Preparation and in vitro, in vivo characterization of elastic liposomes encapsulating cyclodextrin-colchicine complexes for topical delivery of colchicine.

In the present study, an attempt was made to develop a cyclodextrin-colchicine complex and to study its effect on skin permeation and deposition of colchicine. Colchicine beta cyclodextrin (BCD) complex was prepared by freeze-drying method and complex formation was confirmed by NMR and in vitro drug release study. Formulation containing cyclodextrin-drug complex showed 6-fold increase in transdermal flux in comparison with drug solution. Skin retention studies were carried out with the objective of determining the depot effect of elastic liposomes in skin. The amount of drug deposited was 12.4-fold higher in case of elastic liposomes of colchicine-cyclodextrin complex (567+/-1.5 microg) than drug solution (46+/-1.1 microg). The biological evaluation of various vesicular formulations and drug solution was carried out using monosodium urate-induced air pouch model. The results of anti-gout activity in rats showed better and sustained biological effects over 24 h measured in terms of exudate volume, reduction in leukocyte count, decrease in inflammatory cell accumulation, and collagen deposition with colchicine-BCD elastic liposomal formulation than drug solution. Hence the present study reveals that colchicine-cyclodextrin-elastic liposomes approach possesses good potential to enhance skin accumulation, prolong drug release, and improve the site-specificity of colchicine.