Reference

Application of a modified method to the determination of cephalosporins in pharmaceutical formulations by hydroxamic acid formation

Application of a modified method to the determination of cephalosporins in pharmaceutical formulations by hydroxamic acid formation. Fedai, Inci; Sengun, F. Inci (Eczacilik Fak., Univ. Istanbul, Istanbul, Turk.). Istanbul Univ. Eczacilik Fak. Mecm., 20, 123-30 (English) 1984. CODEN: IEFMA9. ISSN: 0367-7524. DOCUMENT TYPE: Journal CA Section: 64 (Pharmaceutical Analysis) Optimum conditions were evaluated for the reaction of cephalosporins with Ni(II)-hydroxylamine and Fe reagents, and the results were applied to detn. of cephacetrile (I) [10206-21-0], cefamandole [34444-01-4], cefamandole nafate [42540-40-9], cefoperazone [62893-19-0],and ceftizoxime [68401-81-0]. Absorbance was measured at 440-480 nm depending on the cephalosporin. Beer's law was valid in the range 50-250 mg/mL. Relative std. deviations ranged 0.51-1.22% compared to 0.57-26.7% for an official method.

Determining antibiotics in biological liquids by colorimetry

Determining antibiotics in biological liquids by colorimetry. Klein, Hilton J. (Dynasciences Corp., USA). Eur. Pat. Appl. EP 134078 A2 13 Mar 1985, 21 pp. DESIGNATED STATES: R: DE, FR, IT, NL. (English). (European Patent Organization). CODEN: EPXXDW. CLASS: ICM: C12Q001-34. APPLICATION: EP 84-303966 12 Jun 1984. PRIORITY: US 83-521857 10 Aug 1983. DOCUMENT TYPE: Patent CA Section: 1 (Pharmacology) A colorimetric method for the detn. of b-lactam ring-contg. antibiotics (cephalosporins and(or) penicillins) in biol. fluids. is described. The method (considered simple, quick, reliable, and inexpensive) involves mixing the test liq. with a b-lactam ring-contg. chromogenic compd. and penicillinase [9001-74-5] (type II) for a predetd. time, measuring (by sight, colorimeter, or spectrophotometer) the amt. of color developed in the test liq., and comparing the color with a color std. Thus, mixing nitrocefin [41906-86-9] as the chromogenic cephalosporin substrate with type II penicillinase resulted in an uninhibited max. reaction (i.e. breaking of the lactam ring and producing of a red color); the addn. of cephalothin [153-61-7], cefazolin [25953-19-9], cephapirin [21593-23-7], cefamandole nafate [42540-40-9], or oxacillin [66-79-5] inhibited the reaction and formation of the red color.