using the formulations described herein for treatment of such gastric and gastroesophageal disorders.

BACKGROUND

[0002] Gastric acid plays a critical role in the digestion and breakdown of food within the stomach. Due to its caustic nature, gastric acid is maintained at precisely balanced levels in the stomach to avoid injury to the lining of the stomach upon prolonged contact with the acid. The stomach also secretes mucus, which typically protects the interior of the membranes of the stomach from the acid. However, when the quantity of stomach acid exceeds the body’s capacity to generate mucus or if gastric acid incidentally comes into contact with the esophagus, irritation of the mucous membranes of the stomach and/or esophagus may occur. A number of common gastric and gastroesophageal disorders, such as gastroesophageal reflux disorder, acid reflux, peptic ulcers, non-ulcer dyspepsia, bloating, gastroparesis, aerophagia, diarrhea and constipation arise directly from acute and chronic irritation of these tissues by stomach acid. Yet despite the widespread nature of these disorders, there exist very few treatments that not only alleviate the symptoms associated with these disorders in the short-term but which also provide long-term relief for the same symptoms, facilitate healing of inflamed or irritated mucosae and prevent further damage to these tissues. [0003] Thus, there is a need for improved formulations to treat gastric and gastroesophageal disorders that provide both short-term and long-term symptomatic relief, as well as healing effects to damaged tissue and prevention against further injury and irritation.

BRIEF SUMMARY

[0004] The present disclosure provides liquid oral antacid formulations comprising combinations of alginic acid or pharmaceutically acceptable salts thereof, with either pectin or carrageenan, or both, as part of a highly mucoadhesive hydrocolloid and raft-forming system to treat gastric and gastroesophageal disorders. The liquid formulations described herein possess more enduring mucoadhesion than stronger rafts as compared to existing, commercially available treatments. The liquid formulations of the present disclosure provide symptomatic relief to gastric and esophageal tissues and prevent further irritation by stomach acid. The long-lasting mucoadhesion of these formulations may also promote healing of damaged mucosae.

[0005] In one aspect, provided herein is a liquid formulation, comprising: alginic acid or a pharmaceutically acceptable salt thereof; at least one of pectin and carrageenan; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin, and any carrageenan present in the liquid formulation is 2-20% w/w.

[0006] In another aspect, provided herein is a liquid formulation, comprising: 1-18% w/w alginic acid or a pharmaceutically acceptable salt thereof; 1-10% w/w pectin, carrageenan, or a combination thereof; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin, and any carrageenan present in the liquid formulation is 3.5-20% w/w.

[0007] In yet another aspect, provided herein is A liquid formulation, comprising: 1-8% w/w alginic acid or a pharmaceutically acceptable salt thereof; 3.5-10% w/w pectin, carrageenan, or a combination thereof; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin, and any carrageenan present in the liquid formulation is 4.5-15% w/w.

[0008] In still yet another aspect, provided herein is a container, comprising a liquid formulation as described herein. [0009] In one aspect, provided herein is a method for treating gastroesophageal reflux disorder (GERD) and/or peptic ulceration, comprising administering to a human in need thereof a liquid formulation as described herein.

[0010] In another aspect, provided herein is a method for treating acute or chronic gastritis, comprising administering to a human in need thereof a liquid formulation as described herein.

[0011] In a further aspect, provided herein is a method for treating acid reflux, comprising administering to a human in need thereof a liquid formulation as described herein.

DESCRIPTION OF THE FIGURES

[0012] The present application can be understood by reference to the following description taken in conjunction with the accompanying figures.

[0013] FIG. 1A depicts an exemplary apparatus for conducting raft strength tests, employing a texture analyzer (TA-XT2) fitted with an L-shaped wire probe.

[0014] FIG. IB and 1C depict an exemplary apparatus for bioadhesion tests using a texture analyzer fitted with a polyethylene attachment.

[0015] FIGS. 2A-2C show the raft strength (rafting force), raft thickness and raft weight for various formulations subjected to raft formation tests. The raft formation tests were carried out before and after storage at 40°C for 1 month (IM).

[0016] FIGS. 3A-3D depict the migration of sample formulations subjected to bioadhesion tests using a transparent sample tray at an initial position of 0° (horizontal, FIG.

3A and FIG. 3C) and after being held for thirty seconds at a 45° angle (FIG. 3B and FIG.

3D)

[0017] FIGS. 4A-4D show photographs of Formulations #1-4 before (FIGS. 4A and 4C) and after (FIGS. 4B and 4D) storage at 40°C and 75% relative humidity (RH) for 1 month.

[0018] FIGS. 5A and 5B show photographs of Formulations #1-4 before (FIG. 5A) and after (FIG. 5B) three cycles of freeze-thaw cycling (-20°C for 3 days and 25°C, 60% relative humidity for 4 days, for each cycle). DETAILED DESCRIPTION

[0019] The following description sets forth exemplary methods, parameters and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure but is instead provided as a description of exemplary embodiments.

[0020] Gastric and gastroesophageal disorders affect a significant percentage of people in Western populations on a protracted basis. The majority of over-the-counter treatments address these disorders by using orally administered active pharmaceutical ingredients that attempt to regulate the pH of the gastric environment and the amount of stomach acid generated. Typical actives may include antacids, which serve to neutralize excess acid in the stomach, or proton-pump inhibitors, which inhibit acid secretion into the stomach. Other formulations may contain ingredients that may actively form a continuous gel layer (known as a raft) that acts as a physical barrier within the stomach to prevent acid reflux into the esophagus. Alternative treatments may contain ingredients that may coat ulcerated or exposed mucosa in the esophagus and stomach to mitigate any additional irritation by gastric acid. Although the various approaches can successfully ameliorate certain symptoms of these gastric and gastroesophageal disorders, many of these formulations often do not address multiple symptoms at the same time. Furthermore, these existing treatments are specially formulated to achieve either immediate pain relief or long-term relief but are frequently limited in their ability to provide both.

[0021] Few formulations exist that can alleviate multiple short-term and long-term symptoms in a single formulation. The difficulty in manufacturing a single formulation to address the symptoms arises from the complexity of identifying suitable ingredients to achieve the desired balance of physical properties that would simultaneously reduce acidity, provide a lastingly adhesive coating, and form a robust raft barrier while also remaining palatable to the end consumer in both mouthfeel and flavor.

[0022] For example, the ability of a formulation to adhere to and coat mucous membranes, which may be referred to herein interchangeably as “mucoadhesion” or “bioadhesion”, exists in a delicate balance. If a formulation is too thin, the liquid formulation may not coat and adhere to the mucosae; however, if too thick or viscous, the liquid formulation may adhere to itself but form an overly thick coating which fails to bond to the lining of the esophagus or stomach due to its weight. Even greater difficulty arises in maintaining mucoadhesion to the membranes of the stomach or esophagus for extended periods of time, particularly when exposed to swallowed saliva and stomach acid that could contribute to the removal of the coating over time. The viscosity of the liquid formulations may also affect their ability to produce suitably uniform rafts to prevent reflux; if too thick, the liquid formulations may generate rafts having variable density across the gel layer. From the standpoint of palatability, highly viscous formulations may be off-putting when consumed and can even cause dysphagia (difficulty in swallowing) or odynophagia (pain while swallowing), whereas overly thin formulations may be palatable but ineffectual.

[0023] Raft-forming systems involve a separate set of physical criteria from that of mucoadhesive formulations. In raft-forming systems, components within the liquid formulations come into contact with gastric acid to form a continuous gel layer. The density of the gel layer is such that the layer, or raft, floats on top of the gastric fluid and thus serves as a physical barrier to stop reflux of any material in the stomach into the esophagus. In order to form such a gel layer, the liquid formulations may incorporate ingredients that cross-link when exposed to stomach acid, such as polysaccharides, starches or vegetable gums. Additional carbon dioxide-generating ingredients, such as bicarbonate and carbonate salts, are incorporated to ensure that resulting cross-linked gel exhibits the desired buoyancy to float to the top of the gastric fluid. On the other hand, the ingredients that form the raft are preferably selected such that, once formed, the buoyant raft is sufficiently dense to obstruct acid reflux, as well as adequately robust and long-lasting to remain intact in the stomach for several hours.

[0024] Certain formulations may deliver active pharmaceutical ingredients to the stomach, such as antacids. Common antacids include but are not limited to alkaline salts of aluminum, calcium, magnesium and sodium. However, many antacid formulations employing aluminum-, magnesium-, or calcium-based actives possess an apparent metallic flavor, which could be distasteful when taken.

[0025] Preparing a liquid formulation that manages to achieve the physical characteristics of a mucoadhesive, raft-forming antacid system and possesses a favorable organoleptic profile while further preserving all of these properties with a long shelf-life and high storage stability presents a complex problem. The present disclosure addresses this problem by providing liquid oral antacid formulations employing unique combinations of naturally mucoadhesive polysaccharide ingredients which also have substantial cross-linking capacity to form durable rafts.

[0026] The present disclosure details liquid formulations that employ alginic acid or a pharmaceutically acceptable salt thereof along with pectin and/or carrageenan to produce hydrocolloid, raft-forming systems which possess substantial mucoadhesion and high storage stability, as evidenced by their ability to form rafts and retain mucoadhesiveness after exposure to elevated temperature conditions. As described herein, it was observed that combinations of naturally bioadhesive polysaccharide components, particularly alginic acid or a pharmaceutically acceptable salt thereof with pectin, carrageenan, or a combination of pectin and carrageenan, could achieve the both the degree of gelation and adhesiveness to mucous membranes to provide a raft-forming system, a mucosal coating, and general antacid in a single formulation.

[0027] The liquid formulations provided herein not only combine raft-forming capabilities with mucoadhesion to provide a single formulation that provides immediate and extended pain relief from chronic acidity, that is, when administered on an empty stomach, but also provides sustained relief and protection against GERD. The liquid formulations of the present disclosure can be tailored to exhibit superior raft performance and/or superior mucoadhesion both before and after storage, as compared to commercially available treatments for the same gastric disorders, such as Gaviscon ® Extra Strength, Gaviscon ® Advance, and Boots Heartburn Relief.

[0028] Furthermore, the mucoadhesive properties of the liquid formulations provided herein not only provide a physical barrier against direct contact of ulcerated mucosae to stomach acid but may also provide enhanced healing effect to the ulcerated membranes themselves. The ability of the hydrocolloid formulations of the present disclosure to maintain mucoadhesion over extended periods of time may, in concert with antacid ingredients, provide similar or even superior healing properties for ulcer treatment as observed to hydrotalcite. Hydrotalcite is a mineral having a double layer of hydroxide of aluminum and magnesium hydroxide and carbonate. Due to favorable ionic interactions with ulcers, hydrotalcite used as an antacid, anti-reflux agent and antiulcerant. Although the precise role of hydrotalcite in promoting healing of and protecting against ulcers is not fully understood, hydrotalcite may achieve enhanced healing of gastric epithelial cells by various potential mechanisms including, but not limited to, activating Coxl and Cox2 in gastric mucosa, increasing prostaglandin synthesis/release, increasing bicarbonate and mucus secretion, binding and inactivating pepsin and H. pylori toxins, among others. However, in contrast to the hydrocolloid formulations provided herein, the mineral properties of hydrotalcite may not lend themselves to extended mucoadhesion in the gastric environment. Thus, the liquid formulations provided herein may lead to longer contact times of antacids with the lining of the stomach than can be achieved with hydrotalcite.

[0029] Additionally, it should be recognized that the liquid formulations of the present disclosure are oral suspensions, similar to many other commercially available gastric and gastroesophageal treatments. In typical oral suspensions, not all of the ingredients provided in the formulation may be fully dissolved in liquid. As a result, the majority of end consumers may find these typical oral suspensions unpalatable and displeasing, particularly antacid formulations containing metallic-tasting, gritty alkaline salts. However, by virtue of utilizing alginic acid or a pharmaceutically acceptable salt thereof, pectin and carrageenan in further combination with taste-modifying excipients, the liquid formulations provide improved tastemasking, mouthfeel, and aroma as compared to existing antacid formulations.

[0030] The following description sets forth exemplary methods, parameters and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure but is instead provided as a description of exemplary embodiments.

[0031] Reference to “about” a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se. For example, description referring to “about X” includes description of “X”. In some embodiments, the term “about” when used in association with a measurement, or used to modify a value, a unit, a constant, or a range of values, refers to variations of +/- 2%.

[0032] Reference to “between” two values or parameters herein includes (and describes) embodiments that include those two values or parameters per se. For example, description referring to “between x and y” includes description of “x” and “y” per se.

[0033] It is understood that aspects and variations described herein also include “consisting” and/or “consisting essentially of’ aspects and variations.

Liquid Formulations [0034] In one aspect of the present disclosure, provided herein are liquid formulations comprising alginic acid or a pharmaceutically acceptable salt thereof; at least one of pectin and carrageenan; sodium bicarbonate, at least one antacid; and water. In still other embodiments, the liquid formulation is an oral suspension.

[0035] Provided herein are liquid formulations for use in the treatment of gastric and gastroesophageal disorders. As detailed above, the liquid formulations of the present disclosure are antacid formulations provided in an oral suspension, which may further form a hydrocolloid coating on mucous membranes and a continuous gel raft in the stomach. The liquid formulations not only manage to achieve a highly mucoadhesive, raft-forming system in a single composition but further demonstrate superior mucoadhesion and raft-forming ability as compared to existing, commercially available treatments. The superior therapeutic properties arise from a unique selection of naturally bioadhesive, cross-linking polysaccharides that, when used in combination, confer the physical characteristics that allow acid-neutralizing effect, long-lasting mucoadhesion and raft-forming capacity to exist in in a single formulation.

[0036] The naturally bioadhesive, cross-linking ingredients include alginic acid or a pharmaceutically acceptable salt thereof, pectin and carrageenan. In some embodiments of the present aspect, the liquid formulation comprises alginic acid or a pharmaceutically acceptable salt thereof and at least one of pectin and carrageenan. As employed in the liquid formulations herein, alginic acid or the pharmaceutically acceptable salts thereof, pectin and carrageenan all contribute to the resulting mucoadhesion, raft-forming capacity, viscosity, and other properties of the liquid formulations.

Alginic Acid or a Pharmaceutically Acceptable Salt thereof

[0037] In some embodiments of the present aspect, the liquid formulation comprises alginic acid or a pharmaceutically acceptable salt thereof. Alginic acid is a naturally occurring hydrophilic polysaccharide that is found in brown seaweed. When exposed to water, alginic acid and its salts may form viscous gels and biofilms. As a typical component in pharmaceutical formulations and food products, alginic acid or pharmaceutically acceptable salts thereof may be incorporated for any number of functionalities, including but not limited to as a thickening agent, viscosity increaser/enhancing agent, a stabilizer, or a gelling agent. Common alginate salts may include but are not limited to sodium alginate and calcium alginate.

[0038] In certain embodiments, the liquid formulation comprises alginic acid. In certain other embodiments, the liquid formulation comprises a pharmaceutically acceptable salt of alginic acid. In certain other embodiments, the liquid formulation comprises sodium alginate, calcium alginate, potassium alginate, ammonium alginate, magnesium alginate, or any combinations thereof. In still certain other embodiments, the liquid formulation comprises sodium alginate.

[0039] The quantity of any ingredients provided in the liquid formulations herein may be expressed as a weight percentage of the total weight of the liquid formulation. In some embodiments, the liquid formulation comprises at least about 0.1% w/w, at least about 0.5% w/w, at least about 1% w/w, at least about 2% w/w, at least about 3% w/w, at least about 4% w/w, at least about 5% w/w, at least about 6% w/w, at least about 7% w/w, at least about 8% w/w, at least about 9% w/w, at least about 10% w/w, at least about 12% w/w, at least about 15% w/w, or at least about 18% w/w alginic acid or a pharmaceutically acceptable salt thereof. In certain embodiments, the liquid formulation comprises at least about 1% w/w, at least about 5% w/w, or at least about 8% w/w alginic acid or a pharmaceutically acceptable salt thereof.

[0040] In other embodiments, the liquid formulation comprises less than or equal to about 20% w/w, less than or equal to about 18% w/w, less than or equal to about 15% w/w, less than or equal to about 12% w/w, less than or equal to about 10% w/w, less than or equal to about 8% w/w, less than or equal to about 7% w/w, less than or equal to about 6% w/w, less than or equal to about 5% w/w, less than or equal to about 4% w/w, less than or equal to about 3% w/w, less than or equal to about 2% w/w, or less than or equal to about 1% w/w alginic acid or a pharmaceutically acceptable salt thereof. In certain other embodiments, the liquid formulation comprises less than or equal to about 18% w/w, less than or equal to about 15% w/w, less than or equal to about 12% w/w, less than or equal to about 10% w/w, or less than or equal to about 8% w/w alginic acid or a pharmaceutically acceptable salt thereof.

[0041] In still other embodiments, the liquid formulation comprises about 0.1-20% w/w, about 0.1-18% w/w, about 0.1-15% w/w, about 0.1-12% w/w, about 0.1-10% w/w, about 0.1- 8% w/w, about 0.1-7% w/w, about 0.1-6% w/w, about 0.1-5% w/w, about 0.1-4% w/w, about 0.1-3% w/w, about 0.1-2% w/w, about 0.1-1% w/w, about 0.5-20% w/w, about 0.5-18% w/w, about 0.5-15% w/w, about 0.5-12% w/w, about 0.5-10% w/w, about 0.5-8% w/w, about 0.5- 7% w/w, about 0.5-6% w/w, about 0.5-5% w/w, about 0.5-4% w/w, about 0.5-3% w/w, about 0.5-2% w/w, about 0.5-1% w/w, about 1-20% w/w, about 1-18% w/w, about 1-15% w/w, about 1-12% w/w, about 1-10% w/w, about 1-8% w/w, about 1-7% w/w, about 1-6% w/w, about 1-5% w/w, about 1-4% w/w, about 1-3% w/w, about 1-2% w/w, about 2-20% w/w, about 2-18% w/w, about 2-15% w/w, about 2-12% w/w, about 2-10% w/w, about 2-8% w/w, about 2-7% w/w, about 2-6% w/w, about 2-5% w/w, about 2-4% w/w, about 2-3% w/w, about 3-20% w/w, about 3-18% w/w, about 3-15% w/w, about 3-12% w/w, about 3-10% w/w, about 3-8% w/w, about 3-7% w/w, about 3-6% w/w, about 3-5% w/w, about 3-4% w/w, about 4-20% w/w, about 4-18% w/w, about 4-15% w/w, about 4-12% w/w, about 4-10% w/w, about 4-8% w/w, about 4-7% w/w, about 4-6% w/w, about 4-5% w/w, about 5-20% w/w, about 5-18% w/w, about 5-15% w/w, about 5-12% w/w, about 5-10% w/w, about 5-8% w/w, about 5-7% w/w, about 5-6% w/w, about 6-20% w/w, about 6-18% w/w, about 6-15% w/w, about 6-12% w/w, about 6-10% w/w, about 6-8% w/w, about 6-7% w/w, about 7-20% w/w, about 7-18% w/w, about 7-15% w/w, about 7-12% w/w, about 7-10% w/w, about 7-8% w/w, about 8-20% w/w, about 8-18% w/w, about 8-15% w/w, about 8-12% w/w, about 8- 10% w/w, about 10-20% w/w, about 10-18% w/w, about 10-15% w/w, about 10-12% w/w, about 12-20% w/w, about 12-18% w/w, about 12-15% w/w, about 15-20% w/w, about 15- 18% w/w, or about 18-20% w/w alginic acid or a pharmaceutically acceptable salt thereof. In certain embodiments, the liquid formulation comprises 1-18% w/w, 1-8% w/w, 1-5% w/w, or 5-8% w/w alginic acid or a pharmaceutically acceptable salt thereof.

Pectin

[0042] In some embodiments, the liquid formulation comprises pectin. Pectin broadly refers to a complex group of heterogeneous polysaccharides derived from plants. Similar to alginic acid, pectin may be employed in pharmaceutical formulations and food products as a thickening agent, viscosity enhancing agent, gelling agent, and stabilizer. As utilized in the present disclosure, pectin provides gelling, thickening and stabilizing properties as well as natural mucoadhesive properties to the resulting liquid formulations. As pectin encompasses a variety of heteropolysaccharides, the term “pectin” as used herein may refer to and encompass the set of heteropolysaccharides generally known as pectic polysaccharides, or alternatively may be used to refer to particular subcategories of heteropolysaccharides within the broader class of pectic polysaccharides. In still certain embodiments, the pectin used herein may be further characterized by other chemical characteristics, such as the degree of methoxylation of the saccharide units within polysaccharide molecules, which may influence the physical properties of the liquid formulations. Suitable pectins for the formulations of the present disclosure may include but are not limited to high-methoxylated (HM) pectin, low- methoxlated (LM) pectin, and/or amidated low-methoxylated (LM) pectin.

[0043] As described herein, the terms “high-methoxylated”, “high-methoxy”, “high- methoxyl” and “high-ester” pectin refers to pectic polysaccharides having greater than or equal to about 50% of saccharide carboxyl groups esterified or methoxylated. Similarly, the terms “low-methoxylated”, “low -methoxy”, “low -methoxyl” and “low -ester” pectin refers to pectic polysaccharides having less than about 50% of saccharide carboxyl groups esterified or methoxylated. Both high-methoxylated and low-methoxylated pectin may form continuous gel structures but may do so under differing conditions. For example, highly methoxylated pectin may readily form cross-linked gels under acidic conditions, whereas low-methoxylated pectin may require calcium ions to facilitate gelation but can form cross-linked gels at higher pH levels.

[0044] In some embodiments, the liquid formulation comprises high-methoxylated pectin, low-methoxylated pectin, a combination thereof. In other embodiments, the pectin present in the liquid formulations comprises high-methoxylated pectin, low-methoxylated pectin, a combination thereof. In some embodiments, the liquid formulation comprises low- methoxylated pectin. In other embodiments, the pectin is low-methoxylated pectin. In still other embodiments, the liquid formulation comprises amidated low-methoxylated pectin. In other embodiments, the pectin is amidated low-methoxylated pectin. In certain embodiments wherein the pectin is low-methoxylated pectin or amidated low-methoxylated pectin, the liquid formulation further comprises calcium ions. In certain embodiments wherein the pectin is low-methoxylated pectin or amidated low-methoxylated pectin and the liquid formulation further comprises calcium ions, the at least one antacid in the liquid formulation comprises a pharmaceutically acceptable calcium salt. In some embodiments, the liquid formulation comprises high-methoxylated pectin. In other embodiments, the pectin is high-methoxylated pectin.

[0045] In some embodiments, the liquid formulation comprises at least about 0.1% w/w, at least about 0.5% w/w, at least about 0.8% w/w, at least about 1% w/w, at least about 2% w/w, at least about 3% w/w, at least 3.5% w/w, at least about 4% w/w, at least about 5% w/w, at least about 6% w/w, at least about 7% w/w, at least about 8% w/w, at least about 9% w/w, at least about 10% w/w, at least about 12% w/w, at least about 15% w/w, or at least about 18% w/w pectin. In certain embodiments, the liquid formulation comprises at least about 0.5% w/w, at least about 0.8% w/w, at least about 1% w/w, at least 3.5% w/w, at least about 5% w/w, or at least about 8% w/w pectin.

[0046] In other embodiments, the liquid formulation comprises less than or equal to about 20% w/w, less than or equal to about 18% w/w, less than or equal to about 15% w/w, less than or equal to about 12% w/w, less than or equal to about 10% w/w, less than or equal to about 8% w/w, less than or equal to about 7% w/w, less than or equal to about 6% w/w, less than or equal to about 5% w/w, less than or equal to about 4% w/w, less than or equal to about 3% w/w, less than or equal to about 2% w/w, or less than or equal to about 1% w/w pectin. In certain other embodiments, the liquid formulation comprises less than or equal to about 18% w/w, less than or equal to about 15% w/w, less than or equal to about 12% w/w, less than or equal to about 10% w/w, less than or equal to about 8% w/w, less than or equal to about 5% w/w, or less than or equal to about 3% w/w pectin.

[0047] In still other embodiments, the liquid formulation comprises about 0.1-20% w/w, about 0.1-18% w/w, about 0.1-15% w/w, about 0.1-12% w/w, about 0.1-10% w/w, about 0.1- 8% w/w, about 0.1-7% w/w, about 0.1-6% w/w, about 0.1-5% w/w, about 0.1-4% w/w, about 0.1-3% w/w, about 0.1-2% w/w, about 0.1-1% w/w, about 0.5-20% w/w, about 0.5-18% w/w, about 0.5-15% w/w, about 0.5-12% w/w, about 0.5-10% w/w, about 0.5-8% w/w, about 0.5- 7% w/w, about 0.5-6% w/w, about 0.5-5% w/w, about 0.5-4% w/w, about 0.5-3% w/w, about 0.5-2% w/w, about 0.5-1% w/w, about 1-20% w/w, about 1-18% w/w, about 1-15% w/w, about 1-12% w/w, about 1-10% w/w, about 1-8% w/w, about 1-7% w/w, about 1-6% w/w, about 1-5% w/w, about 1-4% w/w, about 1-3% w/w, about 1-2% w/w, about 2-20% w/w, about 2-18% w/w, about 2-15% w/w, about 2-12% w/w, about 2-10% w/w, about 2-8% w/w, about 2-7% w/w, about 2-6% w/w, about 2-5% w/w, about 2-4% w/w, about 2-3% w/w, about 3-20% w/w, about 3-18% w/w, about 3-15% w/w, about 3-12% w/w, about 3-10% w/w, about 3-8% w/w, about 3-7% w/w, about 3-6% w/w, about 3-5% w/w, about 3-4% w/w, about 3.5-20% w/w, about 3.5-18% w/w, about 3.5-15% w/w, about 3.5-12% w/w, about 3.5- 10% w/w, about 3.5-8% w/w, about 3.5-7% w/w, about 3.5-6% w/w, about 3.5-5% w/w, about 3.5-4% w/w, about 4-20% w/w, about 4-18% w/w, about 4-15% w/w, about 4-12% w/w, about 4-10% w/w, about 4-8% w/w, about 4-7% w/w, about 4-6% w/w, about 4-5% w/w, about 5-20% w/w, about 5-18% w/w, about 5-15% w/w, about 5-12% w/w, about 5- 10% w/w, about 5-8% w/w, about 5-7% w/w, about 5-6% w/w, about 6-20% w/w, about 6- 18% w/w, about 6-15% w/w, about 6-12% w/w, about 6-10% w/w, about 6-8% w/w, about 6- 7% w/w, about 7-20% w/w, about 7-18% w/w, about 7-15% w/w, about 7-12% w/w, about 7- 10% w/w, about 7-8% w/w, about 8-20% w/w, about 8-18% w/w, about 8-15% w/w, about 8- 12% w/w, about 8-10% w/w, about 10-20% w/w, about 10-18% w/w, about 10-15% w/w, about 10-12% w/w, about 12-20% w/w, about 12-18% w/w, about 12-15% w/w, about 15- 20% w/w, about 15-18% w/w, or about 18-20% w/w pectin. In certain embodiments, the liquid formulation comprises 1-10% w/w, 3.5-10% w/w, 0.5-5% w/w, or 0.5-3% w/w pectin.

Carrageenan

[0048] In some embodiments, the liquid formulation comprises carrageenan. Carrageenan is a sulfated polysaccharide derived from red seaweed. Similar to alginic acid and pectin, carrageenan is commonly used as a multifunctional agent for its gelling, thickening and stabilizing properties. As incorporated in the liquid formulations of the present disclosure, carrageenan contributes to the mucoadhesion, overall viscosity, and raft-forming properties of the resulting oral suspension.

[0049] Carrageenan exists in three main varieties with respect to the degree of sulfation present per disaccharide unit. Kappa-carrageenan contains one sulfate group per disaccharide unit, iota-carrageenan has two sulfates per disaccharide, and lambda-carrageenan possesses three sulfate groups. Higher levels of sulfation result in lower strength gels or, in the case of lambda-carrageenan may even inhibit gelation. In some embodiments the carrageenan is kappa-carrageenan, iota-carrageenan, lambda-carrageenan, or any combination thereof. In other embodiments, the carrageenan is kappa-carrageenan.

[0050] In some embodiments, the liquid formulation comprises at least about 0.1% w/w, at least about 0.5% w/w, at least about 0.8% w/w, at least about 1% w/w, at least about 2% w/w, at least about 3% w/w, at least 3.5% w/w, at least about 4% w/w, at least about 5% w/w, at least about 6% w/w, at least about 7% w/w, at least about 8% w/w, at least about 9% w/w, at least about 10% w/w, at least about 12% w/w, at least about 15% w/w, or at least about 18% w/w carrageenan. In certain embodiments, the liquid formulation comprises at least about 0.5% w/w, at least about 0.8% w/w, at least about 1% w/w, at least 3.5% w/w, at least about 5% w/w, or at least about 8% w/w carrageenan.

[0051] In other embodiments, the liquid formulation comprises less than or equal to about 20% w/w, less than or equal to about 18% w/w, less than or equal to about 15% w/w, less than or equal to about 12% w/w, less than or equal to about 10% w/w, less than or equal to about 8% w/w, less than or equal to about 7% w/w, less than or equal to about 6% w/w, less than or equal to about 5% w/w, less than or equal to about 4% w/w, less than or equal to about 3% w/w, less than or equal to about 2% w/w, or less than or equal to about 1% w/w carrageenan. In certain other embodiments, the liquid formulation comprises less than or equal to about 18% w/w, less than or equal to about 15% w/w, less than or equal to about 12% w/w, less than or equal to about 10% w/w, less than or equal to about 8% w/w, less than or equal to about 5% w/w, or less than or equal to about 3% w/w carrageenan.

[0052] In still other embodiments, the liquid formulation comprises about 0.1-20% w/w, about 0.1-18% w/w, about 0.1-15% w/w, about 0.1-12% w/w, about 0.1-10% w/w, about 0.1- 8% w/w, about 0.1-7% w/w, about 0.1-6% w/w, about 0.1-5% w/w, about 0.1-4% w/w, about 0.1-3% w/w, about 0.1-2% w/w, about 0.1-1% w/w, about 0.5-20% w/w, about 0.5-18% w/w, about 0.5-15% w/w, about 0.5-12% w/w, about 0.5-10% w/w, about 0.5-8% w/w, about 0.5- 7% w/w, about 0.5-6% w/w, about 0.5-5% w/w, about 0.5-4% w/w, about 0.5-3% w/w, about 0.5-2% w/w, about 0.5-1% w/w, about 1-20% w/w, about 1-18% w/w, about 1-15% w/w, about 1-12% w/w, about 1-10% w/w, about 1-8% w/w, about 1-7% w/w, about 1-6% w/w, about 1-5% w/w, about 1-4% w/w, about 1-3% w/w, about 1-2% w/w, about 2-20% w/w, about 2-18% w/w, about 2-15% w/w, about 2-12% w/w, about 2-10% w/w, about 2-8% w/w, about 2-7% w/w, about 2-6% w/w, about 2-5% w/w, about 2-4% w/w, about 2-3% w/w, about 3-20% w/w, about 3-18% w/w, about 3-15% w/w, about 3-12% w/w, about 3-10% w/w, about 3-8% w/w, about 3-7% w/w, about 3-6% w/w, about 3-5% w/w, about 3-4% w/w, about 3.5-20% w/w, about 3.5-18% w/w, about 3.5-15% w/w, about 3.5-12% w/w, about 3.5- 10% w/w, about 3.5-8% w/w, about 3.5-7% w/w, about 3.5-6% w/w, about 3.5-5% w/w, about 3.5-4% w/w, about 4-20% w/w, about 4-18% w/w, about 4-15% w/w, about 4-12% w/w, about 4-10% w/w, about 4-8% w/w, about 4-7% w/w, about 4-6% w/w, about 4-5% w/w, about 5-20% w/w, about 5-18% w/w, about 5-15% w/w, about 5-12% w/w, about 5- 10% w/w, about 5-8% w/w, about 5-7% w/w, about 5-6% w/w, about 6-20% w/w, about 6- 18% w/w, about 6-15% w/w, about 6-12% w/w, about 6-10% w/w, about 6-8% w/w, about 6- 7% w/w, about 7-20% w/w, about 7-18% w/w, about 7-15% w/w, about 7-12% w/w, about 7- 10% w/w, about 7-8% w/w, about 8-20% w/w, about 8-18% w/w, about 8-15% w/w, about 8- 12% w/w, about 8-10% w/w, about 10-20% w/w, about 10-18% w/w, about 10-15% w/w, about 10-12% w/w, about 12-20% w/w, about 12-18% w/w, about 12-15% w/w, about 15- 20% w/w, about 15-18% w/w, or about 18-20% w/w carrageenan. In certain embodiments, the liquid formulation comprises 1-10% w/w, 3.5-10% w/w, 0.5-5% w/w, or 0.5-3% w/w carrageenan.

Combinations of Polysaccharides and Relative Ratios of Pectin-to-Carrageenan

[0053] As detailed herein, alginic acid and pharmaceutically acceptable salts thereof, pectin and carrageenan exhibit properties that make them multifunctional ingredients, the specific classification of which may depend on the quantity present. Although each of the three polysaccharide components share multiple functionalities in common, it was surprisingly observed that the combinations of the ingredients yielded more favorable properties than those commercial formulations containing only one of the components. For example, when compared to existing formulations containing alginic acid or a pharmaceutically acceptable salt thereof without pectin or carrageenan, the liquid formulations of the present disclosure demonstrated improved mucoadhesion and raft strength.

[0054] In some embodiments, the liquid formulation comprises alginic acid or a pharmaceutically acceptable salt thereof and pectin. In still other embodiments, the liquid formulation comprises alginic acid or a pharmaceutically acceptable salt thereof and carrageenan. In still yet other embodiments, the liquid formulation comprises alginic acid or a pharmaceutically acceptable salt thereof, pectin and carrageenan.

[0055] It was further determined that the combination of the naturally mucoadhesive, raft-forming polysaccharide ingredients could be adjusted on the basis of the combined weight percentage contributions of alginic acid and pharmaceutically acceptable salts thereof and any pectin and/or carrageenan present to achieve enhancement one or more specific physical properties in the liquid formulation as desired. For example, it was observed that with higher quantities of carrageenan relative to the amount of pectin, stronger rafts could be obtained, whereas with increased pectin relative to a fixed amount of carrageenan, higher mucoadhesion could be achieved. [0056] In some embodiments, the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin and any carrageenan present in the liquid formulation is at least about 2% w/w, at least about 3% w/w, at least about 3.5% w/w, at least about 4% w/w, at least about 4.5% w/w at least about 5% w/w, at least about 7% w/w, at least about 10% w/w, at least about 12% w/w, at least about 15% w/w, at least about 17% w/w, or at least about 20% w/w of the total weight of the liquid formulation. In certain embodiments, the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin and any carrageenan present in the liquid formulation is at least about 2% w/w, at least about 3.5% w/w, or at least about 4.5% w/w of the total weight of the liquid formulation.

[0057] In other embodiments, the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin and any carrageenan present in the liquid formulation is less than or equal to about 30% w/w, less than or equal to about 27% w/w, less than or equal to about 25% w/w, less than or equal to about 22% w/w, less than or equal to about 20% w/w, less than or equal to about 17% w/w, less than or equal to about 15% w/w, less than or equal to about 12% w/w, less than or equal to about 10% w/w, less than or equal to about 7% w/w, or less than or equal to about 5% w/w of the total weight of the liquid formulation. In certain embodiments, the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin and any carrageenan present in the liquid formulation is less than or equal to about 20% w/w, less than or equal to about 15%, less than or equal to about 10% w/w, or less than or equal to about 5% w/w of the total weight of the liquid formulation.

[0058] In yet other embodiments, the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin and any carrageenan present in the liquid formulation is about 2-30% w/w, about 2-27% w/w, about 2-25% w/w, about 2-22% w/w, about 2-20% w/w, about 2-17% w/w, about 2-15% w/w, about 2-12% w/w, about 2-10% w/w, about 2-7% w/w, about 2-5% w/w, about 3-30% w/w, about 3-27% w/w, about 3-25% w/w, about 3-22% w/w, about 3-20% w/w, about 3-17% w/w, about 3-15% w/w, about 3- 12% w/w, about 3-10% w/w, about 3-7% w/w, about 3-5% w/w, about 3.5-30% w/w, about

3.5-27% w/w, about 3.5-25% w/w, about 3.5-22% w/w, about 3.5-20% w/w, about 3.5-17% w/w, about 3.5-15% w/w, about 3.5-12% w/w, about 3.5-10% w/w, about 3.5-7% w/w, about

3.5-5% w/w, about 4-30% w/w, about 4-27% w/w, about 4-25% w/w, about 4-22% w/w, about 4-20% w/w, about 4-17% w/w, about 4-15% w/w, about 4-12% w/w, about 4-10% w/w, about 4-7% w/w, about 4-5% w/w, about 4.5-30% w/w, about 4.5-27% w/w, about 4.5- 25% w/w, about 4.5-22% w/w, about 4.5-20% w/w, about 4.5-17% w/w, about 4.5-15% w/w, about 4.5-12% w/w, about 4.5-10% w/w, about 4.5-7% w/w, about 4.5-5% w/w, about 5-30% w/w, about 5-27% w/w, about 5-25% w/w, about 5-22% w/w, about 5-20% w/w, about 5- 17% w/w, about 5-15% w/w, about 5-12% w/w, about 5-10% w/w, about 5-7% w/w, 7-30% w/w, about 7-27% w/w, about 7-25% w/w, about 7-22% w/w, about 7-20% w/w, about 7- 17% w/w, about 7-15% w/w, about 7-12% w/w, about 7-10% w/w, about 10-30% w/w, about 10-27% w/w, about 10-25% w/w, about 10-22% w/w, about 10-20% w/w, about 10-17% w/w, about 10-15% w/w, about 10-12% w/w, about 12-30% w/w, about 12-27% w/w, about 12-25% w/w, about 12-22% w/w, about 12-20% w/w, about 12-17% w/w, about 12-15% w/w, about 15-30% w/w, about 15-27% w/w, about 15-25% w/w, about 15-22% w/w, about 15-20% w/w, about 15-17% w/w, about 17-30% w/w, about 17-27% w/w, about 17-25% w/w, about 17-22% w/w, about 17-20% w/w, about 20-30% w/w, about 20-27% w/w, about 20-25% w/w, about 20-22% w/w, about 22-30% w/w, about 22-27% w/w, about 22-25% w/w, about 25-30% w/w, about 25-27% w/w, or about 27-30% w/w of the total weight of the liquid formulation. In certain embodiments, the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin and any carrageenan present in the liquid formulation is about 2-20% w/w, about 3.5-20% w/w, or about 4.5-15% w/w of the total weight of the liquid formulation.

[0059] In some embodiments, provided herein are liquid formulations comprising alginic acid or a pharmaceutically acceptable salt thereof; at least one of pectin and carrageenan; sodium bicarbonate, at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin and any carrageenan present in the liquid formulation is about 2-20% w/w of the total weight of the liquid formulation. In other embodiments, the present disclosure provides liquid formulations comprising alginic acid or a pharmaceutically acceptable salt thereof; pectin; sodium bicarbonate, at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof and pectin present in the liquid formulation is about 2-20% w/w of the total weight of the liquid formulation. In yet other embodiments, provided herein are liquid formulations comprising alginic acid or a pharmaceutically acceptable salt thereof; carrageenan; sodium bicarbonate, at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof and carrageenan present in the liquid formulation is about 2-20% w/w of the total weight of the liquid formulation. In still other embodiments, provided herein are liquid formulations comprising alginic acid or a pharmaceutically acceptable salt thereof; pectin; carrageenan; sodium bicarbonate, at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, pectin and carrageenan present in the liquid formulation is about 2- 20% w/w of the total weight of the liquid formulation.

[0060] In still other embodiments, the present disclosure provides liquid formulations comprising about 1-18% w/w alginic acid or a pharmaceutically acceptable salt thereof; about 1-10% w/w pectin, carrageenan, or a combination thereof; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin, and any carrageenan present in the liquid formulation is about 3.5-20% w/w of the total weight of the liquid formulation. In some embodiments, the present disclosure provides liquid formulations comprising about 1- 18% w/w alginic acid or a pharmaceutically acceptable salt thereof; about 1-10% w/w pectin; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof and pectin present in the liquid formulation is about 3.5-20% w/w of the total weight of the liquid formulation. In other embodiments, the present disclosure provides liquid formulations comprising about 1-18% w/w alginic acid or a pharmaceutically acceptable salt thereof; about 1-10% w/w carrageenan; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof and carrageenan present in the liquid formulation is about 3.5-20% w/w of the total weight of the liquid formulation. In still other embodiments, the present disclosure provides liquid formulations comprising about 1-18% w/w alginic acid or a pharmaceutically acceptable salt thereof; about 1-10% w/w a combination of pectin and carrageenan; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, pectin, and carrageenan present in the liquid formulation is about 3.5-20% w/w of the total weight of the liquid formulation.

[0061] In yet other embodiments, the present disclosure provides liquid formulations comprising about 1-8% w/w alginic acid or a pharmaceutically acceptable salt thereof; about 3.5-10% w/w pectin, carrageenan, or a combination thereof; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin, and any carrageenan present in the liquid formulation is about 4.5-15% w/w of the total weight of the liquid formulation. In some embodiments, the present disclosure provides liquid formulations comprising about 1- 8% w/w alginic acid or a pharmaceutically acceptable salt thereof; about 3.5-10% w/w pectin; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof and pectin present in the liquid formulation is about 4.5-15% w/w of the total weight of the liquid formulation. In other embodiments, the present disclosure provides liquid formulations comprising about 1- 8% w/w alginic acid or a pharmaceutically acceptable salt thereof; about 3.5-10% w/w carrageenan; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof and carrageenan present in the liquid formulation is about 4.5-15% w/w of the total weight of the liquid formulation. In yet other embodiments, the present disclosure provides liquid formulations comprising about 1-8% w/w alginic acid or a pharmaceutically acceptable salt thereof; about 3.5-10% w/w a combination of pectin and carrageenan; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, pectin, and carrageenan present in the liquid formulation is about 4.5-15% w/w of the total weight of the liquid formulation.

[0062] In still other embodiments wherein the liquid formulation comprises pectin and carrageenan, the quantities of pectin and carrageenan may be described in relative terms to one another, such as in a weight ratio. In some embodiments, the liquid formulation has a ratio of pectin-to-carrageenan of about 10-to-l, about 7-to-l, about 5-to-l, about 2-to-l, about 1-to-l, about l-to-2, about l-to-5, about l-to-7, or about l-to-10. In other embodiments, the liquid formulation has a ratio of pectin-to-carrageenan between about 10-to-l and about l-to- 10. In certain embodiments, the liquid formulation has a ratio of pectin-to-carrageenan between about 5-to-l and about l-to-5.

Antacids

[0063] In some embodiments, the liquid formulation comprises at least one antacid. As detailed above, the liquid formulations of the present disclosure may be used for the treatment of various gastric and gastroesophageal disorders. Many commercially available treatments utilize alkaline active pharmaceutical ingredients, known also as antacids, to directly neutralize stomach acid. The liquid formulations described herein comprise at least one antacid, which actively reduces the amount of gastric acid that can irritate the stomach and esophagus.

[0064] In some embodiments, the at least one antacid comprises calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, or any combination thereof. In certain embodiments, the at least one antacid comprises calcium carbonate and magnesium hydroxide. In certain other embodiments, the at least one antacid comprises magnesium carbonate, magnesium hydroxide, aluminum hydroxide, or any combination thereof.

[0065] In addition to the immediate and direct relief that is provided through the antacid effect of these alkaline components, the combination of the antacid(s) with the long-lasting, strongly mucoadhesive coating formed by the naturally bioadhesive polysaccharides provided herein may also confer enhanced healing properties to liquid formulations when applied to ulcerated mucosae. As observed in the art, hydrotalcite, a magnesium-aluminum hydroxycarbonate mineral used as an antacid, anti-reflux agent and antiulcerant, may promote healing of ulcerated tissue. The ability of the hydrocolloid formulations of the present disclosure to maintain mucoadhesion over extended periods of time may, in concert with antacid ingredients, provide similar or even superior healing effect for reduction and elimination of ulcers as observed with hydrotalcite.

[0066] In some embodiments, the liquid formulation comprises at least about 5% w/w, at least about 7% w/w, at least about 10% w/w, at least about 11% w/w, or at least about 12% w/w at least one antacid. In certain embodiments, the liquid formulation comprises at least about 10% w/w at least one antacid. In other embodiments, the liquid formulation comprises less than or equal to about 20% w/w, less than or equal to about 17% w/w, less than or equal to about 15% w/w, less than or equal to about 14% w/w, less than or equal to about 13% w/w, or less than or equal to about 12% w/w at least one antacid. In certain other embodiments, the liquid formulation comprises less than or equal to about 20% w/w at least one antacid. In still other embodiments, the liquid formulation comprises about 5-20% w/w, about 5-17% w/w, about 5-15% w/w, about 5-14% w/w, about 5-13% w/w, about 5-12% w/w, about 5-11% w/w, about 5-10% w/w, about 5-7% w/w, about 7-20% w/w, about 7-17% w/w, about 7-15% w/w, about 7-14% w/w, about 7-13% w/w, about 7-12% w/w, about 7-11% w/w, about 7- 10% w/w, about 10-20% w/w, about 10-17% w/w, about 10-15% w/w, about 10-14% w/w, about 10-13% w/w, about 10-12% w/w, about 10-11% w/w, about 11-20% w/w, about 11- 17% w/w, about 11-15% w/w, about 11-14% w/w, about 11-13% w/w, about 11-12% w/w, about 12-20% w/w, about 12-17% w/w, about 12-15% w/w about 12-14% w/w, about 12- 13% w/w, about 13-20% w/w, about 13-17% w/w, about 13-15% w/w about 13-14% w/w, about 14-20% w/w, about 14-17% w/w, abut 14-15% w/w, about 15-20% w/w, about 15-17% w/w or about 17-20% w/w at least one antacid. In still certain other embodiments, the liquid formulation comprises about 10-20% w/w at least one antacid.

Sodium Bicarbonate, or Other In situ Carbon Dioxide Source

[0067] The liquid formulations of the present disclosure comprise sodium bicarbonate. Sodium bicarbonate is an alkaline ingredient and may interact with an acid, such as stomach acid, to produce carbon dioxide in situ. The use of sodium bicarbonate in the liquid formulations provided herein contributes to the formation of a raft system having suitable buoyancy to float on top of gastric acid and other solid contents, as well as sufficiently uniform density throughout to obstruct or inhibit any reflux of gastric acid into the esophagus.

[0068] In some embodiments, the liquid formulation comprises at least about 0.5% w/w, at least about 1% w/w, at least about 1.2% w/w, at least about 1.5% w/w, at least about 1.7% w/w, at least about 2% w/w, at least about 2.2% w/w sodium bicarbonate. In certain embodiments, the liquid formulation comprises less than or equal to about 4% w/w, less than or equal to about 3.5% w/w, less than or equal to about 3% w/w, less than or equal to about 2.7% w/w, less than or equal to about 2.5% w/w, less than or equal to about 2.2% w/w, or less than or equal to about 2.0% w/w sodium bicarbonate.

[0069] In certain embodiments, the liquid formulation comprises about 0.5-4% w/w, about 0.5-3.5% w/w, about 0.5-3% w/w, about 0.5-2.7% w/w, about 0.5-2.5% w/w, about 0.5-2.2% w/w, about 0.5-2% w/w, about 0.5-1.7% w/w, about 0.5-1.5% w/w, about 0.5-1.2% w/w, about 0.5-1% w/w, about 1-4% w/w, about 1-3.5% w/w, about 1-3% w/w, about 1-2.7% w/w, about 1-2.5% w/w, about 1-2.2% w/w, about 1-2% w/w, about 1-1.7% w/w, about 1- 1.5% w/w, about 1-1.2% w/w, about 1.2-4% w/w, about 1.2-3.5% w/w, about 1.2-3% w/w, about 1.2-2.7% w/w, about 1.2-2.5% w/w, about 1.2-2.2% w/w, about 1.2-2% w/w, about 1.2-1.7% w/w, about 1.2-1.5% w/w, about 1.5-4% w/w, about 1.5-3.5% w/w, about 1.5-3% w/w, about 1.5-2.7% w/w, about 1.5-2.5% w/w, about 1.5-2.2% w/w, about 1.5-2% w/w, about 1.5-1.7% w/w, about 1.7-4% w/w, about 1.7-3.5% w/w, about 1.7-3% w/w, about 1.7- 2.7% w/w, about 1.7-2.5% w/w, about 1.7-2.2% w/w, about 1.7-2% w/w, about 2-4% w/w, about 2-3.5% w/w, about 2-3% w/w, about 2-2.7% w/w, about 2-2.5% w/w, about 2-2.2% w/w, about 2.2-4% w/w, about 2.2-3.5% w/w, about 2.2-3% w/w, about 2.2-2.7% w/w, about 2.2-2.5% w/w, about 2.5-4% w/w, about 2.5-3.5% w/w, about 2.5-3% w/w, about 2.5-2.7% w/w, about 2.7-4% w/w, about 2.7-3.5% w/w, about 2.7-3% w/w, about 3-4% w/w, about 3- 3.5% w/w, or about 3.5-4% w/w sodium bicarbonate.

[0070] It should be recognized that sodium bicarbonate, which is alkaline, also possesses acid neutralizing (antacid) properties, and may further contribute to the alleviation of symptoms associated with any of the gastric and gastroesophageal disorders described herein.

Water and Other Solvents

[0071] As described herein, the liquid formulations of the present disclosure are liquid formulations containing water. In some embodiments, the liquid formulations comprise water. More specifically, the liquid formulations of the present disclosure are water-based suspensions.

[0072] In some embodiments, the liquid formulation comprises at least about 70% w/w, at least about 72% w/w, at least about 75% w/w, at least about 77% w/w, at least about 80% w/w water. In other embodiments, the liquid formulation comprises less than or equal to about 85% w/w, less than or equal to about 82% w/w, less than or equal to about 80% w/w, less than or equal to about 77%, less than or equal to about 75% w/w, or less than or equal to about 72% w/w water. In still other embodiments, the liquid formulation comprises about 70- 85% w/w, about 70-82% w/w, about 70-80% w/w, about 70-77% w/w, about 70-75% w/w, about 70-72% w/w, about 72-85% w/w, about 72-82% w/w, about 72-80% w/w, about 72- 77% w/w, about 72-75% w/w, about 75-85% w/w, about 75-82% w/w, about 75-80% w/w, about 75-77% w/w, about 77-85% w/w, about 77-82% w/w, about 77-80% w/w, about 80- 85% w/w, about 80-82% w/w, or about 82-85% w/w water. In certain embodiments, the liquid formulation comprises about 70-82% w/w water.

[0073] In still other embodiments, the liquid formulations of the present disclosure may also comprise one or more additional solvents. In some embodiments, the liquid formulations of the present disclosure may also comprise one or more additional solvents, wherein the one or more additional solvents are ethanol, propyl glycol, glycerin, or any combinations thereof. [0074] In some embodiments wherein the liquid formulations comprise one or more additional solvents in addition to water, the one or more additional solvents are present in the liquid formulation at less than or equal to about 20% w/w, less than or equal to about 15% w/w, less than or equal to about 10% w/w, less than or equal to about 7% w/w, less than or equal to about 5% w/w, less than or equal to about 2% or less than or equal to about 1% w/w of the total weight of the liquid formulation. In other embodiments wherein the liquid formulations comprise one or more additional solvents in addition to water, the one or more additional solvents are present in the liquid formulation at greater than or equal to about 0.5% w/w, greater than or equal to about 1% w/w, greater than or equal to about 2% w/w, greater than or equal to about 5% w/w, greater than or equal to about 7% w/w, greater than or equal to about 10% w/w, greater than or equal to about 12% w/w, or greater than or equal to about 15% w/w of the total weight of the liquid formulation. In still other embodiments, the liquid formulation comprises about 0-20% w/w, about 0-15% w/w, about 0-10% w/w, about 0-5% w/w, about 1-20% w/w, about 1-15% w/w, about 1-10% w/w, or about 1-5% w/w one or more additional solvents by total weight of the liquid formulation. In certain embodiments, the liquid formulation comprises about 0-10% w/w one or more additional solvents by total weight of the liquid formulation.

Additional excipients

[0075] In still other embodiments of the present aspects, the liquid formulations of the present disclosure, which comprise alginic acid or a pharmaceutically acceptable salt thereof, at least one of pectin and carrageenan, at least one antacid and water, may further comprise one or more additional pharmaceutically acceptable excipients.

[0076] It should be recognized that the liquid formulations of the present disclosure may comprise viscosity -modifying agents, in addition to alginic acid, pectin and carrageenan, such as various gums, including but not limited to guar gum, xanthum gum, and locust bean gum. As described herein, the viscosity-modifying agents are incorporated in addition to the principal components of alginic acid or a pharmaceutically acceptable salt thereof, pectin and carrageenan, which serve as the chief source of the observed raft-forming and mucoadhesive properties of the liquid formulations herein. In still further embodiments wherein viscosity modifying agents are included, the liquid formulation may comprise less than or equal to about 0.2% w/w, less than or equal to about 0.1% w/w, less than or equal to about 0.05%, or less than or equal to about 0.02% w/w viscosity-modifying agents. [0077] In some embodiments, the liquid formulation further comprises one or more preservatives and/or one or more flavorants. In some embodiments, the liquid formulation comprises one or more sweeteners. In certain embodiments, the one or more sweeteners comprises sugar or an artificial sweetener, such as sucralose. In other embodiments, the liquid formulations one or more flavorants. In certain embodiments, the one or more flavorants comprises chocolate flavor or mint flavor.

[0078] In other embodiments, the liquid formulation comprises one or more preservatives. Suitable preservatives may include but are not limited to sodium benzoate, benzyl alcohol, methyl paraben, propyl paraben, and edetate sodium.

[0079] In some embodiments, the liquid formulations of the present disclosure may not include cellulosic polymers, such as hypromellose, hydroxypropylcellulose, hydroxymethylcellulose. In other embodiments, the liquid formulations provided herein may not include a surfactant.

Properties of the Formulations

[0080] As described above, the liquid formulations of the present disclosure were found to exhibit exemplary properties suitable for the treatment of various gastric and gastroesophageal disorders. In some embodiments, the liquid formulations provided herein may be described or characterized by these properties, which may include but are not limited to pH, raft formation properties and performance, mucoadhesion, viscosity, and storage stability. pH

[0081] The liquid formulations of the present aspect may contain one or more antacids. Antacids, as described herein, are alkaline active pharmaceutical ingredients that can neutralize acid, thereby providing relief to the consumer. Due to the presence of alkaline antacids, the liquid formulations of the present disclosure may be characterized by their degree of alkalinity, for example, as measured by the pH scale, which reports the negative logarithm of the concentration of free protons (H⁺). Due to its relationship to the concentration of free protons, the pH values of the liquid formulations described herein may also be used as a proxy for the acid neutralizing capacity of the liquid formulations, with higher pH reflective of greater neutralization capacity. The pH of the liquid formulations provided herein are maintained carefully such that sufficient neutralization of gastric acid occurs when administered but without reducing the quantities of gastric acid present beyond necessary to mitigate symptoms. Below pH 7, a liquid formulation would not contribute to the neutralization of gastric acid. Conversely, above pH 9.5, a liquid formulation may also cause irritation within the stomach and discomfort to the end consumer.

[0082] In some embodiments, the liquid formulation has a pH of at least about pH 7. In certain embodiments, the liquid formulation has a pH greater than or equal to about pH 7, greater than or equal to about pH 7.5, greater than or equal to about pH 8, greater than or equal to about pH 8.5, or greater than or equal to about pH 9. In certain other embodiments, the liquid formulation has a pH less than or equal to pH 9.5, less than or equal to pH 9, less than or equal to pH 8.5, less than or equal to pH 8, or less than or equal to pH 7.5. In other embodiments, the liquid formulation has a pH of between about pH 7 and about pH 9.5.

Raft Formation

[0083] The liquid formulations of the present disclosure comprising alginic acid or a pharmaceutically acceptable salt thereof in combination with pectin and/or carrageenan are raft-forming systems. Upon coming into contact with gastric acid, the liquid formulations described herein form a continuous cross-linked gel layer, which floats atop the gastric fluid and is referred to herein as a “raft”. The raft formed in the stomach serves as a physical barrier that prevents the reverse flow stomach acid into the esophagus, thereby reducing irritation to inflamed esophageal tissue.

[0084] Due to the difficulty of observing raft formation and evaluating the raft characteristics in vivo, the liquid formulations of the present disclosure may be evaluated for their raft-forming ability (including time to form a raft) and the properties of the resulting rafts (such as raft strength, raft thickness and raft weight) according to in vitro methods known in the art, such as the Raft Strength Test as described in the British Pharmacopeia (2007).

Raft Strength

[0085] In some embodiments, the raft-forming systems provided by the liquid formulations described herein may be characterized by the strength of the continuous gel layer, or raft, formed. The strength of the raft may be indicative of the density of the raft and its rigidity, which may further correlate to its ability of the raft to prevent reflux and to remain intact in the stomach for extended periods of time. In some embodiments, the raft strength is rated by the force that must be applied to pull an L-shaped wire probe through the developed raft, as determined in accordance with the Raft Strength Test described herein.

[0086] The Raft Strength Test according to the British Pharmacopeia (2007) provides an acidic environment (hydrochloric acid) intended to simulate the gastric environment, which reacts with the liquid formulation to form the aerated, cross-linked raft. In the Raft Strength Test, a formulation to be tested is poured into a 150 mL glass beaker containing a 0.1 M hydrochloric acid solution at 37°C. Upon contact with the acid solution, alginic acid or pharmaceutically acceptable salt thereof, pectin and/or carrageenan within the liquid formation begin to form a cross-linked continuous gel layer, while sodium bicarbonate, or other carbon dioxide-generating ingredients, present in the liquid formulation reacts with the acid to produce carbon dioxide and aerates the cross-linked gel. The raft is allowed to form around an L-shaped wire that is suspended in the acid solution with the shorter segment of the L-shaped wire immersed in solution and with the longer segment pierced through and held in place by filter paper, which rests on the rim of the beaker. The L-shaped wire is positioned such that the raft formed by the liquid formulation forms several inches above the shorter segment of the L-shaped wire. The test beaker is allowed to remain untouched for thirty minutes to allow for full raft development.

[0087] Once the raft is fully formed, the L-shaped wire probe is fitted to suitable apparatus, such as a texture analyzer, that can provide an upward pulling force on the probe. The force (in grams) applied to the probe in order for the shorter segment of the L-shaped wire probe to be pulled through the raft is recorded as the raft strength force. The British Pharmacopeia stipulates a raft strength force of 7.5 g as minimum acceptable raft strength force in the monograph for Alginate-Only Raft Forming Oral Suspensions (ARFOS).

[0088] In some embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of at least about 7.5 g, at least about 8 g, at least about 9 g, at least about 10 g, at least about 12 g, at least about 14 g, at least about 15 g, at least about 16 g, at least about 18 g, at least about 20 g, at least about 22 g, at least about 25 g, at least about 27 g, at least about 30 g, at least about 32 g, at least about 35 g, or at least about 37 g, as determined in accordance with the Raft Strength Test. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of at least 7.5 g, as determined in accordance with the Raft Strength Test. In certain other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of at least about 10 g, as determined in accordance with the Raft Strength Test.

[0089] In other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of less than or equal to about 50 g, at least about 47 g, at least about 45 g, at least about 42 g, at least about 40 g, at least about 37 g, at least about 35 g, at least about 32 g, at least about 30 g, at least about 27 g, at least about 25 g, at least about 22 g, at least about 20 g, at least about 18 g, at least about 16 g, at least about 15 g, or at least about 14 g, as determined in accordance with the Raft Strength Test.

[0090] In still other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of between about 7.5 g and about 50 g, between about 7.5 g and about 40 g, between about 7.5 g and about 30 g, between about 10 g and about 50 g, between about 10 g and about 40 g, between about 10 g and about 30 g, between about 10 g and about 20 g, between about 20 g and about 50 g, between about 20 g and about 40 g, between about 20 g and about 30 g, between about 30 g and about 50 g or between about 30 g and about 40 g, as determined in accordance with the Raft Strength Test. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of between about 20 g and about 40 g.

[0091] In addition to the raft strength, the time elapsed for the raft to form as well as the thickness and weight of the resulting raft are among the properties that can be assessed during and after the Raft Strength Test described above.

Raft Formation Time

[0092] In some embodiments of the present aspect, the liquid formulations may be characterized by their raft formation times. The raft formation time is the time elapsed from initiation of the Raft Strength Test, for example, as started upon contact with the acid solution, to the time point at which initial formation of a raft structure is visually observed. The amount of time for the liquid formulations described herein to form the continuous gel layer in vitro may reflect the speed at which a raft will form in vivo in the stomach and, thus, can provide relief from acid reflux into the esophagus.

[0093] In some embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in less than or equal to about 30 minutes, less than or equal to about 20 minutes, less than or equal to about 10 minutes, less than or equal to about 5 minutes, less than or equal to about 3 minutes, less than or equal to about 2 minutes or less than or equal to about 1 minute. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in less than or equal to about 3 minutes. In certain other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in less than or equal to about 2 minutes. In still certain other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in less than or equal to about 1 minute.

[0094] In other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in at least about 5 seconds, at least about 10 seconds, at least about 20 seconds, at least about 30 seconds, at least about 40 seconds, at least about 50 seconds, at least about 60 seconds, at least about 70 seconds, at least about 80 seconds, at least about 90 seconds, at least about 120 seconds, at least about 150 seconds, at least about 3 minutes or at least about 5 minutes. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in at least about 5 seconds.

[0095] In yet other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in between about 5 seconds and 30 minutes, between about 5 seconds and about 20 minutes, between about 5 seconds and about 10 minutes, between about 5 seconds and about 5 minutes, between about 5 seconds and about 3 minutes, between about 30 seconds and 30 minutes, between about 30 seconds and about 20 minutes, between about 30 seconds and about 10 minutes, between about 30 seconds and about 5 minutes, between about 30 seconds and about 3 minutes, between about 60 seconds and 30 minutes, between about 60 seconds and about 20 minutes, between about 60 seconds and about 10 minutes, between about 60 seconds and about 5 minutes, between about 60 seconds and about 3 minutes, 60 seconds, between about 120 seconds and 30 minutes, between about 120 seconds and about 20 minutes, between about 120 seconds and about 10 minutes, between about 120 seconds and about 5 minutes, or between about 120 seconds and about 3 minutes. In some embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in between about 5 seconds and about 30 minutes. In other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in between about 5 seconds and about 3 minutes.

Raft Thickness and Weight

[0096] The liquid formulation may be further characterized by the thickness and/or weight of the raft formed in the Raft Strength Test. The thickness and weight of the rafts may be measured following completion of the Raft Strength Test and removal of the L-shaped wire probe. The raft thickness and weight may reflect the overall sturdiness of the raft and its ability to remain intact in the stomach once formed.

[0097] In some embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least about 10 mm, at least about 11 mm, at least about 12 mm, at least about 13 mm, at least about 14 mm, at least about 15 mm, at least about 17 mm, at least about 20 mm, at least about 22 mm, or at least about 25 mm. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least about 12 mm, at least about 15 mm, at least about 17 mm, at least about 20 mm, or at least about 22 mm. In certain other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least about 12 mm. In still other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least about 15 mm.

[0098] In other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of less than or equal to about 35 mm, less than or equal to about 32 mm, less than or equal to about 30 mm, less than or equal to about 27 mm, less than or equal to about 25 mm, less than or equal to about 22 mm, or less than or equal to about 20 mm. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of less than or equal to about 30 mm, less than or equal to about 27 mm, less than or equal to about 25 mm, or less than or equal to about 22 mm. In certain other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of less than or equal to about 25 mm.

[0099] In yet other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of between about 10 mm and about 35 mm, between about 10 mm and about 30 mm, between about 10 mm and about 25 mm, between about 10 mm and about 20 mm, between about 12 mm and about 35 mm, between about 12 mm and about 30 mm, between about 12 mm and about 25 mm, between about 12 mm and about 20 mm, between about 15 mm and about 35 mm, between about 15 mm and about 25 mm, between about 15 mm and about 20 mm, between about 20 mm and about 35 mm, between about 20 mm and about 30 mm, or between about 20 mm and about 25 mm. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of between 15 mm and 25 mm.

[0100] In some embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of at least about 20 g, at least about 22 g, at least about 25 g, at least about 27 g, at least about 30 g, at least about 32 g, at least about 35 g, or at least about 37 g. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of at least about 30 g.

[0101] In other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of less than or equal to about 50 g, less than or equal to about 47 g, less than or equal to about 45 g, less than or equal to about 42 g, less than or equal to about 40 g, less than or equal to about 37 g, or less than or equal to about 35 g. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of less than or equal to about 45 g.

[0102] In still other embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of between about 20 g and about 50 g, between about 20 g and about 45 g, between about 20 g and about 40 g, between about 20 g and about 35 g, between about 20 g and about 30 g, between about 25 g and about 50 g, between about 25 g and about 45 g, between about 25 g and about 40 g, between about 25 g and about 35 g, between about 25 g and about 30 g, between about 30 g and about 50 g, between about 30 g and about 45 g, between about 30 g and about 40 g, between about 30 g and about 35 g, between about 35 g and about 50 g, between about 35 g and about 45 g, between about 35 g and about 40 g, between about 40 g and about 50 g, between about 40 g and about 45 g, or between about 45 g and about 50 g. In certain embodiments, the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of between about 20 g and about 45 g.

[0103] In still other embodiments, the liquid formulations of the present disclosure may be characterized by the density of the raft formed, the level of carbon dioxide trapped within the raft or the period of time for which the raft remains intact once formed. In some embodiments, the raft strength and raft density may reflect and/or be correlated to the mucoadhesiveness of the liquid formulations.

[0104] In any of the preceding embodiments, the properties of rafts may be measured in accordance with the raft formation test as detailed by the British Pharmacopoeia. For example, in some embodiments, the raft formation time, the raft strength, the raft weight, the density of the raft formed, the level of carbon dioxide trapped within the raft or the period of time for which the raft remains intact once formed may all be measured in six replicates.

Mucoadhesion

[0105] In some embodiments, the liquid formulations as described herein may be characterized by their ability to adhere to mucous membranes. Their mucoadhesiveness may be evaluated by various in vitro methods, for example, employing biologically simulated conditions (tripe with saliva/saline) or a proxy for a mucosal surface, such as a plastic tray or attachment.

[0106] For example, in an in vitro bioadhesion test described herein in Example 4 Part I, a polyethylene attachment attached to a texture analyzer is dipped into a sample of the liquid formulation to be tested in five separate trials (or dips). The quantity of sample retained on the polyethylene attachment after each trial is recorded. The amount of the liquid formulation removed from the initial sample is used to calculate the percentage of formulation adhered to (and retained by) the polyethylene attachment after five dips and, thus, provide a measure of bioadhesion. [0107] In some embodiments, the liquid formulation has a bioadhesion of at least about 4%, at least about 5%, at least about 6%, at least about 7%, at least about 8%, at least about 9% or at least about 10%, at least about 12%, at least about 14%, at least about 16%, at least about 18%, at least about 20%, at least about 25%, at least about 30% or at least about 35% as determined by the in vitro bioadhesion test using a texture analyzer described herein. In certain embodiments, the liquid formulation has bioadhesion of at least about 10% as determined by the in vitro bioadhesion test using a texture analyzer described herein.

[0108] In other embodiments, the liquid formulation has a bioadhesion of less than or equal to about 50%, less than or equal to about 45%, less than or equal to about 40%, less than or equal to about 37%, less than or equal to about 35%, less than or equal to about 32%, or less than or equal to about 30% as determined by the in vitro bioadhesion test using a texture analyzer described herein.

[0109] In still other embodiments, the liquid formulation has a bioadhesion of between about 4% and about 50%, between about 4% and about 45%, between about 4% and about 40%, between about 4% and about 37%, between about 4% and about 35%, between about 4% and about 32%, between about 4% and about 30%, between about 5% and about 50%, between about 5% and about 45%, between about 5% and about 40%, between about 5% and about 37%, between about 5% and about 35%, between about 5% and about 32%, between about 5% and about 30%, between about 7% and about 50%, between about 7% and about 45%, between about 7% and about 40%, between about 7% and about 37%, between about 7% and about 35%, between about 7% and about 32%, between about 7% and about 30%, between about 10% and about 50%, between about 10% and about 45%, between about 10% and about 40%, between about 10% and about 37%, between about 10% and about 35%, between about 10% and about 32%, between about 10% and about 30%, between about 20% and about 50%, between about 20% and about 45%, between about 20% and about 40%, between about 20% and about 37%, between about 20% and about 35%, between about 20% and about 32%, between about 20% and about 30%, between about 30% and about 50%, between about 30% and about 45%, between about 30% and about 40%, between about 30% and about 37%, between about 30% and about 35%, or between about 30% and about 32% as determined by the in vitro bioadhesion test using a texture analyzer described herein.

[0110] In yet other embodiments, the liquid formulations of the present disclosure may be characterized by their mucoadhesion as determined by the mucoadhesion test using tripe as described herein. In the mucoadhesion test described in Example 4 Part II, the adhesiveness of the liquid formulations provided herein are assessed with respect to a biological membrane (tripe). A fixed quantity of the liquid formulation to be tested is applied to a sample of tripe having a known weight (uncoated tripe). The coated tripe sample is then washed with controlled volumes of artificial saliva solution (e.g., 1.5 mL per rinse), and the weight of the coated tripe sample is measured after each rinse to determine the amount of liquid formulation retained by the sample after each rinse. The percentage of liquid formulation retained by the tripe is calculated as a percentage of the total weight of the uncoated tripe sample. The mucoadhesion of the liquid formulation to the tripe samples may be characterized by either the number of rinses required to wash away formulation such that the weight of the tripe sample is approximately the same as the original uncoated weight, or alternatively by the weight of formulation retained on the tripe sample after a fixed number of rinses, e.g., 10 rinses.

[OHl] In some embodiments, the liquid formulation has a mucoadhesion of at least about 2%, at least about 3%, at least about 4%, at least about 5%, at least about 7%, at least about 10%, or at least about 12% as determined by the mucoadhesion test with tripe described herein. In certain embodiments, the liquid formulation has a mucoadhesion of at least about 2% as determined by the mucoadhesion test with tripe described herein.

[0112] In other embodiments, the liquid formulation has a mucoadhesion of less than or equal to about 20%, less than or equal to about 17%, less than or equal to about 15%, less than or equal to about 12%, or less than or equal to about 10%, as determined by the mucoadhesion test with tripe described herein. In certain embodiments, the liquid formulation has a mucoadhesion of less than or equal to about 20% as determined by the mucoadhesion test with tripe described herein.

[0113] In still other embodiments, the liquid formulation has a mucoadhesion of between about 2% and about 20%, between about 2% and about 17%, between about 2% and about 15%, between about 2% and about 12%, between about 2% and about 10%, between about 4% and about 20%, between about 4% and about 17%, between about 4% and about 15%, between about 4% and about 12%, between about 4% and about 10%, between about 5% and about 20%, between about 5% and about 17%, between about 5% and about 15%, between about 5% and about 12%, between about 5% and about 10%, between about 7% and about 20%, between about 7% and about 17%, between about 7% and about 15%, between about 7% and about 12%, between about 7% and about 10%, between about 10% and about 20%, between about 10% and about 17%, between about 10% and about 15%, between about 10% and about 12%, between about 12% and about 20%, between about 12% and about 17%, between about 12% and about 15%, between about 15% and about 20%, between about 15% and about 17%, or between about 17% and about 20% as determined by the mucoadhesion test using tripe described herein.

[0114] In still other embodiments, the liquid formulations of the present disclosure may be characterized by their mucoadhesion as determined by the surface adhesion test described herein. In the surface adhesion test described in Example 4 Part III, the adhesiveness of the liquid formulations provided herein are assessed with respect to the extent of sample migration observed when the samples are monitored on a plastic tray angled at a 45° tilt. The protocol for the surface adhesion test, in brief, is as follows: A fixed quantity of each liquid formulation to be tested is applied to a plastic sample tray held horizontal (parallel to the floor). The liquid formulations are applied to the tray as single circular masses along one edge of the plastic tray, in which the centers of each circular mass are equidistant from the central rotational axis of the tray. The tray is subsequently tilted at a 45° angle so that the end of the tray at which the liquid formulations were applied is elevated. The tray is held at the 45° tilt for 30 seconds. During this 30 second period, gravity causes less mucoadhesive samples to migrate down the tray in a linear path, whereas more mucoadhesive formulations are expected migrate to a lesser extent or not at all. After 30 seconds, the tray is reverted back to its horizontal position and the distance migrated by each sample is recorded. The distance traveled may be measured as the distance between the initial edge of the liquid formulation closest to the central rotational axis at the prior to being tilted and the edge of the liquid formulation sample farthest from the initial position after being held at 45° tilt for 30 seconds.

[0115] The distance migrated by the liquid formulations as determined by the surface adhesion test may be described in any suitable unit of length, such as inches, centimeters, or millimeters. In some embodiments, the liquid formulations provided herein have a migration of less than or equal to about 2.5 inches, less than or equal to about 2 inches, less than or equal to 1.5 inches, less than or equal to 1 inch, less than or equal to 0.5 inches, or less than or equal to about 0.2 inches as determined by the surface adhesion test. In other embodiments, the liquid formulations provided herein have a migration of less than or equal to about 6 cm, less than or equal to about 5.5 cm, less than or equal to about 5 cm, less than or equal to about 4.5 cm, less than or equal to about 4 cm, less than or equal to about 3.5 cm, less than or equal to about 3 cm, less than or equal to about 2.5 cm, less than or equal to about 2 cm, less than or equal to about 1.5 cm, less than or equal to about 1 cm, or less than or equal to about 0.5 cm. In certain embodiments, the liquid formulations provided herein may not exhibit any discernible or measurable migration. In some embodiments, the liquid formulation has a negligible migration.

Viscosity and Thixotropic Behavior

[0116] As described herein, the liquid formulations comprising alginic acid or a pharmaceutically acceptable salt thereof, in combination with pectin and/or carrageenan may be further characterized by their viscosity and/or thixotropic behavior. In addition to the ability of the liquid formulations to achieve both mucoadhesion and raft formation, the liquid formulations of the present disclosure demonstrate viscosity reflective of their mucoadhesiveness as well as their thixotropic behavior. Thixotropy is a property of certain viscous fluids which exhibit a change in viscosity to become less viscous over time when exposed to agitation (such as stirring or shaking) or shear force. Thixotropy, which is also known as time-dependent shear thinning, may further reflect the ability of the liquid formulations described herein to flow during administration and provide even coating of administration but also to remain static and securely adhered to the mucosae once administered. The thixotropic behavior achieved in the liquid formulations of the present disclosure enables the liquid formulations to provide a long-lasting but uniformly distributed coating in the esophagus and stomach for short-term and long-term relief. The viscosity of the liquid formulations provided herein may also influence the ability of the liquid formulations to produce a raft having a uniform density.

[0117] In some embodiments, the liquid formulations provided herein may be characterized by their viscosities. Viscosity (q, centipoise) of the liquid formulation as provided herein may be determined by viscosity testing methods known in the art including, for example, a three-interval thixotropy test. A three-interval thixotropy test measures the time-dependent viscosity under different conditions of applied shear, including the viscosity at rest, the viscosity during application or administration (e.g., shear thinning behavior), and the viscosity after application or administration (e.g., hysteresis effects and structural recovery from applied forces). In a controlled shear rate three-interval thixotropy test, a liquid sample is subjected to shear force applied by a rotational rheometer at three discrete intervals of shear speed or rate (y, s'¹), with a constant shear stress (T, pascal) for a defined period of time (e.g., two minutes): (1) low shear rate (such as 1/s), (2) high shear rate (such as 1000/s); and (3) low shear rate (identical to shear rate of the first interval). In an alternative method known as the controlled shear stress three-interval thixotropy test, the liquid sample is subject to three intervals of shear stress: (1) low shear stress, (2) high shear stress; and (3) low shear stress. It should be recognized that additional parameters for the operation of the rheometer and for the measurement may be specified, including cone plate diameter, active length, position length, trim position, and torsional com.

[0118] In some embodiments, the viscosity of the liquid formulation may be characterized by the initial viscosity (measured at the start of the first interval at low shear) and/or the recovery viscosity (measured at the end of the third interval at low shear).

[0119] In some embodiments, the liquid formulation has an initial viscosity of at least about 1000 centipoise (cP), at least about 2500 cP, at least about 5000 cP, or at least about 10000 cP as determined by the three-interval thixotropy test described herein. In certain embodiments, the liquid formulation has an initial viscosity of at least about 1000 centipoise (cP) as determined by the three-interval thixotropy test described herein. In other embodiments, the liquid formulation has an initial viscosity of less than or equal to about 25000 cP, less than or equal to about 20000 cP, less than or equal to about 15000 cP, or less than or equal to about 10000 cP as determined by the three-interval thixotropy test described herein. In certain embodiments, the liquid formulation has an initial viscosity of less than or equal to about 20000 cP as determined by the three-interval thixotropy test described herein. In still other embodiments, the liquid formulation has an initial viscosity of between about 1000 cP and about 25000 cP, between about 1000 cP and about 20000 cP, between about

1000 cP and about 15000 cP, between about 1000 cP and about 10000 cP, between about

2500 cP and about 25000 cP, between about 2500 cP and about 20000 cP, between about

2500 cP and about 15000 cP, between about 2500 cP and about 10000 cP, between about

5000 cP and about 25000 cP, between about 5000 cP and about 20000 cP, between about

5000 cP and about 15000 cP, between about 5000 cP and about 10000 cP, between about

10000 cP and about 25000 cP, between about 10000 cP and about 20000 cP, or between about 10000 cP and about 15000 cP as determined by the three-interval thixotropy test described herein. [0120] In other embodiments, the liquid formulation has a recovery viscosity of at least about 1000 centipoise (cP), at least about 2000 cP, at least about 5000 cP, or at least about 7500 cP as determined by the three-interval thixotropy test described herein. In certain embodiments, the liquid formulation has a recovery viscosity of at least about 1000 centipoise (cP) as determined by the three-interval thixotropy test described herein. In other embodiments, the liquid formulation has a recovery viscosity of less than or equal to about 15000 cP, less than or equal to about 12000 cP, less than or equal to about 10000 cP, or less than or equal to about 7500 cP as determined by the three-interval thixotropy test described herein. In certain embodiments, the liquid formulation has a recovery viscosity of less than or equal to about 15000 cP as determined by the three-interval thixotropy test described herein. In still other embodiments, the liquid formulation has a recovery viscosity of between about 1000 cP and about 15000 cP, between about 1000 cP and about 12000 cP, between about 1000 cP and about 10000 cP, between about 1000 cP and about 7500 cP, between about 2000 cP and about 15000 cP, between about 2000 cP and about 12000 cP, between about 2000 cP and about 10000 cP, between about 2000 cP and about 7500 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 10000 cP, between about 5000 cP and about 7500 cP, between about 7500 cP and about 15000 cP, between about 7500 cP and about 12000 cP, or between about 7500 cP and about 10000 cP as determined by the three-interval thixotropy test described herein.

[0121] In still other embodiments, the viscosity of the liquid formulation may be described as having an initial viscosity and a recovery viscosity. For example, in some embodiments, the liquid formulation has an initial viscosity of between about 1000 cP and about 25000 cP, between about 1000 cP and about 20000 cP, between about 1000 cP and about 15000 cP, between about 1000 cP and about 10000 cP, between about 2500 cP and about 25000 cP, between about 2500 cP and about 20000 cP, between about 2500 cP and about 15000 cP, between about 2500 cP and about 10000 cP, between about 5000 cP and about 25000 cP, between about 5000 cP and about 20000 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 10000 cP, between about 10000 cP and about 25000 cP, between about 10000 cP and about 20000 cP, or between about 10000 cP and about 15000 cP and a recovery viscosity of between about 1000 cP and about 15000 cP, between about 1000 cP and about 12000 cP, between about 1000 cP and about 10000 cP, between about 1000 cP and about 7500 cP, between about 2000 cP and about 15000 cP, between about 2000 cP and about 12000 cP, between about 2000 cP and about 10000 cP, between about 2000 cP and about 7500 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 10000 cP, between about 5000 cP and about 7500 cP, between about 7500 cP and about 15000 cP, between about 7500 cP and about 12000 cP, or between about 7500 cP and about 10000 cP as determined by the three-interval thixotropy test described herein.

[0122] In still other embodiments, the liquid formulations described herein may be characterized by viscosity range, for example, as set by the initial viscosity and recovery viscosity as measured by the three-interval thixotropy test under a specified shear rate or specified shear stress. In some embodiments, the liquid formulation has a between about 1000 cP and about 25000 cP, between about 1000 cP and about 20000 cP, between about

10000 cP and about 25000 cP, between about 10000 cP and about 20000 cP, or between about 10000 cP and about 15000 cP as determined by the three-interval thixotropy test described herein. In certain embodiments, the liquid formulation has a viscosity of between about 1000 centipoise (cP) and about 20000 cP as determined by the three-interval thixotropy test described herein.

[0123] In some embodiments, the viscosity of the liquid formulation may be characterized by the thixotropy index, which is calculated as difference of the logarithm of the viscosity measured at low shear at the end of the third interval (e.g., after 360 seconds) and the logarithm of the viscosity measured at high shear the end of the second interval (e.g., after 240 seconds). The thixotropy index provides a measure of how readily a liquid will flow during dispensing but will stay in place once dispensed.

Stability after Storage

[0124] In still further embodiments, the liquid formulations described herein may be characterized by any of the preceding metrics after storage. The ability of the liquid formulations of the present disclosure not only to demonstrate the properties detailed above but to demonstrate them after storage, especially under extreme conditions, reflects the storage stability and overall shelf-life of the liquid formulations.

[0125] In some embodiments, the storage stability of the liquid formulations provided herein is evaluated after storage at a specified time, temperature and/or humidity. In some embodiments, the storage stability of the liquid formulation is evaluated after storage at 25°C or storage at 40°C. In some embodiments, the storage stability of the liquid formulation is evaluated at no humidity, e.g. , isolated from external humidity, at ambient relative humidity, at 60% relative humidity or at 75% relative humidity. In other embodiments, storage stability of the liquid formulation is evaluated after 1 month of storage, after 3 months of storage, or after 6 months of storage. In certain embodiments, the storage stability of the liquid formulation is evaluated after 1 month of storage at 25°C and 60% relative humidity (RH). In certain other embodiments, the storage stability of the liquid formulation is evaluated after 1 month of storage at 40°C and no humidity. In still other embodiments, the storage stability of the liquid formulation is evaluated after 1 month of storage at 40°C and 75% relative humidity.

Raft Formation Properties After Storage

[0126] In some embodiments, the storage stability of the liquid formulations provided herein may be characterized by the raft forming ability, including time elapsed for raft formation, raft strength force, and/or raft thickness, of the liquid formulations after storage. In certain embodiments, the storage stability of the liquid formulations as characterized by raft strength force may be evaluated by the raft strength test in accordance with the British Pharmacopeia as described above. In certain embodiments, the properties of the rafts formed by the liquid formulations described herein may be determined after 1 month of storage at 40°C.

[0127] In some embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of at least about 7 g, at least about 8 g, at least about 9 g, at least about 10 g, at least about 12 g, at least about 14 g, at least about 15 g, at least about 16 g, at least about 18 g, at least about 20 g, at least about 22 g, at least about 25 g, at least about 27 g, at least about 30 g, at least about 32 g, at least about 35 g, or at least about 37 g, as determined in accordance with the Raft Strength Test. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of at least 7 g, as determined in accordance with the Raft Strength Test. In certain other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of at least about 10 g, as determined in accordance with the Raft Strength Test.

[0128] In other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of less than or equal to about 50 g, at least about 47 g, at least about 45 g, at least about 42 g, at least about 40 g, at least about 37 g, at least about 35 g, at least about 32 g, at least about 30 g, at least about 27 g, at least about 25 g, at least about 22 g, at least about 20 g, at least about 18 g, at least about 16 g, at least about 15 g, or at least about 14 g, as determined in accordance with the Raft Strength Test.

[0129] In still other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of between about 7 g and about 50 g, between about 7 g and about 40 g, between about 7 g and about 30 g, between about 10 g and about 50 g, between about 10 g and about 40 g, between about 10 g and about 30 g, between about 10 g and about 20 g, between about 20 g and about 50 g, between about 20 g and about 40 g, between about 20 g and about 30 g, between about 30 g and about 50 g or between about 30 g and about 40 g, as determined in accordance with the Raft Strength Test. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of between about 20 g and about 40 g.

[0130] In some embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in less than or equal to about 30 minutes, less than or equal to about 20 minutes, less than or equal to about 10 minutes, less than or equal to about 5 minutes, less than or equal to about 3 minutes, less than or equal to about 2 minutes or less than or equal to about 1 minute. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in less than or equal to about 3 minutes. In certain other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in less than or equal to about 2 minutes. In still certain other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in less than or equal to about 1 minute.

[0131] In other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in at least about 5 seconds, at least about 10 seconds, at least about 20 seconds, at least about 30 seconds, at least about 40 seconds, at least about 50 seconds, at least about 60 seconds, at least about 70 seconds, at least about 80 seconds, at least about 90 seconds, at least about 120 seconds, at least about 150 seconds, at least about 3 minutes or at least about 5 minutes. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in at least about 5 seconds.

[0132] In yet other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in between about 5 seconds and 30 minutes, between about 5 seconds and about 20 minutes, between about 5 seconds and about 10 minutes, between about 5 seconds and about 5 minutes, between about 5 seconds and about 3 minutes, between about 30 seconds and 30 minutes, between about 30 seconds and about 20 minutes, between about 30 seconds and about 10 minutes, between about 30 seconds and about 5 minutes, between about 30 seconds and about 3 minutes, between about 60 seconds and 30 minutes, between about 60 seconds and about 20 minutes, between about 60 seconds and about 10 minutes, between about 60 seconds and about 5 minutes, between about 60 seconds and about 3 minutes, 60 seconds, between about 120 seconds and 30 minutes, between about 120 seconds and about 20 minutes, between about 120 seconds and about 10 minutes, between about 120 seconds and about 5 minutes, or between about 120 seconds and about 3 minutes. In some embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in between about 5 seconds and about 30 minutes. In other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in between about 5 seconds and about 3 minutes. [0133] In some embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least about 10 mm, at least about 11 mm, at least about 12 mm, at least about 13 mm, at least about 14 mm, at least about 15 mm, at least about 17 mm, at least about 20 mm, at least about 22 mm, or at least about 25 mm. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least about 12 mm, at least about 15 mm, at least about 17 mm, at least about 20 mm, or at least about 22 mm. In certain other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least about 12 mm. In still other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least about 15 mm.

[0134] In other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of less than or equal to about 35 mm, less than or equal to about 32 mm, less than or equal to about 30 mm, less than or equal to about 27 mm, less than or equal to about 25 mm, less than or equal to about 22 mm, or less than or equal to about 20 mm. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of less than or equal to about 30 mm, less than or equal to about 27 mm, less than or equal to about 25 mm, or less than or equal to about 22 mm. In certain other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of less than or equal to about 25 mm.

[0135] In yet other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of between about 10 mm and about 35 mm, between about 10 mm and about 30 mm, between about 10 mm and about 25 mm, between about 10 mm and about 20 mm, between about 12 mm and about 35 mm, between about 12 mm and about 30 mm, between about 12 mm and about 25 mm, between about 12 mm and about 20 mm, between about 15 mm and about 35 mm, between about 15 mm and about 25 mm, between about 15 mm and about 20 mm, between about 20 mm and about 35 mm, between about 20 mm and about 30 mm, or between about 20 mm and about 25 mm. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of between 15 mm and 25 mm.

[0136] In some embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of at least about 20 g, at least about 22 g, at least about 25 g, at least about 27 g, at least about 30 g, at least about 32 g, at least about 35 g, or at least about 37 g. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of at least about 30 g.

[0137] In other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of less than or equal to about 50 g, less than or equal to about 47 g, less than or equal to about 45 g, less than or equal to about 42 g, less than or equal to about 40 g, less than or equal to about 37 g, or less than or equal to about 35 g. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of less than or equal to about 45 g-

[0138] In still other embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of between about 20 g and about 50 g, between about 20 g and about 45 g, between about 20 g and about 40 g, between about 20 g and about 35 g, between about 20 g and about 30 g, between about 25 g and about 50 g, between about 25 g and about 45 g, between about 25 g and about 40 g, between about 25 g and about 35 g, between about 25 g and about 30 g, between about 30 g and about 50 g, between about 30 g and about 45 g, between about 30 g and about 40 g, between about 30 g and about 35 g, between about 35 g and about 50 g, between about 35 g and about 45 g, between about 35 g and about 40 g, between about 40 g and about 50 g, between about 40 g and about 45 g, or between about 45 g and about 50 g. In certain embodiments, the liquid formulation, after 1 month of storage at 40°C and when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft weight of between about 20 g and about 45 g.

Mucoadhesion After Storage

[0139] In other embodiments, the storage stability of the liquid formulations provided herein may be characterized by the bioadhesiveness or mucoadhesiveness of the liquid formulations after storage. In certain embodiments, the mucoadhesive properties of the liquid formulations described herein may be determined after 1 month of storage at 40°C.

[0140] In some embodiments, the liquid formulation has a bioadhesion of at least about 4%, at least about 5%, at least about 6%, at least about 7%, at least about 8%, at least about 9% or at least about 10% as determined by the in vitro bioadhesion test using a texture analyzer as described herein after 1 month of storage at 40°C. In some embodiments, the liquid formulation has bioadhesion of at least about 4% as determined by the in vitro bioadhesion test using a texture analyzer described herein after 1 month of storage at 40°C.

[0141] In other embodiments, the liquid formulation has a bioadhesion of less than or equal to about 20%, less than or equal to about 17%, less than or equal to about 15%, less than or equal to about 12%, or less than or equal to about 10% as determined by the in vitro bioadhesion test using a texture analyzer described herein after 1 month of storage at 40°C.

[0142] In other embodiments, the liquid formulation has a bioadhesion of between about

4% and about 20%, between about 4% and about 17%, between about 4% and about 15%, between about 4% and about 12%, between about 4% and about 10%, between about 5% and about 20%, between about 5% and about 17%, between about 5% and about 15%, between about 5% and about 12%, between about 5% and about 10%, between about 7% and about 20%, between about 7% and about 17%, between about 7% and about 15%, between about 7% and about 12%, between about 7% and about 10%, between about 10% and about 20%, between about 10% and about 17%, between about 10% and about 15%, or between about 10% and about 12% as determined by the in vitro bioadhesion test using a texture analyzer described herein after 1 month of storage at 40°C.

Viscosity and Thixotropic Behavior After Storage [0143] In still other embodiments, the storage stability of the liquid formulations provided herein may be characterized by the viscosities of the liquid formulations after storage. In certain embodiments, the storage stability of the liquid formulations may be evaluated by the three-interval thixotropy test as described above. In still further embodiments, which may be combined with the preceding embodiments, the viscosities of the liquid formulations may be evaluated after 1 month of storage at 40°C and at 75% relative humidity.

[0144] In some embodiments, the liquid formulation has an initial viscosity of at least about 1000 centipoise (cP), at least about 2500 cP, at least about 5000 cP, or at least about 10000 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In certain embodiments, the liquid formulation has an initial viscosity of at least about 1000 centipoise (cP) as determined by the three- interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In other embodiments, the liquid formulation has an initial viscosity of less than or equal to about 30000 cP, less than or equal to about 27000 cP, less than or equal to about 25000 cP, less than or equal to about 20000 cP, less than or equal to about 15000 cP, or less than or equal to about 10000 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In certain embodiments, the liquid formulation has an initial viscosity of less than or equal to about 20000 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In still other embodiments, the liquid formulation has an initial viscosity of between about 1000 cP and about 30000 cP, between about 1000 cP and about 27000 cP, between about 1000 cP and about 25000 cP, between about 1000 cP and about 20000 cP, between about 1000 cP and about 15000 cP, between about 1000 cP and about 10000 cP, between about 2500 cP and about 25000 cP, between about 2500 cP and about 20000 cP, between about 2500 cP and about 15000 cP, between about 2500 cP and about 10000 cP, between about 5000 cP and about 25000 cP, between about 5000 cP and about 20000 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 10000 cP, between about 10000 cP and about 25000 cP, between about 10000 cP and about 20000 cP, or between about 10000 cP and about 15000 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. [0145] In other embodiments, the liquid formulation has a recovery viscosity of at least about 1000 centipoise (cP), at least about 2000 cP, at least about 5000 cP, or at least about 7500 cP as determined by the three-interval thixotropy test described herein. In certain embodiments, the liquid formulation has a recovery viscosity of at least about 1000 centipoise (cP) as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In other embodiments, the liquid formulation has a recovery viscosity of less than or equal to about 15000 cP, less than or equal to about 12000 cP, less than or equal to about 10000 cP, or less than or equal to about 7500 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In certain embodiments, the liquid formulation has a recovery viscosity of less than or equal to about 15000 cP as determined by the three- interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In still other embodiments, the liquid formulation has a recovery viscosity of between about 1000 cP and about 15000 cP, between about 1000 cP and about 12000 cP, between about 1000 cP and about 10000 cP, between about 1000 cP and about 7500 cP, between about 2000 cP and about 15000 cP, between about 2000 cP and about 12000 cP, between about 2000 cP and about 10000 cP, between about 2000 cP and about 7500 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 10000 cP, between about 5000 cP and about 7500 cP, between about 7500 cP and about 15000 cP, between about 7500 cP and about 12000 cP, or between about 7500 cP and about 10000 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity.

[0146] In still other embodiments, the viscosity of the liquid formulation may be described as having an initial viscosity and a recovery viscosity. For example, in some embodiments, the liquid formulation has an initial viscosity of between about 1000 cP and about 30000 cP, between about 1000 cP and about 27000 cP, between about 1000 cP and about 25000 cP, between about 1000 cP and about 20000 cP, between about 1000 cP and about 15000 cP, between about 1000 cP and about 10000 cP, between about 2500 cP and about 25000 cP, between about 2500 cP and about 20000 cP, between about 2500 cP and about 15000 cP, between about 2500 cP and about 10000 cP, between about 5000 cP and about 25000 cP, between about 5000 cP and about 20000 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 10000 cP, between about 10000 cP and about 25000 cP, between about 10000 cP and about 20000 cP, or between about 10000 cP and about 15000 cP and a recovery viscosity of between about 1000 cP and about 15000 cP, between about 1000 cP and about 12000 cP, between about 1000 cP and about 10000 cP, between about 1000 cP and about 7500 cP, between about 2000 cP and about 15000 cP, between about 2000 cP and about 12000 cP, between about 2000 cP and about 10000 cP, between about 2000 cP and about 7500 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 15000 cP, between about 5000 cP and about 10000 cP, between about 5000 cP and about 7500 cP, between about 7500 cP and about 15000 cP, between about 7500 cP and about 12000 cP, or between about 7500 cP and about 10000 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity.

[0147] In still other embodiments, the liquid formulations described herein may be characterized by viscosity range, for example, as set by the initial viscosity and recovery viscosity as measured by the three-interval thixotropy test after storage. In some embodiments, the liquid formulation has a viscosity of between about 1000 cP and about 30000 cP, between about 1000 cP and about 27000 cP, between about 1000 cP and about

25000 cP, between about 1000 cP and about 20000 cP, between about 1000 cP and about

15000 cP, between about 1000 cP and about 10000 cP, between about 2500 cP and about

25000 cP, between about 2500 cP and about 20000 cP, between about 2500 cP and about

15000 cP, between about 2500 cP and about 10000 cP, between about 5000 cP and about

25000 cP, between about 5000 cP and about 20000 cP, between about 5000 cP and about

15000 cP, between about 5000 cP and about 10000 cP, between about 10000 cP and about 25000 cP, between about 10000 cP and about 20000 cP, or between about 10000 cP and about 15000 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In certain embodiments, the liquid formulation has a viscosity of between about 1000 centipoise (cP) and about 30000 cP as determined by the three-interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity. In some embodiments, the liquid formulation has a viscosity of between 1000 cP and 27000 cP as measured by the controlled shear rate three- interval thixotropy test described herein after 1 month of storage at 40°C and at 75% relative humidity.

Suspension Stability [0148] The liquid formulations of the present disclosure are suspensions. As understood in the art, a suspension is a biphasic preparation consisting of solid particles dispersed throughout a liquid phase. For pharmaceutical compositions, a common type of suspension contains solid particles of one or more active pharmaceutical ingredients and/or excipients suspended throughout a liquid medium of one or more solvents. It should be recognized when an ingredient is indicated as “in suspension” or “suspended”, at least a portion of the ingredient is undissolved in the primary liquid medium.

[0149] Depending upon the maximum solubility of ingredient in the chosen liquid medium and the quantity of the excipients, some ingredients may be completely dissolved (i.e., exist in solution) while others are entirely undissolved/suspended (i.e. exist in suspension) or are partially dissolved/partially suspended (i.e., a fraction exists in solution and the remaining fraction exists in suspension). It should be understood that the suspension as described herein may encompass all possible combinations of the suspension having some ingredients in solution, or in suspension, or in partial suspension. The liquid formulations of the present disclosure are suspensions having water as the primary liquid medium.

[0150] It should be recognized that the liquid formulations provided herein may be characterized by observations of their formulation stability or lack thereof following exposure to particular temperature and humidity conditions, such as set forth in a freeze-thaw cycling procedure according to the Handbook of Stability Testing in Pharmaceutical Development: Regulation, Methodologies and Best Practices, K. Huynh-Ba (ed.), Springer, November 2008, Chapter 2 (e.g., three cycles of (1) storage at -20°C for four days followed by (2) storage at 25°C, and 60% relative humidity (RH) for three days). Formulation stability may be visually assessed, for example, by observation for any phase separation.

[0151] In some embodiments, the liquid formulations provided herein do not exhibit phase separation after being subjected to freeze-thaw cycling. In other embodiments, the liquid formulations provided herein exhibit phase separation after being subjected to a freezethaw cycling. In certain embodiments wherein the liquid formulations exhibit phase separation after being subjected to a freeze-thaw cycling, the liquid formulations may be resuspended or re-dispersed by shaking.

Methods of Preparing Thereof [0152] In still another aspect, provided herein are methods for preparing the liquid oral antacid formulations of the present disclosure.

[0153] In some embodiments of the present aspect, the method comprises: (a) combining at least one antacid, alginic acid or a pharmaceutically acceptable salt thereof, at least one of pectin and carrageenan, sodium bicarbonate; and water to provide a mixture; (b) optionally adding one or more additional pharmaceutically acceptable excipients to the mixture of step (a); and (c) stirring the mixture to provide the liquid formulation.

[0154] To further ensure that the suspensions produced by the present methods are uniformly dispersed, the active pharmaceutical ingredients, excipients, or any mixtures thereof used to prepare the suspensions can be subjected to heating, stirring, or homogenization in order to improve dispersion and/or reduce particle size. For example, in some embodiments, the active pharmaceutical ingredient(s) and/or excipients may be homogenized using a 20 mesh sieve, e.g., to a particle size less than or equal to about 850 pm. The processing conditions of the methods and steps as described herein including, but not limited to, temperature, mixing times, and stir rates (rpm) may adjusted.

[0155] In some embodiments of the present aspect, the step (a) of combining comprises homogenizing the at least one antacid, alginic acid or a pharmaceutically acceptable salt thereof, at least one of pectin and carrageenan, sodium bicarbonate; and water to reduce the particle size of the at least one antacid, alginic acid or a pharmaceutically acceptable salt thereof, at least one of pectin and carrageenan, and/or sodium bicarbonate. In other embodiments of the present aspect, the step (b) of optionally adding one or more additional pharmaceutically acceptable excipients comprises adding one or more flavorants to the mixture of step (a).

[0156] As described herein, any of the steps of the present methods are preferably performed under agitation to ensure uniformity and even distribution of the mixtures and suspensions generated. In some embodiments, agitation includes mixing or stirring. In certain embodiments, the agitation is continuous or intermittent. In other embodiments, the steps of the present methods are performed in one or more reactors capable of agitating the mixtures and suspensions described herein. For example, active ingredients and excipients in the suspension may be combined in, added to, heated in, cooled in, or stored in such a reactor or reactors. Methods of Use, Containers and Kits Thereof

[0157] In still other aspects, provided herein are methods of using the liquid formulations as described herein. As described above, the liquid oral antacid formulations of the present disclosure may be employed for treatment of various gastric and gastroesophageal disorders.

[0158] Exemplary gastric and gastroesophageal disorders of the present disclosure may include but are not limited to gastroesophageal reflux disorder (GERD), acid reflux, peptic ulceration, acute or chronic gastritis, esophagitis, non-ulcer dyspepsia, bloating, gastroparesis, aerophagia, diarrhea and constipation, etc.

[0159] In one aspect, the present disclosure provides a method for treating gastroesophageal reflux disorder (GERD) and/or peptic ulceration, comprising administering to a human in need thereof a liquid formulation as described herein.

[0160] In another aspect, the present disclosure provides a method for treating acute or chronic gastritis, comprising administering to a human in need thereof a liquid formulation as described herein.

[0161] In some embodiments of any of the preceding methods, the liquid formulation is administered once, twice, three times or four times daily. In certain embodiments, the liquid formulation is administered once or twice daily. It should be recognized that the number of times the liquid formulation is administered daily may depend upon the amount to be administered per dose. In some embodiments, the liquid formulation is administered at a dosage of about 5 mL, about 10 mL, about 15 mL, about 20 mL, about 25 mL, or about 30 mL. In other embodiments, the liquid formulation is administered at a dosage of between about 5 mL and about 30 mL, between about 5 mL and about 25 mL, between about 5 mL and about 20 mL, between about 5 mL and about 15 mL, between about 5 mL and about 10 mL, between about 10 mL and about 30 mL, between about 10 mL and about 25 mL, between about 10 mL and about 20 mL, between about 10 mL and about 15 mL, between about 15 mL and about 30 mL, between about 15 mL and about 25 mL, or between about 15 mL and about 20 mL.

[0162] In still another aspect, provided herein is a method for treating acid reflux, comprising administering to a human in need thereof a liquid formulation as described herein. [0163] In other aspects, provided is an article of manufacture, such as a container comprising the liquid formulations as described herein, and a label containing instructions for use of the liquid formulations. In some embodiments, the container is a bottle.

[0164] In yet other aspects, provided is a kit comprising the liquid formulations as described herein; and a package insert containing instructions for use of such liquid formulations.

[0165] In some embodiments of any of the foregoing aspects, the instructions for use of the liquid formulations may include instructions for dosage amount and/or frequency of administration, for treating various gastric and gastroesophageal disorders. In certain embodiments, the instructions for use of the liquid formulations comprise instructions for dosage amount and/or frequency for the treatment of gastroesophageal reflux disorder (GERD), peptic ulceration, acute gastritis, chronic gastritis, acid reflux, non-ulcer dyspepsia, bloating, gastroparesis, aerophagia, diarrhea and/or constipation.

EXAMPLES

[0167] The presently disclosed subject matter will be better understood by reference to the following Examples, which are provided as exemplary of the invention, and not by way of limitation.

Example 1: Preparation of Liquid Oral Antacid Formulation

[0168] The present example details the preparation of an exemplary liquid oral antacid formulation according to the present disclosure. Table 1 details ingredients (and function) and theoretical amount to be combined for an exemplary antacid formulation.

[0169] The ingredients as provided in Table 1 were combined at the quantities as specified and mixed to form an opaque suspension.

Table 1

Example 2: Antacid Formulations and pH

[0170] The present example describes the composition of various formulations prepared in accordance with the present disclosure and their respective pH values as compared to four commercially available antacid suspension formulations.

[0171] The liquid formulations evaluated in the present example included four commercially available products — Rennie Duo® Suspension (calcium carbonate, magnesium carbonate, sodium alginate, xanthan gum, sodium bicarbonate, benzyl alcohol, mint flavor, purified water, parabens), Gaviscon ® Advance, Gaviscon ® Extra Strength, and Boots Heartburn Relief — and four formulations as provided in the present disclosure — Formulations #1-4. The compositions of the liquid formulations are shown in Tables 2-5.

[0172] The Rennie Duo ® Suspension contained alginate but no pectin or carrageenan. Gaviscon ® Extra Strength similarly contained alginate but did not contain any pectin and carrageenan. The Gaviscon ® Advance formulation contained alginate at a level of lOOOmg per dose, and a carbomer at an unknown level.

Table 2

” indicates ingredient present per ingredient label, precise percentage not disclosed

Table 3

” indicates ingredient present per ingredient label, precise percentage unknown

Table 4

Table 5

[0173] The liquid formulations as described above were evaluated for their pH values after preparation, and after storage at 40°C for 1 month to assess formulation storage stability. The pH value for each formulation was measured using a pH meter (calibrated with buffer solution at pH 2.0, at pH 4.0, at pH 7.0 and at pH 10.0, prior to use). Each formulation was measured twice and the average pH value was calculated for the two replicate measurements. The pH levels for any oral suspension and/or solution are typically maintained within a range between 5.50 and 9.50, as pH values outside the range could potentially induce some irritability within the gastric environment. As the liquid formulations evaluated in this example are expected to serve as antacids, a basic pH (greater than pH 7) was expected and observed for each formulation as shown in Table 6. With the exception of Gaviscon ® Extra Strength, all formulations increased in basicity (higher pH value) after storage as compared to their initial basicity (pH value).

Table 6

Example 3: Raft Formation Tests

[0174] The present example describes assays of formulations as provided herein to evaluate their ability to form rafts, and to assess the raft formation time and raft strength. The assay for determining raft strength provided herein were performed in accordance with the Raft Strength Test as described in the British Pharmacopeia (2007). The liquid formulations evaluated in this example were the liquid formulations as provided in Example 2 above.

[0175] Raft formation and strength tests in this example were performed in accordance with British Pharmacopeia (2007) Raft Strength Test. FIG. 1A depicts an exemplary apparatus for conducting raft strength tests. [0176] Rafts were formed by adding a maximum dose of liquid formulation to be tested to 150 mL of 0.1 M hydrochloric acid, maintained at 37°C in a 250 mL low form glass beaker. Each raft was formed around an L-shaped stainless steel wire probe held upright in the beaker throughout the whole period (30 min) during raft development. The wire probe was supported vertically in the beaker by a piece of circular filter paper through which it was centrally placed, such that the filter paper rested on the rim of the test beaker, and the wire probe was suspended in the beaker. During the 30-minute raft development period, the time elapsed to initial raft formation (as observed visually) was recorded for each formulation. After 30 min of raft development, the filter paper support was removed from the wire probe without disruption to the hook or the formed raft. The beaker was placed on the table of a texture analyzer, the wire probe was hooked onto the texture analyzer arm. The tests were started with the hook slightly lifted from the base of the beaker (by 1-2 mm) to avoid any false force offset in the data at the start of the test. To measure raft strength, the wire probe was pulled vertically up through the raft at a rate of 5mm/s, and the force (g) required to pull the wire probe up through the raft was recorded.

[0177] The liquid formulations as described above were evaluated for their raft formation properties both after initial preparation and after storage at 40°C for 1 month to assess formulation storage stability. The time observed for rafts to form for each formulation are shown in Table 7. FIG. 2A shows a plot of the force required to pull the wire probe through the rafts formed for each formulation. The raft strength results are also shown in Table 8.

Table 7

*N/A = not applicable, rafts did not form for the Rennie Duo® Suspension or the Gaviscon® Extra Strength formulations after storage at 40°C/75% RH for 1 month

Table 8

*ND = not determined; raft properties were not recorded for these metrics for Boots Heartbum Relief formulation [0178] Following completion of the raft strength tests, the rafts formed for each formulation were removed from the test beakers and their wire probes removed to be analyzed for raft thickness (mm) and weight (g). Formulations #1- 4 exhibited slight lag times in raft formation of around 120 seconds or longer while the leading marketed formulations formed rafts in less than 60 seconds.

[0179] As shown in Table 7 and Table 8, it was observed that rafts having an initial raft weight of greater than 30 g also exhibited higher initial raft strength. No correlations between raft formation time and raft strength or between raft thickness and raft strength were observed. In Table 8, Formulations #1, 2 and 4 (which contained alginate in combination with pectin and carrageenan in Formulations #1 and 2, or with carrageenan in Formulations #4) demonstrated superior initial raft strengths to the commercially available products, which contained only alginate.

Example 4: Mucoadhesion Tests

[0180] The present example describes two in vitro bioadhesion tests of formulations as provided herein to evaluate their ability to adhere to surfaces and, more specifically, to mucous membranes. The liquid formulations evaluated in the present example — Gaviscon ® Advance, Gaviscon ® Extra Strength, Formulation #1 and Formulation #2 — were the same as the liquid formulations evaluated in Example 2 above. In the first test, the adhesive properties of the liquid formulations were assessed with respect to their ability adhere to a polyethylene probe. In the second test, the liquid formulations were assessed with respect to their abilities to adhere to a biological membrane (tripe). In the third test, formulations were evaluated for their ability to an angled surface under the force of gravity.

[0181] It was observed that the adhesion results of the liquid formulations in the first and third tests (using a polyethylene probe and angled surface, respectively) had a strong correlation to the results observed in the second test with tripe. Thus, the first and third tests were considered to reflect and provide a relative measure of mucoadhesion.

Parti. Bio-Adhesion Test using Texture Analyzer (in vitro method)

[0182] The sample formulations to be tested were placed into tared, clean glass or stainless steel beakers and the initial sample weights were recorded. Each sample beaker was individually placed beneath a texture analyzer fitted with a polyethylene attachment (initial weight 94.67 g), positioned over the beaker. FIG. IB depicts an exemplary apparatus for conducting the bioadhesion test of the present example. FIG. 1C shows an photograph of the polyethylene attachment. The polyethylene attachment was mechanically dipped into the beaker containing the sample and allowed to remain stationary for 10 seconds. After 10 seconds had elapsed, the texture analyzer arm was adjusted so that the polyethylene attachment was removed from contact with the sample. The polyethylene attachment was allowed to remain stationary for an additional period of 10-15 seconds to allow for any excess sample to drop. The polyethylene attachment was then removed from the texture analyzer arm and weighed to determine the combined final weight of the polyethylene attachment and sample adhered to attachment. Each sample beaker was subjected to a total of five trials (dips). After five trials, the final weight of the sample remaining in the beaker was measured, and the percentage of sample retained by the polyethylene attachment (that is, removed from the sample beaker) was calculated. Table 9, Table 10, and Table 11 show the bioadhesion results for the four formulations tested, as represented by the amount of sample retained on the texture analyzer polyethylene attachment after each trial (Table 9 and Table 10) and by the total amount of sample retained (removed from the sample container by the attachment) after the five trials (Table 11).

[0183] As shown in Table 9 and Table 10, Formulations #1 and #2 showed superior adhesion to the on average and, in Table 11, yielded a higher overall adhesion as demonstrated by the percentage of sample retained by the polyethylene attachment.

Table 9

Table 10

Table 11

[0184] The liquid formulations were also assessed for their adhesive properties after storage at 40°C for 1 month, according to the bioadhesion test described above. The results for the bioadhesion test recorded for various formulations both after initial preparation and after storage are shown in Table 12. After storage, Formulation #4 was observed to exhibit comparable bioadhesion to the Gaviscon ® Extra Strength Formulation though, as shown in Table 8, the Gaviscon ® Extra Strength did not form a raft after storage. Formulations #1-2 provided superior bio adhesiveness when compared to all marketed consumer products before and after storage. Formulations #3-4 provided consistent bioadhesion before and after storage and had superior bioadhesion to that of the marketed consumer products after storage.

Table 12

Part II Mucoadhesion Test Method with Biological Membrane (Tripe)

[0185] Freshly frozen and thawed food grade bovine stomach (reticulum region, commercially sourced) was purchased. The bovine reticulum, or tripe, was employed as a surrogate mucous membrane for a human stomach.

[0186] To prepare the tripe samples, 2”by 2” squares of tripe were excised from the initial reticulum stock. Each square section was thawed in commercially available artificial human saliva (potassium salt (e.g., potassium chloride or potassium hydrogen phosphate), sodium chloride, calcium chloride, sodium hydroxide (for pH adjustment)) for 1 hour prior to use. The tripe samples were gently pat dried to remove excess saliva solution and weighed in a tared polyethylene bottle with a cap to record the initial sample weights (uncoated tripe). The liquid formulation to be tested for a given tripe sample was applied to a sample square (time zero, t = 0 min), and weighed to determine the sample weight of the coated tripe (with formulation). Each sample was then washed with 1.5 mL of artificial saliva solution (SS) for 15 seconds by gentle manual agitation/rotation of the sealed bottle. Each wash with artificial saliva solution was carried out in order to simulate in vivo conditions, under which it was assumed that some saliva produced in the mouth would be swallowed, and wash the lining of the empty stomach. After agitation, each sample was removed from the bottle and weighed. The samples were then placed back into the bottle and subjected to successive iterations of 1.5 mL washes with artificial saliva, agitation and weight until all of the applied formulation had been removed. Table 13 and Table 14 show the recorded weights for each rinse, up to the first ten rinses (if applicable) and the final rinse (if applicable). Table 15 summarizes the percentage of each formulation that adhered to (was retained by) the tripe after rinsing for a specified number of rinses.

[0187] As shown in the Tables below, more of mass of the Formulations #1 and #2 remained adhered to the tripe samples over the same number of rinses. Gaviscon ® Extra Strength and Gaviscon ® Advance were completely removed after the 8^th and 9^th rinses. In contrast, Formulation #1 remained on the sample until the 10^th rinse and Formulation #2 required 22 rinses for complete removal. Table 13

Table 14

Table 15

Part III. Surface Adhesion

[0188] Two grams of the samples to be assessed were loaded onto one end a horizontal transparent sample tray as shown in FIG. 3A, from left-to-right, Gaviscon ® Extra Strength, Rennie Duo ® Suspension, Gaviscon ® Advance, Formulation #1, Formulation #2, Formulation #3, and Formulation #4. The sample tray was tilted at a 45°, with the samples at the elevated end of the tray, for thirty seconds to allow gravity to provide slight downward force on the samples. After thirty seconds, the tray was reverted to a horizontal position and the samples were visually assessed for migration of the liquid formulations towards the opposing end of the tray from their initial positions. As shown in FIG. 3B (same sample order from left-to-right as in FIG. 3A), all three commercial formulations — Gaviscon ® Extra Strength, Rennie Duo ® Suspension, and Gaviscon ® Advance — showed substantial migration of the liquid formulation towards the opposite end of the tray after thirty seconds; Gaviscon ® Extra Strength, which demonstrated the least migration was determined to exhibit the greatest adhesion out of the three commercial formulations. Formulation #4 showed comparable signs of migration to that of Gaviscon ® Extra Strength. In contrast, Formulations #1-3 exhibited showed no apparent movement on the tray, and thus had superior adhesion as compared to the commercial formulations.

[0189] In FIG. 3C and FIG. 3D, the same surface adhesion test was repeated as described above. The samples in FIG. 3C and FIG. 3D were arranged from left-to-right, Gaviscon ® Extra Strength, Rennie Duo ® Suspension, Gaviscon ® Advance, Formulation #1, Formulation #2, Formulation #3, and Formulation #4. Table 16 below shows the sample migration of the various formulations tested.

Table 16

Example 5: Viscosity and Thixotropic Behavior Tests

[0190] The present example describes tests to determine the thixotropic behavior of the liquid formulations provided herein.

[0191] In the present example, the viscosity and thixotropy measurements were carried out on a cone-plate rotational rheometer (Anton Paar MCR 302; Position length (mm) 100; Trim Position (pm) 25; Torsional Com (rad.Nm) 0.001025). Each formulation was subjected to a controlled shear rate three-interval thixotropy measurement as described herein to measure initial and recovery viscosity values (in centipoise). In brief, each sample was subjected to three-intervals of controlled shear rate, including a first interval at a low shear rate (1/s), a second interval at a high shear rate (1000/s) and a third interval at the same low shear rate as the first interval (1/s). The shear rate was held for each interval for a duration of 2 minutes (120 seconds). The viscosity was recorded at the start of the first interval (initial) and at the end of the third interval (recovery). The liquid formulations were evaluated both after initial preparation and after storage at 40°C for 1 month to observe changes in thixotropic behavior. The results from the three-interval thixotropy test are shown in Table 17 below.

[0192] As illustrated in Table 17, the commercial formulations exhibited lower initial and recovery viscosities than those of Formulations #1-4 immediately after preparation (initial, t=0). Gaviscon ® Advance demonstrated a similar initial viscosity to that of Formulation #4 but did not recover to its initial viscosity, whereas Formulation #4 did. After storage at 40°C for 1 month, Formulations #1-3 increased in initial and recovery viscosities measured as compared to their initial and recovery viscosities observed immediately after preparation. Commercial formulations for Gaviscon ® Extra Strength and Gaviscon ® Advance exhibited a reduction in their initial and recovery viscosities after storage relative to the viscosities observed before storage. The Rennie Duo ® suspension and Formulation #4 both demonstrated slight increases in their initial viscosities after storage (relative to the initial viscosities at t=0) but their recovery viscosities were comparable to the values recorded prior to storage (at t=0).

Table 17

Example 6: Storage Stability

[0193] The present example describes the evaluation of Formulations #1-4 as provided in Example 2 for physical stability after storage at 40°C and 75% relative humidity for 1 month and after freeze-thaw cycling to assess each formulation’s stability to extreme temperature conditions.

Part I. Storage at 40°C/75% RH

[0194] Samples of the liquid formulations to be tested were placed in clear glass wide- mouth jars and sealed, as shown in FIGS. 4A and 4C. The sealed jars were stored at 40°C, 75% relative humidity, for 1 month, undisturbed. After 1 month, the samples in the jars were visually assessed for any apparent phase separation, in FIGS. 4B and 4D. As shown in FIGS. 4B and 4D, phase separation was observed in Formulations #2-4 after storage. However, the liquid formulations were readily re-dispersed to form suspensions upon shaking.

Part II. Freeze-Thaw Cycling Evaluation

[0195] The freeze-thaw cycling procedure was carried out in accordance with the Handbook of Stability Testing in Pharmaceutical Development: Regulation, Methodologies and Best Practices, K. Huynh-Ba (ed.), Springer, November 2008, Chapter 2. [0196] The liquid formulations to be tested were each placed in a screw-top clear glass scintillation vial and sealed with a cap. FIG. 5A shows the four samples prior to undergoing freeze-thaw cycling. Each sample was subjected to three freeze-thaw cycles, in which each cycle involved storage at -20°C for 4 days followed by storage at 20°C and 60% relative humidity (%RH) for 3 days, for a total duration of 21 days (three cycles). After the three freeze-thaw cycles, each sample formulation was visually assessed in the sealed scintillation vial for any sign of phase separation. None of the tested formulations (Formulations #1-4) exhibited any phase separation after freeze-thaw cycling as shown in FIG. 5B.

Example 7: Effects of Pectin, Alginate and Carrageenan on Liquid Formulation Properties

[0197] The present example details the evaluation of various liquid oral antacid formulations prepared in accordance with the disclosure herein. The quantities of sodium alginate, pectin, and carrageenan were varied in each formulation to assess and compare any changes in pH, raft formation time and raft strength, and bioadhesion as a result of the differing quantities of these three components. The compositions for various formulations evaluated in this example are described in Table 18, Table 19, and Table 20 below. Commercial formulations Rennie Duo ® Suspension, Gaviscon ® Extra Strength, and Gaviscon ® Advance, and Formulations #1-2 and #4 (as detailed in Example 2) were included in the comparison.

Table 18

Table 19

Table 20

[0198] The pH measurements, raft formation tests, and bioadhesion tests were performed in accordance with the protocols described in Example 2, Example 3, and Example 4, Part I. The results are provided in Table 21 below.

Table 21

[0199] As observed in Table 21, Formulations #5-7, which contained alginate at levels of 350 mg per dose, exhibited a raft strength force between 15 g and 20 g, which was above the Alginate Rafting Forming Oral Suspension (ARFOS) limits of 7.5.

[0200] Formulations #8-10 were prepared with alginate levels ranging from 300 mg per dose to 500 mg per dose, and a 1-to-l ratio of pectin-to-carrageenan (90 mg or 225 mg). The rafting force was observed to range from 13 to 22 grams of force. However, with increasing quantities of alginate relative to the quantities of pectin and carrageen, the rafting force was found to decrease even with a fixed 1-to-l ratio of pectin and carrageenan.

[0201] Formulations #4, #11, #12 and #13 were prepared with a fixed alginate content of 300 mg per dose and either no pectin (Formulation #4) or varied ratios of pectin-to- carrageenan (approximately l-to-5, 5-to-l and 1-to-l) (Formulations #11-13). Ratios of pectin-to-carrageenan at l-to-5 and 5-to-l in Formulations #11 and 12 resulted in the raft strengths at levels greater than 15 g of force. However, with a decrease in carrageenan (at the 5-to-l ratio, Formulation #12), the bioadhesiveness was observed to be slightly higher than that of the l-to-5 ratio formulation (Formulation #11).

Claims

CLAIMS What is claimed is:

1. A liquid formulation, comprising: alginic acid or a pharmaceutically acceptable salt thereof; at least one of pectin and carrageenan; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin, and any carrageenan present in the liquid formulation is 2-20% w/w.

2. A liquid formulation, comprising:

1-18% w/w alginic acid or a pharmaceutically acceptable salt thereof;

1-10% w/w pectin, carrageenan, or a combination thereof; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin, and any carrageenan present in the liquid formulation is 3.5-20% w/w.

3. A liquid formulation, comprising:

1-8% w/w alginic acid or a pharmaceutically acceptable salt thereof;

3.5-10% w/w pectin, carrageenan, or a combination thereof; sodium bicarbonate; at least one antacid; and water, wherein the combined weight percentage of alginic acid or a pharmaceutically acceptable salt thereof, any pectin, and any carrageenan present in the liquid formulation is 4.5-15% w/w.

4. The liquid formulation of any one of claims 1 to 3, wherein the liquid formulation comprises 1-5% w/w alginic acid or a pharmaceutically acceptable salt thereof.

5. The liquid formulation of any one of claims 1 to 3, wherein the liquid formulation comprises 5-8% w/w alginic acid or a pharmaceutically acceptable salt thereof.

6. The liquid formulation of any one of claims 1 to 5, wherein the liquid formulation comprises pectin.

7. The liquid formulation of claim 6, wherein the pectin is low methoxylated pectin and wherein the liquid formulation further comprises calcium ions.

8. The liquid formulation of claim 6, wherein the pectin is high methoxylated pectin.

9. The liquid formulation of any one of claims 1 to 8, wherein the liquid formulation comprises 0.5-3% w/w pectin.

10. The liquid formulation of any one of claims 1 to 5, wherein the liquid formulation comprises carrageenan.

11. The liquid formulation of any one of claims 1 to 5 and 10, wherein the liquid formulation comprises 0.5-5% w/w carrageenan.

12. The liquid formulation of any one of claims 1 to 11, wherein the liquid formulation comprises a combination of pectin and carrageenan.

73 The liquid formulation of claim 12, wherein the liquid formulation comprises pectin and carrageenan and has a ratio of pectin-to-carrageenan between 10-to-l and l-to-10. The liquid formulation of claim 13, wherein the liquid formulation comprises pectin and carrageenan and has a ratio of pectin-to-carrageenan between 5-to-l and l-to-5. The liquid formulation of any one of claims 1 to 14, wherein the liquid formulation comprises at least 10% w/w of the at least one antacid by total weight of the liquid formulation. The liquid formulation of claim 15, wherein the liquid formulation comprises 10-20% w/w of the at least one antacid by total weight of the liquid formulation. The liquid formulation of any one of claims 1 to 16, wherein the at least one antacid comprises calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, or any combination thereof. The liquid formulation of claim 17, wherein the at least one antacid comprises calcium carbonate and magnesium hydroxide. The liquid formulation of any one of claims 1 to 18, wherein the liquid formulation has a pH of at least pH 7. The liquid formulation of claim 19, wherein the liquid formulation has a pH of between pH 7 and pH 9.5. The liquid formulation of any one of claims 1 to 20 wherein the liquid formulation further comprises one or more preservatives and/or one or more flavorants. The liquid formulation of any one of claims 1 to 21, wherein the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in between 5 seconds and 30 minutes. The liquid formulation of claim 22, wherein the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft in between 5 seconds and 3 minutes. The liquid formulation of any one of claims 1 to 23, wherein the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of at least 7.5 g, as determined in accordance with the Raft Strength Test. The liquid formulation of claim 24, wherein the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of at least 10 g, as determined in accordance with the Raft Strength Test. The liquid formulation of claim 24, wherein the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft strength force of between 20 g and 40 g, as determined in accordance with the Raft Strength Test. The liquid formulation of any one of claims 1 to 26, wherein the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of at least 12 mm. The liquid formulation of claim 27, wherein the liquid formulation, when contacted with a solution of 0.1 N aqueous hydrochloric acid, forms a raft having a raft thickness of between 15 mm and 25 mm. The liquid formulation of any one of claims 1 to 28, wherein the liquid formulation has bioadhesion of at least 10% as determined by the in vitro bioadhesion test using a texture analyzer. The liquid formulation of any one of claims 1 to 29, wherein the liquid formulation has bioadhesion of at least 4% as determined by the in vitro bioadhesion test using a texture analyzer after 1 month of storage at 40°C and 75% RH.

74 The liquid formulation of any one of claims 1 to 30, wherein the liquid formulation has a viscosity of between 1000 cP and 20000 cP as determined by the three-interval thixotropy test described herein. The liquid formulation of any one of claims 1 to 31, wherein the liquid formulation has a viscosity of between 1000 cP and 27000 cP as measured by the three-interval thixotropy test described herein after 1 month of storage at 40°C and 75% RH. A container, comprising the liquid formulation according to any one of claims 1 to 32. A method for treating gastroesophageal reflux disorder (GERD) and/or peptic ulceration, comprising administering to a human in need thereof a liquid formulation according to any one of claims 1 to 32. A method for treating acute or chronic gastritis, comprising administering to a human in need thereof a liquid formulation according to any one of claims 1 to 32. A method for treating acid reflux, comprising administering to a human in need thereof a liquid formulation according to any one of claims 1 to 32. The method of any one of claims 34 to 36, wherein the liquid formulation is administered once or twice daily.

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