Oxacillin analysis

It was recognized quite some time ago that DTA analysis could be used to deduce the compatibility between a drug substance and its excipients in a formulation. The effect of lubricants on performance was as problematic then as it is now, and DTA proved to be a powerful method in the evaluation of possible incompatibilities. Jacobson and Reier used DTA to study the interaction between various penicillins and stearic acid [17]. For instance, the addition of 5% stearic acid to sodium oxacillin monohydrate completely obliterated the thermal events associated with the antibiotic. Since that time, many workers employed DTA analysis in the study of drug-excipient interactions, although the DTA method has been largely replaced by differential scanning calorimetry technology. 

Fig. 6. A Chromatogram of a mixture containing the print molecule (oxacillin), two other p-lactam-antibiotics (penicillin G and penicillin V) and a non- 3-lactam-antibiotic (bacitracin) on an oxacillin imprinted MIP containing 4-vinylpyridine residues, cross-linked with TRIM. The analysis was performed in organic mobile phase (ACN/AcOH,99 l).B Same conditions but using the respective non-imprinted control polymer. C Structures of penicillin V, penicillin G, and oxacillin. Reprinted with permission from Skudar K, Briiggemann O, Wittelsberger A, Ramstrom O (1999) Anal Commun 36 327. Copyright 1999 The Royal Society of Chemistry...

BenzylpenicUlin (PCG), phenoxymethylpeniciUin (PCV), oxacillin (MPIPC), cloxaciUin (MCIPC), nafcillin (NFPC), and dicloxacillin (MDIPC), aU of which are representative weakly acidic penicUlins, are widely used as veterinary drugs for livestock. We have reported, in our previous studies, the applicability of sample cleanup with an ion-exchange cartridge, in combination with ion-pair HPLC, for the analysis of ionizable compounds. We therefore applied the same technique to develop an analytical method for the quantitative determination of these residual penicillins in bovine muscle, kidney, and liver. ... 

Ito, Y. Ikai, Y. Oka, H. Matsumoto, H. Kagami, T. Takeha, K. Application of ion-exchange cartridge clean-up in food analysis, in. Determination of henzylpenicillin, phenox3methylpenicilhn, oxacillin, cloxacillin, nafcillin, and dicloxacillin in hovine hver and kidney hy liquid chromatography with ultraviolet detection. J. Chromatogr., A 2000, 880, 85-91. 

Fig. 2 ESI LC/MS/MS analysis of penidUins fortified at a concentration of 0.05 mg/kg in bovine liver, a. Mass chromatograms monitored at [M-H-141] b, tandem mass spectra of penicillins recorded at the top of each peak on the mass chromatograms (a), (h-1) BenzylpeniciUin (b-2) phenoxymethylpeniciUin (b-3) oxacillin (b-4) cloxacillin (b-5) nafcUlin (b-6) dicloxacillin.

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