Design and characterization of microemulsion system for fentanyl citrate

This research was aimed to formulate and characterize micro-emulsion systems as a sublingual delivery system of fentanyl citrate an opioid pain medicine used for treatment of breakthrough cancer pain that is not controlled by other medicines. The three phases i.e. oil, surfactant and co-surfactant were selected on the basis of their drug solubility and their efficiency to form ME. Pseudo-ternary phase diagrams were constructed and on the basis of ME existence ranges various formulations of FC were developed. The influence of S_mix ratio on the ME formation and in vitro permeation of ME through cellophane membrane was studied respectively. The optimized ME formulation C2 consists of a globule size of 96.9 nm, polydispersity index of 0.263, pH 4.18, viscosity 20.4 cps, a zeta potential of -8.5and conductance of 131.7±0.42μS. The optimized ME formulation C2 exhibited a steady state flux of about 361.92±0.57 and thus exhibiting higher drug permeation through ME for mulations. Apart from this, the formulation was also evaluated for drug content, centrifugation and stability study. The results indicate that, the investigated MEmay be used as a promising alternative for FC therapy for breakthrough pain management.