Vitamin В<sub>12</sub> in drug delivery systems

Vitamin B12 is a vital biologically active compound for human and is involved in a wide range of metabolic processes. The widespread vitamin B12 deficiency and vitamin’s low penetrating ability into cells determine the urgency of delivery systems development for the design of formulations with improved biopharmaceutical properties. This work provides a brief discussion of the main chemical and biochemical properties of the vitamin B12, as well as considers oral, injectable and transdermal multicomponent dosage forms of vitamin B12 that are aimed at solving the issue. Moreover, the literature analysis of the prospects of using vitamin B12 as an auxiliary component for both passive and active delivery of other drug molecules, for example, peptide nucleic acids and antitumor drugs, is presented. The review describes in detail the types of proposed delivery systems for biologically active compounds, in which vitamin B12 is one of the components.