Slow release polymer-drug systems obtained by moisture promoted polyreactions. 1. Codeine resinate encapsulated in poly(alkyl α-cyanoacrylates)

Abstract

Samples of codeine resinate consisting of a carboxylic cation exchanger (as a polymeric carrier) and codeine (as a drug) were coated with poly(alkyl α-cyanoacrylates) by suspending and stirring wet resinate beads in a toluene solution of the monomer. Methyl, ethyl and n-butyl α-cyanoacrylates were used as monomers. Each coated material released codeine more slowly than the non-coated. The data obtained confirmed that water promoted the polymerization of alkyl α-cyanoacrylates, which proceeded at the surface of the wet resinate beads. The rate of codeine release depended on the type of monomer used for coating, the monomer/resinate feed ratio and the plymerization time.

Key Words:

• Codeine resinate
• microencapsulation
• poly(alkyl α-cyanoacrylates)
• slow release
• kinetics