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High-Performance Liquid Chromatography
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Joel J. Kirschbaum, Adorjan Aszalos
Chromatographic properties of bulk cephalothin were studied using an octadecylsilane column at 55°C and a mobile phase of 0.001 M tetrabutylammonium hydrogen sulfate, 0.001 M tetrabutylammonium hydroxide, and 7.5% methanol in 0.01 M sodium phosphate buffer, pH 7.5, flowing at 0.5 ml/min into a 254 nm detector. The influence of temperature, organic modifier, and ion-pairing agent was studied. Cephapirin, desacetylcephapirin, cefazolin and 7-amino-cephalosporanic acid (7-ACA) can be satisfactorily resolved by this method [210].
Benzylpenicillin (Penicillin G)
Published in M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson, Kucers’ The Use of Antibiotics, 2017
Alasdair M. Geddes, Ian M. Gould, Jason A. Roberts, Jason A. Trubiano, M. Lindsay Grayson
The penicillin used initially was an amorphous compound containing impurities, which were introduced during the fermentative process; its activity and dosage were expressed in units. Early penicillin was also a mixture of several penicillin compounds, designated F, G, X, and K. Penicillin G (benzylpenicillin; Pen G) was the most satisfactory, and this is now used in a purified and crystalline form for clinical purposes. Pen G, similar to all penicillins and cephalosporins, is a beta-lactam antibiotic, thereby containing a beta-lactam ring that incorporates a beta-lactam bond. The penicillin nucleus, 6-aminopenicillanic acid (6-APA), consists of three components—a thiazolidine ring, the beta-lactam ring, and a side chain. The cephalosporin nucleus, 7-aminocephalos-poranic acid (7-ACA), is similar, but the five-member thiazolidine ring characteristic of the penicillins is replaced by a six-member dihydrothiazide ring (Waldvogel, 1982). Both 6-APA and 7-ACA were isolated some 50 years ago, and they have provided convenient starting points for the synthesis of other penicillins and cephalosporins that are described elsewhere in this book.
Research on the relationship between cephalosporin structure, solution clarity, and rubber closure compatibility using volatile components profile of butyl rubber closures
Published in Drug Development and Industrial Pharmacy, 2019
Xiao-Meng Chong, Xin Dong, Shang-Chen Yao, Chang-Qin Hu
To verify the specific adsorption of ceftriaxone sodium C3-side chain on BHT and its effect on the turbidity of samples further, the interaction of 7-ACA (C3-side chain was acetoxy) and 7-ACT (C3-side chain was triazine ring) with BHT was investigated by simulated adsorption experiments. The experimental results showed that there was no significant difference in the adsorption capacity of BHT between 7-ACA and 7-ACT. The adsorption of 7-ACT on BHT resulted in turbidity of the sample, while the adsorption of 7-ACA on BHT had little effect on the turbidity of the sample (Table 5). It was suggested that the triazine ring structure in 7-ACT had a stronger effect on the adsorption of BHT, indicating that the turbidity value of the sample was not only related to the amount of volatile substances adsorbed, but also to the binding strength of the two.