Imran M, Singh R S P, Chandran S
Formulation Development & Pharmacokinetic Laboratory, Pharmacy Group, Birla Institute of Technology & Science, Pilani, India.
Pharmazie. 2006 Sep;61(9):766-9.
In this study, new and rapid stability indicating ultraviolet spectroscopic methods were developed and validated for the estimation of ezetimibe and carvedilol in pure form and in their respective formulations. Since both the drugs are poorly water soluble, 20% v/v acetonitrile in triple distilled water was selected as the solvent system for both the drugs. This ensured adequate drug solubility and maximum assay sensitivity. The linearity range for ezetimibe and carvedilol at their respective wavelength of detection of 232 nm and 238 nm was obtained as 2-50 microg/ml and 2-20 microg/ml respectively. The linear regression equations obtained by least square regression method, were Y = 0.0443 x (X) + 0.0106 for ezetimibe and Y = 0.1080 x (X) + 0.034 for carvedilol, where Y is the absorbance and X is the concentration (in microg/ml) of pure drug solution. The detection and quantitation limit as per the error propagation theory were found to be 0.4 microg/ml and 1.3 microg/ml respectively for ezetimibe and 0.7 microg/ml and 2.1 microg/ml respectively for carvedilol. The methods were employed with high degree of precision and accuracy for the estimation of total drug content in two commercial tablet formulations of each of the two drugs. It was concluded that both the developed methods are accurate, sensitive, precise, and reproducible. They can be applied directly for the estimation of drug content in pharmaceutical formulations.
在本研究中，开发并验证了新的快速稳定性指示紫外光谱法，用于测定纯形式以及各自制剂中的依折麦布和卡维地洛。由于两种药物的水溶性都很差，因此选择三重蒸馏水中20%（v/v）的乙腈作为两种药物的溶剂系统。这确保了药物有足够的溶解度以及最大的测定灵敏度。依折麦布和卡维地洛在其各自检测波长232 nm和238 nm处的线性范围分别为2 - 50 μg/ml和2 - 20 μg/ml。通过最小二乘法回归得到的线性回归方程，依折麦布为Y = 0.0443x(X) + 0.0106，卡维地洛为Y = 0.1080x(X) + 0.034，其中Y为吸光度，X为纯药物溶液的浓度（μg/ml）。根据误差传播理论，依折麦布的检测限和定量限分别为0.4 μg/ml和1.3 μg/ml，卡维地洛分别为0.7 μg/ml和2.1 μg/ml。这些方法以高度的精密度和准确度用于测定两种药物各自两种市售片剂制剂中的总药物含量。得出的结论是，所开发的两种方法准确、灵敏、精密且可重现。它们可直接用于药物制剂中药物含量的测定。
