Applications of steroid drugs entrapped in cyclodextrins

Steroids are abundant in living organisms and are responsible for various biological functions. They are good candidates for inclusion complexes formation with cyclodextrins; therefore, plenty of literature describes these complexes and their application in various fields. There are, however, hardly any reviews summarizing this tremendous amount of information. Here, we review steroid drugs in relation to their complexation with cyclodextrins, highlighting the effect of cyclodextrin–steroid interaction on the solubility, stability and bioavailability of the entrapped steroid drugs. We have collected data on the changes in the pharmacokinetics of cyclodextrin-formulated steroid drugs designed for various routes of administration. We show some cyclodextrin-enabled steroid formulations introduced to the market. Sugammadex, the first cyclodextrin derivative approved as active pharmaceutical ingredient, which revolutionized anesthesia, is also discussed. Several examples demonstrate the catalysis and inhibition of various biotransformation reactions of steroids by cyclodextrin complexation used in biotechnology. The laboratory- and pilot-scale experiments for environmental application of cyclodextrin–steroid interaction are based on cyclodextrin-containing sorbents for capturing residual steroid drugs, such as contraceptives from purified wastewater.