Formulation and Evaluation of Metformin Tablets

Metformin hydrochloride is an oral hypoglycemic drug that enhances glucose tolerance in type 2 diabetes patients & lowers basal plasma glucose levels. The purpose of the study was to formulate and optimize MET matrix tablets for SR use. The SR matrix tablet of MET was prepared by wet granulation technique using Polyvinyl pyrrolidone K30 and hydroxyl propyl methylcellulose of different viscosity grades. The influence of varying the polymer ratios was evaluated. The excipients used in this study did not modify physicochemical properties of the drug. MET has relatively short plasma half-life, low absolute bioavailability.
The need for the administration 2 to 3 times a day when larger doses are required can reduce patient satisfaction.SR formulation which would sustain plasma level for 8-12 h may be adequate for once daily dosing of MET.SR formulations are required for MET to extend its action duration and to enhance patient compliances. The formulation of oral sustained release systems has been a challenge to formulation scientists because of the failure of such systems to restrain and localize the system in the desired sites of the gastrointestinal tract. Out of all the formulation trial batches, F3 formulation reveals optimum results. It has been noted that HPMC K100M is incapable of providing good drug release profile but the combination of HPMC K100M and Polyvinyl pyrrolidone K30 in combination provide the best drug release kinetics. So, controlled release matrix tablets of metformin hydrochloride can be anticipated to minimize the administration frequency and reduce dose dependent side effects.