ABSTRACT
A stable Madhuca indica oil-in-water nanoemulsion (99-210 nm, zeta potential: > - 30 mV) was produced employing Tween 20 (surfactant) and Transcutol P (co-surfactant) (3:1). The nanoemulsion (oil: Smix = 3:7, 5:5, and 7:3) were subsequently incorporated into oxcarbazepine-loaded carboxymethylxanthan gum (DS = 1.23) dispersion. The hydrogel microspheres were formed using the ionic gelation process. Higher oil concentration had a considerable impact on particle size, drug entrapment efficiency, and buoyancy. The maximum 92 % drug entrapment efficiency was achieved with the microspheres having oil: Smix ratio 5:5. FESEM study revealed that the microspheres were spherical in shape and had an orange peel-like surface roughness. FTIR analysis revealed a hydrogen bonding interaction between drug and polymer. Thermal and x-ray examinations revealed the transformation of crystalline oxcarbazepine into an amorphous form. The microspheres had a buoyancy period of 7.5 h with corresponding release of around 83 % drug in 8 h in simulated stomach fluid, governed by supercase-II transport mechanism. In vivo neurobehavioral studies on PTZ-induced rats demonstrated that the microspheres outperformed drug suspension in terms of rotarod retention, number of crossings, and rearing activity in open field. Thus, Madhuca indica oil-in-water nanoemulsion-entrapped carboxymethyl xanthan gum microspheres appeared to be useful for monitoring oxcarbazepine release and managing epileptic seizures.
