Comparative chemical and biological analysis of coal tar-based therapeutic agents to other coal-derived materials

In this study, methodologies developed for the analysis of synthetic fuel products were applied to the coal tar fractions isolated from coal tar-based pharmaceutical products. A pharmaceutical stock solution of 20% coal tar in alcohol, a 50% coal tar bath emulsion and a 4.3% coal tar shampoo were studied. The toxicology and chemical composition of the coal tar fractions isolated from these materials were compared with an industrial coal tar and with a direct-liquefaction coal liquid product. The coal tars and coal liquid product were fractionated into chemical classes by alumina column chromatography and individual components were identified and quantitated by high-resolution gas chromatography. The microbial mutagenicity of these materials was measured against S. typhimurium, TA 98. In addition, the industrial coal tar, coal-liquid product, and coal tar isolate from the 20% coal tar in alcohol solution were tested for initiating activity in an initiation/promotion mouse skin painting assay for carcinogenicity. The chemical compositions of the coal tar-based therapeutic agents, the industrial coal tar and direct-liquefaction coal liquid were similar. With the exception of the 50% bath emulsion, the microbial mutagenicity and tumor-initiating activity in mouse skin for those materials tested were also similar.