WO2021038601A1

WO2021038601A1 - Liquid pharmaceutical compositions of melatonin for oral and parenteral administration

Info

Publication number: WO2021038601A1
Application number: PCT/IN2020/050759
Authority: WO
Inventors: Vijayendrakumar Virendrakumarji Redasani; Ritesh Anil Chavan; Poonam Sanjay BHATJIRE; Shweta V REDASANI
Original assignee: Vijayendrakumar Virendrakumarji Redasani
Priority date: 2019-08-30
Filing date: 2020-08-31
Publication date: 2021-03-04
Also published as: EP4021411A4; AU2020339867A1; EP4021411A1

Abstract

The present invention relates to a liquid compositions for the oral and parenteral administration of melatonin in the form of aqueous solutions comprising melatonin and at least one but preferably two ingredients for enhancing properties of the composition wherein the ingredient(s) belong to the group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, chelating agent and complexing agent and combinations thereof and the properties enhanced are at least solubility and stability. Preferably the compositions are pharmaceutical compositions. Preferably, the compositions are nutraceutical compositions.

Description

LIQUID PHARMACEUTICAL COMPOSITIONS OF MELATONIN FOR ORAL AND PARENTERAL ADMINISTRATION Field of invention:

The present invention relates to a liquid compositions for the oral and parenteral administration of melatonin in the form of aqueous solutions comprising melatonin and at least one or two ingredients for enhancing properties of the composition wherein the ingredient(s) belong to the group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, chelating agent and complexing agent and combinations thereof and the properties enhanced are at least solubility and stability. Preferably the compositions are pharmaceutical compositions. Preferably, the compositions are nutraceutical compositions.

Background of the Invention:

Melatonin is a hormone that regulates the sleep-wake cycle. It is primarily released by the pineal gland. Its chemical name is N-acetyl-5-methoxytriptamine. As a supplement, it is often used for the short-term treatment of trouble sleeping such as from jet lag or shiftwork. The pharmaceutical forms proposed for these applications were those traditional forms already used for oral administration, such as capsules and tablets, wherein melatonin was administered alone or in association with several other pharmaceutically active ingredients and with the typical excipients of these pharmaceutical forms. Many other therapeutic applications of melatonin have been proposed, for instance in the treatment of Parkinson's disease, depression, osteoporosis, migraine, and even in the treatment of tumour forms.

Melatonin is characterised by low solubility in water (Shida C, Journal of Pineal Research, 16:198-201, 1994) and, when administered orally to humans, it exhibits a low bioavailability (about 30%) and high variability (10 to 56%) in the same subject, due both to liver metabolism reactions and absorption variability dependent on the different administration conditions and characteristics of the subject treated (Wei-Li D., New England Journal of Medicine, 336: 1028-1029, 1997).

The oral bioavailability of melatonin is low and very variable. Furthermore, melatonin is poorly soluble in water and degrades quickly.

In plasma, the concentration of melatonin, which circulates bound to albumin, varies in the range 10-300 pg/ml. Its half-life is short (30-60 minutes), due to the 90% clearance following its first passage through the liver. Approximately 75% of the melatonin metabolised by the liver cells is converted into 6-hydroxymelatonin, then conjugated with sulphate (70%) and, to a lesser extent, with glucuronic acid (6%). Bioavailability is low and equal to approximately 15%. Melatonin appears to be rapidly absorbed if administered as oral solutions, and the peak blood concentration is the highest of those reported for similar doses in healthy individuals. After oral administration, its peak blood concentration (Cmax) is influenced by the solubility of the melatonin in the formulation, bioavailability alterations and clearance.

WO 2012/156565 describes the various uses of melatonin such as regulation of the circadian rhythm, regulation of the inflammatory response, treatment of systemic inflammatory response syndrome (SIRS), treatment the multiple organ dysfunction syndrome (MODS), the treatment of sepsis in neonates, treatment of sepsis in adults, the treatment of myocardial infarction, the treatment of mitochondrial damage, the treatment of pulmonary edema, treatment failure kidney or liver, or treating oxidative stress situation generated during surgery, and particularly during abdominal surgery.

US20180028498 describes pharmaceutical composition for the parenteral administration of melatonin in the form of an aqueous solution, comprising melatonin and physiological saline solution, said pharmaceutical composition having a melatonin concentration of between 0.2 and 0.4 mg/ml and being completely free of any excipients, co-solvents and/or diluents different from said physiological saline solution. This pharmaceutical composition is used in the treatment of hypoxic-ischemic encephalopathy in neonatal patients. WO2012156565 describes injectable composition comprising water, propylene glycol and melatonin, a derivative, a salt, a pro-drug or a solvate of same, which contains no other solvent, co-solvent or dispersing agent. In these compositions, propylene glycol significantly enhances solubilization of as high as 50 mg/ml melatonin.

WO2013068565 describes preparation for injection in the form of a solution obtained by dissolving a powder to be reconstituted comprising melatonin, at least one soluble excipient and at least one surfactant, wherein the powder is prepared by spray drying wherein said powder has 90 % particles below 100 m.

US10342779 describes a concentrated melatonin solution, wherein melatonin is present in a quantity of 10% or higher in a substantially water-free carrier mixture of ethanol and a polyethoxylated derivative. This patent also highlights the stability problems (such as crystallization of the solution) associated with the formulations of WO 2012156565 and WO2013068565.

US20170112810 describes a pharmaceutically acceptable composition comprising propylene glycol, polyethylene glycol and melatonin or a derivative, salt, prodrug, or solvate thereof.

US10307398 describes a resuscitation composition comprising about 40 mM to 45 mM melatonin, about 3.8 M to about 4.2 M beta-hydroxybutyrate (BHB) or a pharmaceutically acceptable salt thereof in a solution of about 8% to about 12% hydroxypropyl-beta-cyclodextrin (HPbCD), about 4% to about 6% polyvinylpyrrolidone (PVP) and about 4% to about 6% polyethylene glycol (PEG). WO2018167162 describes a pharmaceutical formulation for use by parenteral administration for the treatment of brain injuries caused by birth asphyxia in a neonate comprising 2.5 or 5.0 mg/ml melatonin, 25 or 50 mg/ml sulfobutylether- cyclodextrin, 0.2 mg/ml phosphate buffer, optionally 4.5 mg/ml sodium chloride, and water for injection.

US9468626 describes pharmaceutical formulations comprising nanoparticles of melatonin are useful for the treatment of neonatal brain injury. WO20 10062153 describes a pharmaceutical composition and the method of manufacture thereof, wherein said composition serves to treat internal tissue and organ burns caused by corrosive substances, comprising pharmaceutically acceptable melatonin, polyethylene glycol, vehicles and excipients in the preparations.

W09947175 discloses pharmaceutical compositions containing inclusion complexes of melatonin in a polymeric material, in particular in b-cyclodextrin. Complex techniques such as spray-drying are required to prepare inclusion complexes. WO2013068565 provides a powder composition of melatonin for reconstitution before use for preparations for injection containing melatonin.

The solubility and stability issues of melatonin are discussed in the prior arts. There is a continuous need to find out newer compositions of melatonin which are both stable and soluble. The present invention provides liquid pharmaceutical compositions for the oral and parenteral administration of melatonin in the form of aqueous solutions wherein solubility and stability of melatonin are greatly enhanced.

Object of the invention

The first object of the invention is to provide compositions of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex also collectively termed as melatonin in any acceptable form and at least one or two ingredients enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidant, solubilizer which is also an anti-oxidant, chelating agent and complexing agent and combinations thereof. Preferably the compositions are pharmaceutical or nutraceutical compositions. The second object of the invention is to provide compositions of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex also collectively termed as melatonin in any acceptable form and at least one ingredient enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, solubilizer which is also an anti-oxidant, chelating agent and complexing agent and combinations thereof wherein melatonin and the said ingredient are in a ratio of 10:1 to 1:10 and both melatonin and the said ingredient are present in amounts of 0.01 to 10 % and preferably 0.01 to 5 % and more preferably 0.05 to 5 % and most preferably 0.05 to 2 % of the composition when % is expressed as g/100ml.. Preferably the compositions are pharmaceutical or nutraceutical compositions. The third object of the invention is to provide process of preparing compositions of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex also collectively termed as melatonin in any acceptable form and at least one but preferably two ingredients belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, solubilizer which is also an anti-oxidant and combinations thereof. Preferably the compositions are pharmaceutical or nutraceutical compositions. The compositions are free of cosolvent and free of preservative. Preferably, compositions are free of conventional surfactants.

The fourth object of the invention is to provide use of the pharmaceutical composition of melatonin in the manufacture of a medicament for various treatments wherein the composition is for an oral or a parenteral application in the form of liquid or solutions comprising A) at least two ingredients for enhancing properties of the pharmaceutical composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, solubilizer which is also an anti-oxidant chelating agent and complexing agent and combinations thereof; or B) at least one ingredient wherein melatonin and the said ingredient are in a ratio of 10:1 to 1:10 and both melatonin and the said ingredient are present in amounts of 0.01 to 10 % and preferably 0.01 to 5 % and more preferably 0.05 to 5 % and most preferably 0.05 to 2 % of the composition when % is expressed as g/100ml.. Preferably the compositions are pharmaceutical or nutraceutical compositions..

Summary of the Invention

Under the first aspect, the invention provides a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex and at least one but preferably two ingredients enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, solubilizer which is also an anti-oxidant chelating agent and complexing agent and combinations thereof.

The second aspect provides a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex (melatonin in any acceptable form) and at least one ingredient enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti oxidants, solubilizer which is also an anti-oxidant, chelating agent and complexing agent and combinations thereof wherein melatonin and the said ingredient are in a ratio of 10:1 to 1:10 and both melatonin and the said ingredient are present in amounts of 0.01 to 10 % and preferably 0.01 to 5 % and more preferably 0.05 to 5 % and most preferably 0.05 to 2 % of the composition when % is expressed as g/100ml.. Preferably the compositions are pharmaceutical or nutraceutical compositions.. Under the third aspect, the invention provides process of preparing a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex and at least one but preferably two ingredients belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti oxidants, solubilizer which is also an anti-oxidant, chelating agents and combinations thereof and also process of preparing a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex and at least one ingredient enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti oxidants, solubilizer which is also an anti-oxidant, chelating agent and complexing agent and combinations thereof wherein melatonin and the said ingredient are in a ratio of 10:1 to 1:10 and both melatonin and the said ingredient are present in amounts of 0.01 to 10 % and preferably 0.01 to 5 % and more preferably 0.05 to 5 % and most preferably 0.05 to 2 % of the composition when % is expressed as g/100ml.. Preferably the compositions are pharmaceutical or nutraceutical compositions. The compositions are free of cosolvent and free of preservative. Preferably, compositions are free of conventional surfactants.

Under the fourth aspect, the invention provides use of the pharmaceutical composition of melatonin in the manufacture of a medicament for various treatments wherein the composition comprises

A) at least one but preferably two ingredients for enhancing properties of the pharmaceutical composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti -oxidants, solubilizer which is also an anti-oxidant, chelating agent and complexing agent and combinations thereof; or

B) at least one ingredient enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti -oxidants, solubilizer which is also an anti-oxidant, chelating agent and complexing agent and combinations thereof wherein melatonin and the said ingredient are in a ratio of 10: 1 to 1:10 and both melatonin and the said ingredient are present in amounts of 0.01 to 10 % and preferably 0.01 to 5 % and more preferably 0.05 to 5 % and most preferably 0.05 to 2 % of the composition when % is expressed as g/ 100ml.. Preferably the compositions are pharmaceutical or nutraceutical compositions.

Brief Description of Drawings Figure 1 presents Effect on Locomotor activity after administering single dose.

Figure 2 presents Decrease or depression in locomotor activity after multiple dosing of melatonin solutions intraperitoneally

Detailed description of the invention:

Melatonin compositions are used for regulating the circadian rhythm, regulation of the inflammatory response, treatment of systemic inflammatory response syndrome (SIRS), treatment the multiple organ dysfunction syndrome (MODS), the treatment of sepsis in neonates, treatment of sepsis in adults, the treatment of myocardial infarction, the treatment of mitochondrial damage, the treatment of pulmonary edema, treatment failure kidney or liver, or treating oxidative stress situation generated during surgery, and particularly during abdominal surgery.

The present invention provides various novel compositions of melatonin for oral or parenteral administration in the form of liquids and solutions. Preferably the compositions are pharmaceutical or nutraceutical compositions.

The melatonin used for preparing the compositions of the invention may be for instance synthetic melatonin in powder of injectable pharmaceutical grade, or wherein melatonin can be in the form of a derivative, a salt, a solvate, a prodrug or an inclusion complex also collectively termed as melatonin in any acceptable form.

The composition of the invention includes melatonin or its derivative, a salt, a solvate or a prodrug of melatonin or an inclusion complex of melatonin. For example, pharmaceutically acceptable salts are synthesized from melatonin by conventional chemical methods, generally, by reacting with an appropriate acid in water or in an organic solvent or a mixture of the two. Generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol or acetonitrile are preferred. Examples of salts of acid addition salts include mineral acid addition such as, for example, hydrochloride, hydrobromide, hydroiodide, sulfate, nitrate, phosphate, and salts of organic acid addition such as, for example, acetate, maleate fumarate, citrate, oxalate, succinate, tartrate, malate, mandelate, methanesulfonate and p- toluenesulfonate.

In the prior art various melatonin derivatives are known, which are also included in the present invention. According to a particular embodiment, the melatonin derivative is defined according to formula (I), as

Formula I where, Ri and R3 are independently selected from the group consisting of linear or branched alkyl C1-C4;

R₂ is selected from the group consisting of hydrogen, linear or branched C₁-C₄ alkyl,

-C(=0)0Ra and -C(=0)-N(H)-Ra, wherein Ra is a linear or branched C1-C4 alkyl group; and n is an integer selected from the group consisting of 1, 2, 3 and 4.

The term "prodrug" as used in this application is defined herein to mean a chemical compound which has undergone a chemical derivation such as a substitution or addition of a further chemical group to change (for pharmaceutical use) any of physicochemical, such as solubility or bioavailability of, for example ester derivatives, ether or amide of an active compound provide the active compound itself upon administration to a subject properties.

Inclusion complexes are defined as formations made up of a polymeric material and an active ingredient, where the active ingredient is included in the polymer. The polymer helps carrying the drug in the aqueous medium changing some of the physical properties typical of the active ingredient so that, after the complex has formed, the solubility of the active ingredient in aqueous solvents increases to a particularly significant extent.

The materials for active-ingredient inclusion complexes which can be used to implement the present invention include water-soluble complexing agents such as, for example, a- cyclodextrin, b-cyclodextrin, g-cyclodextrin and their derivatives such as, for example, hydroxypropyl-P-cyclodextrin.

The term "solvate" according to this invention is understood as meaning any form of melatonin according to the invention having another molecule (most likely a polar solvent) attached via a noncovalent bond. Examples of such solvates include hydrates and alcoholates, for example methanolates. The preparation of salts, solvates and prodrugs can be carried out by methods known in the art. It will be appreciated that salts, solvates or prodrugs not pharmaceutically acceptable are also within the scope of the invention since those may be useful in the preparation of salts, prodrugs or pharmaceutically acceptable solvates.

Solubility and stability issues of melatonin are discussed in the prior arts. Solubility of melatonin is reported in literature as 1 mg / ml or even 2 mg/ml. The present inventors carried out an extensive study on solubility of melatonin. Part of the study relevant to the present invention is as reported in table 18. The inventors have noted that the actual melatonin solubility is not even 1 mg / ml. Heating may temporarily enhance solubility but upon cooling the insoluble particles become visible. Even if particles are not visible, turbid solution is sometimes resulted. This is probably one of the reasons why there are no liquid compositions of melatonin in market.

The inventors have come up with compositions wherein solubility of melatonin is greatly enhanced. The solubility is enhanced two times, four times, five times and even greater.

In the prior art some compositions are reported wherein co-solvent propylene glycol is used in high amounts.

The present invention does not employ any co-solvent to dissolve melatonin. The compositions are entirely aqueous without employing any solvent other than water. The aqueous compositions can be prepared even without employing conventional surfactant.

Further the compositions do not require adding preservatives. Stability studies conducted on several compositions indicate that single maximum impurity and total impurities after 6 months stability comply with the drug regulation.

The compositions of the present invention have been prepared by a process of preparation comprising dissolving the melatonin and at least one but preferably two ingredients from the group of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti -oxidants, solubilizer which is also an anti-oxidant, chelating agent and complexing agent and combinations thereof in Water for Inj ection. The solution obtained can be deaerated with an inert gas, preferably with filtered nitrogen.

In an embodiment, a pharmaceutical composition of the present invention has been prepared by a process of preparation comprising dissolving the melatonin, crystal inhibitor and Solubilizer in Water for Injection. The, solution obtained can be deaerated with an inert gas, preferably with filtered nitrogen.

The content of oxygen dissolved in solution is constantly monitored at the aim of maintaining it at values lower than 2 ppm. Also the processing of the solution subject of the invention after the solution's preparation, including the bottling, or anyway the packaging in containers of the desired dosage, are carried out under inert gas, preferably under filtered nitrogen, controlling again the content of oxygen dissolved in the solution.

The present pharmaceutical compositions of melatonin are packed in containers made of Type I glass, i.e. of glass of amber colour, suitable for the preparations of products sensitive to ultraviolet rays. Containers of Type I glass suitable for packing and storing the present compositions are for instance vials, in particular 2 ml, 5 ml and 10 ml vials. Obviously these containers have to guarantee maintenance of the desired conditions of deaeration, wherein the content of oxygen is always lower than 2 ppm; so, for instance, the vials, once they are filled up under inert gas atmosphere, are closed by torch welding of the molten glass and checked with an apparatus of the type Leaker Test to test the seal of the vial. The oral compositions are filled in vials in polypropylene vials or suitable vials with actuator to apply as an oral spray.

The present pharmaceutical compositions are sterilisable, in particular they are autoclavable, for example by treatment in a super-heated water autoclave. A sterilisation cycle commonly used for injectable products in glass vials may be used, at 121°C and 15 lb Pressure.

The specific conditions of the process of preparation and the use of deaerated water for Injection, that maintain the pH values of the compositions between 6.5 and 7.5, cause the present pharmaceutical compositions to be characterised by a good stability over time irrespective of concentration of melatonin.

The pharmaceutical compositions according to the present invention are suitable for the oral or parenteral administration in the form of liquids and solutions of melatonin by any one of the known oral or parenteral administration in the form of liquids and solutions routes, such as the injection or infusion route, that may be intramuscular, intravenous, intradermal, subcutaneous, intra-arterial, or intrathecal. The liquids and solutions of melatonin can be administered orally as oral spray or oral liquid or can be administered parenterally as shots. The compositions comprise of at least one ingredient is specific amounts or at least one but preferably two ingredients enhancing properties of the composition. The composition for oral use may additionally have sweeteners, flavours etc.

The sweeteners is selected from the group consisting of sucrose, fructose, dextrose, high fructose corn syrup, xylitol, maltitol, sorbitol, mannitol, erythritol, sucralose, stevia, aspartame, advantame, acesulfame potassium, saccharin, sodium saccharin, neotame and any combinations thereof and any other suitable sweetener.

The pharmaceutical compositions of melatonin comprise of ingredients which enhance properties of the composition. The properties enhanced are solubility and stability. Under the first aspect, the invention provides a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex and at least one but preferably two ingredients enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, solubilizer which is also an anti-oxidant, chelating agent and complexing agent and combinations thereof.

The preferred ingredients used in combination to enhance properties of pharmaceutical composition of melatonin for oral or parenteral administration in the form of liquids and solutions are as follows: a) solubilizer + polymeric solubilizer; b) solubilizer + crystal inhibitor; c) crystal inhibitor + polymeric solubilizer; d) solubilizer + antioxidant; e) polymeric solubilizer + antioxidant; f) solubilizer + crystal inhibitor + antioxidant; g) solubilizer alone; h) solubilizer which is also anti-oxidant alone.

Preferred crystal inhibitor according to the invention includes polyvinylpyrrolidone (PVP).

In an embodiment, meglumine is preferred as a solubilizer and PVP K-30 as crystal inhibitor. In another embodiment, PVP K-30 is preferred as crystal inhibitor and Soluplus® is preferred as polymeric solubilizer.

In yet another embodiment, Soluplus® is preferred as polymeric solubilizer and Vitamin E Acetate (Tocopheryl acetate) is preferred as an anti-oxidant. Soluplus® is available commercially from BASF Corporation.

Soluplus® is a graft copolymer comprised of polyethylene glycol, polyvinylcaprolactam and polyvinylacetate. The second aspect provides a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex and at least one ingredient enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, chelating agent and complexing agent and combinations thereof wherein melatonin and the said ingredient are in a ratio of 10: 1 to 1:10 and both melatonin and the said ingredient are present in amounts of 0.01 to 10 % and preferably 0.01 to 5 % and more preferably 0.05 to 5 % and most preferably 0.05 to 2 % of the composition.

A preferred solubilizer is meglumine. In an embodiment meglumine is used in an amount of 0.1 % of the total composition. In another embodiment, meglumine is used in an amount of 0.2 % of the total composition.

In an embodiment, ratio of melatonin to meglumine is from 1:0.5 - 1:1. In another embodiment the ratio is 1 :2. In yet another embodiment the ratio is 1:5.

In an embodiment, crystal inhibitor is present to enhance properties of the solution wherein ratio of melatonin to a crystal inhibitor is from 1:2 to 2:1 and the amount of the crystal inhibitor in the composition is from 0.01% to 10% w/v, measured relative to the total volume of the solution.

When an additional ingredient is used for enhancing properties of the pharmaceutical composition of melatonin, the additional ingredient also belongs to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, chelating agent and complexing agent and combinations thereof wherein ratio of melatonin (in any form): first ingredient and the additional ingredient are as follows: 10:1:1 to 1:10:10.

In an embodiment, the ratio employed between melatonin, first ingredient and second ingredient is 1:2:1.

In yet embodiment, the ratio is 1:1:1. In one more embodiment, the ratio is 2:1:1. In yet another embodiment, the ratio is 1 :2:2. In one more embodiment, the ratio is 1:1:2. In an embodiment, a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions comprising melatonin, or its derivative, a salt, a solvate or a prodrug of melatonin or an inclusion complex of melatonin, a solubilizer and Water for Injection and optionally, an antioxidant. Whether there is a single ingredient or two ingredients enhancing properties of the pharmaceutical composition of the melatonin, Polyvinylpyrrolidone (PVP) is one of the or the only preferred crystal inhibitor. Polyvinylpyrrolidone (PVP) is made from the monomer, N-vinylpyrrolidone, and is soluble in water. PVP binds to polar molecules exceptionally well, owing to its polarity. PVP is approved by the FDA for many uses and is generally considered safe. For example, and without limitation, PVP K12, PVP K17 or PVP K30 can be used in a composition.

Under the third aspect, the invention provides process of preparing a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex and at least one but preferably two ingredients belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti oxidants, chelating agents and combinations thereof and also process of preparing a pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions wherein melatonin can be in the form of melatonin or in a form of a derivative, a salt, a solvate, a prodrug or an inclusion complex and at least one ingredient enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, chelating agent and complexing agent and combinations thereof wherein melatonin and the said ingredient are in a ratio of 10:1 to 1:10 and both melatonin and the said ingredient are present in amounts of 0.01 to 10 % and preferably 0.01 to 5 % and more preferably 0.05 to 5 % and most preferably 0.05 to 2 % of the composition.

The process comprises 1) dissolving two ingredients for enhancing properties of the pharmaceutical composition of melatonin in water for injection to prepare first solution;

2) adding melatonin under inert atmosphere;

3) optionally stirring unless melatonin is dissolved;

4) adjusting pH of the solution from 6.5 - 7.5 whenever required using 0.1 N HC1 or 0.1 NNaOH to prepare second solution; and optionally adding suitable sweetener only for oral preparation;

5) adjusting the volume of the second solution to desired volume with Water for Injection (parenteral) or purified water (oral) to prepare third solution;

6) filtering the third solution through one or two filters to obtain final solution;

7) filling final solution in primary package and either subjecting to autoclaving at 121°C at 15 lb pressure for parenteral preparation or filling in suitable vials with actuators for oral preparations.

In another aspect, when only one ingredient enhancing properties of the pharmaceutical composition of melatonin exists, the process comprises:

1) Selecting first ingredient and ratio of melatonin and first ingredient from 10: 1 to 1:10.

2) dissolving first ingredient for enhancing properties of the pharmaceutical composition of melatonin in water for injection to prepare first solution and optionally adding second ingredient;

3) adding melatonin under inert atmosphere in such a way that ratio of melatonin to the first ingredient is from 10:1 to 1:10 and the amount of both first ingredient and melatonin are from 0.01 to 10 % of the final melatonin solution.

4) optionally stirring unless melatonin is dissolved;

5) adjusting pH of the solution from 6.5 - 7.5 whenever required using 0.1 N HC1 or 0.1 NNaOH to prepare second solution; and optionally adding suitable sweetener only for oral preparation;

6) adjusting the volume of the second solution to desired volume with Water for Injection (parenteral) or purified water (oral) to prepare third solution;

7) filtering the third solution through one or two filters to obtain final solution; 8) filling final solution in primary package and either subjecting to autoclaving at 121°C at 15 lb pressure for parenteral preparation or filling in suitable vials with actuators for oral preparations. wherein if second ingredient is selected for enhancing the properties of the composition, ratio of melatonin and such second ingredient is from 10: 1 to 1 : 10 and the second ingredient is added along with the first ingredient.

The fourth aspect of the invention relates to the use of the composition of the invention in the manufacture of a medicament. Under the fourth aspect, the invention relates to the use of the pharmaceutical composition of melatonin in the manufacture of a medicament for regulating the circadian rhythm, regulation of the inflammatory response, treatment of systemic inflammatory response syndrome (SIRS), treatment the multiple organ dysfunction syndrome (MODS), the treatment of sepsis in neonates, treatment of sepsis in adults, the treatment of myocardial infarction, the treatment of mitochondrial damage, the treatment of pulmonary edema, treatment failure kidney or liver, or treating oxidative stress situation generated during surgery, and particularly during abdominal surgery. Therefore, the present invention relates to a method for regulating the circadian rhythm, regulation of the inflammatory response, treatment of systemic inflammatory response syndrome (SIRS), the treatment of multiple organ dysfunction syndrome (MODS), the treatment of sepsis in neonates, treatment of myocardial infarction, the treatment of mitochondrial damage, the treatment of pulmonary edema, treatment of kidney or liver failure, or treatment of the situation of oxidative stress caused by surgery, method comprising administering to a patient in need of such treatment a therapeutically effective amount of the composition of the invention wherein the pharmaceutical composition comprises either

A) at least one but preferably two ingredients enhancing properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, chelating agent and complexing agent and combinations thereof; or B) at least one ingredient enhancing the properties of the composition and belonging to a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, chelating agent and complexing agent and combinations thereof wherein the ratio of melatonin to such ingredient is from 10:1 to 1:10; and wherein further both melatonin and that ingredient are present in amounts from 0.01 to 10 % and preferably 0.01 to 5 % and more preferably 0.05 to 5 % and most preferably 0.05 to 2 % of the composition.

The present invention also relates to the composition of the invention for use in the regulation of circadian rhythms, regulation of the inflammatory response, treatment of systemic inflammatory response syndrome (SIRS), the treatment of multiple organ dysfunction syndrome (MODS), the treatment of sepsis in neonates, treatment of myocardial infarction, the treatment of mitochondrial damage, the treatment of pulmonary edema, treatment of kidney or liver failure, or treatment of oxidative stress caused by surgery.

The melatonin may find a therapeutic application in the treatment of hypoxic- ischemic encephalopathy in infants, and therefore the present pharmaceutical compositions are particularly useful in the treatment of this serious disease.

In an embodiment, the melatonin concentration is between 0.1 and 50 mg/ml of composition. The composition of the invention also allows high loads of melatonin while are stable. Thus, in another particular embodiment of the invention, the melatonin concentration is greater than 5 mg/ml of composition. In another particular embodiment, the melatonin concentration is between 5 and 50 mg/ml of composition. These concentrations allow administration in adults of high amounts of melatonin without risk of poisoning by any of the excipients present.

In an embodiment, the composition of the invention is injectable intravenously. A particular aspect includes the presence of a second drug in the composition of the invention. Said second drug may be part of the composition or may be provided as a separate administration simultaneously or at different times composition. According to the present invention, a composition or a component thereof "pharmaceutically acceptable" it indicates that are physiologically tolerable and whose administration has a low risk of allergies, side effects, adverse events or other similar reactions, such as gastric disorders, dizziness and the like, when administered to a human. Preferably, as used herein, the term "pharmaceutically acceptable" means that has been approved by a generally recognized for use in animals government regulatory agency state or federal or which is listed in the US Pharmacopoeia or other pharmacopoeia and more particularly in humans. Therefore, the composition of the invention is pyrogen free.

Generally, a "therapeutically effective amount" of the composition of the invention, and therefore melatonin, depend on various factors such as the severity of the condition being treated, the sex, age, or weight of the patient, among others. For example, the composition of the invention may be administered once or more times a day for example 1, 2, 3 or 4 times daily, with typical total daily doses in the range of from 0.01 to 1000 mg / kg / day, preferably, 0.01 to 100 mg/kg/day and more preferably, 0.01 - 10 mg/kg/day.

In an embodiment, the administration is by infusion. In another embodiment, melatonin, its salts, prodrugs, derivatives or solvates, administered 1, 2, 3, 4, 5 or 6 times a day up to the total daily dose indicated in the previous paragraph. In a particular embodiment the administration is 1, 2 or 3 times daily, preferably once a day. The treatment period can vary according to the evolution of the patient and lasts normally between 1 and 30 days.

In the context of the present invention it is considered that an adult is a patient with an age of 18 years or more. Specifically, it is generally considered that a neonate is a patient aged between 0 and 27 days, a baby between 28 days and 23 months a child of 24 months to 11 years and a teenager from 12 to 17 years. Although there is a correlation between the weight and the dose, the correlation is not always linear and must be identified for each patient group.

The term "treatment" or "treat" in the context of this document refers to the administration of a compound or formulation according to the invention to prevent, ameliorate or eliminate the disease or one or more symptoms associated with such disease. "Treatment" also encompasses preventing, ameliorating or eliminating the physiological sequelae of the disease.

Throughout the description and claims the word "comprises" and its variants are not intended to exclude other technical features, additives, components or steps. To those skilled in the art, other objects, advantages and features of the invention will emerge partly from the description and partly from the practice of the invention.

Thus, the invention provides melatonin aqueous compositions which are free of co solvent and free of preservative and stable.

The compositions exhibited enhanced solubility of melatonin which is enhanced two times, four times, five times and even greater.

The aqueous compositions can be prepared even without employing conventional surfactant.

The aqueous composition of the present invention can be used in treatment of one or more of regulation of circadian rhythms, regulation of the inflammatory response, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), sepsis in neonates, myocardial infarction, mitochondrial damage, pulmonary edema, kidney or liver failure, or oxidative stress caused by surgery.

The invention relates to method of treating one or more of regulation of circadian rhythms, regulation of the inflammatory response, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), sepsis in neonates, myocardial infarction, mitochondrial damage, pulmonary edema, kidney or liver failure, or oxidative stress caused by surgery comprising administering the aqueous composition of any of the preceding claim.

The following examples are provided by way of illustration and are not intended to be limiting on the scope of the present invention.

Examples Example 1 Pharmaceutical composition of melatonin for the parenteral administration in the form of liquids and solutions Table 1:

pH of Solution 6.5 - 7.5 (to be adjusted with 0.1 N HC1 or 0.1 N NaOH, as required)

Procedure: (Batch size: 100 ml)

PVP K 30 (100 mg) and Meglumine (200 mg) were dissolved in 60 ml of Water for Injection. Then, Melatonin (100 mg) was added under Nitrogen atmosphere and stirred till it gets dissolved. The pH of the solution was adjusted in between 6.5 to 7.5, using 0.1 N HC1 or 0.1 N NaOH, as required. The volume was adjusted up to 100 ml with Water for Injection. The solution was filtered through 0.45 micron filter and followed by 0.2 micron filter. The vials were filled with 2 ml and 5 ml volume in USP type I glass Vials. The vials were subjected to Autoclave at 121°C at 15 lb Pressure.

Example 2

Pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions Table 2

pH of Solution 6.5 - 7.5 (to be adjusted with 0.1 N HC1 or 0.1 N NaOH, as required) Procedure: (Batch size: 100 ml)

PVP K 30 (100 mg) and Meglumine (200 mg) were dissolved in 60 ml of Water for Injection. Then, Melatonin (200 mg) was added under Nitrogen atmosphere and stirred till it gets dissolved. The pH of the solution was adjusted in between 6.5 to 7.5, using 0.1 N HC1 or 0.1 N NaOH, as required. The volume was adjusted up to 100 ml with Water for Injection. The solution was filtered through 0.45 micron filter and followed by 0.2 micron filter. The vials were filled with 2 ml and 5 ml volume in USP type I glass Vials. The vials were subjected to Autoclave at 121°C at 15 lb Pressure.

Example 3

Pharmaceutical composition of melatonin for the parenteral administration in the form of liquids and solutions Table 3

PVP K 30 (100 mg) and Soluplus® (200 mg) were dissolved in 60 ml of Water for Injection. Then, Melatonin (100 mg) was added under Nitrogen atmosphere and stirred till it gets dissolved. The pH of the solution was adjusted in between 6.5 to 7.5, using 0.1 N HC1 or 0.1 N NaOH, as required. The volume was adjusted upto 100 ml with Water for Injection. The solution was filtered through 0.45 micron filter and followed by 0.2 micron filter. The vials were filled with 2 ml and 5 ml volume in USP type I glass Vials. The vials were subjected to Autoclave at 121°C at 15 lb Pressure.

Example 4

Pharmaceutical composition of melatonin for the parenteral administration in the form of liquids and solutions Table 4

Procedure: (Batch size: 100 ml)

Vitamin E Acetate (Tocopheryl acetate) (100 mg) and Soluplus® (100 mg) were dissolved in 60 ml of Water for Injection. Then, Melatonin (100 mg) was added and stirred till it gets dissolved. The pH of the solution was adjusted in between 6.5 to 7.5, using 0.1 N HC1 or 0.1 N NaOH, as required. The volume was adjusted upto 100 ml with Water for Injection. The solution was filtered through 0.45 micron filter and followed by 0.2 micron filter. The vials were filled with 2 ml and 5 ml volume in USP type I glass Vials. The vials were subjected to Autoclave at 121°C at 15 lb Pressure.

Example 5

Pharmaceutical composition of melatonin for the oral administration in the form of liquids and solutions Table 5

PVP K 30 (100 mg) and Meglumine (200 mg) were dissolved in 60 ml of Purified water. Then, Melatonin (200 mg) was added under Nitrogen atmosphere and stirred till it gets dissolved. The pH of the solution was adjusted in between 6.5 to 7.5, using 0.1 N HC1 or 0.1 N NaOH, as required. Add Acesulfame Potassium, as sweetener and make up the volume up to 100 ml with Purified water. The solution was filtered through 0.45 micron filter. The vials were filled with 2 ml and 5 ml volume in polypropylene vials or suitable vials with actuator.

Example 6

Pharmaceutical composition of melatonin for the oral administration in the form of liquids and solutions Table 6

PVP K 25 (100 mg) were dissolved in 60 ml of Purified Water. Then, Melatonin (200 mg) was added under Nitrogen atmosphere and stirred till it gets dissolved. The pH of the solution was adjusted in between 6.5 to 7.5, using 0.1 N HC1 or 0.1 NNaOH, as required. The sucralose 20 mg was added, and the volume was adjusted up to 100 ml with Purified Water. The solution was filtered through 0.45 micron filter. The solution was filtered through 0.45micron filter. The vials were filled with 2 ml and 5 ml volume in polypropylene vials or suitable vials with actuator.

Example 7: Pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions Table 7

Procedure: (Batch size: 100 ml)

PVP K 30 (50 mg / 100 mg / 150 mg ) and Meglumine (100 mg/ 200 mg/ 300 mg) were dissolved in 60 ml of Water for Injection. Then, Melatonin (50 mg / 100 mg/ 150 mg) was added under Nitrogen atmosphere and stirred till it gets dissolved. The pH of the solution was adjusted to 7.4 (6.5 to 7.5), using 0.1 N HC1 or 0.1 N NaOH, as required. The volume was adjusted up to 100 ml with Water for Injection. The solution was filtered through 0.45-micron filter and followed by 0.2-micron filter. The vials were filled with 2 ml and 5 ml volume in USP type I glass Vials and were subjected to Autoclave at 121 °C at 15 lb Pressure.

Table 8

Example 8: Pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions

Table 9

pH of Solution 6.5 - 7.5 (to be adjusted with 3.7 % HC1 orO.l NNaOH, as required) Procedure: (Batch size: 200 ml)

PVP K 30 (300 mg) and Meglumine (600 mg) were dissolved in 150 ml of Water for Injection. Then, Melatonin (300 mg) was added under stirring till it gets dissolved. The pH of the solution was adjusted to 7.4 (6.5 to 7.5), using 3.7% HC1 or 0.1 N NaOH, as required. The volume was adjusted up to 200 ml with Water for Injection. The solution was filtered through 0.45-micron filter and followed by 0.2- micron filter. The vials were filled with 2 ml and 5 ml volume in USP type I glass Vials with chlorobutyl rubber closer and were subjected to Autoclave at 121°C at 15 lb Pressure.

Table 10

Example 9: Pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions

Table 11

pH of Solution 7.0 - 7.5 (to be adjusted with 0.37%v/v HC1 or 0.01 N NaOH, as required)

Procedure: (Batch size: 100ml, 1000ml and 225 ml respectively for batches BB001008X BB001010A BB001011A )

Procedure for BB001008X: (Batch size: 100 ml)

The Vitamin E TPGS (300 mg) was dissolved in hot water (50 ml) at 65°C (±5°C) under stirring and allowed to get clear solution. The PVP K 30 (150 mg) was dissolved in same under stirring. Then, Melatonin (150 mg) was added under stirring till it gets dissolved. The pH of the solution was adjusted to 7.4 (7.0 to 7.5), using 0.37%v/v HC1 or 0.01 N NaOH, as required. The volume was adjusted up to 100 ml with Water for Injection. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2-micron PVDF filter. The vials were filled with 2 ml and 5 ml volume in USP type I glass Vials with chlorobutyl rubber closer and were subjected to Autoclave at 121°C at 15 lb Pressure.

Procedure for BB001010A: (Batch size: 1000 ml)

The Vitamin E TPGS (3.0 gm) was dissolved in hot water (100 ml) at 60°C (±5°C) under stirring for 10 min and allowed to get clear solution. The PVP K 30 (3.0 gm) was dissolved in same under stirring. To the solution 600 ml of Water for Injection, was added. Then, Melatonin (3.0 gm) was added under stirring till it gets dissolved, if required warm the solution to NMT 65°C, under stirring. The pH of the solution was adjusted to 7.4 (7.0 to 7.5), using 0.37%v/v HC1 or 0.01 N NaOH, as required. The volume was adjusted up to 1000 ml with Water for Injection. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2-micron PVDF filter. The vials were filled with 2 ml and 5 ml volume in USP type I glass Vials with chlorobutyl rubber closer and were subjected to Autoclave at 121°C at 15 lb Pressure. The batches were charged for the stability study and also to study any adverse effect of same on the animal models.

Procedure for BB001011A: (Batch size: 225 ml)

The Vitamin E TPGS (0.90 gm) was dissolved in hot water (150 ml) at 60°C (±5°C) under stirring for 30 min and allowed to get clear solution. The PVP K 30 (0.45 gm) was dissolved in same under stirring. To the solution 60 ml of Water for Injection, was added. Then, Melatonin (0.90 gm) was added under stirring till it gets dissolved. The solution was mixed for 20 min. The pH of the solution was adjusted to 7.4 (7.0 to 7.5), using 0.37%v/v HC1 or 0.01 N NaOH, as required. The volume was adjusted up to 225 ml with Water for Injection. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2-micron PVDF filter. The vials were filled with 2 ml (8 mg / vial) and 5 ml (20 mg / vial) volume in USP type I glass Vials with chlorobutyl rubber closer and were subjected to Autoclave at 121°C at 15 lb Pressure. The batches were charged for the stability study and also to study the locomotor activity on the animal models. Table 12

Example 10: Pharmaceutical composition of melatonin for the oral administration in the form of solutions

Table 13

Procedure for BB001012A: (Batch size: 1000 ml)

The Vitamin E TPGS (0.600 gm) was dissolved in hot water (100 ml) at 60°C (±5°C) under stirring for 10 min and allowed to get clear solution. The PVP K 30 (0.300 gm) was dissolved in same under stirring. To the solution 600 ml of Water for Injection, was added. Then, Melatonin (0.600 gm) was added under stirring till it gets dissolved, if required warm the solution to NMT 65°C, under stirring. Then, add Xylitol (0.800 gm) and Acesulfame Potassium (0.100 gm) to the bulk solution and adjust the pH of the solution to 7.4 (7.0 to 7.5), using 0.37%v/v HC1 or 0.01 N NaOH, as required. The volume was adjusted up to 1000 ml with Purified Water. The solution was filtered through 0.45-micron PVDF filter and filled in 5 ml of Plastic bottles. Procedure for BB001013A : (Batch size: 10 Ltr)

The Vitamin E TPGS (5.0 gm) was dissolved in hot water (100 ml) at 60°C (±5°C) under stirring for 10 min and allowed to get clear solution. The PVP K 30 (3.0 gm) was dissolved in same under stirring. To the solution 600 ml of Water for Injection, was added. Then, Melatonin (5.0 gm) was added under stirring till it gets dissolved, if required warm the solution to NMT 65°C, under stirring. Then, add Xylitol (8.0 gm) , Citric Acid (1.00 gm) and Acesulfame Potassium (1.00 gm) to the bulk solution and adjust the pH of the solution to 7.4 (7.0 to 7.5), using 0.37%v/v HC1 or 0.01 N NaOH, as required. Add the suitable flavor (1.00 gm) and adjust the volume was up to 1000 ml with Purified Water. The solution was filtered through 0.45-micron PVDF filter and filled in 100 ml of PET bottles with dispenser.

Example 11: Pharmaceutical composition of melatonin for the oral or parenteral administration (slow IV infusion) in the form of liquids and solutions Table 14

required) Procedure for BB001014A : (Batch size: 1000 ml) The Vitamin E TPGS (0.100 gm) was dissolved in hot water (500 ml) at 60°C (±5°C) under stirring for 30 min and allowed to get clear solution. The PVP K 30 (0.05 gm) was dissolved in same under stirring. To the solution 300 ml of Water for Injection, was added. Then, Melatonin (0.100 gm) was added under stirring till it gets dissolved. Add Sodium Chloride (0.90 gm) to the solution and was mixed for 20 min. The pH of the solution was adjusted to 7.4 (7.0 to 7.5), using 0.37%v/v HC1 or 0.01 N NaOH, as required. The volume was adjusted up to 1000 ml with Water for Injection. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2-micron PVDF filter. The solution to be filled in 100 ml USP Type I glass bottle, with rubber closer and were subjected to Autoclave at 121 °C at 15 lb Pressure. The solution can be given as slow IV infusion.

Procedure for BB001015A: (Batch size: 100 ml)

The Vitamin E TPGS (1.00 gm) was dissolved in hot water (40 ml) at 60°C (±5°C) under stirring for 30 min and allowed to get clear solution. The PVP K 30 (0.50 gm) was dissolved in same under stirring. To the solution 30 ml of Water for Injection, was added. Then, Melatonin (1.00 gm) was added under stirring till it gets dissolved. The pH of the solution was adjusted to 7.4 (6.0 to 8.0), using 0.37%v/v HC1 or 0.01 N NaOH, as required. The volume was adjusted up to 100 ml with Water for Injection. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2-micron PVDF filter. The solution to be filled in 1ml USP Type I glass bottle, with rubber closer and were subjected to Autoclave at 121 °C at 15 lb Pressure. The solution can be given as slow IV infusion or can be diluted to normal saline solution or dextrose solution prior to use.

Procedure for BH001018A: (Batch size: 200 ml)

The Vitamin E TPGS (2.000 gm) was dissolved in hot water (100 ml) at 60°C (±5°C) under stirring for 30 min and allowed to get clear solution. The PVP K 30 (1.200 gm) was dissolved in same under stirring. To the solution 60 ml of Water for Injection, was added. Then, Melatonin (1.200 gm) was added under stirring till it gets dissolved. The solution was mixed for 20 min. The pH of the solution was adjusted to 7.4 (7.0 to 7.5), using 0.37%v/v HC1 or 0.01 N NaOH, as required. The volume was adjusted up to 200 ml with Water for Injection. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2-micron PVDF filter. The vials were filled with 2 ml (8 mg / vial) and 5 ml (20 mg / vial) volume in USP type I glass Vials with chlorobutyl rubber closer and were subjected to Autoclave at 121 °C at 15 lb Pressure.

Example 12: Animal Studies:

The healthy mice were selected as an animal for investigational purpose. The Animals were divided into group of three each and were grouped as Test 1 (Placebo Treatment), Test 2 (Receiving 1.5 mg / ml dose), Test 3 (Receiving 3.0 mg / ml dose), Test 4 (Receiving 4.0 mg / ml dose) and Test 5 (Receiving 10 mg / ml dose). Initial locomotor activity of every animal from each group is recorded. This activity is the activity before administration of dose to that animal. In each group the dose was administered by two major routes that include the IP (Intra Peritoneal) and iv (Intravenous). On the first day, one dose is administered intraperitoneally and change in locomotor activity is recorded. The dose is continued for a total of seven days including the first day and change in the locomotor activity is recorded. This is termed as multiple dose. The onset of action for each animal was monitored post dose along with the duration of action and Locomotor activity. Beside the activity the major objective was to understand side effects, if any that including but not limited to seizures, long hypnotism or even death. Finally based on the groups studied, the recovery rate of animal was calculated. Table 15: Effect on Locomotor activity after administering single dose.

Conclusion: i) As dose is increased four times from 1.5 mg/ml to 10 mg/ml, the depression or decrease in locomotor activity rises almost 10 times viz. from -7 to -69. ii) No seizures or no other side effect was observed. iii) No mortality was observed. iv) All doses were found safe.

Table 16: Onset and duration of action of Melatonin and recovery rate.

Conclusion i) Melatonin injections have quick onset and comparatively shorter duration of action. ii) Onset of action by both the intravenous and intraperitoneal routes are acceptable iii) To enhance duration, intramuscular depot preparations or slow infusion as prepared under example 11 (table 14) viz. batches BB001014A and BB001015A are preferred. The batch BB001014A can be directly used as a slow IV infusion whereas batch BB001014A can be suitably diluted with saline for such use.

Table 17: Decrease or depression in locomotor activity after multiple dosing of melatonin solutions intraperitoneally

Conclusion i) No side effects, no seizures are observed after multiple dosing. ii) No mortality was observed after multiple dosing and hence it is found to be safe. iii) Melatonin injections at dose of 1.5 mg/ml does not show much further depression in locomotor activity after multiple dosing (7 doses over seven days) when compared with depression after a single dose. iv) Melatonin injections at dose from 3 mg/ml and above have shown significant depression after multiple doses when compared with a single dose which is 150 % for 3 mg/ml and more than 200 % for 4 mg/ml. v) Multiple dosing of 10 mg/ml (7 doses over 7 days) of melatonin solution has caused 84 % depression in locomotor activity. This is quite significant as extrapolation of the graph suggest that 100 % depression can be achieved. The results are also provided in figures 1 (single dose) and 2 (multiple dose).

Example 13: Solubility testing of melatonin in water alone and in the solution of crystal inhibitors, solubilizers, anti-oxidant is done as provided in table 18.

The addition of ingredients as per weights specified are done at room temperature in test tubes and the test tubes are swirled. The first observation of solubility is made and recorded after 15 minutes. In the second step, the solution is heated to 60°C and observation is made again. In the third step, the hot solution is cooled to room temperature and observation of solubility is made and recorded for third time.

Table 18: Solubility of Melatonin in Aqueous Solution:

Solubility observations i) The melatonin did not dissolve in water at a concentration of 4 mg/ml, however, when heated at 60 °C, solubility is enhanced but after cooling to room temperature, solution did not remain clear. ii) The melatonin did not dissolve in water at a concentration of 1 mg/ml, however, when heated at 60 °C, solubility is enhanced and a clear solution is noted but after cooling to room temperature, solution did not remain clear. iii) melatonin 4 mg / ml along with crystal inhibitor PVP K-30 also at 4 mg/ml did not dissolve in water. However, when heated at 60 °C, solubility is enhanced and a clear solution is noted but after cooling to room temperature, solution did not remain clear and became turbid. iv) melatonin 4 mg / ml along with solubilizer meglumine at 8 mg/ml dissolved in water to produce clear solution. No effect of heating and subsequent cooling on solubility is noted. v) 10 mg of melatonin along with 5 mg of crystal inhibitor PVP K-30 remained insoluble at room temperature in saline solution (0.9 g sodium chloride in 100 ml water) but when heated formed a clear solution which upon cooling to room temperature showed turbidity. In contrast to this, 10 mg of melatonin along with 5 mg of Vitamin E TPGS even though remained insoluble at room temperature in saline solution (0.9 g sodium chloride in 100 ml water) but when heated formed a clear solution which upon cooling to room temperature also remained clear. vi) melatonin 4 mg / ml along with solubilizer and anti -oxidant Vitamin E TPGS at 4 mg/ml did not dissolve in water to produce clear solution. However, effect of heating is evident as heating produced a clear solution which was clear even upon subsequent cooling to room temperature. vii) A combination of melatonin 4mg/ml, meglumine 8 mg/ml and PVP K-30 2 mg/ml did not dissolve in water to produce clear solution. However, effect of heating is evident as heating produced a clear solution which was clear even upon subsequent cooling to room temperature. viii) A combination of melatonin 4mg/ml, Vitamin E TPGS 4 mg/ml and PVP K- 30 4 mg/ml did not dissolve in water to produce clear solution. However, effect of heating is evident as heating produced a clear solution which was clear even upon subsequent cooling to room temperature.

Solubility Study conclusions i) Melatonin on its own has a poor solubility in water which is not even 1 mg / ml even though 1 mg/ml and 2 mg/ml are reported by some literature. Even heating did not dissolve the same. ii) Drug solubilizer and anti-oxidant Vitamin E TPGS alone and along with crystal inhibitor PVP K-30 produced enhanced effect on solubility after heating and subsequent cooling produced clear solution. iii) meglumine alone is found best to solubilize melatonin but required heating when crystal inhibitor PVP K-30 is added. iv) Combination of meglumine and vitamin E TPGS can be tried for solubility. Also, meglumine alone and vitamin tpgs alone can be used to solubilize melatonin.

Based on above results a batch was prepared using a combination meglumine and vitamin E TPGS. Example 14: Pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions Table 18: Melatonin along with two solubilizers

pH of Solution 6.0 - 9.0 (to be adjusted with 0.37%v/v HC1 or 0.01 N NaOH, as required)

Procedure for BH001017A: (Batch size: 100 ml)

The Vitamin E TPGS (0.750 gm) was dissolved in hot water (50 ml) at 60°C (±5°C) under stirring for 30 min and allowed to get clear solution. The Meglumine (1.125 gm) was dissolved in same under stirring. To the solution 30 ml of Water for Injection, was added. Then, Melatonin (0.750 gm) was added under stirring till it gets dissolved. The solution was mixed for 45 min. The pH of the solution was adjusted to 8.5 (6.0 to 9.0), using 0.37 %v/v HC1 or 0.01 NNaOH, as required. The volume was adjusted up to 100 ml with Water for Injection. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2-micron PVDF filter. The vials were filled with 2 ml (15 mg / vial) volume in USP type I glass vials with rubber closer and were subjected to Autoclave at 121 °C at 15 lb Pressure.

Example 15: Pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions Table 19: Melatonin along with meglumine alone

pH of Solution 7.0 - 9.0 (to be adjusted with 0.37%v/v HC1 or 0.01 N NaOH, as required)

Procedure for BH001020A: (Batch size: 200 ml)

1. The Meglumine (3.60 gm) was dissolved in hot water (50 ml) at 60°C (±5°C) under stirring for 10 min and allowed to get clear solution.

2. Melatonin (1.200 gm) was added to 100 ml of purified water slowly under stirring till it gets dispersed completely.

3. Homogenized the solution for 60 min. and mix with step 1 solution for 120 min.

4. The pH of the solution was adjusted to 8.0 (7.0 to 9.0), using 0.37%v/v HC1 or 0.01 NNaOH, as required. 5. The volume was adjusted up to 200 ml with Water for Injection.

6. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2-micron PVDF filter.

7. The vials were filled with 1 ml (6 mg / vial) , 2 ml (12 mg / vial) and 5 ml (30 mg / vial) volume in USP type I glass Vials with chlorobutyl rubber closer and were subjected to Autoclave at 121°C at 15 lb Pressure.

8. The solution can be used as IV infusion or Iv bolus administration, by diluting with the dextrose solution or saline solution.

Example 16: Pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions Table 20: Melatonin along with Vitamin TPGS alone

Procedure: (Batch size: 200 ml) 1. The Vitamin E TPGS (1.50 gm) was dissolved in hot water (60 ml) at 60°C

(±5°C) under stirring for 30 min and allowed to get clear solution.

2. Melatonin (1.000 gm) was added to 100 ml of water for injection and homogenized for 60 min.

3. Add step 2 dispersion, under stirring, to step 1 solution and mix till it gets dissolved.

4. The solution was mixed for 60 min.

5. The pH of the solution was adjusted to 7.4 (7.0 to 7.5), using 0.37%v/v HC1 or 0.01 NNaOH, as required.

6. The volume was adjusted up to 200 ml with Water for Injection. 7. The solution was filtered through 0.45-micron PVDF filter and followed by 0.2- micron PVDF filter.

8. The vials were filled with 2 ml (10 mg / vial) and 4 ml (20 mg / vial) volume in USP type I glass Vials with chlorobutyl rubber closer and were subjected to Autoclave at 121 °C at 15 lb Pressure. 9. The solution can be used as IV infusion or Iv bolus administration, by diluting with the dextrose solution or saline solution. Example 16: Pharmaceutical composition of melatonin for the oral or parenteral administration in the form of liquids and solutions

Table 20: Melatonin with combination of solubilizer, anti-oxidant and crystal inhibitor.

Finally, melatonin solution is prepared using a combination of solubilizer, solubilizer which is also an anti-oxidant and crystal inhibitor. This solution is converted into granules which are further processed to prepare other compositions such as dispersible tablets, orally disintegrating tablets, granules for oral solution, granules for filling into capsules etc. The aqueous melatonin solution can be sprayed on to another ingredient such as diluent for example, xylitol, mannitol, sugar alcohol, polyol, saccharide, cellulose to produce granules which are processed further into capsules or compressed into tablets etc.

Following example provides first a convertible aqueous solution of melatonin and its further processing on to another ingredient mannitol to convert into granules which are mixed with one of the excipients such as glidant or lubricant etc. and compressed into tablets.

Procedure: (Batch size: 1000 Units)

The Vitamin E TPGS (6.00 gm) was dissolved in hot water (300 ml) at 60°C (±5°C) under stirring for 30 min and allowed to get clear solution. The Meglumine (16.00 gm) was dissolved in same under stirring. To the solution 300 ml of Purified water, was added. Then, Melatonin (8.00 gm) was added under stirring till it gets dissolved. The solution was homogenized for 45 min. To the above solution Polyvinyl Pyrrolidone (PVP K 12) was added with 300 ml of Purified water. The pH of the solution was adjusted to 7.5 (6.0 to 9.0), using 0.37%v/v HC1 or 0.01 N

NaOH, as required. The volume was adjusted up to 1000 ml with Purified water. The solution was filtered through 0.45-micron PVDF filter and were filled with suitable container with rubber closer and were subjected to Autoclave at 121 °C at 15 lb Pressure.

The solution was used as granulating fluid to adsorb on to the Mannitol 25 C using Top spray granulation. The dried granules (LOD NMT - 2.0% w/w) were passed through 40 mesh. Mix the granules with Sodium Stearyl Fumarate (1.00 gm) and compress the tablets using 5.00 mm round punch.

Claims

Claims We claim

1. An aqueous composition of melatonin comprising melatonin or melatonin in any acceptable form and at least one ingredient selected from a group consisting of solubilizers, crystal inhibitors, stabilizers, anti-oxidants, solubilizer which is also an anti-oxidant, chelating agents, complexing agents and a combination thereof wherein the concentration of melatonin in the composition is 0.5 mg/ml to 10 mg/ml and the aqueous composition is essentially free of preservative and optionally free of surfactant and co-solvent.

2. The aqueous composition of claim 1 wherein the concentration of melatonin in the composition is from 1.5 mg/ml to 7.5 mg/ml.

3. The aqueous composition of claim 2 wherein the concentration of melatonin in the composition is from 3 mg/ml to 6 mg/ml.

4. The aqueous composition of melatonin in accordance with the claim 1 wherein at least one ingredient is selected from meglumine, polyvinyl caprolactam- polyvinyl acetate-polyethylene glycol graft copolymer, polyvinyl pyrrolidone, a- Tocopheryl acetate (Vitamin E acetate), and D-a-tocopheryl polyethylene glycol succinate (Vitamin E TPGS or TPGS).

5. The aqueous composition of melatonin in accordance with the claim 4 comprising melatonin, meglumine and optionally, polyvinyl pyrrolidone.

6. The aqueous composition of melatonin in accordance with the claim 4 comprising melatonin, a-Tocopheryl acetate (Vitamin E acetate) and optionally polyvinyl pyrrolidone.

7. The aqueous composition of melatonin in accordance with the claim 4 comprising melatonin, polyvinyl pyrrolidone, meglumine and D-a-tocopheryl polyethylene glycol succinate (Vitamin E TPGS or TPGS).

8. The aqueous composition of melatonin in accordance with the claim 1 in a form of an aqueous solution wherein the aqueous solution is administrable orally or parentally, and is convertible into at least one of the composition selected from granules for oral solution, powder for filling into capsule, spray dried powder, dispersible tablet, and orally disintegrating tablets.

9. The aqueous composition of claim 8, wherein the aqueous composition is a pharmaceutically acceptable composition or a dietary supplement used for alleviation, treatment, prevention, cure, diagnosis, and/or prophylaxis, of a health condition, illness, disease and/or disorder in human.

10. The aqueous composition of claim 9, wherein the a health condition, illness, disease and/or disorder in human comprises at least one of disturbed sleep-wake cycle, ADHD, hyperactivity, COPD, cancer (as an adjuvant), pre-operative and post-operative stress, GI disorders (e.g. irritable bowel syndrome, peptic ulcers, pancreatic ulcers), ulcerative colitis, ulcers, insominia, Intensive Care Situation, neurodegenerative disorders, carcinogenic disorders, immunomodulatory disorders, Alzheimer’s disease, etc.

11. The aqueous composition of melatonin in accordance with the claim 8 wherein the composition is for oral administration and comprises at least one sweetener selected from the group consisting of sucrose, fructose, dextrose, high fructose corn syrup, xylitol, maltitol, sorbitol, mannitol, erythritol, sucralose, stevia, aspartame, advantame, acesulfame potassium, saccharin, sodium saccharin, neotame and any combinations thereof and/or at least one taste modifier selected from citric acid, tartaric acid, natural flavorings substance, nature identical flavoring substance and a combination thereof.

12. The aqueous composition of melatonin in accordance with the claim 11 comprising acesulfame potassium and citric acid.

13. The aqueous composition of melatonin in accordance with the claim 8 for parenteral administration is the aqueous solution administered via at least one route of administration comprising Intravenous (IV), Intramuscular (IM), Subcutaneous (SC), Intra-peritonial (IP), and Intradermal (ID).

14. The aqueous composition of melatonin in accordance with the claim 13 for parenteral administration is the aqueous solution which optionally is diluted with saline solution or dextrose solution before administration.

15. The pharmaceutical composition of melatonin in accordance with the claim 14 for parenteral administration comprising 0.9 g / 100 ml of sodium chloride.

16. Method of enhancing solubility of melatonin comprising: adding Melatonin and at least one ingredient selected from a group consisting of solubilizers, polymeric solubilizers, crystal inhibitors, stabilizers, anti-oxidants, chelating agents, complexing agents, and combination thereof to a in water to obtain an aqueous solution of Melatonin, wherein concentration of melatonin in the composition is 0.5 mg/ml to 10 mg/ml and characterized in that the method is optionally free of surfactant and co-solvent.

17. Method of enhancing solubility of melatonin in accordance with claim 16 comprising adding at least two ingredients selected from a group consisting of meglumine, polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, polyvinyl pyrrolidone, xylitol, a-Tocopheryl acetate (Vitamin E acetate) and D-a-tocopheryl polyethylene glycol succinate (Vitamin E TPGS or TPGS).

18. Method of enhancing solubility of melatonin in accordance with claim 17 wherein the composition is in the form of aqueous solution for oral administration comprising following steps: i) dissolving meglumine and polyvinyl pyrrolidone in water to obtain a clear solution; or i) dissolving D-a-tocopheryl polyethylene glycol succinate in hot water to obtain a clear solution and dissolving polyvinyl pyrrolidone in the same solution; ii) optionally adding water / water for injection; iii) adding melatonin to above solution and stirring to obtain clear solution and optionally warming if required; iv) adding sweetener and taste modifier; iv) optionally filtering solution using a suitable filter.

19. Method of enhancing solubility of melatonin in accordance with claim 17 wherein the composition is in the form of aqueous solution for parenteral administration comprising following steps: i) dissolving meglumine and polyvinyl pyrrolidone in water to obtain a clear solution; or i) dissolving D-a-tocopheryl polyethylene glycol succinate in hot water to obtain a clear solution and dissolving polyvinyl pyrrolidone in the same solution; ii) adding water for injection; iii) adding melatonin to above solution and stirring to obtain clear solution and optionally warming if required; iv) filtering solution using a suitable filter.

20. The aqueous composition of melatonin in accordance with claim 8 in the form of an aqueous solution wherein the composition is spray dried to convert it into a spray dried powder or granules

21. The aqueous composition of melatonin in accordance with claim 8 in the form of an aqueous solution wherein the composition is sprayed on an ingredient to convert it into granules which can be filled in capsule or compressed into an orally disintegrating or dispersible tablets.

22. The aqueous composition of melatonin in accordance with claim 8 in the form of an aqueous solution wherein the composition is sprayed on an ingredient to convert it into granules which can be compressed into an orally disintegrating or dispersible tablets.

23. The aqueous composition of any of the preceding claim for use in treatment of one or more of regulation of circadian rhythms, regulation of the inflammatory response, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), sepsis in neonates, myocardial infarction, mitochondrial damage, pulmonary edema, kidney or liver failure, or oxidative stress caused by surgery.

24. Method of treating one or more of regulation of circadian rhythms, regulation of the inflammatory response, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), sepsis in neonates, myocardial infarction, mitochondrial damage, pulmonary edema, kidney or liver failure, or oxidative stress caused by surgery comprising administering the aqueous composition of any of the preceding claim.