Manzo R H, Luna E, Allemandi D A
Departamento de Farmacia, Facultad de Ciencias Quimicas, Universidad Nacional de Córdoba, Argentina.
J Pharm Sci. 1991 Jan;80(1):80-4. doi: 10.1002/jps.2600800120.
The use of differential scanning potentiometry (DSP) to assay pure drugs and mixtures is illustrated through a set of model cases. The profiles obtained by scanning glycine (0.3 mmol), sulfanilamide (0.3 mmol), epinephrine (0.06 mmol), and norfloxacin (0.05 mmol) are reported, as well as the areas (A+, A-, and At) obtained in each scan. Such information is useful to assess identity and/or chemical purity and to get the pKa of the ionizing groups of the drugs. The degree of hydrolysis of a parenteral solution of procaine hydrochloride is also determined through DSP as an example of mixture assay. Comparison with conventional aqueous acid-based potentiometry shows that the new technique exhibits much better performance to assay small samples or samples carrying weak acidic and/or basic groups.
通过一系列模型案例说明了使用差示扫描电位法（DSP）分析纯药物和混合物的方法。报告了扫描甘氨酸（0.3 mmol）、磺胺（0.3 mmol）、肾上腺素（0.06 mmol）和诺氟沙星（0.05 mmol）所获得的图谱，以及每次扫描中获得的面积（A+、A-和At）。这些信息有助于评估药物的同一性和/或化学纯度，并获得药物电离基团的pKa值。作为混合物分析的一个例子，还通过DSP测定了盐酸普鲁卡因注射液的水解程度。与传统的基于水酸的电位法相比，新技术在分析小样品或带有弱酸性和/或碱性基团的样品时表现出更好的性能。
