Determination of 50mg sodium diclofenac content in generic and similar reference medicinal product by ultraviolet-visible spectrophotometry

Diclofenac classified pharmacologically as an anti-inflammatory non-steroidal (NSAID), is used to treat pain and inflammation, especially. It is found on the market in the pharmaceutical forms of suppository, ointment, gel and tablet. Quality control of this substance plays a large role in manufacturing, as it is of great value to identify and analyze the raw materials to be used as well as all inputs relevant to the drug development process. One of the tests that are used to determine the content of Diclofenac Sodium in tablets is the ultraviolet spectrophotometry technique. This study aimed to verify the content of the drug Diclofenac sodium in a reference drug, generic and similar, and to analyze the application of the visible ultraviolet spectrophotometric method described in the Brazilian Pharmacopoeia V. After the spectrophotometric analysis, the following results were obtained: the samples reference drugs had masses of R1 = 72.205 mg; R2 = 54.926 mg; R3 = 70.857 and the average concentration content 131.99%. Generic drugs had mass values equal to G1 = 69.509 mg; G2 = 70.980 mg; G3 = 70.367 mg and the average concentration content is 140.56%. Similar drugs had masses of S1 = 89.362 mg; S2 = 61.666 mg; S3 = 71.593 mg and the average concentration content 148.41%. Only the analyzed sample (R2) met the requirement for this test, being considered approved according to the content informed by Pharmacopoeia (90-110), indicating a possible failure in Good Manufacturing Practices and Quality Control.