Research Information System
Ankara Universitesi Eczacilik Fakultesi Dergisi, vol.37, no.1, pp.1-10, 2008 (Scopus)
The objective of this study was to evaluate effect of gamma irradiation sterilization on release of granisetron hydrochloride from injectable in situ implants prepared for suppressing emesis induced by radiotherapy for 21 days. Investigated formulations contain 32% (w/w) poly (DL-lactide-co-glycolide) 50:50 (PLGA) having varied molecular weight (Mw) (12, 18, 34 kDa), 64% (w/w) benzyl benzoate and 4% (w/w) drug. Formulations were injected by 20G needle independent of polymer type at this ratio, however injectability hardened by increasing Mw of polymer. Following injection of formulations into 10 ml phosphate buffered saline pH 7.4, in vitro dissolution test was carried out in a shaker bath (37°C, 30 rpm) for 21 days and samples were analyzed by UV spectrophotometer. Drug release profiles were obtained for non-sterile and sterile form of three different formulations. Obtained profiles showed that initial drug burst decreased by increase in Mw of polymer and high Mw PLGA (-COOH end uncapped) provided more uniform release profile. Drug release accelerated and injectability facilitated for all formulations after sterilization by γ-irradiation. Sterilization showed a significant effect on in vitro drug release according to dissolution comparison test values of three coupled formulations which were all except the limits of f1=0-15 and f2=50-100. Consequently injectable phase sensitive polymeric systems were found as sensitive to gamma irradiation sterilization.