Liquid chromatographic and spectrophotometric methods for the determination of erythromycin stearate and trimethoprim in tablets

Green analytical methods for simultaneous determination of compounds having relatively disparate absorbance; application to antibiotic formulation of azithromycin and levofloxacin

Green validated spectrophotometric methods are developed for simultaneous determination of Azithromycin (AZI) and Levofloxacin (LEVO) antibiotic mixture. Determination of AZI presents a real analytical challenge as its structure lacks any chromophore, and hence it cannot be determined by direct spectrophotometry. However, the reaction of AZI with perchloric acid produces a green product that can be accurately determined spectrophotometrically. Thus, the work presented demonstrates simple green and sensitive methods for the simultaneous determination of AZI and LEVO mixture. Method I depends on direct measurement of absorbance of azithromycin and levofloxacin in perchloric acid methanolic solution at 482 nm and 224 nm, respectively. While, Method II depends on measuring the first derivative spectrophotometric peak-to-peak amplitudes of AZI and LEVO in perchloric acid methanolic solution at 475-490 nm and 280-253 nm, respectively. Regression analysis shows good linearity for AZI and LEVO over the concentration ranges of 5-50 and 2.5-20 μg/mL for method I and 5-50 and 5-40 μg/mL for method II for AZI and LEVO, respectively. The proposed methods were validated in compliance with ICH guidelines. The suggested procedures are successfully applied for the assay of AZI and LEVO mixture in bulk powder and laboratory-prepared tablets. Greenness profile of the proposed methods were compared with other published methods through applying the Eco-scale protocol. Assessment results demonstrated that the proposed methods are greener than other reported methods. Moreover, upon comparison with other methods, the proposed methods showed better or comparable sensitivity in addition to being selective and rapid with no requirement for laborious extraction techniques. These advantages encourage the application of the proposed methods in routine analysis of AZI and LEVO in quality control laboratories as green and simple analytical tool.

Brief Overview of Frequently used Macrolides and Analytical Techniques for their Assessment

Background:

Macrolide antibiotics are known as versatile broad-spectrum antibiotics. Macrolides belong to the oldest group of antibacterial agents. The macrolides which are frequently used for clinical purposes are broadly categorized in three classes depending on the number of membered macrocyclic lactone ring. These three classes actually consist of 14, 15 or 16 atoms in macrocyclic lactone ring which are linked through glycosidic bonds. Erythromycin, azithromycin clarithromycin and roxithromycin are frequently used to control against bacterial infections.

Methods:

The quality assurance and quality controls are important tasks in the pharmaceutical industries. Consequently, to check the quality of drugs, there is a strong need to know about alternative analytical methods for the routine analysis. Many methods have been reported in the literature for the quantitative determination of erythromycin, clarithromycin, azithromycin and clarithromycin in pharmaceutical formulations and biological samples.

Results:

This review will cover a brief introduction of erythromycin, azithromycin, clarithromycin and roxithromycin as well as analytical techniques for their assessment. Each developed method has its own merits and demerits.

Conclusion:

Any accurate method could be used for the quality control and quality assurance of macrolide antibiotics according to the availability, performance and procedure of selected instrument as well as skill and expertise of the analyst.

Isolation and characterization of a high-efficiency erythromycin A-degrading Ochrobactrum sp. strain

In this work, Erythromycin A(EA)- degrading bacteria was isolated from the contaminated soil obtained from a pharmaceutical factory in China. The isolate designated as strain WX-J1 was identified as Ochrobactrum sp. by sequence analysis of its 16S rDNA gene. It can grow in a medium containing EA as the sole source of carbon and its optimal growth pH and temperature were 6.5 and 32°C, respectively. Under these conditions, when the initial Erythromycin A concentration was 100mg·L^-1, 97% of Erythromycin A has been degraded. HPLC-MS analyses indicated that Erythromycin A degradation produced intermediates contained the following three substances: 3-depyranosyloxy erythromycin A, 7,12-dyhydroxy-6-deoxyerythronolide B, 6-deoxyerythronolide B and propionaldehyde. Since Erythromycin A-degrading Ochrobactrum sp. strain rapidly degraded Erythromycin A, this strain might be useful for bioremediation purposes.

Highly sensitive and selective erythromycin nanosensor employing fiber optic SPR/ERY imprinted nanostructure: Application in milk and honey

An erythromycin (ERY) detection method is proposed using the fiber optic core decorated with the coatings of silver and an over layer of ERY imprinted nanoparticles. Synthesis of ERY imprinted nanoparticles is carried out using miniemulsion method. The operating range of the sensor is observed to be from 1.62×10^-3 to 100µM while the sensor possesses the linear response for ERY concentration range from 0.1 to 5µM. The sensing method shows a maximum sensitivity of 205nm/µM near ERY concentration of 0.01µM. The detection limit and the quantification limit of the sensor are found to be 1.62×10^-3µM and 6.14×10^-3µM, respectively. The sensor's applicability in real samples is also examined and is found to be in good agreement for the industrial application. The sensor possesses numerous advantages like fast response time (<15s), simple, low cost, highly selective along with abilities towards online monitoring and remote sensing of analyte.