Influence of ion-pairing and chemical enhancers on the transdermal delivery of meloxicam

Abstract

Purpose: To investigate the influence of ion pairing and chemical enhancers on the transdermal delivery of meloxicam.

Method: We examined the increased permeation of meloxicam produced by ion pair formation with six organic bases, diethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, and N-(2'-hydroxyethanol)-piperidine, and four normal permeation enhancers, oleic acid, menthol, azone, and N-methyl-2-pyrrolidone. The cumulative permeation was markedly increased in the presence of either a counter ion or chemical enhancers. In particular, we proved the formation of a meloxicam/amine ion-pair in solution by (13)C-NMR (nuclear magnetic resonance).

Results and conclusion: The cumulative permeation was markedly increased in the presence of either a counter ion or chemical enhancers. These results suggest that the degree of enhancement possibly depends on the structure and hydrophilicity of the counter ions.