Formulation, development and optimization of gastroretentive floating drug delivery system of Olmesartan Medxomil

Abstract

Objective: The objective of the present study was to develop an optimized gastroretentive floating drug delivery system of Olmesartan Medoxomil and investigate the effect of hydrophilic retardant on invitro release by using 32 full factorial design. Methods: Floating tablets of olmesartan medoxomil were prepared by direct compression method using effervescent technique by employing two different grades of HPMC. (HPMC K4M and HPMC K100M). Sodium bicarbonate was incorporated as gas generating agent. The concentration of HPMC K4M (X1) and concentration of HPMC K100M (X2) were selected as independent variables. The floating lag time, total floating time and time taken to 80% drug release were selected as dependent variables. Targets were defined for each response so as to select the optimim formula using numerical optimization. All the floating matrix tablets formulations were subjected to pre-compression and post-compression parameter evaluation. Result: The results indicated that the concentration of X1 and X2 significantly affected the floating lag time, total floating time and T80. Drug release properties were affected by concentration of HPMC K4M and HPMC K100M. Optimized formulation F9 with increased equal concentrations of X1 and X2 and sodium bicarbonate showed good physical propreties with short lag time of 55sec and T80 of 18 hrs. Conclusion: The drug release from the tablet was sustained and non fickian transport of drug from the tablet was confirmed. The optimized formulation was stable when kept for short term stability study for one month.