Spectrophotometric Methods as Solutions to Pharmaceutical Analysis of β-Lactam Antibiotics

Cielecka‐Piontek, Judyta; Zalewski, Przemysław; Krause, Anna; Milewski, Marek

doi:10.5772/48062

Cited by 1 publication

(1 citation statement)

References 47 publications

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“…It is interesting to note that amoxicillin degraded after a 20 min incubation period in 0.2 N NaOH solution, leading to the complete hydrolysis of the antibiotic [4], shows no visible changes in the absorbance spectra in the entire range between 240 -600 nm, even though the β-lactam ring underwent degradation. This indicates that the β-lactam ring opening itself does not produce absorbance signals in the visible region of radiation [7]. Figure 3 presents changes in the UV-spectra of an amoxicillin/iodine solution and also its absorbance at 350 nm during the titration of amoxicillin with an iodine reagent.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of the Chemical Integrity of Beta-Lactam Antibiotics by Iodine-Based Assay

Salois¹,

Perez²,

Palma³

et al. 2015

JBM

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One of the major problems associated with the therapeutic application of β-lactam antibiotics is their significant instability [1]-[3]. Analogs from that group are easily degraded in aqueous solutions and in solid state, which happens predominantly as a result of β-lactam ring chemical degradation. Because of this, the chemical integrity of β-lactam antibiotics must be closely monitored to meet FDA requirements. The original iodometric method based on visual detection of the end products of beta-lactamase hydrolysis that has been used to test beta-lactamase activity [4] was modified to quantitatively assess the amount of degraded product in amoxicillin. A UV-visible spectrophotometric method has been used, focusing on the ability of the products from the degradation of β-lactam analogs to absorb iodine from bulk solution, resulting in a significant reduction in the absorption spectra. Amoxicillin trihydrate tablets with different expiration dates and amoxicillin samples pre-loaded with known amounts of degraded amoxicillin have been used to generate a calibration curve and quantify the presence of degraded materials. Results show that the changes in the absorption spectra of iodine reagent directly correlate with the fraction of degraded β-lactam antibiotics, such as amoxicillin, in commercial products. The proposed assay might be as close as one step from simpler and cheaper methods of quantitative analysis of degraded β-lactam analogs, with estimated sensitivity in the range of 1%-2%, which is better than the current FDA requirements.

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Section: Resultsmentioning

confidence: 99%