Formulation of Self-Nanoemulsifying Drug Delivery System for Telmisartan with Improved Dissolution and Oral Bioavailability

To improve the dissolution and oral absorption of poorly water soluble drug-telmisartan, a self-nanoemulsifying system (SNES) was developed, characterized, and its relative bioavailability was compared to commercially available formulation. Safsol-218, Tween-20, and Transcutol P were chosen as oil, surfactants, and cosurfactants respectively as they show highest solubility for telmisartan. The solubility of drug was further improved by adding sodium hydroxide (0.67%). The droplet size of the optimized emulsion was also evaluated and was observed to be in nano range. The dissolution of drug was rapid in simulated gastric fluid (pH 1.2) as well as in simulated intestinal fluid (pH 6.8) and was found to be pH independent. The pharmacokinetic parameters (AUC(0 -> t) +/- SD, C-max, and T-max) of optimized formulation of telmisartan after oral administration as SNES were compared with oral tablet and API suspension of drug. The results showed a 4.34-fold increase in oral bioavailability of drug in comparison to tablet. The results demonstrate that SNES composed of Sefsol-218, Tween-20, and Transcutol P substantially enhanced the bioavailability of telmisartan. Further, it showed highly significant fall (p < 0.001) in mean blood pressure of hypertensive rats for 48 hours. Thus, our study provides a useful oral dosage form for telmisartan.