title: Design and development of nevirapine loaded surfactant free chitosan microemulsion.
abstract: Emulsification of liquid paraffin oil in aqueous solutions of chitosan without adding any additional surfactant is studied. The main objective of this study was to evaluate the dispersion of castor oil in aqueous phase in the presence of chitosan, and how this polymer promotes the stability of the obtained emulsions. Nevertheless, chitosan promotes emulsion production by increasing the matrix viscosity and provides stabilization of the oil-water interface by forming a dense hydrophilic polyelectrolytic brush on the water side of interface, which presents a significant barrier for coalescence--both steric and electrostatic. Chitosan stabilizes the emulsion mainly by the steric effect. These steric effects generate Van der Waals repulsion forces when two particles are too close. After loading with antiviral drug nevirapine, these emulsions were characterized in terms of phase contrast microscopy, hot stage microscopy, fluorescence microscopy, particle size, zeta potential, viscosity, entrapment efficiency and release studies using dialysis bag method. The prepared emulsions were stable in terms of mean globule size, change in drug content and retain they cationicity. The formulated emulsions are a promising carrier for nevirapine and other lipophilic drugs.
authors: Adarsh Vijendra Institute of Pharmaceutical Sciences, Gangoh, Saharanpur (U.P.) 247341, India. himanibajaj@gmail.com
authors: Himani
authors: H
authors: Bajaj
authors: Seema
authors: S
authors: Bisht
authors: Mayank
authors: M
authors: Yadav
authors: Vinod
authors: V
authors: Singh
authors: Mamta
authors: M
authors: Singh
mesh_terms: D002368:Castor Oil / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000737:chemistry*; D004337:Drug Carriers; D004339:Drug Compounding; D004355:Drug Stability; D004655:Emulsions; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D019829:Nevirapine / Q000737:chemistry*; D010316:Particle Size; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry*; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods; D014783:Viscosity
chemical_list: D004337:Drug Carriers; D004655:Emulsions; D018894:Reverse Transcriptase Inhibitors; D013501:Surface-Active Agents; D002368:Castor Oil; D048271:Chitosan; D019829:Nevirapine