METHOD FOR DETERMINING THE CONTENT OF DIPHENHYDRAMINE HYDROCHLORIDE (DIMEDROL) IN PHARMACEUTICAL SUBSTANCES AND PREPARATIONS Russian patent published in 2022 - IPC G01N33/15 

FIELD: pharmaceutical industry.

SUBSTANCE: invention relates to the field of pharmaceuticals, namely to methods for the quantitative determination of diphenhydramine used for quality control of products manufactured by pharmaceutical industries and manufactured in pharmacies, in particular for the determination of dimedrol (diphenhydramine hydrochloride) in pharmaceutical substances and preparations (liquid and solid dosage form). The method includes preliminary conversion of the analyzed preparation into liquid form, placing it in an absorption cell for photochemical titration containing a certain amount of photogenerated iodine obtained by irradiation in the presence of oxygen in the air with visible light of an auxiliary solution containing 40 ml of 0.1 M potassium iodide solution, 10 ml of 0.01% uranin solution and 20 ml of acetate buffer solution with a pH of 6.0, fixing the reduction in the amount of iodine carried out amperometrically, with subsequent irradiation of the absorption solution with visible light and measurement of the iodine generation time required to replenish the loss of iodine to the initial amount. Then, the content of diphenhydramine hydrochloride in the preparation is determined according to the formulas.

EFFECT: method provides a reduction in the limits of quantitative determination and detection of diphenhydramine, analysis from smaller attachments, while maintaining the accuracy and reproducibility of the technique.

1 cl, 3 tbl, 2 ex