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