Uri J V
Acta Microbiol Hung. 1986;33(3):177-82.
Cefatrizine (SK & F 60771; BL--S640), like most other phenylglycine-type cephalosporins, has a tendency to lose potency in aqueous solutions and in normal sera even at low temperatures. Cefatrizine can be stabilized during storage by sodium metabisulphite (Na2S2O5), a reducing agent partially in tap water, better in deionized water, and to a lesser degree in citric acid-phosphate buffer (pH 6). Although this partial stabilizing effect of sodium metabisulphite is temperature-dependent, storage at 4 degrees C gives better results than storage in the frozen state (-20 degrees C). In these aqueous solutions and in sera, the potency of cefatrizine can be preserved even at room temperature for up to four weeks by the addition of 0.1 ml of 2 N hydrochloric acid to each 2 ml of aqueous solutions or sera.
头孢曲嗪（SK&F 60771；BL--S640）与大多数其他苯甘氨酸型头孢菌素一样，即使在低温下，在水溶液和正常血清中也有失去效力的倾向。头孢曲嗪在储存期间可用焦亚硫酸钠（Na2S2O5）稳定，焦亚硫酸钠是一种还原剂，在自来水中有一定程度的稳定作用，在去离子水中效果更好，在柠檬酸-磷酸盐缓冲液（pH 6）中稳定作用较小。尽管焦亚硫酸钠的这种部分稳定作用与温度有关，但在4℃储存比在冷冻状态（-20℃）储存效果更好。在这些水溶液和血清中，通过向每2 ml水溶液或血清中加入0.1 ml 2 N盐酸，即使在室温下，头孢曲嗪的效力也可保存长达四周。
