WO2014191884A1

WO2014191884A1 - Pharmaceutical compositions comprising an excipient prepared by manilkara zapota (linn.) p. royen syn. seeds

Info

Publication number: WO2014191884A1
Application number: PCT/IB2014/061686
Authority: WO
Inventors: Sudarshan SINGH; Sunil B BOTHARA
Original assignee: Singh Sudarshan; Bothara Sunil B
Priority date: 2013-05-31
Filing date: 2014-05-24
Publication date: 2014-12-04

Abstract

Pharmaceutical compositions comprising at least one active pharmaceutical ingredient, to which parts of one or more additional complimentary active pharmaceutical ingredient may be optionally added; and the mucilage prepared from Manilkara zapota (Linn.) P. Royen syn. seeds. The invention also provides for methods of preparation of the compositions.

Description

PHARMACEUTICAL COMPOSITIONS COMPRISING AN EXCIPIENT PREPARED BY MANILKARA ZAPOTA (LINN.) P. ROYEN SYN. SEEDS.

FIELD OF THE INVENTION:

The present invention relates to the field of pharmaceutical compositions comprising an excipient prepared by Manilkara zapota (Linn.) P. Royen syn.

BACKGROUND:

In the field of pharmaceutical medicines, an excipient plays an important role in composition and administration of a medicament.

Among the typically used excipients, especially those acting as a mucoadhesives or mucoadhesive agents are HPMC (hydroxypropyl methycellulose), Carbopol, Xanthan gum and Guar Gum as mucoadhesive agent most.

The present invention provides a suitable alternative to the excipients existing in the prior art especially those acting as a mucoadhesive agents, in the form of mucilage from Manilkara zapota (Linn.) P. Royen syn. seed based excipient, thereby providing the following advantages:

(1) Increased contact time for the drug to allow for local activity in the stomach, intestine or other locus of activity.

(2) Increased or more efficient absorption for drugs which have specific absorption sites.

(3) The ability to reduce the number of dosages per period of time.

(4) Minimization or elimination of local and/or systemic side effects.

(5) Minimization of drug accumulation associated with chronic dosing.

(6) Improved efficiency and safety of treatment.

(7) Reduced fluctuation of drug level.

(8) Cost of other available polymer in international market is very high, so isolated mucilage can compete with other available polymer.

Manilkara zapota (Linn.) P. Royen syn. is a large, evergreen, forest tree more than 30 m in height (family: Sapotaceae) popularly known as Naseberry or Sapodilla in English and Chiku/Sapota in local languages in India. The fruit contains fructose, a and β glucose and sucrose. The seeds contain protien (8 %) amino acid composition as leucine 8.0; lysine 4.1; methionine 0.4; phenylalanine 3.0; and valine 5.8 %. The plant is a rich source of Saponins, tannin, sugars, proteins, ascorbic acid, phenolics, carotenoids and minerals like iron, copper, zinc, calcium, potassium and vitamins like folate, niacin and pantothenic acid.

PRIOR ART

EP 0080673 describes these problems in detail, and discloses the use of 5 to 30 % of highly dispersed silica gel in Guar gum containing tablet.

Charles M. Higgins: U. S. Patent No. 466240; Invented certain new and improvement in mucilages or adhesive compounds.

Andrew R. Gallopo: U. S Patent No. 5077051; Describe the use of Xanthan gum and locust gum as a delivering of sustained release bioadhesive microcapsule.

Jens Hansen: U.S. Patent No. 6288383B1; Described the use of fatty acids esters as bioadhesive substance.

Pratibha S. Pilganokar: U.S. Pub. No: US 2004/0228932A1; Described about multifunctional fiber rich fraction useful as excipient for pharmaceutical dosage form for various routes of administration. This excipient can be used as a binder, disintegrants, filler, dispersing agent, coating agent, film forming agent, thickener etc. for preparation of various dosage form.

David B. Masters: U.S. Pub No: US 2005/0196440 Al; Described about mucoadhesive drug delivery devices comprised of one or more biocompatible purified protein combined with one or more biocompatible solvents and one or mucoadhesive agent.

Juels S Jacob: U.S. Pub No: US 2005/0249799 Al; Describe about oral delivery system for class II drugs that have oral bioavailability due to their insolubility in water and slow dissolution kinetics. The immediate release formulation contains a class II drug, together with a hydrophobic polymer, preferably bioadhesive polymer. The controlled release formulations contain a BCS class II drug and a bioadhesive polymer. The controlled release formulation may be in the form of tablet, capsule, mini-tab, micro particulate system or osmotic pump. David Hoikhman: U.S. Pub No: US 2006/0177497 Al; Prepared controlled-release dosage from, which comprised a matrix formed of ingredients (a) and (b): (a) gellan gum, and (b) one or more hydrophilic polymers; and further comprising a drug incorporated within said matrix. The invention also describes a method for the preparation of said controlled-release dosage forms.

Myatt Graham John (The Procter & Gamble Company) International application No: PCT/US03/16013; Oral Composition, suitable for chewing, comprising a gel-forming polysaccharide isolated from pshyllium seed husks and an excipient that is fast dissolving in the oral cavity, provide good aesthetics and acceptable mouth feel as perceived by the consumer.

Marlett Judith A. (Wisconsin Alumni Research Foundation) International application No: PCT/US2005/017185; A purified fraction of the gel-forming component of pshyllium seed husks, along with process for purification and use of the fraction.

Avachat Makarnd K (Blue Cross Laboratory Limited) International application No: PCT/IN02/00097; A solid controlled release oral unit dose pharmaceutical composition, comprising one or more of therapeutic agent/drug and a gel forming husk powder obtained from Lepidium sativum seeds. Cross-Linking enhancers and /or pharmaceutically acceptable excipient may present. The gel forming husk powder obtained from Lepidium sativum seeds is present in the range of 10 to 70 % of the total weight of dosage form, the cross-linking enhancer selected from xanthan gum, Karaya gum and other similar gums in the range of 3- 10% by weight of the dosage from to give a release profile between 4 to 20 hours. The composition may be in the form of tablet, capsules and pellets.

Satheesh Madhav NV, Uma Shankar MS. Indian patent application filed. 2008; 95. A smart biopolymeric material from Arachis hypogea seeds for formulation of amikacin loaded bioplates.

Senthil et al, prepared mucoadhesive tablet and evaluate the adhesive property of the gum obtained from seed of Caesalpinia pulcherrima by comparing with Carbopol, HPMC, and Chitosan. Physical parameter such as bulk density, tapped density, compressibility index, and Hausner ratio values indicate good flow, the percentage of drug content obtained was 96.4 ± 0.97%, and various adhesive evaluation result reveal a good mucoadhesive property. The barium sulphate loaded tablet possess a strong mucoadhesive property, which was evident for prolong adhesion in the same location of the stomach up to a period of 10 hr., were duration of adhesion was found comparatively less with other polymers. From the result of in vitro and in vivo adhesive test and in vitro release study the test agent (gum) appears to exhibit considerable mucoadhesive property and mean residence time values when compared with tablet of Carbopol, HPMC, and Chitosan (Asian Journal of pharmaceutics, 2010; 1: 64 - 68).

Deshmukh et al, designed oral controlled release theophylline anhydrous bioadhesive tablet, optimize bioadhesive strength and drug release profile. Different type of natural hydrophilic polymer such as xanthan gum, locust bean gum, guar gum, karaya gum, and their combination were used to formulate matrix tablet. The tablet of anhydrous theophylline were prepared by direct compression method and subjected to in-vitro drug dissolution for 12 hr. The bioadhesive strength of the tablets was measured as the force of detachment against the porcine gastric mucosa. The combination of karaya gum: guar gum tablet showed greater bioadhesive strength as compare to single gum and other gum combination tablets. Karaya gum: Guar gum loaded tablet were not discharge from mucosa membrane and were dissolved in the gastric fluidic. An increase in concentration increase the drug release profile beyond 12 hr. was there is no significant effect on bioadhesive strength of tablet (Asian journal of pharmaceutics, 2009; 3 (1): 54 - 58).

SUMMARY OF THE INVENTION:

The present invention in a preferred embodiment provides pharmaceutical compositions comprising at least an active pharmaceutical ingredient, to which parts of one or more additional complimentary active pharmaceutical ingredient may be optionally added; and an excipient prepared by Manilkara zapota (Linn.) P. Royen syn. seeds. The invention also provides for methods of preparation of the pharmaceutical compositions.

BRIEF DESCRIPTION OF DRAWINGS:

Figure 1 represents Particle Size Analysis of Dried Mucilage Obtained from seeds of M. zapota using Zetatrac Particle Size Analyzer. Figure 2 shows a set of images obtained by Scanning electron Microscopy of M. zapota at different magnification (35x, lOOx, 270x and 500x) which further confirms the amorphous Nature of powder mucilage.

Figure 3 shows Molecular Weight Characterization of Mucilage extracted from MMZ using Gel Permeation Chromatography.

Figure 4 shows Powder X-Ray Diffraction Spectra of Mucilage Obtained from seeds of M. zapota using Goyenimeter (Amorphous Form).

Figure 5 represents Differential Scanning Calorimetric (DSC) characterization of MMZ illustrating the transition in temperature.

Figure 6 represents Differential Thermal Analysis (DTA) characterization of MMZ illustrating the transition in temperature.

Figure 7 shows Thermogravimetry Analysis (TGA) characterization of MMZ using TGA Analyzer demonstrating the thermal stability of MMZ.

Figure 8 displays Comparative Dissolution of Fl to F4 through the study of in vitro dissolution.

Figure 9 a show X-rays of formulation containing Barium sulphate in control (Lactose) and standard (Guar Gum) after zero, four, ten hours of oral administration to white New Zealand Rabbit.

Figure 9 b show X-rays of formulation containing Barium sulphate in standard (HPMC E5) and test (MMZ) after zero, four, ten hours of oral administration to white New Zealand Rabbit. DESCRIPTION OF THE INVENTION:

The present invention in a preferred embodiment provides pharmaceutical compositions comprising at least an active pharmaceutical ingredient, to which parts of one or more additional complimentary active pharmaceutical ingredient may be optionally added; and an excipient formed by Manilkara zapota (Linn.) P. Royen syn. seeds. The invention also provides for methods of preparation of the pharmaceutical compositions.

In an embodiment of the invention, the excipient formed using Manilkara zapota (Linn.) P. Royen syn. seeds is a bioadhesive.

In an embodiment of the invention, the excipient formed using Manilkara zapota (Linn.) P. Royen syn. seeds is a mucoadhesive.

In an embodiment of the invention, the compositions of the present invention may be administered to a subject as a controlled release drug delivery system.

The present invention in a preferred embodiment provides the use of Manilkara zapota (Linn.) P. Royen syn. seeds as excipient along with an active pharmaceutical ingredient for preparation of a pharmaceutical composition.

The present invention in an embodiment provides the use of pharmaceutical composition wherein the types of drugs or therapeutic agents of said composition which provides controlled release oral drug delivery system is selected from the group comprising highly soluble, moderately soluble, insoluble, acidic and basic or any combination thereof.

The present invention in an embodiment provides use of pharmaceutical composition, wherein the composition is provided in the form of once or twice daily formulation just by changing the amount of gel forming compound i.e. mucilage from Manilkara zapota (Linn.) P. Royen syn. seeds either alone or optionally one or more cross-linking enhancers.

The present invention in an embodiment provides use of pharmaceutical composition, wherein said composition provides oral drug delivery system with controlled release of drugs with dosage ranging from 1 mg to 200 mg. The present invention in an embodiment provides a controlled release unit dose pharmaceutical composition consisting essentially of an effective dose of therapeutic agent or drug alone or in combination, a gel forming mucilage powder separated from Manilkara zapota (Linn.) P. Royen syn. seeds and optionally one or more cross-linking enhancers.

The term mucoadhesive, as used herein, is a material that adheres to a mucosal tissue surface in-vivo and/or in-vitro.

The excipient formed using Manilkara zapota (Linn.) P. Royen syn. seeds herbs used for the compositions in accordance with the present invention shall include excipient formed using seeds of other plant of the species or family or genus which display similar medicinal properties as that of Manilkara zapota (Linn.) P. Royen syn.

The term subject for the purpose of the invention means one or more of a human or any other animal.

In an embodiment of the invention, a solvent may be used for preparing pharmaceutical compositions of the present invention, and the solvent used may be any suitable solvent such as but not limited to one or more of methanol, ethanol, n-propanol, isopropanol, hexane, heptane, petroleum ether, cyclohexane, diethyl ether, dusopropyl ether, ethyl acetate, methyl acetate, ethyl formate, methyl formate, isobutyl acetate, n-butyl acetate, methylene chloride, ethylene chloride, chloroform, carbon tetrachloride, acetone, ethyl methyl ketone, diisobutyl ketone, methyl isobutyl ketone, 1,4- dioxane, toluene, ammonia solution, glacial acetic acid, water and other solvents known by those of skilled in the art.

In an embodiment of the invention, the pharmaceutical compositions of the present invention may be formulated for oral administration in the form of tablets, pellets, granules, capsules, solutions, emulsions, suspensions, and any other form suitable for use, wherein the tablets, pellets, granules, capsules may be single layered, bi-layered or multi-layered.

In an embodiment of the invention, auxiliary, stabilizing, thickening, flavoring, fragrance and coloring agents may be added to the pharmaceutical compositions in accordance with the present invention. In an embodiment of the invention, compositions in accordance with the present invention may include one or more of the excipients like talc, water, glucose, lactose, gum acacia, gelatin, mannitol, starch paste, magnesium trisilicate, corn starch, keratin, colloidal silica, potato starch, urea, and other excipients suitable for use in manufacturing preparations, in solid, semisolid or liquid form, or any combination thereof.

In an embodiment of the invention, the pharmaceutical compositions can be administered in a solid form such as but not limited to tablets, capsules, pills, pellets, granules, boluses or powder. For preparing the solid form, the pharmaceutical compositions may be mixed with a pharmaceutical excipient such as but not limited to corn starch, lactose, sucrose, sorbitol, talc, stearic acid, magnesium stearate, dicalcium phosphate or gums, along with other pharmaceutical diluents. The solid compositions may be further subdivided into unit dosage forms containing an effective amount of compositions of the present invention.

In an embodiment of the invention, the pharmaceutical compositions can be administered in a liquid form such as but not limited to aqueous solution, syrups, aqueous suspensions, oil suspensions, tinctures, tisanes, macerates and flavored emulsions with edible oils as well as elixirs or similar pharmaceutical carriers with or without flavours and/or taste modifying substances. The liquid form may include suitable dispersing or suspending agents for aqueous suspensions such as but not limited to tragacanth, acacia, alginate, dextran, sodium carboxymethyl cellulose, methylcellulose, polyvinylpyrrolidone or gelatin. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for reconstitution with water or other suitable vehicles before use.

In an embodiment of the invention, the pharmaceutical compositions may be delivered as a semi-solid form or gelatinous solid, such as but not limited to paste, jelly, gel or chutney.

In an embodiment of the invention, the desirable dose of the compositions may vary depending on the condition and the weight of the subject, severity, drug form, route and period of administration.

In an embodiment of the invention, the terms compositions and formulations may be alternately used for the purpose of this invention. In an embodiment of the invention, a method of preparing an excipient from Manilkara zapota (Linn.) P. Royen syn. seeds for formulating a pharmaceutical composition comprises the steps of:

a) preparing a powder form of Manilkara zapota (Linn.) P. Royen syn. seed;

b) defatting the powder form of Manilkara zapota (Linn.) P. Royen syn. seed;

c) extracting mucilage after defatting of the powder form of Manilkara zapota (Linn.) P.

Royen syn. seed;

d) filtering solution comprising the mucilage after extracting the mucilage and defatting the powder form of Manilkara zapota (Linn.) P. Royen syn. seed;

e) precipitating mucilage after filtering the solution comprising mucilage;

f) isolating mucilage after precipitating the mucilage; and

g) drying mucilage after isolating the mucilage.

In an embodiment of the invention, a method of preparing an excipient from Manilkara zapota (Linn.) P. Royen syn. seed for formulating a pharmaceutical composition further comprises the step of sieving the mucilage after the drying of the mucilage and isolating of the mucilage.

In an embodiment of the invention, the defatting of the powder form of Manilkara zapota (Linn.) P. Royen syn. seed is done by Soxhlet extractor.

In an embodiment of the invention, the defatting of the powder form of Manilkara zapota (Linn.) P. Royen syn. seed is done by Soxhlet extractor using petroleum ether as a solvent at temperature 60 °C - 70 °C.

In an embodiment of the invention, the filtration of the solution comprising the mucilage after extracting is done through muslin cloth.

In an embodiment of the invention, the filtering of the solution comprising the mucilage after extracting is done through eight fold of muslin cloth. In an embodiment of the invention, the precipitation of mucilage after filtering of the solution comprising the mucilage is done by addition of either methanol or acetone or any such agent.

In an embodiment of the invention, the step of drying the mucilage after isolating the mucilage is done in hot-air oven.

In an embodiment of the invention, the step of drying the mucilage after isolating the mucilage is done in hot-air oven at 40 °C - 45 °C.

The terms 'M. zapota', 'MMZ', 'Manilkara zapota', 'Manilkara zapota (Linn.) P. Royen syn' may be alternatively used for the purpose of this invention.

The aim of this specification is to describe the invention without limiting the invention to any one embodiment or specific collection of features. A person skilled in the relevant art may realize the variations from the specific embodiments that will nonetheless fall within the scope of the invention, and such variations are deemed to be within the scope of the current invention.

It may be appreciated that various other modifications and changes may be made to the embodiment described without departing from the spirit and scope of the invention.

The below described procedures, details of tests and details of test results along with the drawings were carried out for the purpose of the present invention and are included herein are to illustrate certain aspects of the invention and are not to be considered to limit the scope of the invention.

EXAMPLES:

1. Isolation of Mucilage

Seed powder (20 gm) of Manilkara zapota was defatted by Soxhlet extractor using petroleum ether as a solvent at temperature 60 °C - 70 °C. This was repeatedly performed using hot water till the whole of mucilage was extracted. The mucilaginous solution was then filtered through eight fold of muslin cloth. The mucilage was then precipitated by addition of sufficient amount of an organic solvent such as but not limited to methanol or acetone. The isolated mucilage was then dried at 40 °C - 45 °C in hot-air oven (Bio-Tech) until drying. The obtained powder was then sieved through # 120 to get fine powder.

2. Physicochemical characterization of isolated mucilage

The above isolated mucilage was subjected for physicochemical characterization in order to provide a separate identity to this tree gum. The methods employed for the analysis include (i) Particle size analysis by Microtrac, (ii) Scanning electron microscopy (SEM), (iii) Gel permeation chromatography (GPC), (iv) Differential scanning Calorimetry (DSC), (v) Deferential thermal analysis (DTA), (vi) Thermogravimetry analysis (TGA), (vii) Zeta potential by zetatrac, (viii) X-ray diffraction spectrometry (XRD).

The average particle size as determined by Zetatrac particle size analyzer indicated that obtained mucilages were in fine particle average size of 551nm diameter (Figure 1). Scanning electron microphotographs (SEM) of mucilage obtained is represented in Figure 2 at different magnifications. The microphotographs of mucilages are indicative of an amorphous material. The particles are mostly seen as aggregates of irregular shapes and dimensions which were fibrous in nature. The molecular weight of mucilages were determined by gel permeation chromatography and expressed as the 'Dextran polysaccharide equivalent' molecular weight. The computed average molecular weights (Mw), number average molecular weight (Mn), and polydispersity (Mw/Mn) is presented in Figure 3. The term 'MP' means Peak molecular weight and 'Mz' refers to Z-average molecular weight as mentioned in the Figure 3. The zeta potential measurement was performed to collect information on the stability and charge behavior of the polymer. The Zeta potential of mucilage in aqueous medium (water) was recorded to be 18.05mV and in 0.1N NaCl was recorded to be 5.15mV respectively. Powder XRD (PXRD) analysis of mucilage is represented in Figure 4. The result indicated that there were no characteristic peaks in the spectrum were observed, indicating that the mucilages were completely amorphous in nature.

3. Formulation of Diltiazem HC1 Oral Mucoadhesive Tablets:

Diltiazem HC1, an API (Active Pharmaceutical Ingredient) was sieved through # 100 followed by a mucoadhesive polymer (test and standard) of different concentration (20, 40 and 50 %) and lactose (control) through sieve # 80. The entire sifted ingredients were mixed thoroughly until it became homogenous powder. A mixture of Polyvinyl Pyrolidone (PVPK- 30) and isopropyl alcohol was added to this homogenous powder to prepare dough. The dough mass was milled through sieve # 16 and dried in hot air dryer for sufficient time to get dry granules.

These granules were passed through sieve # 18 to get uniform granules which were again dried at 40 °C. These dried granules were again passed through mess # 18. Subsequently Lubrication material such as Aerosil was passed through sieve # 50 and mixed thoroughly with granules. The lubricated granules were compressed into tablet using 6.0 mm flat punch with eight station single rotary machine and keeping average weight 120 mg.

4. Thermal Characterization of mucilage of M. zapota

Differential Scanning Calorimeter (DSC) analysis for mucilage was performed using a differential scanning calorimeter (Mettler Toledo Star System). Accurately weighed (5 mg) samples were placed into platinum cups and sealed. The temperature range was from 0 to 300 °C under N atmosphere at a heating rate of 10 °C/min.

Differential Thermal Analysis (DTA) (Stapt Linseis) is a very popular thermal analysis technique measuring endothermic and exothermic transitions as a function of temperature. Accurately weighed (5 mg) samples were placed into platinum cups and sealed. The temperature range was from 0 to 240 °C at a heating rate of 15 °C/min.

The outcome of differential scanning calorimetric (DSC) and Differential Thermal Analysis (DTA) analysis of MMZ reveals the transition temperature as 89 °C (As shown in Figure 5 and Figure 6).

Thermogravimetric analysis (TGA) is a simple and accurate method for studying the decomposition pattern and the thermal stability of polymers. Table 1 and Table 2 provide the details of thermal behaviour according to the primary thermograms and derivative thermograms of mucilage's. The representative thermograms of thermo gravimetric analysis carried out on the mucilage's under lean oxygen (5% oxygen in nitrogen) atmosphere are shown in Figure 7. The details of thermal behaviour and thermal stability data according to the primary thermograms and derivative thermograms for the gum show that heating at a rate of 10 °C per minute from 0 °C to a maximum of 900 °C results in two mass loss events. The weight loss onset (representing the onset of oxidation or decomposition) of polymer suggests that mucilage's good thermal stability. Table 1: Thermogravimetry Analysis of MMZ

DTG: Derivative Thermogravimetry

Table 2: Thermal Stability Characterization of MMZ

'Initial decomposition temperature (TGA curve on-set).

'Integral procedural decomposition temperature

5. Mucoadhesive Strength Measurements:

The isolated mucilage powder was subjected for mucoadhesive strength measurements by following reported method and with the Formulation Code for Mucoadhesive strength measurements as provided in Table 3.

Table 3: Formulation Code for Mucoadhesive strength measurements

5.1 Detachment Force Measurement

To characterize the mucoadhesive strength, the detachment force method was performed. Goat intestine was collected from slaughter house and transferred in Tyrode solution. During this experiment the intestine was taken from specified area and placed on one glass slide and tied on both side. The glass slide with the intestine was affixed on one side floor below the modified physical balance. The tablets (125 mg) prepared from standard and test mucoadhesive polymer tablet was pasted on another glass slide and balanced on the assembled physical balance with a beaker on other side which was used to hold the water. Now the balance (National Balance Company) was calibrated and weight required to detach the tablet were determined.

The result of mucoadhesive strength evaluation using Detachment force measurement analysis showed that the force of adhesion in Newton required to detach mucilage tablet from the intestine after 30 minute was around 0.0318 N for MMZ as shown in Table 4. However standard polymer HPMC E5LV showed poor adhesive character with around 0.0049 N to detach the plate, in comparison with test material. The mucoadhesive strength of MMZ was significantly higher than HPMC, however the strength was significantly lower than standard i.e. Guar Gum. The overall result obtained indicated that MMZ shows good adhesion property as per the wetting and the diffusion theory of mucoadhesion.

Table 4: Comparison between Mucoadhesive Strength of Guar Gum and HPMC E5LV (Standard) and MMZ (Test Materials) and Lactose (Control)

Values are expressed as mean ± SEM (n = 6)

Data was analyzed by one way ANOVA followed by Dunnett test (Compared with standard Guar Gum), ^(ns)P>0.05; *P<0.05; **P<0.01;***P<0.001 5.2 Recording of Adherence

The recording of adherence method was used to characterize the mucoadhesive strength. The tablet (125 mg) prepared using test ( zapota) and standard mucoadhesive agent (Guar Gum, HPMC E5LV) were placed on the slide with Goat's intestine segment, the assembly kept in undistributed condition for a fixed time interval 5, 10, 15 and 30 min. Later, water was added slowly in drop-wise manner into a beaker kept aside. The amount of water required to pull out the tablet from intestinal segment represent the force required to pull the tablet against the adhesion. The above procedure is repeated for the comparative study the force in Newton's is calculated by equation: F=0.00981W/2

Whereas, W is the amount of water.

The result of mucoadhesive strength evaluation using Recording of adherence analysis showed that the force of adhesion in Newton required to detach mucilage tablet from the intestine after 30 minute was around 0.0714 N for MMZ as shown in Table 5. However standard polymer HPMC E5LV showed poor adhesive character with around 0.0229 N to detach the plate, in comparison with test material. The mucoadhesive strength of MMZ was significantly higher than HPMC E5LV, however the strength was significantly lower than standard i.e. Guar Gum.

The results of Detachment Force and Recording of Adherence indicated that force (in Newton) required to detach the tablet is gradually increasing for test as well as standard with respect to time except control i.e. Lactose, which suggested that the test material have potential of mucoadhesiveness.

Table 5: Comparison between Mucoadhesive Strength of Guar Gum and HPMC E5LV (Standard) and MMZ (Test Materials) and Lactose (Control)

Values are expressed as mean ± SEM (n = 6)

Data was analyzed by one way ANOVA followed by Dunnett test (Compared with standard Guar Gum), ^(ns)P>0.05; *P<0.05; **P<0.01;***P<0.001

6. Rotating Cylinder Method

To characterize the mucoadhesive strength, rotating cylinder method was performed. The tablet of standard (Guar Gum and HPMC E5LV) and test mucoadhesive polymer ( zapota) (125 mg.) was compressed using 6.0 mm punch in a rotary compression machine, keeping the compression pressure between 4 - 5 kg/cm² for each polymer. The tablet is prepared in such a way that it can adhere on freshly excised intestine of goat by just hydrating it with little amount of water. The whole system was then adhered on the stainless steel basket of USP XXVI apparatus with the aid of thread and the basket was immersed in the dissolution jar filled with phosphate buffer pH 7.2 at 37 °C and was rotated at 125 rpm. The time required for the detachment, disintegration or erosion of the test disc was recorded.

6.1. Rotating Cylinder Analysis

The result of rotating cylinder analysis indicated that detachment time and erosion time for M. zapota (XI) is comparably similar to X2 which comprises of Guar Gum, but significantly higher than (X3) and lowest for X4 which comprises of lactose as shown in the Table 6. The statistical analysis of the study indicate the results of test material ( zapota) is very significant (P<0.01).

Table 6: Detachment and Erosion Time of Formulation XI to X4 during Rotating Cylinder Analysis.

Values are expressed as mean ± SEM (n = 6)

7. Ex-vivo Residence Time

The residence time was measured using modified USP dissolution test apparatus. The test and standard mucoadhesive polymer tablets (125 mg) were pressed over excised goat mucosa for 30 sec after previously being secured on glass slab and was immersed in a jar of dissolution apparatus containing 750 ml of phosphate buffer with pH 6.2 at 37 °C. The paddle of the dissolution apparatus as adjusted at a distance of 5 cm above from the tablet and rotated at 25 rpm. The time for complete erosion or detachment from the mucosa was recorded.

8. In-vitro Wash off Test

Mucoadhesive study was conducted using modification of disintegration test (DT) assembly. The cylindrical part of disintegration apparatus was replaced with a glass slide (10 x 2 cm²) attached with an iron stick. The tissue of stomach (l x l cm²) was fixed on slide with thread in such a way that the mucosal part will be outside. The tablet was fixed on mucosal part of tissue with little pressure. The said assembly was deep in 500 ml of 0.1N HCl and the motor of DT apparatus was switched on. The time of detaching the tablet from the tissue surface was considered as wash off time for that tablet.

The result of ex-vivo residence and in-vitro wash off time indicated that the polymer tablets of X2 have longer ex-vivo residence and in-vitro wash off time, and polymer tablet of X4 have shortest one. The results of ex-vivo residence and in-vitro wash off time as shown in the Table 7 was obtained in following order Guar Gum >M. zapota > HPMC E5LV > Lactose.

Table 7: Mucoadhesive Strength Evaluation by ex-vivo Residence and in-vitro Wash off Test for Formulation X1-X4

9. Physical Characterizations of Mucilage tablet

9.1 Radial and Axial Swelling of the Tablet

The initial diameter and thickness of the tablet were measured, and the tablet was stored in distilled water. The increase in diameter and height were measured at selected time interval up to 5 hrs. The equilibrium degree of swelling (Q) was calculated from the radial and axial swelling ratio using the following equation

Q= ( Vo) = (R,/Ro)²x(I,/Io)

Where V_t and Vo are the tablet volume, R, and Ro are the radius and I_t and I₀ are the thickness at the time zero, respectively (Refer Table 8).

Table 8: Technological Physical Characterization Mucoadhesive tablet

Q-Radial and Axial swelling, R-Water Absorption Ratio

Values are expressed as mean ± SEM (n = 6)

Data was analyzed by one way ANOVA followed by Dunnett test (Compared with standard Guar Gum), (ns) P>0.05; *P<0.05; **P<0.01;***P<0.001.

9.2 Moisture Absorption

Moisture absorption study was performed by dissolving Agar (5 % w/v) in hot water. It was transferred into petri dishes and allowed to solidify. Six mucoadhesive tablets from each formulation were placed in a vacuum oven overnight prior to the study to remove moisture, if any, and laminated on one side with a water impermeable backing membrane. Accordingly, it was weighed and the percentage of moisture absorption was calculated.

The observation indicated that the formulation which was prepared using Guar Gum and M. zapota have high degree of radial and axial swelling. The result of modified moisture absorption study indicated that changing the concentration the moisture absorbing ratio decreases. 10. In vivo Bioadhesive Study

Preparation of Barium Sulphate Tablet

The in-vivo residence time of tablet was measured using white New Zealand Rabbit. The protocol for animal studies was approved by Institutional Animal ethical committee (IEAC/HNSIPER/RJK/07/2010). The standard and test mucoadhesive polymer (125 mg) tablets were prepared in ratio of 1 : 1 with barium sulphate (Microbar HD) and mucoadhesive agent standard (Guar Gum and HPMC E5LV) and Test as (MMZ) and Lactose as control, by addition of 5% w/v binding agent solution to make dough mass and this mass was passed through sieve no. 10. Thus obtained granules were passed through the sieve no. 18 to remove coarse particles. Tablets of 6 mm were prepared on eight station compression (Clit Jemkay Engineering) machine.

To study the bioadhesive characteristic and the mean residence time of natural polymer in the stomach, barium sulphate loaded tablet was used. Six healthy white New Zealand rabbits weighing about 2.5 kg were selected, and administered orally with the tablet using modified oral feeding tube. X-ray photograph were taken at specific intervals with the help of X-ray Machine (GE ELPRO), Power supply was 73 KVP, 120 mAs for two second.

The X-ray images revealed that the tablet containing Guar Gum and MMZ remain in intact form for 10 hrs while tablets containing HPMC E5LV although present but not in intact form as represented in Figure 9a and 9b. The lactose containing tablet was disintegrated in stomach just after ingestion of tablet.

Table 9: Formulation Code for the X-ray Study

11. In vitro dissolution study

The in vitro dissolution study indicated that release of drug from mucoadhesive tablet of formulation F1-F4 as shown in Figure 8 varied according to the amount and grade of mucoadhesive polymer used. The tablets containing Guar gum as mucoadhesive agent controls the release of medicament up to 8 hours and had initial high burst of 31.17 % in 1 hour. The batches which contain MMZ in higher amount retard the release up to 8 hours. The total amount was released in 6 hours in the same manner which had used HPMC E5LV as a mucoadhesive polymer. The in vitro release study showed that the isolated mucilage MMZ had retarded the release profile for 8 hours and had most confirmed suitability of mucoadhesive property.

STATISTICAL ANALYSIS OF DATA AND FIGURE:

The statistical data was analyzed by ANOVA (one way) followed by the Dunnett test. The readings for MMZ show that the difference is statistically significant. Further, it signifies that all the data estimated for MMZ are reliable. Barium sulphate which is added in formulation aids in visualizing the effect of MMZ as seen in all the images of Figure 9 a and b. Control (Lactose) with BaSC>4 gradually progresses till anorectal area displaying no mucoadhesion. Also, wherein the formulation has travelled less distance shows mucoadhesion to a certain extent in the case of addition of mucoadhesive agents - Guar Gum, HPMC E5 and MMZ. Further, the distance travelled is considerably proportional to that of in-vitro results.

The values provided in the tables are expressed using Standard Error Mean (SEM) technique.

For the purpose of this invention, the term 'PVP' refers to Polyvinylpyrrolidone.

The term (p-value) refers to the probability value of a statistical hypothesis test which is the probability of getting a value of the test statistic as extreme as or more extreme than what has been that observed by chance alone, if the null hypothesis ¾ is true.

In the present invention, the term "statistically significant" or "significantly" refers to the likelihood that a result would have occurred by chance, given that an independent variable has no effect, or, that a presumed null hypothesis is true. The statistical significance is determined by obtaining the p-value which refers to the probability value. The p-value indicates how likely it is that the result obtained by the experiment is solely due to chance. For the purpose of this invention, p-value hypothesis states that values which are < 0.01 : very strong presumption against neutral hypothesis; equal to 0.05: strong presumption against neutral hypothesis; 0.05-0.1 : low presumption against neutral hypothesis and >0.1 indicates no presumption against the neutral hypothesis.

For the purpose of this invention, the differential distribution curve expressed in Log M is often labelled as dw/d (log M) dwt/d (log M), where w or wt indicates the weight fraction and Log M is log molecular weight.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, or components, but do not preclude or rule out the presence or addition.

In the description, any or all numbers disclosed are deemed to be approximate values, regardless whether the word "about" or "approximate" is used in connection therewith. They may vary by 1 percent, 2 percent, 5 percent, or, sometimes, 10 to 20 percent. Whenever a numerical range with a lower limit, RL and an upper limit, Ru, is disclosed, any number falling within the range shall be specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=RL+k*(Ru-R ), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent,..., 50 percent, 51 percent, 52 percent,..., 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed.

In addition to this, all patents, publications and patent applications identified are expressly incorporated herein by reference for the purpose of disclosing and describing, for instance, the methodologies described in such publications that might be used in connection with the present invention. Nothing in this regard should be construed as an admission that the applicants are not entitled to antedate such disclosure by virtue of prior invention or for any other reason. The aim of this specification is to describe the invention without limiting the invention to any one embodiment or specific collection of features. A person skilled in the relevant art may realize the variations from the specific embodiments that will nonetheless fall within the scope of the invention, and such variations are deemed to be within the scope of the current invention.

Claims

WE CLAIM:

1) A pharmaceutical composition comprising an active pharmaceutical ingredient and an excipient, the excipient prepared from Manilkara zapota (Linn.) P. Royen syn. seeds.

2) A pharmaceutical composition as claimed in claim 1, wherein the excipient acts as mucoadhesive, bioadhesive, and combination thereof.

3) A pharmaceutical composition as claimed in claim 1, wherein the pharmaceutical composition is administered into body of subject by route selected from a group comprising oral, gastrointestinal/ enteral, intradermal, nasal, intravenous, intramuscular, intrathecal, and combination thereof.

4) A method of preparing an excipient from Manilkara zapota (Linn.) P. Royen syn. seeds for formulating a pharmaceutical composition as claimed in claim 1, the method comprising the steps of :

a) preparing a powder form of Manilkara zapota (Linn.) P. Royen syn. seed; b) defatting the powder form of Manilkara zapota (Linn.) P. Royen syn. seed; c) extracting mucilage after defatting of the powder form of Manilkara zapota (Linn.) P. Royen syn. seed;

d) filtering solution comprising the mucilage after extracting the mucilage and defatting the powder form of Manilkara zapota (Linn.) P. Royen syn. seed; e) precipitating mucilage after filtering the solution comprising mucilage; f) isolating mucilage after precipitating the mucilage; and

g) drying mucilage after isolating the mucilage.

5) A method of preparing an excipient as claimed in claim 4, wherein the excipient acts as an agent selected from a group comprising mucoadhesive, bioadhesive, and combination thereof.

6) A method of preparing an excipient from as claimed in claim 4 further comprising the step of sieving the mucilage after drying the mucilage.

7) A method of preparing an excipient from Manilkara zapota (Linn.) P. Royen syn. seed as claimed in claim 4 wherein the defatting of the powder form of Manilkara zapota (Linn.) P. Royen syn. seed is done by extraction method selected from a group comprising Soxhlet extractor, Kumagawa extractor, and combination thereof.

8) A method of preparing a pharmaceutical composition comprising an active pharmaceutical ingredient Diltiazem hydrochloride and an excipient prepared from Manilkara zapota (Linn.) P. Royen syn. seed mucilage comprising the steps of:

a) sifting Diltiazem HC1, Guar Gum, HPMC E5LV, MMZ, and lactose separately through sieves;

b) mixing Diltiazem HC1, Guar Gum, HPMC E5LV, MMZ, and lactose together to obtain an uniform mixture;

c) adding granulating fluid to the uniform mixture to obtain a dough mass; d) milling the dough mass through sieves and drying with hot air dryer to obtain a fine powder;

e) repeating step(d);

f) mixing the fine powder with a lubricating material to obtain uniform granules; and

g) compressing the lubricated and uniform granules into tablet.

9) A pharmaceutical composition as claimed in claim 1, further comprises one or more excipients selected from a group comprising talc, glucose, lactose, gum acacia, gelatin, mannitol, starch paste, magnesium trisilicate, corn starch, keratin, colloidal silica, potato starch, urea in solid, semisolid or liquid form, and combination thereof.

10) A pharmaceutical composition as claimed in claim 1, wherein the pharmaceutical composition is in forms selected from a group comprising injectable forms; solid tablets, pellets, granules, capsules, forms; oral usage form; topical application form; semi-solid form; gaseous form; and combination thereof.

11) The use of Manilkara zapota (Linn.) P. Royen syn. seeds as excipient along with an active pharmaceutical ingredient for preparation of a pharmaceutical composition.

12) The use of pharmaceutical composition as claimed in claim 11, wherein the types of drugs or therapeutic agents of said composition which provides controlled release oral drug delivery system is selected from the group comprising highly soluble, moderately soluble, insoluble, acidic and basic and combination thereof.

13) The use of pharmaceutical composition as claimed in claim 12, wherein the composition is administered at a frequency selected from the group consisting of once, twice daily formulation by using variable concentration gel forming compound i.e. mucilage and atleast one cross-linking enhancer.

14) The use of pharmaceutical composition as claimed in claim 12, wherein said composition provides oral drug delivery system with controlled release of drugs with dosage ranging from 1 mg to 200 mg.

15) A controlled release unit dose pharmaceutical composition consisting essentially of an effective dose of therapeutic agent or drug alone or in combination, a gel forming mucilage powder separated from Manilkara zapota (Linn.) P. Royen syn. seeds and atleast one cross-linking enhancers.