The quality of Spanish cosmetic-pharmaceutical talcum powders

Abstract

Seven cosmetic-pharmaceutical talcum powders from different commercial brands, currently for sale in Spanish pharmacies, have been studied in order to determine their mineral and pharmacopoeia quality. Four samples met the required conditions to be classified both of “cosmetic quality” and “pharmacopoeia quality”. These conditions are: absence of potentially carcinogenic minerals, talc purity of more than 90%, low levels of toxic elements and suitable compositional levels of Al, Mg and Ca. The remaining three samples were classified as of “industrial quality”. Although these are free from fibrous minerals, the high carbonate content, specifically dolomite (close to 40%) and calcite (about 10%), impacts on the purity in talc by significantly reducing its quantity to the point that the material no longer satisfies many of the compositional tests of the European Pharmacopoeia. The detailed microanalysis with SEM-EDX and size measurements of elongated particles present in the samples showed them to be harmless as their mineral composition is talc and they appear in very low proportions. The SEM-EDX study highlighted the properties for which talcum powder has classically been employed for topical cutaneous use. The comparison of the current results with those of the Spanish market of talcum powder sold in pharmacies in the decade of the 1980s resulted in three principal findings. First, the fibrous minerals have disappeared. In the past, a significant number of samples showed evidence of amphiboles. Second, the purity in talc in samples of cosmetic quality has improved from 94% to 96%. Finally, in the 1980s there were no samples in the Spanish market with talc purity as low as today (60%). Dolomite is currently present in excessive quantities in some talcum powders