Sagar K A, Smyth M R, Munden R
School of Chemical Sciences, Dublin City University, Ireland.
J Pharm Biomed Anal. 1993 Jul;11(7):533-40. doi: 10.1016/0731-7085(93)80002-i.
The oxidative voltammetric behaviour of salbutamol at a glassy carbon electrode surface has been studied using cyclic voltammetry and differential pulse voltammetry. Oxidation of the drug was effected in a single irreversible, adsorption-controlled step in phosphate buffer. The process was found to be dependent on the ionic strength and the pH of the supporting electrolyte. The response was evaluated with respect to accumulation time, scan rate and other variables. Using differential pulse voltammetry following electrochemical pretreatment of the electrode surface, the drug yielded a well-defined voltammetric response in phosphate buffer, pH 5.0, at +0.75 V (vs SCE). This process could be used to determine salbutamol concentrations in the range 8 x 10(-7) M to 8 x 10(-5) M with a detection limit of 2 x 10(-7) M. The method was applied, without any interferences from the excipients, to the determination of the drug in a tablet dosage form and in drug dissolution studies. The absolute recovery for salbutamol was greater than 95% at the concentration levels studied, and reproducible voltammetric signals were obtained with a relative standard deviation of 2.4% for n = 7 at a concentration level of 8 x 10(-5) M.
采用循环伏安法和差分脉冲伏安法研究了沙丁胺醇在玻碳电极表面的氧化伏安行为。该药物在磷酸盐缓冲液中以单一不可逆的吸附控制步骤进行氧化。发现该过程取决于支持电解质的离子强度和pH值。针对富集时间、扫描速率和其他变量对响应进行了评估。在对电极表面进行电化学预处理后，采用差分脉冲伏安法，该药物在pH 5.0的磷酸盐缓冲液中于+0.75 V（相对于饱和甘汞电极）处产生了明确的伏安响应。该方法可用于测定浓度范围为8×10⁻⁷ M至8×10⁻⁵ M的沙丁胺醇，检测限为2×10⁻⁷ M。该方法在无辅料干扰的情况下，应用于片剂剂型中药物的测定以及药物溶出度研究。在所研究的浓度水平下，沙丁胺醇的绝对回收率大于95%，在浓度为8×10⁻⁵ M时，n = 7时获得了可重现的伏安信号，相对标准偏差为2.4%。
