Selected Issues on Regulation of the Circulation of Non-Biological Complex Drugs.

An analytical review of widely discussed issues on the classification of drugs based on the methods/sources of their preparation and the complexity of their structures is presented. According to the classification, drugs are divided into three types: (A) low-molecular-weight synthetic 'conventional' drugs that are completely characterized chemically; (B) biological complex drugs that are not fully characterized chemically (BCD); and (C) non-biological/synthetic complex drugs that are not fully characterized chemically (NBCD). This classification has both scientific and practical significance due to the fact that NBCDs (liposomal drugs, complex iron-carbohydrate complexes, glatiramoids, low-molecular-weight heparins) are similar to BCDs with respect to both structure (a mixture of strongly bound macromolecular fragments not amenable to isolation and complete identification) and biological/pharmacological effects (immunogenicity, insufficient information about the mechanism of action). Recent practice shows that NBCD generic versions in addition to biosimilar drugs are actually not identical to the original drugs because of differences in the manufacturing technology. For this reason, the expedited review and registration of these drugs, which is analogous to that used for conventional low-molecular-weight drugs, seems to be insufficient. [ABSTRACT FROM AUTHOR]