In Vitro Evaluation of Polysorbate -20- Based Niosomal Formulations of Salicylic Acid

Abstract

Niosomes are multiparticulate non-ionic surfactant vesicular systems that consist of lipid (often cholesterol) and a non-ionic surfactant. The objective of the study was to attempt a preliminary formulation of salicylic acid into niosomes for the possible potential improvement of its dermal permeation into warty and corny skin surfaces for expected easy and fast desquamation (for warts and corns) and enhanced penetration in fungal infections. The niosomes were formulated with polysorbate-20 and cholesterol using the Lipid Film Hydration Technique. Veegum and cetylpyridinum were incorporated in subsequent batches to investigate the effect of ionic components on the stability of the niosomes. Drug release profiles in Krebs-Ringer solution and distilled water respectively were studied to also evaluate niosome stability and release characteristics. Results showed that batch A₂ with a concentration ratio of 15 mM: 15 mM of polysorbate-20 and cholesterol, gave the highest encapsulation efficiency (EE), while batch A₄ with a ratio of 5 mM: 5 mM recorded the least EE. The presence of the charged components had a varied effect on the stabilities, release profiles and EEs of the niosomes depending on the molar concentration and the osmotic concentration of the drug release medium. We therefore conclude that the niosomes-stabilized salicylic acid is a potential alternative formulation approach for anticipated improvement on the permeation of salicylic acid into corns, warts and some other inflammatory conditions of the skin.

Keywords: nonionic surfactant, stability, encapsulation efficiency, Veegum, cetylpyridinum, vesicle, salicylic acid, warts

Nigerian Journal of Pharmaceutical Research, Vol. 8 No 1 pp. 218 - 228 (September 2010)