Studies of the Interaction of Betacyclodextrin with Ampicillin, Methicillin and Phenytoin

Abstract

The interactin of .beta.-cyclodextrin with ampicillin, methicillin [antibiotics] and phenytoin [an antiepileptic drug] was investigated. All 3 drugs, (in the unionized form) interact strongly with .beta.-cyclodextrin. The interaction of all 3 drugs with .beta.-cyclodextrin could perhaps be exploited to pharmaceutical advantage. For ampicillin, the complex may have an improved bioavailability and a reduction in the incidence of gastrointestinal side effects in comparison with the uncomplexed drug. For methicillin, the significant extension of the hydrolytic half life for the complex makes the oral route a possibility for this drug, which is normally given i.v. because of stability problems. The interaction of phenytoin with .beta.-acyclodextrin produces a complex with a substantially enhanced solubility likely to give greatly improved bioavailability and reduction in intra- and inter-subject blood level variation.