Design and evaluation of some Gastroretentive drug delivery systems

Abstract

Gastroretentive drug delivery systems are the dosage forms which are retained in the stomach for an extended period of time compared to the normal oral dosage forms which stay for nearly 2 hours in the stomach. GRDDS insist both spatial and time controlled drug release at a controlled rate. The objective of the present research work was to design and evaluate gastroretentive single unit, multiple unit floating effervescent and mucoadhesive drug delivery systems for Atenolol and Dipyridamole. An attempt was also made to develop single and multiple unit floating effervescent drug delivery systems for Pyridoxine HCl and Thiamine mononitrate. These drug candidates were selected either due to their maximum absorption from upper part of gastrointestinal tract such as for Atenolol, Pyridoxine HCl and Thiamine mononitrate or maximum solubility in the lower pH environment for Dipyridamole. The single unit floating effervescent tablets were prepared by direct compression method. Multiple and mucoadhesive tablets were prepared by wet granulation method. To control the drug release from the matrix system, polymers such as HPMC K4M, HPMC K15M, HPMC K100M, ethyl cellulose, chitosan and isabgul husk were utilised in various drug: polymer ratios. Sodium bicarbonate was used as effervescent agent to aid in buoyancy for floating systems. Chitosan, isabgul husk and HPMC K4M were used as mucoadhesive polymers. newline