Influence of poly(ethylene glycol)-α-cyclodextrin complexes on stabilization and transdermal permeation of ascorbic acid

The present study was conducted to investigate the effect of poly(ethylene glycol)-alpha-cyclodextrin (alpha-CD) complexes on stabilization and cutaneous permeation of ascorbic acid from specially prepared transdermal patches. Poly(ethylene glycol) citrate (6-armPEG) and its inclusion complex with a-CD were prepared and used for preparation of the transdermal patches. Duro-Tak 87-2979 was taken as an adhesive matrix in combination with ascorbic acid. A diffusion cell with an artificial membrane was used to evaluate the absorption of ascorbic acid from the patches. The influence of drug release of (c)-CD and two types of its PEG complexes (as the novel permeation enhancers) was tested. The 6-armPEG-alpha-CD complex consisting of a PEG-citric acid ester at a concentration of 0.08-0.1% (w/v) is a suitable stabilizer for ascorbic acid during UV assay. The release studies showed that the type of enhancer is important in diffusion of the drug across membrane. Furthermore, the diffusion of ascorbic acid was considerably enhanced in the presence of 6-armPEG-alpha-CD complex. Inclusion complexes of 6-armPEG with alpha-CD at a concentration of 0.08-0.1% (w/v) is a suitable stabilizer for UV method of assay. The present data suggest that 6-armPEG-alpha-CD complex is also useful in enhancing the release of ascorbic acid from the acrylic type pressure sensitive adhesives. (c) 2006 Wiley Periodicals, Inc.