The aim of the study was to design controlled porosity osmotic pump (CPOP) tablets of Zolpidem tartrate. The porous osmotic pump contains pore forming agent (PEG-400) in the coating membrane which after coming in contact with water, dissolve, resulting in an in situ formation of microporous structure. Zolpidem tartrate is a nonbenzodiazepine analogue of imidazopyridine of sedative and hypnotic category. The dosage regimen of Zolpidem tartrate is 12.5 mg tablet once in a day. The plasma half-life ranges from 2 to 4 hours. Hence, Zolpidem tartrate was chosen to develop a controlled release system for 4 hours. The effect of different formulation variables, namely, ratio of drug to osmogent, membrane weight gain and level of pore former on the in-vitro release was studied using by different ratio of drug to osmogent and different concentration of pore forming agent. Cellulose acetate (4%) was used as the semipermeable membrane. Drug excipients compatibility was studied by FTIR and it indicated that there was no interaction between drug and excipients. Microporous structure of coating membrane of optimized formulation F4C3 was determined by Scanning Electron Microscope (SEM). Drug release was inversely proportional to membrane weight gain however, directly related to the level of pore former in the membrane. Optimized formulation (F4C3) was found to deliver 50% of total dose within 30 minute and above 90% of drug (Zolpidem tartrate) at the end of 4 hours. Optimized formulation F4C3 showed that tablets were stable at accelerated environment condition, for one month.
Loading....