- Cefuroxime hydrolysis kinetics and stability predictions in aqueous solution
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Cefuroxime hydrolysis rate constants (k) were determined to predict the degradation rate of cefuroxime in aqueous solution as a function of pH, temperature, and buffer. At constant temperature, the pH rate expression was: k = k(H)(a(H)+) + k(S1)f1 + k(S2)f2 + k(OH)(a(OH-), where f1 is the fraction of cefuroxime in the undissociated form and f2 is the anionic fraction, k(H) and k(OH) are the catalytic rate constants for hydrogen activity (a(H)+) and hydroxyl ion activity (a(OH-), and k(S1) and k(S2) are first-order rate constants for spontaneous hydrolysis. Formate, acetate, phosphate, and borate buffers did not catalyze degradation. Temperature dependencies for k(H), k(S1), k(S2), and k(OH) were described with values for A (pre-exponential term) and E (energy of activation) calculated from k = Ae(-E/RT) (where R is 1.987 cal/mol-deg and T is absolute temperature). Combining the pH and temperature equations allowed predictions for cefuroxime hydrolysis rates in aqueous solutions at any pH and temperature. Results were validated by predicting the observed rate constants for every experimental condition and also for a reconstituted commercial product stored at 30°C. Maximum stability was observed in the pH-independent region from pH 4 to 7, where the time during which cefuroxime concentration exceeded 90% of its initial concentration at 25 °C was 1.2 days. Rate constants employed in predictions were based on stability-indicating HPLC assays. For selected conditions, additional rate constants were calculated from changes in cefuroxime UV absorbance. These UV constants did not consistently agree with the k values obtained with HPLC assays or with either of the rate constants determined for loss of cefuroxime to descarbamoyl cefuroxime or to the competing route, which is primarily β-lactam hydrolysis.
- Wang,Notari
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- Method for preparing cefuroxime acid
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The invention provides a method for preparing cefuroxime acid. The method is characterized by comprising the following steps: (1) mixing deammonized formyl cefuroxime in liquid ester, adding a strong amino carbamylation reagent sulfonylisocynate, and performing a temperature-controlled reaction; (2) adding purified water after the reaction is completed, and performing hydrolysis; (3) adding the liquid ester after hydrolysis is completed, adjusting the pH value to be 1.9-2.0 by using hydrochloric acid, standing for layering, and performing vacuum concentration on an organic layer so as to obtain an organic layer concentrated solution; (4) adding purified water into the organic layer concentrated solution, performing crystallization, and filtering so as to obtain cefuroxime acid, wherein the liquid ester used in the step (1) and the step (3) is selected from methyl acetate, acetic ether, n-butyl acetate, methyl formate, ethyl formate and propyl formate. The method for preparing cefuroxime acid, which is provided by the invention, is green and environmental-friendly, low in cost, high in yield and good in quality.
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Paragraph 0042; 0047; 0048
(2017/04/03)
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- Cefuroxime sodium compound prepared through advanced on-line process control technology and preparation thereof
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The invention discloses a cefuroxime sodium compound prepared through an advanced on-line process control technology and a preparation thereof. The project of high-grade medical product refining crystallization technology research and development and industrialization receives national scientific and technological progress second prize in 2015. The advanced on-line process control technology belongs to the high-grade medical product refining crystallization technology. An X ray powder diffraction test on cefuroxime sodium shows that in the spectrum, main characteristic peaks represented by diffraction angle 2theta are as follows: 9.71 degrees, 14.18 degrees, 16.19 degrees, 21.10 degrees, 22.88 degrees, 25.16 degrees and 30.77 degrees. The compound has the characteristics of high purity, low impurity content, good fluidity and good stability. The preparation is a cefuroxime sodium injection.
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- A Cefuroxime lysine and its preparation
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The invention relates to a cefuroxime lysine compound. The invention is characterized in that the cefuroxime lysine contains 98-99.99 wt% of cefuroxime lysine and 0.01-2 wt% of descarbamoyl cefuroxime, wherein the molecular formula of the descarbamoyl cefuroxime is disclosed as Formula I. The cefuroxime lysine provided by the invention has higher stability than the cefuroxime lysine in the prior art, and lower impurity content and polymer content than the cefuroxime lysine in the prior art, and is very suitable for clinical application.
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Paragraph 0100-0106
(2016/12/01)
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- A adopt the particle process crystal product molecular assembly and shape optimization technique of the new crystalline form of cefuroxime sodium compound and preparation (by machine translation)
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The invention discloses a new crystalline form of cefuroxime sodium compound and its crystallization preparation method, the new crystalline form of the compound is sodium [...] particle process crystal product molecular assembly and shape optimization technique to prepare. The stability tests prove that the new crystalline form of compound has high purity, low impurity content, guide the low moisture, the good characteristic of stability. At the same time, the invention also discloses the preparation of cefuroxime sodium employing the above described head-injection for the preparation. (by machine translation)
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- Process for the preparation of cefuroxime sodium
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The present invention relates to an improved process for the preparation of the sterile cefuroxime sodium of formula (I). 1
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- A kinetic study on the mechanism of cefuroxime degradation
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As a cephem derivative, cefuroxime is an unstable substance, liable to hydrolysis. Cefuroxime conversions were studied by following the concentrations of cefuroxime and decomposition products in relation to the pH of the medium by using HPLC method (0.5 mol dm-3 HCI, phosphate buffer, 0.1 mol dm-3 NaOH).
- Zajac, Marianna,Stanisz, Beata
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p. 111 - 115
(2007/10/03)
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