DESC:FIELD OF INVENTION

The present invention relates to compositions containing tamarind seed polysaccharide for corneal and conjunctival healing and the process for preparation thereof. In embodiments of the invention, ophthalmic composition is an aqueous ophthalmic solution comprising of tamarind seed polysaccharide.

BACKGROUND OF THE INVENTION

Various damages to the corneal and conjunctival epithelium are common in clinical ophthalmology. Various reasons for this condition could be trauma, ocular surgery, ocular surface diseases (dry eye disease) or as a result of environmental factors. Corneal/conjunctival surfaces can also be damaged by prolonged medications used of ophthalmic conditions. Either drugs in the ophthalmic preparations or its additives used in the formulations can cause this corneal/ conjunctival erosion/damage. Corneal or conjunctival wounds are commonly treated pharmacologically with the aim of promoting formation of an intact epithelial layer as rapidly as possible and then re-establishing the correct flow of biological information between corneal and conjunctival cells. Biopolymers like Hyaluronic acid is reported to have enhancing effect on corneal epithelium, stroma, and endothelium healing. Other biomolecules like epidermal growth factor, collagen lenses and mucin extracted from bovine submaxillary glands are also proven to be effective in treating ocular erosion. During the process of tissue repair/wound healing one of the major event is cellular adhesion to specific substrates of the extracellular matrix, such as the glycoproteins laminin– which is the major glycoprotein of corneal basement membrane and fibronectin. These fibronectins are recognized by specific membrane receptors called integrins. Since polysaccharides and glycosaminoglycans help in integrin recognition there may be an influence of these polysaccharides in cell adhesion and wound-healing process. Further this research question could be justified by the effect of sulphated polysaccharides, i.e. heparin and fucoidans, and of hyaluronic acid on cell adhesion and proliferation. One of such natural polysaccharide is TSP from tamarind seed (xyloglucan, or tamarind seed polysaccharide, TSP) in the repair of corneal wounds and in the integrin-substrate recognition system.

SUMMARY OF THE INVENTION

The present invention provides an ophthalmic compositions of tamarind seed polysaccharide, preferably aqueous ophthalmic solutions.

One embodiment of the present invention provides an aqueous ophthalmic solution comprising tamarind seed polysaccharide.

In embodiments of the present invention, the polysaccharide is selected from group comprising; chitosan, tamarind seed polysaccharide (xyloglucan), arabinogalactan, cellulose derivatives (methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose), hyaluronic acid, alginic acid and gellan gum. Preferable polysaccharide used for the preparation of aqueous ophthalmic solution is tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethylcellulose or combinations thereof.

In another embodiment, the present invention provides an aqueous ophthalmic solution comprising a polysaccharide selected from group consisting of tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethylcellulose or combinations thereof.

In still another embodiment, there is a method of treating dry eye comprising administering to eye an aqueous ophthalmic solution comprising polysaccharide selected from group consisting of tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethylcellulose or combinations thereof.

In a further embodiment, the present invention provides an aqueous ophthalmic solution consisting of tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethyl cellulose.

In another embodiment, there is a method of manufacturing an aqueous ophthalmic solution consisting of tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethyl cellulose.

In another embodiment, the present invention provides an aqueous ophthalmic solution comprising polysaccharide and a surfactant.

In a further embodiment, the present invention provides an aqueous ophthalmic solution comprising polysaccharide selected from the group consisting of tamarind seed polysaccharide and hydroxypropylmethylcellulose or combinations thereof and a surfactant.

In still another embodiment, the present invention provides and aqueous ophthalmic solution consisting of tamarind seed polysaccharide, hydroxypropylmethylcellulose and polysorbate 80.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an aqueous ophthalmic solution comprising of tamarind seed polysaccharide. More particularly, the invention concerns an aqueous ophthalmic solution indicated for treatment of dry eye comprising a polysaccharide.

In embodiments of the invention, the polysaccharide is selected from group comprising; chitosan, tamarind seed polysaccharide (xyloglucan), arabinogalactan, cellulose derivatives (methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose), hyaluronic acid, alginic acid and gellan gum. Preferable polysaccharide used for the preparation of aqueous ophthalmic solution is tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethylcellulose or combinations thereof.

In a specific embodiment, the present invention provides and aqueous ophthalmic solution comprising a polysaccharide selected from group consisting of tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethylcellulose or combinations thereof.

The term “tamarind seed polysaccharide” (Tamarindus indica Seed Polysaccharide or TSP, sometimes also generically referred with term “xyloglucan”) is a natural polysaccharide polymer obtained from seeds of the tamarind tree, the Tamarindus indica, an evergreen plant that may reach 15 m of height and that produces legume fruit and that is wide spread in India, in Africa and the whole the Far East where it is cultivated primarily for food production. The fruit contains big seeds having a high percentage of polysaccharides, which have the function to accumulate and preserve vital energetic substances. The seed, which was considered originally a by-product, has found various applications, once ground to the powder form (known as “tamarind gum” or “tamarind kernel powder”). In the pharmaceutical field, the polysaccharide fraction of tamarind gum (tamarind seed polysaccharide, known as TSP) has mucomimetic and corneal healing properties.

In the embodiments of the present invention tamarind seed polysaccharide (xyloglucan) is present in the range of 0.05% to 0.8% w/w of aqueous ophthalmic solution. Preferably, the tamarind seed polysaccharide (xyloglucan) used in the preparations of the invention has a molecular Weight comprised in the range from 450,000 Da to 750,000 Da (preferably 600,000-750,000 Da).

In the embodiments of the present invention hydroxypropylmethylcellulose is present in the range of 0.05% to 5% w/w of the aqueous ophthalmic solution.

In another embodiment the present invention provides a method of treating dry eye comprising administering to eye an aqueous ophthalmic solution comprising a polysaccharide selected from group consisting of tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethylcellulose or combinations thereof.

In a further embodiment the present invention provides an aqueous ophthalmic solution consisting of tamarind seed polysaccharide (xyloglucan) and hydroxypropylmethylcellulose.

In another embodiment, the present invention provides an aqueous ophthalmic solution comprising tamarind seed polysaccharide and a surfactant.

In still another embodiment, the present invention provides and aqueous ophthalmic solution consisting of tamarind seed polysaccharide, hydroxypropylmethylcellulose and polysorbate 80.

A typical aqueous solution of the present invention may contain additional ingredients which would not affect the basic and novel characteristics of the active ingredients such as tonicity agents, solvents and a vehicle.

Suitable tonicity agents include sodium chloride, potassium chloride, glycerol or mixtures thereof. In one embodiment, the solution contains 0.01% to 0.2% w/w sodium chloride.

Suitable vehicle used for the preparation of the aqueous ophthalmic solution is purified water.

The present invention is also disclosed by the following non-limiting examples, according to some specific embodiments thereof, which illustrates examples of formulations based on tamarind seed polysaccharide, hydroxypropylmethyl cellulose and polysorbate 80 which is used for the treatment of dry eye disease according to what is experimentally ascertained and reported in the experimental statement that follows.

Example 1
Ingredients % by weight
Tamarind seed polysaccharide (xyloglucan) 0.05% to 0.8%
Hydroxypropylmethylcellulose 0.05% to 5%
Polysorbate 80 0.05% to 2%
Sodium chloride 0.01% to 0.2%
Purified water Q.s to 100%

The aqueous ophthalmic solution is prepared by the following process
1. 0.05%w/w to 2%w/w of polysorbate 80 was added to the 50ml of water and stirred to form a homogenous solution
2. The remaining quantity of purified water was heated to 50°C for 4 hours form the hot water and 0.05%w/w to 0.8%w/w tamarind seed polysaccharide (xyloglucan) and 0.05%w/w to 5%w/w hydroxypropylmethylcellulose was added to hot water and stirred to form a clear viscous solution.
3. The contents of step 1 and step 3 was mixed well and the tonicity was adjusted with 0.01% to 0.2%w/w of sodium chloride to form an aqueous ophthalmic solution.

Example 2
Ingredients % by weight
Tamarind seed polysaccharide (xyloglucan) 0.2%
Hydroxypropylmethylcellulose 0.5%
Polysorbate 80 0.9%
Sodium chloride 0.65%
Purified water Q.s to 100%

The process is similar as disclosed in example-1.
,CLAIMS:Claims

1. An aqueous ophthalmic solution comprising a polysaccharide selected from group consisting of tamarind seed polysaccharide and hydroxypropyl methylcellulose.

2. The ophthalmic solution according to claim 1, comprising of about 0.05% w/w to 0.8% w/w tamarind seed polysaccharide.

3. The ophthalmic solution according to claim 2, comprising of about 0.2% w/w tamarind seed polysaccharide.

4. The ophthalmic solution according to claim 1, comprising of about 0.05% w/w to 5.0% w/w hydroxypropyl methylcellulose.

5. The ophthalmic solution according to claim 4, comprising of about 0.5% w/w hydroxypropyl methylcellulose.

6. The ophthalmic solution according to claim 1, further comprising polysorbate 80.

7. The ophthalmic solution according to claim 6, comprising of about 0.05% w/w to 2.0% w/w polysorbate 80.

8. The ophthalmic solution according to claim 7, comprising of about 0.9% w/w of polysorbate 80.

9. The ophthalmic solution according to claim 1, further comprising sodium chloride and water.