Revalidação de método eletrodo íon seletivo para determinação de flúor em gel dental e enxaguatório bucal com aplicação do Ciclo PDCA

Abstract

The growing demand for oral hygiene products with proven efficacy has driven the need for reliable analytical methods to quantify active ingredients, such as fluoride, which is widely used in the prevention of dental caries. Thus, this study aimed to revalidate an analytical method based on the use of an ion-selective electrode (ISE) for determining the fluoride content in dental gels and mouthwashes produced by a cosmetics industry. The methodological approach adopted utilized the PDCA cycle as a quality management tool, enabling planning, execution, verification, and the proposal of improvements in the analytical procedure. The parameters required by current legislation, such as selectivity, linearity, matrix effect, precision, accuracy, detection and quantification limits, were evaluated according to the criteria established by Anvisa. The practical application of the method showed that it could be revalidated and remained suitable, even in the face of small formulation changes observed over the years, with standard deviations below 5% in the average fluoride concentrations. As an improvement proposal, the elimination of the hydrochloric acid and sodium hydroxide addition step was suggested, simplifying the process without compromising analytical efficiency. It was concluded that the method was reliable for continuous use in the company’s routine, and the frequency of revalidation could be reviewed, with the possibility of extending the interval between reapplications to four years.