Determination of grepafloxacin in plasma samples by HPLC: Application to clinical pharmacokinetic studies

Abstract

SummaryA sensitive HPLC assay for the determination of grepafloxacin (GRE) in biological samples is described. Sample preparations were carried out by adding phosphate buffer (pH 7.4, 0.1M), followed by extraction with trichloromethane. GRE and the internal standard, enrofloxacin (ENR), were separated on a reversed-phase column using an aqueous phosphate solution-acetonitrile (78 : 22) mobile phase. The concentrations of ENR and GRE eluting of the column with retention times of 2.55, and 4.90 min, respectively were monitored by fluorescence at 2ex 338 and 2em 425 nm. The method was shown to be linear from 5 to 4000 ng mL -1. The detection and quantitation limits were 5 and 10 ng mL q, respectively. Mean recovery was determined as 90 %. Inter-and intra-assay precisions were 3.0 % and 3.5 % respectively. The method was applied to the determination of GRE in plasma samples collected during clinical pharmacokinetic studies.oquinoline-3-carboxylic acid, is a new antibacterial fluoroquinolone agent (Figure 1), that has been developed for use in the treatment of patients with a variety of disorders, such as pneumonia and urinary infections, and possibly for use in human ophthalmology-medicine [6][7][8][9]. Numerous methods have been developed for the analysis offluoroquinolones in biological samples. The analysis of fluoroquinolones has traditionally been performed using microbiological methods. However, these are slow and suffer from poor precision and specificity, and therefore HPLC methods have become an important tool for the routine determination offluoroquinolones in biological samples [ 10]. To our knowledge, information concerning HPLC assays of GRE from biological samples is very limited [11]. Thus, in this paper, our objective has been to develop and validate a simple, specific, rapid, and costsaving method for the determination of GRE in biological samples by way of HPLC using fluorescence detection. Finally, we have tested this method by describing the pharmacokinetics of GRE after intravenous administration in rabbits.

Grepafloxacin Concentration in Ocular Tissues after Intravenous Infusion in Rabbits with Intraocular Inflammation

“…Grepafl oxacin was assayed in plasma and ocular tissues according to a previously described HPLC method [7] .…”

“…Grepafl oxacin, although not currently marketed, has exhibited good activity against many of the potential pathogens that may cause ocular infections [6] and has shown a good penetration into rabbit eye structures in both albino and pigmented rabbits [7] . Grepafl oxacin has also been shown to be a safe alternative for intravitreal injection in intraocular infections [8] .…”

Histological Toxicity of Grepafloxacin after Intravitreal Injection

“…Analytical Assay GRE was assayed in intravitreal fluid according to the previous HPLC method [10]. A Waters 501 HPLC pump and a Waters M717 autosampler were employed.…”

“…The eluate was continuously monitored by a Waters 420-AC fluorescence detector (Ïex 338 nm and Ïem 425 nm). The calculations were all carried out by an Integration pack program (Kontrol Instrument, Spain) [10].…”

Ocular Penetration of Grepafloxacin after Intravitreal Administration in Albino and Pigmented Rabbits

“…Grepafl oxacin concentrations in the ocular tissues were determined by HPLC with fl uorescence detection according to a previously described analytical method [17] .…”