Correlation between the micromorphological parameters and residual solvent content of a crystalline steroid drug

A small amount of solvents applied at the production of solid drugs is retained in the porous structure of the crystalline product. The regulatory guidelines require that the impurity due to the remaining solvent content of drugs should be a matter for serious concern toward marketing drugs; hence the reduction of the solvent amount is an important task of the technology of production. A steroid drug was crystallized and the correlation between the pore structure of the crystalline product and its residual solvent content was investigated. It was stated that the drug examined has a characteristic meso- and macropore structure, which distribution has a major contribution on the amount of the residual solvent content.