The aim of this study is to determine the potency of Diclofenac sodium tablet available in Port Harcourt metropolis, south-south Nigeria. Diclofenac Sodium is a potent Non-Steroidal Anti-Inflammatory Drug (NSAID) commonly used as an Over the Counter (OTC) drug. Potency determination was performed to evaluate and authenticate whether the marketed samples complies with the declared specification. In vitro dissolution study was, performed to verify the potency of the drug and its relative bioavailability. Hardness was checked to verify whether it interferes with the dissolution, which might ultimately affect the drug bioavailability. In this present study, a simple, cost effective, and spectrophotometric method for the potency determination of marketed diclofenac sodium tablets is used. Six samples were randomly collected from the market and coded as A, B, C, D, E and F, and the potency determined are 80%, 98.7%, 126.9%, 99.6%, 109.2% and 91.4% respectively. Hardness and in vitro dissolution of the six brands of diclofenac sodium tablet were studied and reported. After 1 h dissolution release of samples A, B, C, D,E, and F are 135%, 30%, 70%, 122%, 38%, and 40% respectively. From the various studies it seems that not all the samples analyzed complied with the BP and USP requirements.
