Preparation, Optimization and Physicochemical Characterization of Aripiprazole Loaded Nano-porous in situ Forming Implant

Background Multiple applications of antipsychotic agents are the main obstacle in the treatment of schizophrenia. Due to behavioral abnormalities, low compliance is observed in most of the psychotic patients. Designing of new drug delivery systems to overcome compliance problem seems to be necessary. In situ forming implants are a suitable choice for the delivery of antipsychotic agents due to their easy administration process and sustained release kinetics. Objective In this study, a novel poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) based nanoporous in situ implant system is developed for delivery of aripiprazole. Methods Entrapment efficiency, drug loading, rheological features, morphological characteristics and release profile of nano-porous in situ implant system are analyzed in this study. Results Entrapment efficiency and drug loading coefficient were modeled and impact of different experimental parameters was analyzed using D-optimal study. Entrapment efficiency and drug loading were optimized at 99.32% and 75.23%, respectively. Rheological analyses demonstrated that the developed formulation is a highly cross-linked gel with possible capability for controlled delivery of aripiprazole. According to the FTIR studies, aripiprazole was intact within polymer networks. SEM and light microscopic analyses proved the acceptable morphological characteristics of in situ gels. Release studies demonstrated a biphasic pattern of release. After initial burst release, a sustained pattern was observed for 18 days. The release data was fitted to Korsmeyer-Peppas model and release pattern was found out to be Fickian. In addition, the release profile was compared with novel pluroniccarrageenan based hydrogel system. Conclusion PHBV based in situ forming implant seems to be a novel formulation for delivery of Aripiprazole.