Stabilization of Folic Acid in Liquid Dosage Form: Formulation Development, Method Validation and Comparative Analysis

Vitamins are essential nutrients available as multivitamin combinations. The stability of individual vitamins remains a question since most of the vitamins are decomposed during storage. Folic acid is a water soluble vitamin and found to be unstable in the presence of water and also other vitamins. Due to this stability problem, this vitamin is not available alone in liquid dosage forms. This problem is mainly attributed to the change in pH. So, the present investigation aims to provide a stable liquid preparation of folic acid alone by the usage of suitable solvents and stabilizers in order to maintain the pH. Stability study has been conducted to find out the degradation rate and the shelf-life of formulation has also been determined. The obtained results have been compared with three different innovators multivitamin products containing the folic acid. The experimental studies clearly show that a stable pH range between 5 and 5.5 for folic acid could be maintained very well by using the mixed solvents of sorbitol, glycerine and propylene glycol and the degradation rate has been found to be significantly less in the present formulation as compared with innovator products. For the analysis of folic acid, High Performance Liquid Chromatography method has also been developed, optimized and validated for its precision, accuracy and specificity. The data obtained indicate the suitability of this High Performance Liquid Chromatography method for the analysis of folic acid. This report is the first of its kind in dealing with the stabilization of folic acid in liquid dosage form.