The video of Prof. Thorsteinn Loftsson on the website of CyclonHit project gives the basic information on the effect of cyclodextrins on drug stability. Cyclodextrins can catalize (e.g. beta-lactam antibiotics such as penicillins) or can inhibit drug degradation (e.g. acetylsalicylic acid, chlorambucil, alprazolam). The complexation can hinder the hydrolytic degradation, autooxidation, isomerization, photochemical degradation, transesterification and dehydration reactions.
The video presents several examples and gives explanations on the factors determining if catalysis or stabilization is expected in the presence of cyclodextrins.