Validated microbiological and HPLC methods for the determination of moxifloxacin in pharmaceutical preparations and human plasma

Abstract

The article presents a comparison between microbiological and high performance liquid chromatographic (HPLC) assays for quantification of moxifloxacin in tablets, ophthalmic solutions and human plasma. The microbiological method employed a cylinder-plate agar diffusion assay using a strain of Esherichia coli ATCC 25922 as the test organism and phosphate buffer (pH8) as the diluent. The calibration curves were linear (R2 > 0.98) over a concentration range of 0.125 to 16 µgml-1. The within day and between days precisions were ≤ 4.47% and ≤ 6.39% respectively. Recovery values were between 89.4 and 110.2%. The HPLC assay used Hypersil® BDS C18 reversed phase column (250×4.6 mm, 5µm) with a mobile phase comprising 20 mM ammonium dihydrogen orthophosphate (pH3) and acetonitrile (75:25) and flowing at 1.5 ml/min. The detection was at 295nm. The calibration curves were linear (R2 > 0.999) over the range of 0.125 to 16 µg ml-1. The within day and between days precisions were ≤ 4.07% and ≤ 5.09% respectively. Recovery values were between 97.7 and 107.6%. Similar potencies were obtained after the analysis of moxifloxacin tablets and ophthalmic solutions by both methods. Also pharmacokinetic parameters were calculated after the analysis of plasma samples of six male healthhy volunteers by both validated methods.

Application of microbiological assay to determine the potency of intravenous antibiotics

“…Similar curves were also prepared for with the generic drugs from different companies. The range of different concentrations those were used viz., 18,16,14,12,10,8,6 µg/µl for Ciprofloxacin and 32, 24, 16, 8, 4, 1, 0.25 µg/µl for Cefuroxime respectively. Data were expressed in a linear model (y = mx + b, where b is the y-intercept intercept and m is the slope) best fitting the data in regression analysis (Microsoft Office Excel 2010) with 95% confidence intervals (CI) (25).…”

“…Microbiological assay was first observed by Fleming which was lysozomal activity in agar plate and this assay was shortly followed by Heatley in an agar diffusion assay for penicillin (13). A reduction in the antimicrobial activity can be easily determined by microbiological assay under standard environmental condition which may demonstrate subtle change by chemical methods (14,15). Microbiological assay can be carried out under standard condition to observe the inhibition of growth of fully characterized microbial strains against different concentrations of antibiotics (16).…”

Kinetic Spectrophotometric Determination of Drugs Based On Oxidation by Alkaline Kmno4

“…Moxifloxacin (MOX) [ Fig.1 b] chemically known as l-cyclopropyl-6-fluoro-l, 4-dihydro-8-methoxy-7-[(4aS, 7aS)-octahydro-6H-pyrrolo-[3, 4-b] pyridin-6-yl]-4-oxo-3-quinolinecarboxylic acid is a fourth generation fluoroquinolone broad spectrum antibiotic agent used in Conjunctivitis [7,8]. Some methods such as HPLC [9,10], Fluorimetry [11,12], spectrophotometry [13,14] and Voltammetry [15] are used for the determination of MOX.…”

Selection of appropriate analytical tools to determine the potency and bioactivity of antibiotics and antibiotic resistance

“…A reduction in antimicrobial activity will also reveal subtle changes not demonstrable by chemical methods [16] , [17] . The microbiological assay is the only standard method for the estimation of loss in the activity of an antibiotic [17] .…”