The mesoporous silicate MCM-41 was studied for its properties to adsorb and to influence the photostability and the release of three organic ultraviolet (UV) ray absorbents, namely benzophenone-3 (B3), benzophenone-2 (B2) and p-aminobenzoic acid (PABA). MCM-41 microcrystals have been loaded with the UV absorbents obtaining a good loading w/w percentage. The loaded samples have been characterized by chemical and thermal analyses, X-ray diffraction, N-2 adsorption isotherms. Photochemical studies demonstrated that the UV-shielding properties of B2 were maintained whereas in other cases a small reduction of sunscreen protection range was noticed. B3 and B2 release from loaded MCM-41 formulations were studied and compared to those obtained from formulations containing free UV ray absorbent; no remarkable differences were observed in the release profiles. (c) 2007 Elsevier Ltd. All rights reserved.
机构:
Faculty of Pharmacy, University of Manitoba, Winnipeg, Man.
Faculty of Pharmacy, University of Manitoba, WinnipegFaculty of Pharmacy, University of Manitoba, Winnipeg, Man.
机构:
Faculty of Pharmacy, University of Manitoba, Winnipeg, Man.
Faculty of Pharmacy, University of Manitoba, WinnipegFaculty of Pharmacy, University of Manitoba, Winnipeg, Man.