OPTIMIZATION AND VALIDATION OF THE VOLUMETRIC ANALYTICAL METHOD FOR THE QUANTIFICATION OF THIOGLYCOLIC ACID IN COSMETIC CREAM

Abstract

Thioglycolic acid is an active used in capilar cosmetic creams with the function of smoothing, curling and depilating. Resolution RDC 7/2015, from Anvisa, classifies the products in risk grade I and II. For grade I type the normative does not require detailed information about formulation, such as to the mode and restriction of use. However, grade II type needs specific indications, and their characteristics require proof of safety and/or efficacy. Norm RDC 3/2012 approves the list of substances allowed in cosmetics and establish the maximum limit allowed. The products containing thioglycolic acid are classified as risk II and their content is allowed at the maximum concentration of 8.0% w / w for general use, 11.0% for professional and 5% w / w for depilatories. The Brazilian cosmetics industry has registered a growing increase in the use of capilar straighteners, so the control of this active is important to ensure the safety of its use. The objective of this study was to optimize and validate the method for determination of the thioglycolic acid content in substitution to that published in the Guide of Quality Control of Cosmetic Products from Anvisa. The preconized methods were compared with the validation of the method under study. The method was validated using fortified sample at three concentrations (4.0%, 7.0% and 10.0%). For evaluation of the results the statistical tools were the T and F tests for the comparison and validation of the method under study. The obtained results showed that the validated method is suitable for the determination of thioglycolic acid content.