Gowda Babu G, Seetharamappa Jaldappa, Melwanki Mahaveer B
Department of Chemistry, Karnatak University, Dharwad, India.
Anal Sci. 2002 Jun;18(6):671-4. doi: 10.2116/analsci.18.671.
Two simple and sensitive indirect spectrophotometric methods for the assay of propranolol hydrochloride (PPH) and piroxicam (PX) in pure and pharmaceutical formulations have been proposed. The methods are based on the oxidation of PPH by a known excess of standard N-bromosuccinimide (NBS) and PX by ceric ammonium sulfate (CAS) in an acidic medium followed by the reaction of excess oxidant with promethazine hydrochloride (PMH) and methdilazine hydrochloride (MDH) to yield red-colored products. The absorbance values decreased linearly with increasing concentration of the drugs. The systems obeyed Beer's law over the concentration ranges of 0.5 - 12.5 and 0.3 - 16.0 microg/ml for PPH, and 0.4 - 7.5 and 0.2 - 10 microg/ml for PX with PMH and MDH, respectively. Molar absorptivity values, as calculated from Beer's law data, were found to be 1.36 x 10(4) and 2.55 x 10(4) l mol(-1) cm(-1) for PPH, and 2.08 x 10(4) and 2.05 x 10(4) l mol(-1) cm(-1) for PX with PMH and MDH, respectively. The common excipients and additives did not interfere with their determinations. The proposed methods have been successfully applied to the determinations of PPH and PX in various dosage forms. The results obtained by the proposed methods compare favorably with those of official methods.
已提出两种简单且灵敏的间接分光光度法，用于测定纯品及药物制剂中的盐酸普萘洛尔（PPH）和吡罗昔康（PX）。这些方法基于在酸性介质中，已知过量的标准N-溴代琥珀酰亚胺（NBS）氧化PPH以及硫酸铈铵（CAS）氧化PX，随后过量的氧化剂与盐酸异丙嗪（PMH）和盐酸甲哌替嗪（MDH）反应生成红色产物。吸光度值随药物浓度增加呈线性下降。对于PPH，分别在与PMH和MDH反应时，在0.5 - 12.5和0.3 - 16.0 μg/ml的浓度范围内符合比尔定律；对于PX，分别在与PMH和MDH反应时，在0.4 - 7.5和0.2 - 10 μg/ml的浓度范围内符合比尔定律。根据比尔定律数据计算得出的摩尔吸光系数值，对于PPH与PMH和MDH反应时分别为1.36 x 10⁴和2.55 x 10⁴ l mol⁻¹ cm⁻¹，对于PX与PMH和MDH反应时分别为2.08 x 10⁴和2.05 x 10⁴ l mol⁻¹ cm⁻¹。常见的辅料和添加剂不干扰它们的测定。所提出的方法已成功应用于各种剂型中PPH和PX的测定。所提出的方法获得的结果与官方方法的结果相比具有优势。
