A Study of the Quality of Selected Multivitamin Supplements in Nairobi City, Kenya

Abstract

Vitamins are invaluable nutrients that play integral roles in human bodies such as maintenance of cell functions. Vitamins are broadly classified into two groups: fat-soluble and water-soluble vitamins. Humans do not synthesize vitamins but obtain them from food and therefore it is important to maintain a balanced diet for continuous supply. Vitamin deficiencies mainly arise from malabsorption and malnutrition. In such instances, vitamin supplements become important to augment the diet or act as replacement. Vitamin supplements will contain either one category of vitamins or both, with or without minerals. Data on quality studies and literature reviews on regulation of multivitamin supplements in the Kenya is not available. The main objective of this study was to determine the quality of multivitamin supplements. Quality was assessed for packaging and labelling, assay of content and microbial contamination. Purposive random sampling was applied whereby samples were collected randomly from pharmacy outlets in Nairobi County Central Business District area. Samples collected consisted of liquid and solid dosage forms. A total of 40 samples were collected, consisting of solid dosage forms (14 tablet formulated products and 6 hard gelatin capsules) and liquid dosages forms (19 syrups and 1 oral drop).On conformity with labeling and packaging specifications, manufacturing/expiry dates, batch numbers, patient information leaflets, storage conditions and country of origin were inspected. High Performance Liquid Chromatography adopted methods were used for the assay test, on which one was applied for simultaneous determination of water-soluble vitamins (B1, B3, B6 and folic acid) while the other was used in fat-soluble vitamins ( A, D and E ) analysis. The water- soluble method was verified for accuracy, linearity, range and repeatability as per the ICH guidelines. Microbial Load determination was carried out by plate count method by 10 fold serial dilutions. For the compliance with packaging and labelling, 21% of the samples did not contain patient information leaflets but complied with the Pharmacy and Poisons Board (PPB) packaging and labeling specifications on all other aspects (Presence of manufacturing/expiry dates, batch numbers and storage conditions). The linearity range of the analyzed vitamins spanned from (50-200%) with a regression coefficient (R2) being > 0.99; accuracy was demonstrated by recoveries xv that were in the range of 98-102% while precision was measured using the RSD of six injections which was < 2percentage in all instances. Samples collected originated from six countries: India (37.5%), Kenya (27.5%), England (25%), Bangladesh (5%), Pakistan (2.5%), and Egypt (2.5%). In determination on the label claim compliance, 14.3% of the samples met the pharmacopeial limits. For water- soluble vitamins, two (7.1%) samples complied with the pharmacopeial specifications while none complied with the assay limits for fat-soluble vitamins. Further review of the results for the water - soluble vitamins, 51% failed to meet the pharmacopeia specifications (40.9% below the limits, 31.8% above and 27.3% within the specified range), 21% did not comply on pyridoxine (20% were below and above the specifications, & 60% within the range) , 15% on folic acid (50% below the limits, 8.5% above and 41.7% within) and 13% were outside nicotinamide limits (11.1% below, 16.7% above and 72.2% within the limits). All the samples complied with Total Aerobic Microbial Count (TAMC) as per the BP 2018 specifications while two (10.5%) samples failed to comply with the Total Yeast and Molds Count (TYMC). From the study, all the samples complied with TAMC specifications, while 89% of the samples complied with the BP 2018 specifications for TYMC in non-sterile products as well as labelling and packaging specifications as per the PPB guidelines. On the other hand, 85.7% failed to comply with the assay specifications for both water- and fat- soluble vitamins. These results indicate that there is a gap in the regulation of multivitamin supplements in the country. Therefore, the regulator should adopt a risk-based approach to assure the quality of multivitamin products are in the market. In addition, the Pharmacy and Poisons Board should have an updated database for all multivitamin supplements in the Kenyan market. The university should encourage more research on multivitamin in the Kenyan context to generate more data on the quality of multivitamins