A validated RP-LC method for salmeterol and fluticasone in their binary mixtures and their stress degradation behavior under ICH-recommended stress conditions

Simple, accurate, precise and fully validated analytical methods for the simultaneous determination of salmeterol xinafoate and fluticasone propionate in combined dosage forms have been developed. These drugs were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions, and the stressed samples were detected by the proposed method. Additionally, pK _a values of three ionizable drugs (salmeterol xinafoate, fluticasone propionate and thioridazine) were determined using by the dependence of the retention factor on pH of the mobile phase. The effect of the mobile phase composition on the ionization constant was studied by measuring the pK _a in different acetonitrile-water mixtures, ranging between 50 and 65% (v/v) using LC-UV method.     

A Novel RP-LC Method for Determination of pK a Values of Some Anticancer Agents and Their Assay

A simple, reliable, and rapid RP-LC method has been developed for the determination of some anticancer drugs (daunorubicin, doxorubicin and vincristine sulfate) in their dosage forms and human urine. These compounds are well separated on a C18 column using the mobile phase consisting of a mixture of acetonitrile (50:50; v/v) at a flow rate of 1.5 mL min⁻¹. The analyte peaks were detected at 235 nm for doxorubicin and daunorubicin, and 220 nm for vincristine. Linearity was obtained in different concentration ranges between 0.10 and 12 μg mL⁻¹ for all compounds. Good sensitivity for all analytes was observed with DAD detection. LOD and LOQ of the method were found satisfying. The proposed method has been extensively validated in accordance with ICH guidelines and obtained results proved that the proposed method was precise, accurate, selective, and sensitive for simultaneous analysis of studied compounds. All analytical procedures including sample preparation, flow rate, and run time were at low levels. Also, pK _a values were determined using the dependence of the retention factor on the pH of the mobile phase. The effect of the mobile phase composition on the ionization constant was studied by measuring the pK _a at different methanol–water mixtures, ranging between 45 and 60 % (v/v).

     

A Novel RP-LC Method for Determination of pK a Values of Some Anticancer Agents and Their Assay

A simple, reliable, and rapid RP-LC method has been developed for the determination of some anticancer drugs (daunorubicin, doxorubicin and vincristine sulfate) in their dosage forms and human urine. These compounds are well separated on a C18 column using the mobile phase consisting of a mixture of acetonitrile (50:50; v/v) at a flow rate of 1.5 mL min^?1. The analyte peaks were detected at 235 nm for doxorubicin and daunorubicin, and 220 nm for vincristine. Linearity was obtained in different concentration ranges between 0.10 and 12 μg mL^?1 for all compounds. Good sensitivity for all analytes was observed with DAD detection. LOD and LOQ of the method were found satisfying. The proposed method has been extensively validated in accordance with ICH guidelines and obtained results proved that the proposed method was precise, accurate, selective, and sensitive for simultaneous analysis of studied compounds. All analytical procedures including sample preparation, flow rate, and run time were at low levels. Also, pK _a values were determined using the dependence of the retention factor on the pH of the mobile phase. The effect of the mobile phase composition on the ionization constant was studied by measuring the pK _a at different methanol–water mixtures, ranging between 45 and 60 % (v/v).