Facial visible spectrophotometric determination of metformin hydrochloride in glucosam tablets and industrial waste water : application to content uniformity testing

الملخص EN

Objectives : To determine simple, accurate and highly sensitive spectrophotometric method for determination metformin hydrochloride in pharmaceutical preparations and in industrial waste water sample.

Materials and Method : The method is based on the oxidation of metformin by a known excess of sodium hypochlorite in alkaline medium.

Results : Formation of a yellow-colored chromophore having maximum absorbance at 385nm.

Molar absorptivity was found to be 2 × 104 L.mol-1.cm-1.

Beer’s law is obeyed in the concentration range of 0.5-4 μg .ml-1, relative standard deviation (RSD) is better than ±1.8 (n = 10) .The limits of detection and quantitation are 0.083 and 0.25 μg .mL-1, respectively.

The method is applied successfully to determination of metformin pharmaceutical formulation (tablets).The common excipients do not interfere with the proposed method.

A statistical comparison of these results with those of official method using t and F values at 95 % confidence level shows good agreements and indicated no significant difference in the precision, and the present method has good validity.

Conclusion : The proposed method can be used as a routine quality control and content uniformity tests for determination of metformin in pure form, tablet formulations and industrial waste water sample.