A fusidic acid GEL with chitosan and hydrolyzed collagen for treatment of diabetic ulcers and a process of making it

Abstract

The invention discloses a pharmaceutical composition (a gel) for diabetic ulcer. The gel comprises Fusidic acid and a biopolymer in the form of Chitosan, and a peptide in the form of hydrolyzed Collagen. Specifically, the gel comprises an antibacterial, Fusidic acid with a biopolymer, Chitosan and natural peptide of Type I Collagen. The composition is found to be therapeutically highly effective as a result of the unique and desirable physical, chemical and therapeutic properties of collagen embedded in chitosan gel framework with Fusidic acid.The composition is stable despite incorporation of Chitosan & hydrolyzed Collagen into a process of Fusidic acid of very low particle size. The composition has 0.1% (w / w) to 5% (w / w) of Sodium Fusidate and Chitosan of molecular weight in the range of 250,000 Da to 500,000 Da in the weight proportion of 1.25% (w / w), and the hydrolyzed Collagen of molecular weight in the range of 3000 Da to 6000 Da in the weight proportion of 0.2% (w / w).

Description

[0001]A FUSIDIC ACID GEL WITH CHITOSAN AND HYDROLYZED COLLAGEN FOR TREATMENT OF DIABETIC ULCERS AND A PROCESS OF MAKING IT FIELD OF INVENTION: The invention relates to pharmaceutical composition for diabetic ulcer. In particular the invention relates to a pharmaceutical gel composition comprising fusidic acid and a biopolymer in the form of chitosan, and hydrolyzed collagen. BACKGROUND OF THE INVENTION: The skin is the body’s first barrier against bacteria that cause infections. Infections are common in patients with diabetes and are associated with high morbidity and risk of extremity amputation. Diabetic ulcers (DU) are classified as mild, moderate, or severe. Gram-positive bacteria, such as Staphylococcus aureus and beta-hemolytic streptococci, are the most common pathogens in previously untreated mild and moderate infection. Patients with diabetes are particularly susceptible to foot infection primarily because of neuropathy, vascular insufficiency, and diminished neutrophil function. The diagnosis of diabetic ulcers are based on the clinical signs and symptoms of local inflammation. Infected wounds should be cultured after debridement. Tissue specimens obtained by scraping the base of the ulcer with a scalpel or by wound or bone biopsy are strongly preferred to wound swabs. Imaging studies are indicated for suspected deep soft tissue purulent collections or osteomyelitis. A diabetic patient has the potential risk of pathologic consequences, including ulceration, infection and / or destruction of deep tissues associated with neurologic abnormalities, varying degrees of peripheral vascular disease and / or metabolic complications of diabetes. Literature evidences indicate that about 60% of diabetic patients who are treated for diabetic ulcer receive antibiotic therapy. The concept that reducing the “bioburden” of chronic skin wounds with antimicrobial therapy may improve healing is plausible, and some experimental animal data and studies with burn wounds and skin grafts support this theory. The increasing prevalence of antimicrobial resistance (e.g., Methicillin-Resistant S. aureus [MRSA]) or other complications (e.g., Clostridium difficile infection) has led to a rise in the use of topical antimicrobial treatments for increased wound bioburden. Antimicrobial agents that are used topically have the advantage of not driving resistance. Such agents provide high local concentrations, but do not penetrate intact skin or into deeper soft tissue. Topical antimicrobials may be beneficial in certain situations: where there are concerns regarding reduced antibiotic tissue penetration — for example, where the patient has a poor vascular supply – in non-healing wounds where the classic signs and symptoms of infection are absent, but where there is a clinical suspicion of increased bacterial bioburden. In these situations, topical antimicrobials (either alone or as an adjunctive therapy to systemic therapy) have the potential to reduce bacterial load and may protect the wound from further contamination. In addition, treatment at an early stage may prevent spread of infection to deeper tissues. At present there is no composition that is specifically designed to treat diabetic ulcers. There is therefore a need for a composition specifically designed to treat diabetic ulcers. The product with current composition is specifically designed for the treatment of Diabetic Ulcers for which there is no specific / designed treatment till date. Our product design has taken utmost care for the therapeutic effect to be delivered to patients for the treatment of DU by the incorporation of a high percentage of biopolymer Chitosan in the formulation along with Collagen peptide. The combinatorial effect of the anti-bacterial Fusidic acid processed to achieve sub- micron particle size of the active embedded with Chitosan and Collagen enhances / speeds up the recovery from wounds caused by DU. SUMMARY OF INVENTION: The invention discloses a pharmaceutical composition (a gel) for diabetic ulcer. The gel comprises Fusidic acid and a biopolymer in the form of Chitosan, and Collagen. Specifically, the gel comprises an antibacterial, Fusidic acid with a biopolymer, Chitosan, and natural peptide of Type I Collagen. The composition is found to be therapeutically highly effective as a result of the unique and desirable physical, chemical and therapeutic properties of collagen embedded in chitosan gel framework with Fusidic acid. The composition is stable despite incorporation of Chitosan & hydrolyzed Collagen into a process of Fusidic acid of very low particle size. The composition has 0.1% (w / w) to 5% (w / w) of Sodium Fusidate and Chitosan of molecular weight in the range of 250,000 Da to 500,000 Da in the weight proportion of 1.25% (w / w), and the hydrolyzed Collagen of molecular weight in the range of 3000 Da to 6000 Da in the weight proportion of 0.2% (w / w). BRIEF DESCRIPTION OF FIGURES: Figure 1: Fusidic acid particles embedded in the gel matrix of Chitosan and Collagen. Image from Cryo-SEM at magnification x50 k to x60 k, scale of 100 nm Figures 2 and 2A: Wound healing images at periodic frequency of Fusidic acid gel treated patient Figures 3 and 3A: Wound healing images of patient treated with standard wound care DETAILED DESCRIPTION: Before the present compounds, compositions, articles, devices, and / or methods are disclosed and described, it is to be understood that they are not limited to specific synthetic methods or specific pharmacology methods unless otherwise specified, or to particular reagents unless otherwise specified, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The formulation of the invention is a gel comprising fusidic acid made in situ under oxygen free environment starting from sodium fusidate, chitosan, and hydrolyzed collagen. Chitosan Chitosan is used in the current invention is an excipient, which enhances the wound healing at the local site of action. Chitosan is an un-branched binary polysaccharide consisting of the two units N-acetyl-D-glucosamine and D- glucosamine linked in (1-4) manner. The product is obtained by partial deacetylation of Chitosan leading to a degree of deacetylation of not less than 70%. Chitosan is extracted from the shells of shrimp and crab, both of which should be from edible sources suitable for human use. It was found that chitosan extracted at lower degrees of deacelytation is not effective in providing synergetic effect. Chitosan accelerates wound healing. The combination of improved wound healing and antimicrobial activity makes Chitosan particularly useful for biomedical applications such as wound dressings and periodontal treatment. Clinically available data indicate that chitosan membrane over the wound promotes efficient adherence, hemostasis, healing, and re-epithelialization to re- form the skin to its natural state. Open skin wounds covered with Chitosan membrane were hemostatic and healed quickly and histological examination confirmed that the epithelialization rate was increased and the deposition of collagen in the dermis was well organized as a result of covering the wounds with this asymmetric Chitosan membrane. Burns treated with high molecular weight Chitosan had significantly more epithelial tissue, and the best re-epithelialization and fastest wound closure with advanced granulation tissue formation. Chitosan is available in varying molecular weights ranging from 5000 Da to 5,000,000 Da. However, we have carefully chosen by trials the molecular weight in the chain range of not more than 500,000 Da, which alone would ensure superior therapeutic effect on the indications of the formulated product. The degree of deacetylation of not less than 80% is also critical for Chitosan to have more free amines to react with the anionic mucus membrane for better adhesion & rapid effect of wound re-epithelialization. Since initially all wounds excrete with exudates they are prone to infection. And thus, any topical application on a fresh wound area should have endotoxin level preferably less than 100 IU per g to ensure faster wound healing. Collagen Collagen comes from the Greek word “kólla“, meaning “glue” and the French - gène, meaning “something that produces”. In other words, collagen is a “glue producing” protein. Collagen is the most abundant protein in human bodies, especially type I Collagen. It’s found in muscles, bones, skin, blood vessels, digestive system, and tendons. Amino acids are the building blocks of collagen. Body can produce collagen after it breaks down dietary amino acids from protein-rich foods like chicken, dairy, and meat. Vitamin C is necessary for collagen synthesis. It helps to connect collagen forming amino acids together. Types of Collagen The most abundant protein in the body, collagen makes up more than one-third of total body protein. It’s rich in glycine, proline, and hydroxyproline — the amino acids that help body make new collagen. There are more than two dozen known types of Collagen. However, around 90% of body’s collagen is type I, the 5 most common types being: • Collagen I: Because it’s the most abundant, type I is in almost every tissue of your body: tendons, skin, bones, cartilage, connective tissue, and teeth. Type I Collagen fibrils are incredibly strong. They can resist a lot of pressure without breaking, and gram for gram, Collagen I is stronger than steel. • Collagen II: Found mostly in cartilage. • Collagen III: Type III can be found alongside type I and in muscles, organs, arteries, and a type of special connective tissue called reticular fiber, which forms the liver, adipose tissue, bone marrow, spleen, and more. • Collagen IV: Forms the basal lamina, a layer of the extracellular matrix — the net that supports cells — that sits underneath the epithelium. Basically, the basal lamina gives external support to your skin cells. • Collagen V: Collagen V can be found in the bone matrix, cornea, and in the connective tissue that exists between the cells of the muscles, liver, lungs, and placenta (also known as the interstitial matrix). The present invention of gel discloses novel and unique compositions comprising combinations of antibacterial, Fusidic acid with a biopolymer, Chitosan and natural peptide of Type I Collagen. This novel combination is highly therapeutically effective as a result of the unique and desirable physical, chemical and therapeutic properties of Collagen embedded in Chitosan gel framework with Fusidic acid. Chitosan (as a biopolymer) which is an unbranched binary polysaccharide consisting of the two units N-acetyl-D-glucosamine and D- glucosamine with narrowly defined molecular weight ranging from 250,000 Da to 500, 000 Da, and a degree of deacetylation of not less than 80%. Though not wishing to be bound by the following theory, chitosan functions as a film forming, biocompatible, non-allergenic biopolymer, protecting the skin by acting as a barrier, the natural protein Type I Collagen facilitate in wound healing and setting the skin to its natural state, whereas Fusidic acid attenuates bacterial infection. Until the innovative discoveries by the present inventors, the unique combination of properties such skin protection, inhibiting the mobility of pathogens from one site to another, and other therapeutic advantages had not been realized. The present invention addresses this long felt need by incorporating the use of biopolymers (such as Chitosan) to optimize skin protection (by way of film forming properties), immobilization of pathogenic microbes (due to its cationic electrostatic property) and wound healing along with hydrolyzed Collagen, preferably of type I, which is a polypeptide with molecular weight ranging from 3000 Da to 6000 Da that additionally benefits for rapid healing in case of wide open wounds which occur. Type I Collagen is selected for its abundancy and tensile property which binds the newly formed skin and reforms the skin strata to its natural form. Rationale for Combination of Fusidic acid with Chitosan and hydrolyzed Collagen as gel formulation: Diabetic ulcers are non-healing wounds which might take longer period of treatments. The associated co-morbid conditions & infections make ulcers vulnerable to delirious effects. Various treatments are available for ulcer wounds which may include administration of multiple anti-bacterials with supportive wound care therapy. However, there is no effective therapy control bleeding and faster wound contraction in ulcer wounds. To meet this need at an affordable cost the current invention ensures a safe therapy to the dispersed segment of population across all countries / communities. The current invention - a novel gel formulation – which is a unique combination of Chitosan, a biopolymer and hydrolyzed Collagen of type I that have wound healing properties to build the skin matrix back to natural state along with the anti-bacterial – Fusidic acid for bacterial control / treatment of infections in the ulcer region. If the ulcers are left untreated, the bacteria will multiply, causing pain, redness, swelling, itching, and oozing. Untreated ulcer infections can eventually spread and become much more serious. The inclusion of Chitosan in the formulation has multitude attributes, which are very essential in treating skin ailments. The combination of Chitosan and hydrolyzed Collagen of type I along with the anti- bacterial agent Fusidic acid is unique and novel and is not available across the globe. The concept of the combination is justified by considering the physical, chemical and therapeutic properties of Chitosan and hydrolyzed Collagen with the anti-bacterial agent Fusidic acid. The applicant has found that the therapeutic effect of combination of Fusidic acid with incorporation of Chitosan and hydrolyzed Collagen has enhanced synergistic effect to the diabetic ulcer patients. Chitosan has properties of film forming and is biocompatible and non-allergenic ensuring skin re-epithelialization and helps in rejuvenating and regenerating the skin. Chitosan accelerates wound healing and provides the wound a barrier through bio-degradable micro-film formation. Through Chitosan’s cationic charge the pathogens could be immobilized and this adds to the rapid wound healing effect. In most wounds, complete replacement of harmed tissue to its unharmed state is impossible. The wound has to be healed using extra material to reconnect the tissue. Collagen helps skin to heal by activating coagulation in the wound to stop the bleeding. As the blood vessels form fibrils, fibroblasts — collagen factories — laydown more collagen (aka the “glue”) until the scar looks firmer. During the phase of wound healing, leukocytes gradually abandon the wound area and cells start cranking out type I Collagen– the type that makes up to restore the normal skin. The role of Collagen in the formulation is to build the matrix for rapid skin re- epithelialization and ensure natural strata formation of the skin. In ulcer treatments wound healing, skin regeneration and rejuvenation, microbial protection of the skin, bleeding control and mobility of pathogens from one site to another, etc. are significant therapy considerations which this application has focused and addresses. The current invention fills this gap by an innovative technology of incorporation of Chitosan and hydrolyzed Collagen into the gel matrix with Fusidic acid thus establishing the essential requirements of accelerated wound healing. Chitosan / Polyglucosamine is structurally similar to hyaluronan and is expected to assist scarless wound healing. Heparin enhances mitogen by induction and stabilization of fibroblast growth stimulating factor (FGF). Polyglucosamine may promote tissue growth and wound healing by forming complexes with heparin and acting to prolong the half-life of the growth factors. Chitosan's properties allow it to rapidly clot blood, and it has been approved in the USA for use in bandages and other hemostatic agents. Burns / Cuts / Wounds can happen at any place and time and in the absence of immediate medical support- unattended wounds / cuts / burns often leads to complications and high likelihood of secondary bacterial / fungal infections and multiply manifold the originating medical condition needing a therapeutic response. The present invention would provide first line of response in terms of medical intervention, convenience, affordability, reliability, efficacy, safety which have a critical impact on the skin condition. Currently no treatment is available to heal the superficial or deep wound and also to stop bleeding. The unique innovative formulation of the present invention takes care of the skin conditions by treating them along with protecting the skin and controlling the bleeding at the ulcer site. Further with ever increasing pressures on medical support systems and the attendant scarcity / high cost of the same requires an effective treatment regimen and approach. The current application addresses all these aspects with the Fusidic acid gel formulation with Chitosan and hydrolyzed Collagen. The novel Fusidic acid gel with Chitosan and hydrolyzed Collagen of the present invention is most stable / efficacious at ambient conditions and does not require specific temperature control during transportation or storage thus achieving the social objectives to the benefit of the society at large. The ulcer wound healing rate was much faster for the Fusidic acid gel with Chitosan and hydrolyzed Collagen which was evident through the multi-centric diabetic ulcer clinical trial conducted. The Chitosan used in the invention is sourced from outside India and has the specification as listed in Table 1. Table 1 - SPECIFCIATION OF CHITOSAN ON SELECTED PARAMETERS PARAMETERS GENERAL SPECIFICATION IN SPECIFICATION THIS INVENTION AVERAGE < 1000000 Da (as per < 500000 Da MOLECULAR USP / NF) WEIGHT DEGREE OF 70%-95% (as per > 80% DEACETYLATION USP / NF) VISCOSITY 300 cPs to 400 cPs < 200 cPs (as in prior art) The invention also discloses an innovative and insightful process of making a gel with Sodium Fusidate as the active compound and by in-situ conversion the Sodium Fusidate is converted into Fusidic Acid in a totally oxygen free environment. The Fusidic Acid thus obtained is stabilized Fusidic Acid and is used in the treatment of bacterial skin infections and infected ulcer wounds. The presence of viscosity enhancing agents and the waxy materials imparts viscosity to the formulation composition in a range of 20000 cPs to 70000 cPs. The product with skin friendly pH, nanometric particle size ensuring uniform distribution of the active Fusidic acid and better penetration with optimal viscosity for spreadability and diffusability ensures applicability. The combination is very complex & cumbersome since the stability of the product is hard to achieve due to the incorporation of Chitosan & hydrolyzed Collagen into a process of Fusidic acid of very low particle size. The addition of such a high percentage of Chitosan in the formulation is extremely difficult since it de-stabilizes the formulation by the ejection of Chitosan upon storage. According to the preferred embodiment of the present invention, there is provided a gel composition for the topical treatment of diabetic ulcers in humans, the composition comprising; - from about 0.1% (w / w) to about 5% (w / w) by weight, preferably from about 1% (w / w) to 2% (w / w) by weight, of an acid form active compound, preferably sodium fusidate and, - the biopolymer of compositions disclosed herein is Chitosan of molecular weight in the range of 250,000 Da to 500,000 Da. In certain aspects, the Chitosan is added in an amount between 0.5% (w / w) and 10% (w / w) by weight, preferably in an amount 1.25% (w / w), - the natural protein / peptide hydrolyzed Collagen selected from the range of molecular weight could range from 3000 Da to 6000 Da, in certain aspects, the hydrolyzed Collagen used is of molecular weight is 3000 Da and is added in an amount between 0.05% (w / w) and 1% (w / w) by weight, preferably in an amount 0.2% (w / w), - a gel base containing natural polymers and gelling agents, emulsifiers, waxes, co-solvents, acids, solubilizers, buffering agents, preservatives, anti-oxidants, chelating agents, humectants, water, all weights based on the weight of the composition, wherein - primary and secondary emulsifiers are selected from a group comprising Cetostearyl alcohol, Polyoxyl 20 cetostearyl ether, Polyoxyl 40 hydrogenated castor oil, Polyoxyl 35 hydrogenated castor oil, Sorbitan monosterate and Sorbitan monooleate and added in an amount ranging individually from about 0.5% (w / w) to 20% (w / w); - waxy materials is selected from a group comprising white soft paraffin, liquid paraffin and hard paraffin and added in an amount ranging individually from about 3% (w / w) to 30% (w / w) - co-solvents are selected from a group comprising Glycerol, Propylene Glycol, Hexylene Glycol, Polyethylene Glycol-400 and the like from about 5% (w / w) to 50% (w / w), - acids such as HCl, H2SO4, HNO3, Lactic acid, Citric acid and the like from about 0.005% (w / w) to 5.0% (w / w), - preservatives are selected from a group comprising Chlorocresol, Potassium sorbate, Benzoic acid and the like from about 0.05% (w / w) to 0.5% (w / w), - buffering agents are selected from a group comprising DiSodium Hydrogen Orthophosphate, Sodium Hydrogen Orthophosphate and the like from about 0.01% (w / w) to 1.00% (w / w), - anti-oxidants are selected from a group comprising Butylated Hydroxyanisole, Butylated Hydroxytoluene and the like from about 0.005% (w / w) to 5% (w / w), - chelating agents are selected from a group comprising Disodium EDTA and the like from about 0.05% (w / w) to 1% (w / w), - humectants are selected from a group comprising Glycerol, Sorbitol, and the like from about 5% (w / w) to 40% (w / w). - solubilizers such as Polyoxyl 40 hydrogenated castor oil, Polyoxyl 35 hydrogenated castor oil from 0.1% (w / w) to 5.0% (w / w) - purified water from about 30 % w / w to 60 % w / w. The therapeutic efficacy of topically applied innovative Fusidic acid gel is due partly to the pronounced antibacterial activity of the regenerated Fusidic Acid against the organisms responsible for skin infections and partly to the unique ability of this regenerated Fusidic acid owing to its colloidal sub-micron particle size and incorporation of biopolymer Chitosan & natural peptide hydrolyzed Collagen for faster wound closure and rapid skin re-epithelialization. Table 2: Fusidic acid2% w / w Gel with biopolymer Chitosan 1.25% w / w and hydrolyzed Collagen 0.2% w / w S. Composition Quantity in No. percentage w / w 1. Sodium Fusidate(equivalent to Fusidic acid 2.000%) 2.085 2. Chitosan 1.250 3. Hydrolyzed Collagen 0.200 4. Cetostearyl Alcohol 7.500 5. White Soft Paraffin 7.500 6. Light Liquid Paraffin 5.000 7. Polyoxyl 20 Cetostearyl Ether 2.000 8. Polyoxyl 40 Hydrogenated Castor Oil 2.000 9. Propylene Glycol 16.000 10. Glycerol 7.000 11. Benzoic Acid 0.200 12. Butylated Hydroxytoluene 0.010 13. Disodium Edetate 0.100 14. Disodium Hydrogen Phosphate(Anhydrous) 0.050 15. Lactic Acid 1.250 16. Nitric Acid (concentrated) 0.392 (0.280 mL) 17. Purified Water 47.463 According to another embodiment of the present invention, there is also provided a process for treating Diabetic Wounds / Infections / Ulcers involving contacting human skin with the above-disclosed composition. Details of the process of manufacturing the Fusidic acid Gel: The novel Fusidic acid gel formulation of the present invention is made by modifying the standard procedure of manufacturing pharmaceutical gels. All ingredients are mixed thoroughly at ambient or elevated temperature. A process to make a medicinal gel for topical application comprising the step of using sodium fusidate as the raw active pharmaceutical ingredient and converting said sodium fusidate in situ into fusidic acid under oxygen-free environment and is added into a gel base as follows: Before start of manufacturing process 1M nitric acid is prepared as follows, 0.392g concentrated nitric acid is mixed with 4.165g of purified water to achieve 1M concentration of Nitric acid. The steps of the process are: a. Heating 14.000% of Propylene Glycol in a stainless steel vessel to 67°C ± 2°C followed by adding 0.010% of Butylated Hydroxytoluene, 0.500% of Polyoxyl 20 Cetostearyl Ether and 1.000 % of Polyoxyl 40 Hydrogenated Castor Oil to the vessel and cooling contents to below 45°C and adding 2.085% of Sodium Fusidate to the vessel under oxygen free environment with pure nitrogen flushing &continuous stirring until sodium fusidate dissolves completely, and thereafter adding 1M nitric acid into the vessel with slow stirring to form a solution containing the dissolved Sodium Fusidate converted in situ to Fusidic acid; b. Adding purified water in a stainless steel vessel in an amount of 28.125% to which are added 0.100 % of Disodium Edetate, 0.200% hydrolyzed Collagen and 1.250 % of Lactic Acid with continuous stirring to form a clear solution, to which added 1.250% Chitosan under slow stirring condition until the Chitosan dissolves and forms a clear gel; c. Heating 15.173 % of Purified water in Water Phase Vessel. Adding 0.050 % of Disodium Hydrogen Orthophosphate, Anhydrous to the heated contents at 45°C± 2°C with continuous stirring condition and adding 1.000% of Polyoxyl 40 Hydrogenated Castor Oil and 7.000% of Glycerol to the said water phase vessel and contents heated up to 72°C± 2°C; d. Adding 7.500 % of Cetostearyl Alcohol, 7.500 % of White Soft Paraffin, 5.000 % of Light Liquid Paraffin, 1.500 % of Polyoxyl 20 Cetostearyl Ether and 0.200 % of Benzoic Acid into Wax Phase Vessel. The contents are heated to 72°C± 2°C with continuous stirring. e. Transferring contents of step c (Water phase vessel) and step d (Wax phase vessel) to the final mixing vessel at 72°C± 2°C and mixed to form an emulsion. f. Cooling the contents of step e to 50°C± 2°C and transferring the contents of step a in to it under stirring condition. g. Rinsing the vessel used in step a with 2.000 % propylene glycol and adding to final mixing vessel and continue stirring. h. Cooling the contents of step f to 45°C± 2°C and transfer the content of step b under stirring. i. Cooling the contents of final mixing vessel to 25°C to 30°C± 2°C using cooling water. j. Transferring final content to storage vessel. Processing equipment suitable for preparing the gel, which may include semi- solid manufacturing vessels, mixing tanks, homogenizers, stirrers and the like. The gel of the present invention has a pH range from 3.0 to 5.0 and viscosity from 20000 cPs to 70000 cPs. One of the novel aspects of the process of the present invention is the selection of the API of required quality. It is a well-known fact that the API in the form of Fusidic acid currently available for use in preparation of Fusidic acid cream is unstable when exposed to oxygen or atmosphere during manufacture and storage. Pharmaceutical products made from Fusidic acid suffer from this drawback in that any exposure of Fusidic acid to oxygen environment during the transport and manufacturing process will lead to degradation of the API. There is a need to minimize the degradation of the API used for manufacture of creams containing Fusidic acid. The British Pharmacopeia recommends that both Fusidic acid and Sodium Fusidate are to be stored at a temperature between 2°C to 8°C. Although some degradation is expected of both substances when exposed to oxygen environment, it has been observed that Sodium Fusidate is much more stable than Fusidic acid under the same conditions, hence the current invention has utilized Sodium Fusidate as the starting material for the novel gel product. Table 3: Stability Evaluation of Fusidic acid Gel at ICH Condition long term ICH Condition: 25°C ± 2°C / 60%RH ± 5% RH Composition: Each g of Fusidic acid Gel contains 20 mg of Fusidic acid Parameters evaluated – pH (by pH meter), Average Viscosity (by Brookfield Viscometer) and Assay (by HPLC) Pack: Laminated Tube Description of the product: White creamy gel rdNo. TestSpteiocnifsicaInitialM36th9th12th18th24thth Mth Mth Mth Mth Mth 1. pH (as such)3.0 - 5.0 4.01 3.82 3.94 3.93 3.83 3.90 4.01Average 2. Viscosity 20000 - (cPs)7000036773 38468 35906 38031 38261 31173 30814Assay: 90.00 % 3. Fusidic 101.03 102.74 101.31 100.5 98.8 Acid 2 - 110.00 0 101.2 102.8 % % % 5% % 3% 0% % w / w % Stability data (Table 3) clearly implies that the product is stable for a period of 24 months under tested storage condition and hence the shelf-life shall be for two years when stored as prescribed. pH of the product is in the range of skin compatible region and hence shall not produce any irritation or discomfort. The data based on viscosity and assay indicates that the product is physically and chemically stable for the shelf-life period. Particle Size Evaluation of Fusidic Acid in the Gel Matrix Particle size analysis was carried out through Cryo-SEM equipment on the gel made using the process of the present invention. The results of the analysis clearly distinguish that the product of the current invention has particle size in nanometers (around 200 nm), for the active ingredient Fusidic acid in the gel matrix (refer Figure 1). The results of the particle size distribution analysis clearly indicate the presence of Fusidic acid of fine particle size in the product of the present invention, the size that is advantageously much reduced than the conventional products. This is attributed to the fact that the instant product is made using in situ conversion of Sodium Fusidate to Fusidic acid in a fine colloidal form. Clinical efficacy in Diabetic Wounds A multi-centric open label randomized Phase III clinical trial was conducted in India with the product of current invention for treatment of diabetic wound healing in comparison to standard treatment of care. The primary outcome of the study was to completely heal the wound with 100% epithelialisation or skin closure without drainage. The secondary outcome is to measure percentage of ulcer reduction from baseline to 24 weeks. Out of the 186 patients enrolled 144 subjects completed the study. Patients consented for the study with diabetic ulcers were screened and randomized (1:1) into one of the two groups as follows and the therapeutic agent was applied on the wound exudates twice daily for 24 weeks or till the wound completely healed whichever is earlier. No patients reported with skin irritation, pain, redness, bleeding, or any hypersensitivity reaction noticed among Fusidic acid Gel treated patients. It ensures that the gel is highly safe for external use in diabetic ulcer patients. Complete wound healing was observed with 100% granulation & epithelialization, wound closure without any edema, pain, redness, pus, and exudates in Fusidic acid gel treated patients within 3 to 9 visits. Fastest wound healing was observed with Fusidic acid gel treated patients, which could be attributed due to enhanced permeation and retention of the Fusidic acid. Also, rapid blood flow and granulation were observed in patients treated with Fusidic acid gel and their diabetic ulcers healed within 42 to 126 days from the start of treatment (Figure 2, 2A, 3 and 3A). Overall, Fusidic acid gel is superior in healing diabetic ulcers and its rate of cure is 94.67% compared with the standard of care with heal rate is 60.87% (Table 4). Table4: Diabetic ulcer wound healing rate comparison between Fusidic acid Gel and Standard Care The images shown in Figures 2 and 2A clearly show curing of diabetic ulcer wounds on subsequent visits on application of current invention production in comparison to standard wound care. The images indicate rapid rate of wound healing and wider area of wound closure by Fusidic acid gel is evident when compared with the wound healing rate and area evident from images of patient treated with standard wound care represented in Figures 3 and 3A. While the above description contains much specificity, these should not be construed as limitation in the scope of the invention, but rather as an exemplification of the preferred embodiments thereof. It must be realized that modifications and variations are possible based on the disclosure given above without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.

Claims

Claims:

1. A fusidic acid gel with chitosan and hydrolyised collagen for treatment of diabetic ulcers characterized in that said gel comprises an acid form active compound in the form of Sodium Fusidate, a biopolymer in the form of Chitosan, and a natural protein / peptide in the form of hydrolyzed Collagen in a gel base.

2. The gel as claimed in claim 1, wherein said Sodium Fusidate is added in an amount between 0.1% (w / w) and 5% (w / w) by weight, preferably between 1% (w / w) and 2% (w / w).

3. The gel as claimed in claims 1 to 2 wherein said Chitosan added in an amount between 0.5% (w / w) and 10% (w / w) by weight, preferably in an amount of 1.25% (w / w).

4. The gel as claimed in claim 3 wherein said Chitosan is selected from any grades such as long chain, medium chain, and short chain, and has a molecular weight in the range of 250,000 Da to 500,000 Da.

5. The gel as claimed in claims 1 to 4, wherein said hydrolyzed Collagen selected from the range of molecular weight could range from 3000 Da to 6000 Da, in certain aspects, said hydrolyzed Collagen is of molecular weight is 3000 Da and is added in an amount between 0.05% (w / w) and 1% (w / w) by weight, preferably in an amount of 0.2% (w / w).

6. The gel as claimed in claims 1 to 5, wherein said Collagen is of type I.

7. The gel as claimed in claims 1 to 6, wherein said gel base consists of natural polymers and gelling agents, emulsifiers, waxes, co-solvents, acids, solubilizers, buffering agents, preservatives, anti-oxidants, chelating agents, humectants and water.

8. The gel as claimed in claim 7, wherein said primary and secondary emulsifiers are selected from a group comprising Cetostearyl alcohol, Polyoxyl 20 cetostearyl ether, Polyoxyl 40 hydrogenated castor oil, Polyoxyl 35 hydrogenated castor oil, Sorbitan monosterate and Sorbitan monooleate and added in an amount between 0.5% (w / w) to 20% (w / w).

9. The gel as claimed in claim 7, wherein - said waxy material is selected from a group comprising white soft paraffin, liquid paraffin and hard paraffin and added in an amount between 3% (w / w) to 30% (w / w); - said co-solvents are selected from a group comprising Glycerol, Propylene Glycol, Hexylene Glycol, Polyethylene Glycol-400 and the like from about 5% (w / w) to 50% (w / w); - said acid is selected from a group comprising HCl, H2SO4, HNO3, Lactic acid, Citric acid and the like, and added in an amount between 0.005% (w / w) to 5.0% (w / w); - said preservatives are selected from a group comprising Chlorocresol, Potassium sorbate, Benzoic acid and the like, and added in an amount between 0.05% (w / w) to 0.5% (w / w); - said buffering agents are selected from a group comprising DiSodium Hydrogen Orthophosphate, Sodium Hydrogen Orthophosphate and the like, and added in an amount between 0.01% (w / w) to 1.00% (w / w); - said anti-oxidants are selected from a group comprising Butylated Hydroxyanisole, Butylated Hydroxytoluene and the like, and added in an amount between0.005% (w / w) to 5% (w / w); - said chelating agents are selected from a group comprising Disodium EDTA and the like, and added in an amount between 0.05% (w / w) to 1% (w / w); - said humectants are selected from a group comprising Glycerol, Sorbitol, and the like, and added in an amount between 5% (w / w) to 40% (w / w); - said solubilizers is Polyoxyl 40 hydrogenated castor oil, Polyoxyl 35 hydrogenated castor oil and added in amount between 0.1% (w / w) to 5.0% (w / w); and - purified water in an amount between 30 % w / w to 60 % w / w.

10. A process to make a gel claimed in claims 1 to 9 characterized in that said process comprises the following steps:a. heating 14.000% of Propylene Glycol in a stainless steel vessel to 67°C ± 2°C followed by adding 0.010% of Butylated Hydroxytoluene, 0.500% of Polyoxyl 20 Cetostearyl Ether and 1.000 % of Polyoxyl 40 Hydrogenated Castor Oil to the vessel and cooling contents to below 45°C and adding 2.085% of Sodium Fusidate to the vessel under oxygen free environment with pure nitrogen flushing & continuous stirring until sodium fusidate dissolves completely, and thereafter adding a 1M nitric acid into the vessel with slow stirring to form a solution containing the dissolved Sodium Fusidate converted in situ to Fusidic acid, wherein said 1M Nitric acid is prepared by mixing 0.392g concentrated nitric acid with 4.165g of purified water; b. adding purified water in a stainless steel vessel in an amount of 28.125% to which are added 0.100 % of Disodium Edetate, 0.200% hydrolyzed Collagen and 1.250 % of Lactic Acid with continuous stirring to form a clear solution, to which added 1.250% Chitosan under slow stirring condition until the Chitosan dissolves and forms a clear gel; c. heating 15.173 % of Purified water in Water Phase Vessel. Adding 0.050 % of Disodium Hydrogen Orthophosphate, Anhydrous to the heated contents at 45°C± 2°C with continuous stirring condition and adding 1.000% of Polyoxyl 40 Hydrogenated Castor Oil and 7.000% of Glycerol to the said water phase vessel and contents heated up to 72°C± 2°C; d. adding 7.500 % of Cetostearyl Alcohol, 7.500 % of White Soft Paraffin, 5.000 % of Light Liquid Paraffin,1.500 % of Polyoxyl 20 Cetostearyl Ether and 0.200 % of Benzoic Acid into Wax Phase Vessel. The contents are heated to 72°C± 2°Cwith continuous stirring; e. transferring contents of step c (Water phase vessel) and step d (Wax phase vessel) to the final mixing vessel at 72°C± 2°C and mixed to form an emulsion; f. cooling the contents of step e to 50°C± 2°C and transferring the contents of step a in to it under stirring condition;g. rinsing the vessel used in step a with 2.000 % propylene glycol and adding to final mixing vessel and continue stirring; h. cooling the contents of step f to 45°C± 2°C and transfer the content of step b under stirring; i. cooling the contents of final mixing vessel to 25°C to 30°C± 2°C using cooling water; j. transferring final content to storage vessel.

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