Synthesis of Thiolated Cashew Gum and Its Evaluation as an Improved Mucoadhesive Agent in Drug Delivery

Abstract

The objectives of present research work were to extract cashew exudate gum (CG), perform thiolation of extracted CG, and evaluate the synthesized thiolated cashew exudate gum (TCG) as a mucoadhesive agent in designing metronidazole mucoadhesive gels and metronidazole mucoadhesive buccal discs. The CG was thiolated or thiol-modifi ed via esterifi cation utilizing thioglycolic acid and hydrochloric acid. Metronidazole mucoadhesive gels and metronidazole mucoadhesive buccal discs made of unmodifi ed CG and TCG (as mucoadhesive agent) were formulated and evaluated to reveal their bio-mucoadhesive potentials in drug delivery. The yield of thiolated product (TCG) was 56.24%, and the thiol-group content in TCG was found to be 9.06 mM of thiol group/g of CG. FTIR analysis indicated the thiolation of CG in the synthesized TCG. Both types of formulations (mucoadhesive gels and buccal discs) made of TCG exhibited excellent improved ex-vivo bio-mucoadhesion and consistent pattern of metronidazole releasing over a prolonged time. The synthesized TCG can be utilized as an improved mucoadhesive material in designing bio-mucoadhesive systems for drug delivery.