PHYSICOCHEMICAL CHARACTERISATION OF POLYMER CONJUGATES OF EFAVIRENZ-CHITOSAN, TENOFOVIR-CHITOSAN AND DOLUTEGRAVIR-ALGINATE

Background and purpose: Chitosan nanofibrils are promising scaffold materials for biomedical applications while alginate is mixed with other polymers to improve the biological properties as they are good for molding with a suitable biological nature. The aim of the study is to characterise the physicochemical properties of the three anti-retroviral drug-polymer conjugates of chitosan and alginate. Method: Conjugates of Efavirenz, Tenofovir and Dolutegravir were analysed by determining the stability profile using Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Buffer hydrolysis. Result: The DSC Profile of Efavirenz-chitosan showed an endothermic peak at 138°c indicating conjugation and retention of the integrity of the polymer while that of Tenofovir-chitosan and Dolutegravir-Alginate showed endothermic peaks at 180°c and 258.12°c respectively. Buffer hydrolysis studies gave a drug release rate at half-lives of 4.1 hr, 5.1 hr and 7.5 h respectively and XRD results indicated the Stability of the polymer when conjugated with the drug with broad and sharp peak at 2θ = 22.5°, 20° &24° and 19.5°&23.5° for Efavirenz-chitosan, Tenofovir-chitosan and Dolutegravir-Alginate respectively. Conclusion: The three antiretroviral drugs were successfully conjugated to the polymers and the stability profile showed that the polymers were intact after conjugation.