A study of ofloxacin and levofloxacin photostability in aqueous solutions

Abstract

Introduction. The photostability is one of the most important properties of drugs. A comprehensive study of ofloxacin (OFX) and levofloxacin (LVX) photostability in aqueous solutions was performed. Ofloxacin is a chemotherapeutic agent belonging to the second generation fluoroquinolones and is a racemate of (R)-(+)-ofloxacin and (S)-(-)-ofloxacin (LVX).Material and Methods. Samples of OFX and LVX were subjected to stress conditions of UV irradiation using a mercury-vapor lamp. The study involved development of enantioselective high-performance liquid chromatography (HPLC) and high-performance capillary electrophoresis (HPCE) methods for separation of OFX enantiomers and their degradation products. These methods were used to monitor the degradation process of OFX and LVX under irradiation and to determine the kinetics of degradation of these antibacterial agents. Moreover, the identification of photoproducts was also attempted. The structure of the main photoproducts was examined by mass spectrometry (MS).Results and Conclusions. Using HPLC method it was possible to observe two products of OFX degradation and only one for LVX, while using HPCE method eight products of OFX degradation and six of LVX were observed. Some of the photoproducts retain character of optically active compounds. The trend of the photodegradation of both tested compounds was described by autocatalytic reaction proceeding according to the Prout-Tompkins model. Some of the products of the decomposition catalyze this reaction. The rate of degradation was similar for both enantiomers but t0.5 was slightly longer for LVX than OFX. Based on MS experiments the photodegradation products of the studied fluoroquinolones and possible pathways of UV induced decay were identified.

Adapting Fabric Phase Sorptive Extraction as an Innovative Multitool for Sample Transfer and Extraction in Pharmacokinetic Analysis Followed by LC-MS Determination of Levofloxacin in Plasma Samples

“…LEV, which initially degrades rapidly, is thought to be the part in contact with air and moisture in the top layer of the FPSE. It is already known that LEV cannot remain stable in high temperatures, and excessive moisture can lead to hydrolysis and degradation. − Besides temperature and moisture, oxidation is one of the major degradation factors for LEV. A forced degradation study for LEV reported by Dabhi et al clearly showed that at least 70% of LEV remained stable after 1 h under extreme pH values where acid or base hydrolysis occurred.…”

The Benefits and Challenges of Antibiotics–Non-Steroidal Anti-Inflammatory Drugs Non-Covalent Reaction

“…For example, levofloxacin was widely reported to degrade by UV radiation in both aqueous [103,104] and bulk solid form [105,106], as well as in a mixture with paracetamol [107]. The photolysis produced some toxic and allergenic products.…”

“…Besides the low solubility, instability towards light also becomes the main problem of fluoroquinolones [2,4,5]. Photolysis produces toxic substances immediately after UV exposure, in both liquid [103,104] and solid forms [105][106][107].…”

Green approach for tracking the photofate of ciprofloxacin and levofloxacin in different matrices adopting synchronous fluorescence spectroscopy: a kinetic study

“…Wastewater treatment via photocatalysis for the efficient removal of CIP and LEV was a subject of concern in many articles, whereas the review articles presented by Shurbaji et al [1] and Saya et al [24] represent a good deal to these researches. However, analytical methods proposed for simultaneous estimation of either drug with its photodegradation products are limited, and usually employ high-performance liquid chromatography coupled with mass spectrometry (HPLC/MS) [25][26][27][28]. Even though it has remarkable advantages, many limitations hinder the use of HPLC/MS widely: it requires experienced trained analysts for its operation, has a high cost in terms of analysis and maintenance, only employs volatile buffers and consumes large volumes of organic solvents contradicting basic principles of green chemistry [29].…”