INTRODUCTION: Historically, the oral route of administration has been used the most for both
conventional and novel drug delivery system. These systems have the obvious
advantages of ease of administration and patient acceptance, least sterility constraints
and flexibility in the design of dosage form. One would always like to have an ideal drug
delivery system that will possess two main properties:
1. It will be a single dose for the whole duration of treatment.
2. It will deliver the active drug directly at the site of action.
Unfortunately, such ideal systems are not available. Thus scientists try to
develop systems that can be as close to an ideal system as possible. More than 50% of
drugs, available in the market are meant for oral administration. The conventional drug
therapy results in fluctuation of drug concentration in systemic circulation, causing
either toxic effect or no therapeutic effect. AIM AND OBJECTIVE: Aim of present research is development of formulation, optimization and
evaluation of gastro retentive floating drug delivery system of olmesarten medxomil.
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.
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 t ime taken to 80 % drug release were selected as dependent variables.
Targets were defined for each response so as to select the optimam formula using
numerical optimization.
All the floating matrix tablets formulations were subjected to precompression
and post-compression parameter evaluation. CONCLUSION:In the present work floating tablets of Olmesartan Medoxomil were prepared by
direct compression. All the tablets were subjected to weight variation, hardness,
friability, dissolution, swelling index, drug excipient interaction studies. The tablets were
found to be good in their integrity without any chipping, capping and sticking.
Formulation F9 showed good result than rest of the formulations according to targets
obtained. IR-spectroscopic studies indicated that there are no drug–excipients
interactions. Formulation F9 showed best result with required floating lag time of 55
secs, total floating time of 14 hrs and T80 of18 hrs. drug release was decreased with
increased concentration of polymers. IR spectroscopic studies indicated that there was
no drug excipient interactions. Kinetic studies for optimized formulation F9 follows zero
order and Higuchi model release systems. Zero order release describes the system
where the drug release rate is independent of its concentration of dissolved substance