Development and Validation of a Reverse-Phase HPLC Method for Determination of Some Water-Soluble Vitamins and Preservatives in Pharmaceutical Forms

Necessary diet components are vitamins as if should be existed in the food. The B vitamins and vitamin C (water-soluble vitamins) are substances required for chemical processes and substances that occur within living organisms. In this research, a simple, rapid, and reliable method was developed to isolate and quantify a primary preservative compound (sodium benzoate), some water-soluble vitamins such as ascorbic acid (C) and five vitamin B compounds. An ODS column was used with a UV detector at different wavelengths at 35 °C. The mobile phase was pH 3.0 phosphate buffer-methanol at a flow rate of 1.0 mL min^−1 in a gradient elution approach. The mentioned analytes above were separated in 40 min. The linearity, limit of detection (LOD), and limit of quantification (LOQ), accuracy, and instrument precision terms were used in the method validation. The correlation factor near 1 suggests that the developed method has a good linearity range. The results show that recovery percentage was 99.480% for all compounds. The limit for mean percentage of recovery is 98-102%, and as all the values are within the limit, it can be concluded that the proposed method is accurate. The results showed no HPLC peaks that could disturb the determination of vitamins/preservatives. The data obtained in real sample analysis were consistent with the declared values. The data obtained from subjected multivitamin syrup sample into stress testing (forced degradation) confirmed that there was no interference effects in the quantification of the analytes.