Drug stability is defined as the capacity of a drug substance or drug product to maintain its identity, strength, quality, and purity within official specification throughout its shelf life. 1 The stability of a drug product must have to be maintained throughout its shelf-life otherwise the quality, safety, potency and efficacy will be compromised. 2,3 All form of drug delivery system is subject to changes under the influence of some environmental factors such as light, humidity and temperature. 4-7 These changes could lead to deterioration and degradation usually as a result of oxidation, hydrolysis, photolysis, thermolysis, etc, thus making consumers at risk of some drug related problems ranging from suboptimal treatment, therapeutic failure, adverse reactions, toxicity, etc. 3,8-10 The pharmaceutical changes that can occur to solid dosage forms (tablets) are; changes in tablet dimensions, weight, colour, hardness, friability, drug content, disintegration and dissolution. Environmental factors are unavoidable conditions which drugs will have to pass through during transportation, storage and use. 11-13 This is very essential in determining the integrity of these products. So, for stability to be maintained, these factors are of utmost importance and must be put under control. It has been reported by many authors that, stability