Enhancement of Drug Bioavailability by Cyclodextrins

The reassuring results of toxicity of orally administered ß‐cyclodextrin and the realization of its industrial production opens a new way in the formulation of non‐parenteral drug preparations. It is assumed that the utilization of ß‐cyclodextrin in oral drug preparations will be a common process within a decade. The molecular encapsulation of drugs – i.e. complexation with cyclodextrin – has numerous advantages out of which one of the most important is the improved bioavailability. By inclusion complexation of a drug with cyclodextrin the drug becomes molecularly dispersed in a hydrophylic matrix, therefore the poorly soluble drug will become more soluble and will dissolve with an increased dissolution rate in aqueous milieu. The improved solubility generally leads to higher blood‐level of the drug, which is manifested also in the biological response. The same dose of the drug results in an higher biological effect when applied a cyclodextrin complex, or to achieve an unaltered effect the drug dose can be reduced.