Development and validation of a microwave-assisted digestion technique as a rapid sample preparation method for the estimation of selenium in pharmaceutical dosage forms by ICP-OES

Selenium is a class ۲B element according to ICH Q۳D guidelines. Selenium sulfide is an anti￾infective agent with antifungal and antibacterial properties used to treat dandruff and seborrheic dermatitis. The literature survey revealed that most of the analytical techniques to estimate selenium were found to be time-consuming and/or required high skill. The process involved identifying the isotopes, selecting the measuring approach, and optimizing a typical microwave-aided digesting procedure. To the samples, ammonium hydrogen difluoride, water, and concentrated nitric acid were added. The confirmed microwave digestion program was a two-step program where in the initial step, the samples were ramped at ۲۰۰°C for ۲۰ minutes and held for ۵ minutes. Later, samples were cooled and neutralized by boric acid, then ramped for ۲۰ minutes to a temperature of ۱۸۰°C and held for ۱۰ minutes. Selenium was estimated at ۱۹۶.۰۹۰ nm by ICP-OES. System suitability was run before initiating analysis to ensure that system performance was consistent. Analytical validation parameters like the specificity of the method were demonstrated at ۱۹۶.۰۹۰nm, linearity was proven from ۱۰ ppm to ۱۵۰ ppm of selenium concentration, the detection limit was ۱.۲۸ ppm and the limit of quantification was ۳.۸۹ ppm. Robustness was confirmed for small changes to ICP-OES operating conditions. The method's precision was demonstrated by analyzing the percentage relative standard deviation for six injections was found to be less than ۲.۰%. Accuracy was confirmed from ۱۰ ppm to ۱۵۰ ppm, and all the samples were found to be within the range of ۹۵-۱۰۵%. A common microwave-assisted digestion technique was developed and the same was validated. The preciseness, specificity, linearity, accuracy, and robustness of the method for estimating selenium in selenium sulfide drug substances and various pharmaceutical dosage forms weredemonstrated. This newly developed microwave-assisted digestion technique has optimum sensitivity, highly reproducible and time saving than the existing methods. This method can be applied to numerous matrices for a finished dosage of selenium sulfide formulations.