Formulation and Characterization of Cardioprotective Nanosuspensions from Indigenous Medicinal Plants

Abstract

Present research work was planned for the formulation of cardioprotective nanosuspensions of four indigenous medicinal plants with improved bioavailability and better therapeutic efficacy. Ongoing research was divided into four different phases. First phase of the study was comprised of formulation and optimization of formulative parameters for the preparation of stable nanosuspensions by using CCD design of RSM. Characterization (ZP, SEM, AFM and FTIR) and stability studies of optimized nanosuspensions was the second phase of the study. In third phase of study, in-vitro dissolution testing and in-vivo pharmacokinetic profile of selected nanoformulations was determined. In fourth phase, different in-vitro and in-vivo bioactivities and toxicity studies of optimized nanosuspensions were evaluated with reference to the respective coarse plant suspensions. Results of stabilizer screening demonstrated that SLS was the best stabilizer for the formulation of A. cepa and C. oxyacantha nanosuspensions. HPMC was the selected stabilizer for P. nigrum and P-80 was chosen for the formulation of T. arjuna nanosuspensions. Among the optimized nanosuspensions, minimum particle size with appropriate PDI value was possessed by T. arjuna (79.1nm, 0.244) followed by C. oxyacantha (121.3nm, 0.241), P. nigrum (172.9nm, 0.328) and A. cepa (275.5nm, 0.415) nanosuspension. Results of zeta potential studies confirmed the stability of the optimized nanosuspensions. Results of AFM and SEM illustrated that nanosuspensions were in nanometer range with varied particle size and morphology. FT-IR studies indicated slight interaction between herbal extracts and stabilizers. Moreover, optimized nanosuspensions of all the four medicinal plants showed better stability at refrigerated conditions. Dissolution and pharmacokinetic studies demonstrated improved results for nanosuspensions as compared to coarse suspensions of the respective plant extracts. In-vitro (antioxidant, antimicrobial, hemolytic, thrombolytic) and in-vivo (cardioprotective) bioactivities also revealed better therapeutic efficacy of nanosuspensions over coarse suspensions. Results of toxicity studies confirmed the non-toxic nature of formulated nanosuspensions. From the present results it was concluded that nanosuspensions of the selected herbal extracts can be used as a better alternative to treat cardiovascular diseases with improved therapeutic efficacy as compared to their conventional coarse suspensions.