Influence of cyclodextrins on in vitro human skin absorption of the sunscreen, butyl-methoxydibenzoylmethane.
The effects of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and sulfobutylether-beta-CD (SBE7-beta-CD) on in vitro human skin penetration and retention of the sunscreen agent butyl-methoxydibenzoylmethane (BM-DBM) were investigated. The interaction between the UV filter and the cyclodextrins was studied in water by phase-solubility analysis. Solid complexes were prepared by the co-evaporation method and characterized by (1)H NMR spectroscopy, thermal analysis and powder X-ray diffraction. Solutions containing BM-DBM free or complexed with cyclodextrins were applied to excised human skin in Franz diffusion cells and the amount of sunscreen permeated after 6 h into the stratum corneum, viable epidermis, dermis and receptor fluid was assessed by HPLC. As much as 14.10-16.78% of the applied dose of BM-DBM penetrated within the skin tissue. No sunscreen was detected in the dermis and in the receiver phase. The greater proportion (84.6-95.5%) of the absorbed UV filter was localized in the stratum corneum with no significant differences between uncomplexed or complexed BM-DBM. Notable levels (2.29% of the applied dose) of the sunscreen agent accumulated in the epidermis from the preparation containing free BM-DBM. The epidermal concentration of the UV filter was markedly reduced (0.66% of the applied dose) by complexation with SBE7-beta-CD, whereas HP-beta-CD had no effect. The decreased BM-DBM retention in the epidermal region achieved by SBE7-beta-CD limits direct contact of the sunscreen and of its reactive photolytic products with the skin viable tissues.
Simeoni
S
S
Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44100 Ferrara, Italy.
Scalia
S
S
Benson
H A E
HA
D000328:Adult; D000473:Alkanes / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D047188:Chalcones / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D003505:Cyclodextrins / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D004357:Drug Synergism; D005260:Female; D006801:Humans; D011427:Propiophenones; D012869:Skin Absorption / Q000502:physiology*; D013473:Sunscreening Agents / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*
D000473:Alkanes; D047188:Chalcones; D003505:Cyclodextrins; D011427:Propiophenones; D013473:Sunscreening Agents; C049935:avobenzone