Development of an enhanced formulation for delivering sustained release of buprenorphine hydrochloride.

To control the minimum effective dose, and reduce the number and quantity of administered potent drugs are unique features of advanced drug delivery in situ forming gel formulation. The efficacy, consistency, and increasing the application of existing injection therapies can be enhanced through optimization of controlled released systems by using FDA approved biodegradable PLGA (poly-d,l-lactide-co-glycolide) polymer. The purpose of this study was to develop different in situ forming implant (ISFI) formulations of buprenorphine hydrochloride for post treatment of drug addicts, acute and chronic pains. The drug releases from different ISFIs membranes with and without Tween 80 were compared over a period of time. Kinetic equation followed the Korsmeyer-Peppas model, as the plots showed high linearity. The influence of this additive on polymer properties was investigated using differential scanning calorimetry (DSC), and the membranes structure was studied by X-ray diffractometry (XRD) and scanning electron microscope (SEM). Data revealed that Tween 80 modified the drug release pattern using diffusion mechanism and decreased the glass transition temperature (T g) significantly. The degree of crystallinity was decreased after phase inversion which helps the dissolution of drug from membrane. The porosity of modified membranes was in accordance with release profiles. These findings suggest four different in situ forming implant formulations which can release various dose of the buprenorphine hydrochloride in a prolonged time. Also this surfactant can be an attractive additive for modifying the release rate of drugs from PLGA-based membrane drug delivery systems.