Analysis of interfacial transfer and absorption behavior of drugs following dissolution from .BETA.-cyclodextrin complexes.

Abstract

The interfacial transfer and absorption behavior of drugs following dissolution from inclusion complexes was analyzed by the use of in vitro and in situ models (S-Lw-Lo and S-Lw-in situ). The experiments were carried out using 1 : 1 complexes of β-cyclodextrin (β-CyD) with some barbiturates and p-aminobenzoic acid esters as test compounds. Taking into account the dissolution equilibrium of complexes in the dissolution medium, the drug appearance in the organic phase of the S-Lw-Lo model and the amount of drug absorbed in the S-Lw-in situ model were analyzed in relation to time. The factors affecting the interfacial transfer and in situ absorption behavior of the complexes are discussed. The results indicate that the two experimental models are applicable to β-CyD complexes, and may be suitable for the evaluation of their oral bioavailability.