The Stability of Liquid Multivitamin Preparations During Use

Abstract

The stability during normal use of vitamin A, vitamin C and thiamine in 6 liquid multivitamin preparations has been examined. Three samples were below label claim when purchased but no further losses occurred during storage of unopened bottles. Destruction of the vitamins was increased by daily removal of a portion of the contents and the stability of most samples stored at room temperature was unsatisfactory. The study suggests that the results of stability tests should be examined more critically to ensure not only that the products meet label claim when purchased, but also maintain a satisfactory potency during normal use. From the consumer's point of view the use of expiration dates which take account of loss during normal use would be most valuable. The finding of retrovitamin A in one preparation suggests the need for more detailed study of the complex changes which may take place in these preparations during storage and of methods to evaluate such changes.