Stability of Vitamins in Pharmaceutical Preparations A Review
Vitamins are one of the few groups of food constituents in which it is possible to demonstrate quantitatively deterioration in content over a period. The rate of this reduction in vitamin content is influenced by a number of factors. The stability of the more commonly used vitamins in vitamin concentrates and multivitamin preparations for oral administration has been studied in a variety of basic aqueous solvent mixtures of practical significance under normal storage conditions. The overage required for each vitamin under various conditions and in different formulations has been indicated in order to determine the excess of each vitamin necessary to maintain label declarations for normal storage periods. In general, many physical and chemical factors can have a negative effect on stability of vitamins. Water soluble vitamins are prone to degradation in solutions, particularly when exposed to light. In the present study, the interaction of vitamins in all conventional formulations is discussed.