DESIGN, CHARACTERIZATION AND PHARMACOKINETIC STUDIES OF SOLID LIPID NANOPARTICLES OF ANTIHYPERTENSIVE DRUG TELMISARTANAbstract
In the present study, we explored the potential of Telmisartan loaded solid lipid nanoparticle (SLN), as a new formulation in improving the oral bioavailability of antihypertensive drug Telmisartan which otherwise reported with poor bioavailability. The “modified emulsification-ultrasonication method” was adopted for preparation of SLN, and Design of Experiments (DOE) was applied to optimize the lipid and surfactant composition. The formulations were lyophilized to get free flowing powder. The mean particle size of SLN measured to be 391.7nm with PDI value of 0.324, and zeta potential value of 21.5±0.4 mV was observed. The entrapment efficiency was estimated to be 97.58 % for the optimized formulation. Single dose (10 mg/kg) oral pharmacokinetic studies were performed in Albino Wistar rats to determine the drug delivery potential of SLN. The pharmacokinetic results indicated that the oral bioavailability of Telmisartan was significantly improved after its incorporation into SLN as total AUC obtained with SLN was 28 folds higher than that of AUC of drug suspension. The in vitro release from SLN demonstrated a sustained release with 85.13 % drug released compared to 15.34 % drug released from drug suspension in a period of 24 hours. In addition, DSC, PXRD and FTIR results also confirmed the molecular encapsulation of drug in the lipid matrix. During stability studies, the formulations were found more stable at temperature 5±3°C. These finding explore the potential of proposed SLN formulation as an alternative drug delivery system in improving oral bioavailability Telmisartan.