Spectrophotometric microdetermination of tretinoin, isotretinoinusing iodine and tazarotene microdetermination via reaction with Rose-Bengal reagent

Abstract

T HE REACTIONS of iodine or rose-bengal (Rbng) reagents with three of retinoid drugs tretinoin, isotretinoin and tazarotene had been studied for the development of simple, rapid, sensitive spectrophotometric methods for microdetermining of these drugs in pure and in their pharmaceutical formulation. These methods are based on the formation of reaction product sbetween the drugs and iodine or rose -bengal reagent. The spectra of the formed reaction products were measured at selected proper conditions of time, temperature, pH and selected wavelength. The analytical parameters such as standard deviation (SD), relative standard deviation (RSD), Sandell’s sensitivity (S), LOQ and LOD were calculated in order to check accuracy, sensitivity and precision of the given procedures. The values of SD = 0.1312 - 1.100, RSD = 0.5556 - 1.946 %, S = 0.0229 – 0.0508 μg cm-2, LOQ = 13.17 – 17.45 μg mL-1, LOD = 4.347 – 5.757 μg mL-1 obtained of these parameters refer to the accuracy and sensitivity of the suggested procedures and can be applied for analyses of these drugs in their pharmaceutical formulations. Beer’s law was valid in the range 9.041 – 29.71, 35.75 – 119.6 and 10.48 – 71.11 μg mL-1 with recovery of 97.84 - 102.8 %, 98.67 - 101.8 %, and 98.32 - 102.0 % for Tretinoin, Isotretinoin and Tazarotene respectively, The importance of this research stems from applications of these retinoid derivatives in skin improvements. They are always used as creams and found to be effective for photo-damage and for protection from skin irritation. Therefore, the proposed methods had been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations. The results obtained were found to be in good agreement with those obtained by official methods. This evaluation had been done by F- and t- tests.