Author(s): Hammad Yousaf, Muhammad Jamshaid, Irfan Bashir, and Yasir Mehmood
Increased complications and costs of marketing of innovative drugs focused greater attention to the development of sustained release (SR) or controlled release (CR) drug delivery systems. Delivery systems extended release or controlled release rate can achieve predictable and reproducible, the extended duration of activity for the short time of life - drugs, reduced toxicity, and dose reduction request, the optimized therapy and better patient compliance. It is controlled primarily by the type and the proportion of the polymers used in the preparation. The overall objective of this work was to develop a tablet glipizide oral sustained release (SR) prepared by the method of direct compression, using hydroxy propyl methyl cellulose (HPMC) and guar gum polymer alone and in combination at various concentrations. Glipizide hydrochloride (HCl), a biguanide, has a relatively short plasma half-life and low absolute bioavailability. All lots were evaluated for the thickness, weight variation, hardness and drug content uniformity and drug release in vitro. Dissolution time average is used to indicate the speed of release of the drug from a dosage form, and indicates the drug release retardant efficiency of the polymer. The hydrophilic matrix of HPMC alone cannot control the release Glipizide effective for 12 h while when combined with guar gum, may slow down the release of the drug and, therefore, can be successfully employed for the formulation of matrix tablets SR.