Abstract: Topical skin treatment formulation containing usnic acid or an usnate salt, dissolved in a solvent system comprising (i) dimethyl isosorbide; (ii) a C1 to C9 alkyl salicylate; and (iii) a glyceryl fatty acid ester. The solvent system may also comprise an alcohol, a polyoxyalkylene-based solvent, and/or a C1 to C4 alkyl glucose ester. The formulation may be used in the treatment of microbial conditions, in particular acne. The solvent system assists in the effective dissolution of the usnic acid or usnate and in targeting its delivery to relevant sites on the skin.

Abstract: An antibacterial or anti-acne formulation suitable for topical or local application to human skin containing (a) either usnic acid or an usnate and (b) a metal salt selected from copper salts, bismuth salts, and mixtures thereof, wherein if the component (a) is an usnate, the components (a) and (b) are not the same compound.

Abstract: A benzoquinone or hydroquinone for use in the topical treatment of a condition which is caused, exacerbated or transmitted by bacterial, in particular staphylococcal or propionibacterial, activity. The condition may be a skin or skin structure condition such as acne. The invention also provides the use of a benzo- or hydroquinone in the manufacture of a medicament for the treatment of such a condition.

Abstract: An antimicrobial formulation containing (a) a peroxide selected from the group consisting of diacyl peroxides, alkyl hydroperoxides and metal peroxides and (b) a benzoquinone or hydroquinone. The formulation may in particular be used against staphylococci or propionibacteria, more particularly to treat skin and skin structure conditions such as acne.