Spectroscopic method for the quantification of residue of tetramethylthionine chloride on swab from manufacturing equipment in support of cleaning validation

Tetramethylthionine chloride is approved by the FDA for the treatment of paediatric and adult patients with acquired methaemoglobinaemia. The objective of this research was to develop and validate an Ultraviolet (UV) spectrophotometric method for quantification of Tetramethylthionine chloride in cleaning control swab sample from manufacturing equipment surfaces. Simple, accurate and cost efficient spectrophotometry method has been developed for the estimation and quantification of Tetramethylthionine chloride which is going to be used for the evaluation of cleaning in cleaning validation. The optimum conditions for the quantitative analysis of the drugs were established. The maximum wavelength (Vax) was found to be 663nm. The percent recovery of Tetramethylthionine chloride for 50.0%, 100.0% and 150.0% were 99.13, 97.76 and 101.18 respectively. Linearity of Tetramethylthionine chloride for Validation showed a good linear relationship with Correlation Coefficient (r²) value of 0.999 was obtained. Validation was performed according to the ICH guidelines of Analytical Method Validation. The Sample Solution was chemically stable up to 36 hours. The proposed may be suitable for the Estimation and Quantification of Tetramethylthionine chloride for evaluation of cleaning in cleaning validation for quality control purposes.