Freeze-dried complexes of furosemide with β-cyclodextrin derivatives

A freeze-drying method was used to prepare complexes of furosemide (guest) with three derivatives of beta-cyclodextrin (hosts) in different molecular ratios in order to increase the aqueous solubility and rate of dissolution of the drug, and also to study the influence of this method on different parameters of the guest and the host, such as the diffusion rate constant and the partition coefficient, and additionally the surface tension activity of the host (if any). The hosts were found to have significant, increasing effects on the solubility and the rate of dissolution of furosemide. X-ray diffraction confirmed the host-guest interaction, in support of the earlier results. The freeze-drying method increased the diffusion rate of the drug in complex form, while the partition coefficient varied with the type of beta-cyclodextrin in the product. It is well known that CD derivatives are highly surface active which gives rise to their hemolytic action. Our observations showed that their presence with furosemide in complex form might decrease (if not diminish) the hemolytic action.