Quantitative Determination of Metformin Hydrochloride in Tablet Formulation Containing Croscarmellose Sodium as Disintegrant by HPLC and UV Spectrophotometry

Purpose: To develop and validate a suitable method for the assay of metformin hydrochloride (HCl) in tablets containing croscarmellose sodium as an additive.
Methods: Methanol and ethanol (99%) were assessed as solvents for sample preparation for the assay of metformin HCl in tablets containing croscarmellose sodium by high performance liquid chromatography (HPLC) and ultra violet spectrophotometric (UV) methods. The proposed method was subjected to validation tests.
Results: Recovery of metformin HCl from the placebo-spiked sample was 95.1 to 96.9 % as per BP and USP methods compared with 99.3 to 100.8 % when analyzed by the proposed method. The use of methanol and ethanol as solvents resolved the problem of retention of metformin HCl by croscarmellose sodium in solution during the preparation of sample solution.
Conclusion: The modified UV and HPLC methods are suitable for the determination of metformin HCl in tablets both in the presence and absence of croscarmellose sodium. The method is specific, precise, accurate, robust, rugged and gives a linear response for the quantitative estimation of metformin HCl in tablet formulation.

Keywords
Tablets; Metformin HCl assay; Croscarmellose sodium; Ethanol; Methanol; HPLC, UV