Impact of various nonionic surfactants on self-nanoemulsification efficiency of two grades of Capryol (Capryol-90 and Capryol-PGMC)

The aim of present study was to investigate the impact of various combinations of nonionic surfactants on self-nanoemulsification efficiency of two grades of Capryol (Capryol-90 and Capryol-PGMC) in glibenclamide nanoemulsion. Labrasol, Gelucire-44/14, HCO-60, Tween-80 and Cremophor-EL were selected as surfactants and Transcutol-HP, isopropyl alcohol and ethanol were selected as cosurfactants. Various formulations (C1-C30) were prepared by spontaneous emulsification method and subjected to thermodynamic stability and self-nanoemulsification efficiency test. All these formulations were further characterized for droplet size distribution, viscosity, refractive index and % transmittance. Formulations prepared with Labrasol and Gelucire-44/14 were found to be suitable for self-emulsifying drug delivery system only whereas those prepared using Tween-80, HCO-60 and Cremophor-EL were found to be suitable for self-emulsifying or self-nanoemulsifying or self-microemulsifying drug delivery system of glibenclamide with respect to Capryol-90 or Capryol-PGMC. Based on visual assessment, thermodynamic stability, lowest droplet size (27.4 nm), optimal values of polydispersity index (0.153) & refractive index (1.333), lowest viscosity (12.7 cP) and highest % transmittance (99.6), formulation C30 (Capryol-PGMC/Cremophor-EL/ethanol/water) was optimized as best combination for self-nanoemulsifying drug delivery system of glibenclamide. These results indicated that Cremophor-EL could be the best surfactant in terms of self-nanoemulsification.