In vitro Dissolution Profile at Different Biological pH Conditions of Hydroxychloroquine Sulfate Tablets Is Available for the Treatment of COVID-19

Hydroxychloroquine sulfate is one of an extensive series of 4-aminoquinolines with antimalarial activity. Moreover, it is used for the treatment of rheumatoid arthritis. Sometimes, hydroxychloroquine sulfate is beneficial for the treatment of autoimmune diseases. Based on recent clinical experiments, it is exploited for the treatment of COVID-19, coronavirus across the globe. The chromatogram separation was achieved by using Agilent, Zorbax C8, 250 mm × 4.6 mm i.d., column. The buffer consists of 0.01 M of 1-pentane sulfonic acid and 0.02% of orthophosphoric acid in purified water. Mixed buffer, acetonitrile, and methanol (800:100:100 v/v). The flow rate was 1.0 ml min⁻¹, and injection volume was 10 μl. Detection was made at 254 nm by using a dual absorbance detector (DAD). The reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed and validated as per the current International Conference on Harmonization (ICH) guidelines to estimate hydroxychloroquine sulfate tablets. As part of method validation, specificity, linearity, precision, and recovery parameters were verified. The concentration and area relationships were linear (R2 > 0.999) over the concentration range of 25–300 μg ml⁻¹ for hydroxychloroquine (HCQ). The relative standard deviations for precision and intermediate precision were <1.5%. The proposed RP-HPLC generic method was applied successfully to evaluate the in vitro dissolution profile with different pH conditions such as 0.1 N HCl, pH 4.5 acetate buffer, and pH 6.8 phosphate buffers as US-marketed reference products.