Abstract: A process is provided for making a free-flowing powder of a complex of an alpha-hydroxy acid (AHA) and/or a beta-hydroxy acid (BHA) and a vinylpyrrolidone (PVP) polymer, copolymer or graft polymers, as the complexing agent, at high acid loadings, preferably 20-60% by weight. The presence of VP polymers, copolymers or graft polymers in the complex reduces the skin irritation effect of the acid when applied to the skin of the user. The process involves applying an aqueous solution or slurry of the acid to PVP, and, substantially immediately thereafter, evaporating the water to form a free-flowing powder of the complex of the acid and VP polymers, copolymers or graft polymers.

Abstract: Compositions containing sulfuric acid and one or more of certain chalcogen-containing compounds in which the chalcogen compound/H.sub.2 SO.sub.4 molar ratio is below 2 contain the mono-adduct of sulfuric acid which is catalytically active for promoting organic chemical reactions. Suitable chalcogen-containing compounds have the empirical formula ##STR1## wherein X is a chalcogen, each of R.sub.1 and R.sub.2 is independently selected from hydrogen, NR.sub.3 R.sub.4, and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is hydrogen or a monovalent organic radical, and R.sub.5 is a divalent organic radical. Such compositions are useful for catalyzing organic reactions such as oxidation, oxidative addition, reduction, reductive addition, esterification, transesterification, hydrogenation, isomerication (including racemization of optical isomers), alkylation, polymerization, demetallization of organometallics, nitration, Friedel-Crafts reactions, and hydrolysis.