Johnsson J, Brorson J E
J Antimicrob Chemother. 1983 Sep;12(3):269-71. doi: 10.1093/jac/12.3.269.
Ampicillin, benzylpenicillin, cefaclor and cefuroxime were exposed to strains of Branhamella catarrhalis and Haemophilus influenzae with and without ability to produce beta-lactamase. The antibiotics were dissolved in phosphate buffer at pH 6, 7 and 8 and the mean enzyme activity was calculated from decrease in peak heights by the HPLC technique. Cefuroxime was the most stable drug regardless of pH. For the other antibiotics, changes in pH influenced the results. In infectious processes factors like pH and pCO2 show some variation. This fact may influence the interaction between beta-lactams and beta-lactamases.
氨苄西林、苄青霉素、头孢克洛和头孢呋辛分别作用于有或无β-内酰胺酶产生能力的卡他莫拉菌和流感嗜血杆菌菌株。将抗生素溶解于pH值为6、7和8的磷酸盐缓冲液中，并通过高效液相色谱技术根据峰高降低计算平均酶活性。无论pH值如何，头孢呋辛都是最稳定的药物。对于其他抗生素，pH值的变化会影响结果。在感染过程中，诸如pH值和二氧化碳分压等因素会有一些变化。这一事实可能会影响β-内酰胺类药物与β-内酰胺酶之间的相互作用。
