CLAIMS
1. An effervescent composition comprising Metformin, an acid, a base and optionally, one or more anti-diabetic agents or one or more pharmaceutically acceptable excipients, wherein the composition has a retained carbon dioxide content of at least 90% of the input blend.
2. The effervescent composition according to claim 1, wherein the composition is free of affirmatively added binders and granulating solvents.
3. The effervescent composition according to claim 1, wherein the process for preparation of the composition involves the use of a twin screw processor.
4. The effervescent composition according to claim 1 wherein the acid is selected from
citric acid, tartaric acid, fumaric acid, malic acid, adipic acid, succinic acid, lactic acid,
glycolic acid, alpha hydroxy acid, ascorbic acid, amino acid or mixtures thereof.
5. The effervescent composition according to claim 1 wherein the base is selected from carbonate, sesquicarbonate or bicarbonate salts of potassium, lithium, sodium, calcium, or ammonium; L-lysine carbonate; arginine carbonate; sodium glycine carbonate; or sodium amino acid carbonate or mixtures thereof.
6. The effervescent composition according to claim 1 wherein the pharmaceutically acceptable excipient is selected from fillers, disintegrants, surfactants, taste modifiers, soluble or insoluble lubricants, flavoring substances, coloring agents, sweeteners or mixtures thereof.
7. The effervescent composition according to claim 1, wherein the acid and base are present in a weight ratio ranging from 3:1 to 1:5.
8. The effervescent composition according to claim 1 or 2, wherein the acid and base are anhydrous.

9. The effervescent composition according to claim 1 or 2, wherein the anti-diabetic agent
is selected from Rosiglitazone Maleate, Glyburide, Pioglitazone Hydrochloride,
Glipizide, Glimepiride, Repaglinide, Sitagliptin Phosphate, Canagliflozin, Linagliptin,
Alogliptin Benzoate, Empagliflozin, Saxagliptin Hydrochloride, Vildagliptin,
Teneligliptin, Pioglitazone Hydrochloride and Dapagliflozin Propanediol or their
derivatives or alternative salts thereof.
10. The effervescent composition according to claim 2, wherein the composition has a
disintegration time of less than 3 minutes.
i
11. The effervescent composition according to claim 2, wherein the composition has a disintegration time of less than 2 minutes.
12. A process for preparation of an effervescent Metformin composition comprising the steps of:

a) Processing an acid and a base through a twin screw processor; or
b) Processing an acid, a base and Metformin or atleast one pharmaceutically acceptable salt thereof, optionally with at least one other anti-diabetic agent through a twin screw processor;
i c) Mixing the product of step a) with Metformin or atleast one pharmaceutically acceptable salt thereof, and optionally at least one other anti-diabetic agent, and optionally at least one excipient followed, by compressing into tablets or filling into capsules or sachets; or
d) Compressing the product of step b) into tablets or filling it into capsules or sachets; after optionally mixing with at least one other anti-diabetic agent or at least one excipient; wherein only a portion of acid is melted in Step (a) or Step (b) to serve as an in-situ granulating agent and the said process being free of affirmatively added binders and granulating solvents.
i 13. The process according to claim 12, wherein the acid is selected from citric acid, tartaric acid, fumaric acid, malic acid, adipic acid, succinic acid, lactic acid, glycolic acid, alpha hydroxy acid, ascorbic acid, amino acid or mixtures thereof; and the base is selected

from carbonate, sesquicarbonate or bicarbonate salts of potassium, lithium, sodium, calcium, or ammonium; L-lysine carbonate; arginine carbonate; sodium glycine carbonate; or sodium amino acid carbonate or mixtures thereof; and wherein the effervescent Metformin composition has a retained carbon dioxide content of at least 90% of the input blend.
14. A method for treatment of Type-2 diabetes in a patient, comprising administering orally to the patient, the effervescent composition according to any one of the claims 1 toll.
15. The effervescent composition according to any one of the claims 1 to 11,for use in the treatment of Type-2 diabetes.