In-situ gel of nifedipine for preeclampsia: Optimization, in-vitro and in-vivo evaluation

Present study was conducted to develop and optimize in-situ gel for sustained delivery of Nifedipine by ion sensitive mechanism and its in-vitro and in-vivo evaluation. Factorial design was employed to evaluate the effect of gellan gum and HPMC K4M on drug release and viscosity. Optimized formulation showed 55.12% drug release at 6 h with viscosity of 195.66cps and followed diffusion controlled release mechanism. In-vivo gastroretentive ability was monitored by gamma camera which confirmed that gel remain in human stomach for more than 8 h. Preeclampsia was induced by intra-peritoneal injection of L-NAME for 7 days in pregnant mice which showed that L-NAME mimics the classical signs of preeclampsia and in-situ gel reduced proteinuria from > 1000 mg/dL to 300 mg/dL and improved the foetal litter number from 6.2 +/- 2.3 for preeclampsia induced group to 9.1 +/- 1.2 for treated group. Pharmacokinetic studies showed Cmax, Tmax, MRT and AUC values of optimized formulation to be 512.33 +/- 77.81 ng/ml, 6.00 +/- 0.29h, 8.55 +/- 1.36h and 4358.24 +/- 157.90 ng h/ml respectively with relative bioavailability of 1.24. Thus, it can be concluded that floating in-situ gel can be an alternative approach for routine hypertension management in preeclampsia patients.