Optimization of HPLC method using central composite design for estimation of Torsemide and Eplerenone in tablet dosage form

Abstract A simple, precise, accurate and robust high performance liquid chromatographic method has been developed for simultaneous estimation of Torsemide and Eplerenone in tablet dosage form. Design of experiment was applied for multivariate optimization of the experimental conditions of RP-HPLC method. A Central composite design was used to study the response surface methodology and to analyse in detail the effects of these independent factors on responses. Total eleven experiments along with 3 center points were performed. Two factors were selected to design the matrix, one factor is variation in ratio of Acetonitrile and the second factor is flow rate (mL/min). Optimization in chromatographic conditions was achieved by applying Central composite design. The optimized and predicted data from contour diagram comprised mobile phase (acetonitrile, water and methanol in the ratio of 50: 30: 20 v/v/v respectively), at a flow rate of 1.0 ml/min and at ambient column temperature. Using these optimum conditions baseline separation of both drugs with good resolution and run time of less than 5 minutes were achieved. The optimized assay conditions were validated as per the ICH guidelines (2005). Hence, the results showed that the Quality by design approach could successfully optimize RP-HPLC method for simultaneous estimation of Torsemide and Eplerenone.

Comparison of Efficacy of Dexmeditomidine and Midazolam for Bloodless Surgical Field during Functional Endoscopic Sits Surgery (FESS) under General Anaesthesia

Objective: A comparative study to evaluate the efficacy of dexmedetomidine to provide bloodless surgical field in comparison to midazolam in Functional Endoscopic Sinus Surgery (FESS). Methods: 60 patients ASA I or II scheduled for FESS were equally randomly assigned to receive either Inj. Dexmedetomidine in dose of 1 g/kg over 10 min in infusion or Inj. Midazolam 0.02 mg/kg. In both groups, the infusion rate was adjusted to maintain the mean arterial blood pressure (MAP) of 65-70 mmHg. The induction was done using propofol (2.5 mg/kg) and atracurium (0.5 mg/kg). After the intubation, maintenance was achieved with O (50%), N O 2 2 (50%), Inj. Atracurium infusion and Sevoflurane. Intraoperative bleeding was estimated by the surgeon using Boezzart's scale for the evaluation of operative field visibility during the surgery. Hemodynamic variables (MAP and HR) were recorded. Results: Better achievement of MAP control is achieved with Dexmedetomidine compared to Midazolam. Overall intra-operative blood loss was more in Midazolam group compared to Dexmedetomidine group. Conclusion: Both Dexmedetomidine and Midazolam are safe and effective in FESS for controlled hypotension, though Dexmedetomidine provides excellent surgeon's satisfaction without severe hemodynamic changes