Abstract

Ricinoleic acid (RA) is a C18 fatty acid (FA) with a double bond at the C 9 position and a hydroxyl group at the C(12) position (cis-12-hydroxyoctadeca-9-enoic acid). Recently, RA has been reported as a pro/anti-inflammatory and analgesic agent for topical applications to be considered as an alternative to irritant substances that relive pain. However, RA when it is exposed to air, it reacts with the oxygen and decomposes into short-chain aldehydes and ketones. Moreover, pathologically, small amount of anaesthetic agent acts on peripheral nerves, producing reversible block in transmission of peripheral nerves impulses. However, larger amounts effect potentially in the central nervous system and may cause cardiac arrest. Accordingly, extended release formulations for local anaesthetic agent such as encapsulation, are highly demanded if the drug will be used for long period. In this work, ricinoleic acid, extracted and characterized, was encapsulated into a new matrix made of phospholipid liposomes and chitosan to protect and control RA release. RA release was controlled by crosslinking the matrices using glutaraldehyde. Spectral and morphology analysis are used to characterize the produced microshpers. The cytotoxicity test is considered to examine the final product biocompatibility. The encapsulation efficiency was investigated by UV- Visible spectroscopy.

Key words: Ricinoleic acid; anti-inflammatory; encapsulation; microspheres; drug delivery.