Formulation and Characterization of Tapentadol Loaded Emulgel for Topical Application

Background: Tapentadol is a centrally acting analgesic drug which falls under class III drug as per biopharmaceutical classification systems having poor bioavailability. Aim: Therefore, present study was aimed at solubility and permeability enhancement of Tapentadol using emulsomes loaded emulgel drug delivery system. Methods: Emulgel was prepared using data light liquid paraffin, Tween 20 and PEG 400 as Surfactant and Co-surfactant respectively. For preparation of stable Emulgel, micro emulsion region was identified by constructing pseudo ternary phase diagram containing different proportion of surfactant: co-surfactant (1:1, 2:1 and 3:1), oil and water. Ex vivo drug release study was done and compared to in vitro drug release of optimized formulation X2Q1. Physico-Chemical Evaluation: Total nine Emulgel formulations were prepared and evaluated for self-emulsification time, dispersibility, droplet size analysis, stability studies, turbidimetry, zeta potential, drug content and in vitro and ex vivo drug release. Results: Among all the formulations, optimized formulation X2Q1 with 1.5% carbopol 981 and optimized Q1 emulsion formulation showed in vitro drug release of 90.03 % at the end of 8 hrs. Based on results of self-emulsification time & dispersibility, droplet size analysis, drug content and in vitro drug release the X2Q1 formulation was selected as an optimized formulation which showed a maximum drug release in vitro and ex vivo and extended drug release up to eight hrs. The optimized formulation found to be stable, non-irritant and safe for topical drug delivery. Conclusion: Hence emulgel formulations can be a potential alternative to traditional oral drug delivery systems of Tapentadol to improve its bioavailability.