Studies On Metformin Hydrochloride Osmotic Pump Controlled Release Tablets

Metformin Hydrochloride (MH) is a drug of the biguanides class, which is one of the most useful blood-glucose-lowering drug in clinical. In this paper, based on investigation of the properties of the drug and accessories MH was as the model drug to prepare the elementary osmotic pump tablets. In this controlled tablet NaCl and PVPK90 were added to prepare the tablet core, acetate cellulose and PEG1500 were as coating material.In this paper, formulation of tablet core and coatings, arts of tablet and the conditions of drug release on the release behavior of controlled release MH tablets were investigated under the condition of constant coating parameters. Effects of different factors on drug release behavior were analyzed by ANOVA. Results showed that various PEG, amount of PEG, coating weight had some effects on the drug release behavior, while diameter of orifice, release medium, method of dissolution had no significant effects. Hardness of tablet core also had no obvious effect on the release behavior of controlled release MH tablets.In the paper, based on investigation of factors analysis orthogonal experiment designs were used to optimize the formulation. The results indicated that from 0 to 9 hours drug release profiles of the optimal formulation had the excellent zero-order release character in vitro (r =0.9989). In addition, the results of stability experiments indicated that this product was sensitive to humidity, but was stable on others conditions.The method of determination the drug concentration in plasma was...