Spironolactone

A stability indicating RP-HPLC method was developed for the simultaneous determination of Spironolactone (SRL) and Hydroflumethiazide (HFM) in pharmaceutical dosage form. Inertsil ODS - C18 (250 mm x 4.6 mm, 5 µm) column and mobile phase of methanol: acetonitrile : phosphate buffer in the ratio of 55:40:05 v/v at a flow rate of 1.0 mL/min was used for separation of the components. The components were detected at a wavelength of 221nm using UV detector. The Spironolactone and Hydroflumethiazide were separated at retention time 4.67 and 6.74 min respectively. The developed method was validated in terms of precision, accuracy, linearity, specificity, limit of detection, limit of quantitation. The range of linearity was found to be 5-30 µg/mL for Hydroflumethiazide and 5-30 µg/mL for Spironolactone. The proposed method was applied to study the stability of the drugs under different degradation conditions such as acid, alkali, peroxide, thermal and photo light. The developed method was found to be simple, sensitive and rapid and hence, It can be adopted in any laboratory for quality control analysis.

A simple, accurate and stability indicating high performance liquid chromatographic (HPLC) method was developed for the simultaneous estimation of Torsemide and Spironolactone in combined dosage form. Isocratic RP-HPLC separation was achieved on Kromasil RP- C18 column (250mm×4.6mm; 5µm) using methanol: acetonitrile: water in the ratio of 50:30:20 (v/v), pH6.8, at flow rate of1.0ml/min at ambient temperature. Quantization was achieved by UV detection at 235nm over the concentration range of 10-60μg/ml for torsemide and 25-150μg/ml for spironolactone with percentage recoveries of range 99.688-101.792 and 98.282-101.811for torsemide and spironolactone respectively. Different stress degradation studies like acidic, alkaline, peroxide, thermal etc were measured for both standard drugs and results found that the stress degradation conditions doesn’t affect the elution of the both the drugs and hence the developed method was found to be stability indicating method.

A modified liquid- liquid extraction based reverse phase high performance liquid chromatographic method has been developed and validated for the determination of Furosemide in human plasma. The chromatographic separation was achieved with Pinnacle C18 column (250 x 4.60 mm, 5μm i.d.) and a mobile phase comprising of a mixture of Methanol: Water: Triethylamine (70:30:0.1v/v/v), pH adjusted to 3.2 with orthophosphoric acid was used with UV detection at 274nm. The internal standard spironolactone structurally related to Furosemide was used. The retention time for Furosemide and spironolactone was found to be 3.75min and 8.12min respectively.  A calibration curve was linear in the concentration range of 200-2200ng/ml for Furosemide in blank human plasma. The % recovery from human plasma was found to be in the range of 89.41 to 93.91 for Furosemide. The lower limit of quantitaion was found to be 200ng/ml and no interference was found from endogenous compound. The specificity, linearity, accuracy, precision and stability of the method were evaluated from spiked human plasma sample as per EMA (European Medicine Agency) guideline. The method can be used for supporting therapeutic drug monitoring and pharmacokinetic studies.