Improvement in the percutaneous absorption of beclomethasone dipropionate by γ-cyclodextrin complexation

Abstract

Inclusion complex formation of beclomethasone dipropionate (BMDP) with gamma-cyclodextrin (gamma-CyD) in water and in solid state was assessed by solubility analysis and X-ray diffractometry. The solid complex of BMDP with gamma-CyD in a molar ratio of 1:2 was prepared and its in-vitro release behaviour was investigated using an ointment release simulator. The release of BMDP from hydrophilic ointment was significantly improved by the gamma-CyD complexation. Permeation and uptake studies indicated that the enhanced release of BMDP from the ointment may be due to the faster dissolution and the lower binding affinity of the complex in the ointment base. The vasoconstrictor activity of BMDP in man was found to be increased by gamma-CyD complexation, suggesting an improvement in the percutaneous absorption of BMDP.

Improved Drug Delivery Through the Skin by Hydrophilic β-Cyclodextrins

“…It is evident that the release of BP AA was markedly enhanced by the complexations with /1-CyDs. This may be attributed to the faster dissolution and the lower binding affinity of the complexes in the ointment base, as previously described (Uekama et al 1985). The relative potency of /1-CyDs in enhancing the release of BPAA from the ointment base was in the order of /1-< DM-/1-HP-/1-CyD, which is not simply dependent on the magnitude of the stability constants of the complexes: /1-CyDs may exert the enhancing effect in a different manner (Arima et al 1989).…”

Inclusion complexes of nabumetone with β‐cyclodextrins: thermodynamics and molecular modelling studies. Influence of sodium perchlorate

“…Binding forces involved in inclusion complexation are hydrophobic interactions, hydrogen bonding, van der Waals forces, the relief of high-energy water from the CD cavity and the relief of conformational strain upon guest inclusion (2)(3)(4). The resulting complexes generally lead to an improvement in some of the characteristics of the guest molecules, eg dissolution rate, bioavailability, membrane permeability and stability (5)(6). The alleviation of local or systemic side effects in the presence of CDs has been described.…”

Improvement of Drug Properties by Cyclodextrins

“…Moreover, the drug in the CyD complex may be displaced by some components of the treatment, depending on the stability constant of the complex. 93,94 CyDs also interact with some components of skin. For example, DM-β -CyD markedly extracts cholesterol from rabbit skin in vitro ( Figure 40.8 ), a process which may reduce the function of skin as a barrier and may eventually contribute in part to the enhancement of drug absorption.…”