COMPLEXATION OF THE SUNSCREEN AGENT, BUTYL-METHOXYDIBENZOYLMETHANE, WITH HYDROXYPROPYL-BETA-CYCLODEXTRIN

The interaction between the sunscreen, butyl-methoxydibenzoylmethane ( BM-DBM), and parent and modified alpha-, beta- or gamma-cyclodextrins was investigated in water by phase-solubility analysis. Among the avai lable cyclodextrins, only hydroxypropyl-beta-cyclodextrin (HP-beta-CD) produced a significant increase in the aqueous solubility of BM-DBM. The complexation of the sunscreen agent with HP-beta-CD was studied by circular dichroism, differential scanning calorimetry and X-ray diffr actometry. The data from the solubility and the circular dichroism stu dies suggested the formation of a 1:2 (sunscreen:cyclodextrin) complex . The photodegradation of BM-DBM was reduced by inclusion complexation with HP-beta-CD. Therefore the complex can be used to improve the pho tostability of the sunscreen agent. (C) 1998 Elsevier Science B.V. All rights reserved.