International Journal of Applied Pharmaceutics
Vol 1 Issue 1, 2009
EFFECT OF DIFFERENT VISCOCITY GRADE HPMC POLYMERS ON GASTRORETANTIVE DRUG DELIVERY OF METFORMIN HCL
R.V.KSHIRSAGAR1*, VIKAS JAIN2, S.WATTAMWAR1
1School of Pharmacy, Swami Ramanand Teerth Marathwada University,
Nanded, (M.S.) 431 606 India.
2Department of Pharmaceutical Sciences,Dr. H. S. Gour University, Sagar (M.P.) 470003 India.
The objective of the present study was to develop a hydro dynamically balanced system of metformin as a single unit floating tablet. Various grades of low-density polymers were used for the formulation of this system. They were prepared by physical blending of metformin and the polymers in varying ratios. The formulation was optimized on the basis of in vitro buoyancy and in vitro release in simulated gastric fluid pH 1.2. Effect of Carbopol as a release modifier was studied to ensure the delivery of drug from the floating tables over a prolonged time period. Tablets prepared with HPMC K15M and Carbopol gave the best in vitro percentage release and were taken as the optimized formulation. By fitting the data into zero order, first order, Korsmeyer and peppas, and Higuchi model it was concluded that the release followed Korsmeyer and peppas release, as the correlation coefficient (R2 value) was higher for Korsmeyer and Peppas release.
All the six formulations produced robust tablets with optimum hardness, consistent weight uniformity and low tablet friability. In vitro drug release tests of these tablets indicated controlled sustained release of Metformin HCl and 96-99% released at the end of 8hr in formulation containing high viscosity polymers.
Keywordds: Metformin hydrochloride, gastroretentive, floating drug delivery, sustained release. HPMC, in vitro Buoyancy
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