In-Vitro Quality Assessment of Different Brands of Vitamin C Tablets Available in the Libyan Market

Abstract

A B S T R A C T

Background: Vitamin C, or ascorbic acid, is a vital water-soluble vitamin and a potent antioxidant essential for human health. Vitamin C tablets are widely available as over-the-counter (OTC) products and are often used without medical supervision; therefore, strict adherence to pharmacopeial standards is essential to ensure their safety, efficacy, and quality consistency across different brands.  Objectives: The aim of this study was to evaluate the quality of four brands of 500 mg vitamin C tablets commonly sold over-the-counter in the Libyan market. The four brands were labeled as Brand 1, Brand 2, Brand 3, and Brand 4, and evaluated to assess whether they meet the required quality standards. Methods: The pharmaceutical quality of different vitamin C Brands was assessed using several in-vitro tests according to the United States Pharmacopeia (USP); the assessment included chemical and physical properties such as friability, hardness, uniformity of content, weight variation, dissolution rate, and disintegration time.

Results: All tested brands passed the disintegration and hardness tests and complied with USP standards. However, Brand 2 and Brand 4 failed to meet the requirements for friability test. In addition, the Brand 4 failed to meet the USP specification for weight variation, content uniformity, and the dissolution test. The observed failures in Brand 2 and Brand 4 indicate that not all vitamin C Brands fulfilled the USP requirements, suggesting potential differences in pharmaceutical quality and interchangeability, whereas Both Brand 1 and Brand 3 successfully complied with all quality control tests. However, Brand 3 demonstrated superior performance, achieving a faster drug release rate and a shorter disintegration time compared to the other brands. Conclusion: The findings indicate that not all vitamin C brands available in the Libyan market meet the required pharmacopeial standards. Continuous quality control testing, strict regulatory supervision, and proper storage conditions are essential to ensure that pharmaceutical products distributed in the market provide safe, effective, and reliable therapeutic outcomes.