In vitro skin permeation of sunscreen agents from O/W emulsions.
The effects of different emulsifiers on the in vitro permeation through human skin of two sunscreen agents [octylmethoxycinnamate (OMC) and butylmethoxydibenzoylmethane (BMBM)] were investigated from O/W emulsions. The test formulations were prepared using the same oil and aqueous phase ingredients and the following emulsifier and coemulsifier systems: Emulgade SE((R)) (ceteareth-12 and ceteareth-20 and cetearyl alcohol and cetyl palmitate) and glycerylmonostearate (emulsion 1); Brij 72((R)) (steareth-2), Brij 721((R)) (steareth-21) and cetearyl alcohol (emulsion 2); Phytocream((R)) (potassium palmitoyl-hydrolysed wheat protein and glyceryl stearate and cetearyl alcohol) and glycerylmonostearate (emulsion 3); Montanov 68((R)) (cetearyl glucoside and cetearyl alcohol) (emulsion 4); Xalifin-15((R)) (C(15-20) acid PEG-8 ester) and cetearyl alcohol (emulsion 5). The cumulative amount of OMC that permeated in vitro through human skin after 22 h from the formulations being tested decreased in the order 3 > 1 congruent with 4 > 5 > 2 and was about nine-fold higher from emulsion 3 compared with that from emulsion 2. As regards BMBM, no significant difference was observed as regards its skin permeation from emulsions 1, 3, 4 and 5, whereas formulation 2 allowed significantly lower amounts of BMBM to permeate the skin. In vitro release experiments of OMC and BMBM from emulsions 1-6 through cellulose acetate membranes showed that only emulsions 4 and 5 provided pseudo-first-order release rates only for OMC. The results of this study suggest that the type of emulsifying systems used to prepare an O/W emulsion may strongly affect sunscreen skin permeation from these formulations. Therefore, the vehicle effects should be carefully considered in the formulation of sunscreen products.
Montenegro
L
L
Department of Pharmaceutical Sciences, University of Catania, V.le A. Doria, 95125 Catania, Italy. lmontene@unict.it
Carbone
C
C
Paolino
D
D
Drago
R
R
Stancampiano
A H
AH
Puglisi
G
G
D000287:Administration, Topical; D000328:Adult; D002851:Chromatography, High Pressure Liquid; D003358:Cosmetics / Q000008:administration & dosage / Q000493:pharmacokinetics; D004655:Emulsions / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D012867:Skin / Q000187:drug effects / Q000378:metabolism*; D012869:Skin Absorption; D013473:Sunscreening Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D013501:Surface-Active Agents / Q000008:administration & dosage / Q000494:pharmacology*
D003358:Cosmetics; D004655:Emulsions; D013473:Sunscreening Agents; D013501:Surface-Active Agents