Comparative Assessment of the Physicochemical Properties of Different Brands of Levothyroxine

Anum Sattar, Safila Naveed, Hina Rehman, Sultan Ayaz, Rafia Usman, Sidra Yasmeen, Ghulam Razzaq, Fatima Qamar, Halima Sadia


Levothyroxine is an oral form of drug that is used for hypothyroidism disorder. Hypothyroidism disorder is a condition in which the gland does not produce enough thyroid hormones for the body to perform its functions effectively. In the commercial market, various brands of levothyroxine are available that are frequently prescribed for hypothyroidism. In this study, we determined the comparative assessment of physicochemical properties of different brands of marketed available levothyroxine oral tablets in Karachi, Pakistan. In this study, we evaluated the pharmaceutical equivalency of different marketed brands of levothyroxine by using QC parameters, i.e., weight variation, thickness, hardness, and disintegration. Instruments used for different analyses included digital weighing balance, hardness apparatus, vernier caliper, and disintegration tester. Different brands of levothyroxine were purchased from the different community pharmacies for physicochemical analysis and performed physiochemical tests with the comparison of BP and USP specifications. The physicochemical properties of different marketed brands of levothyroxine were performed through digital weighing balance, hardness apparatus, vernier caliper, and disintegration tester. The weight variation is performed using digital weighing balance. First, we determined the parent drug, i.e., Synthroid .0833; however, the rest of the drugs including Eltroxin, thyroxin, and thyronorm are 0.170, 0.146, and 0.1043. The thickness was measured using vernier caliper, and the calculated values of Synthroid, Eltroxin, thyroxine, and thyronorm were 0.0640, 0.410, 0.0847, and 0.1106. The hardness was measured using hardness tester, and the calculated values for synthroid, Eltroxin, thyroxine, and thyronorm were 3.5400, 3.8300, 3.3700, 3.6800. The disintegration was measured with the disintegration tester, and the calculated values of Synthroid, Eltroxin, thyroxine, and thyronorm were 4 min;10 seconds, 1 min, 2 min; 48 seconds and 1 minutes; 43 seconds. Physicochemical properties of all four brands of levothyroxine showed slight differences within the range of BP and USP. This research compared the physicochemical properties of different marketed available brands of levothyroxine with those of a parent company in Karachi, Pakistan. Drug release investigation and bioequivalence should be performed in the near future for more authenticity and prescription confidence.


Keywords: levothyroxine, physicochemical properties, comparative study, weight variation, thickness, hardness, disintegration.

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