Ofloxacin assay

We then used this Caco-2 cell assay to categorize representative fluoroquinolone drug substance permeability [50], The drugs demonstrated some concentration-dependent permeability indicative of active drug transport. Based upon comparison to labetalol, ciprofloxacin was classified as a LP drug, whereas levofloxacin, lomefloxacin, and ofloxacin were classified as HP drugs, which matched their human in vivo bioavailabilities. All four fluoroquinolone drugs were subject to efflux transport (ciprofloxacin > lomefloxacin > rhodamine 123 > levofloxacin > ofloxacin). 

Lin et al. [52] reported simultaneous determination of vigabatrin and gabapentin in pharmaceutical preparations by simple capillary zone electrophoresis after derivatization with ofloxacin acyl chloride (OAC) with UV detection at 300 nm. The assay was rectilinear for both drugs over the concentration range of 50-500 /iM and the lower limit of detection was 5 /iM. Both the within-day and day-to-day reproducibilities and accuracies are below 3.1% and 4.8%, respectively. 

In another experiment, infusion bags containing 1.6mg/mL of pefloxacin or 0.8 mg/mL of ofloxacin or ciprofloxacin solutions were stored for eight hours without photoprotection. No significant losses of the parent drug were detected (25). No loss of diluted ciprofloxacin, 1.5mg/mL, was found by HPLC assay after 48 hours exposure at 25°C. This study used samples prepared in 5% glucose injection, or 0.9% sodium chloride injection, and all samples were exposed to fluorescent radiation (3). 

Fabre, D. Bressolle, F. Kinowski, J.M. Bouvet, O. Paganin, R Galtier, M. A reproducible, simple and sensitive HPLC assay for determination of ofloxacin in plasma and lung tissue. Application in pharmacokinetic studies. J.Pharm.Biomed.Anal., 1994, 12, 1463-1469 [pharmacokinetics LOQ 5 ng/mL column temp 50 fluorescence detection]... 

Lyon, D.J. Cheung, S.W. Chan, C.Y. Cheng, A.F. Rapid HPLC assay of clinafloxacin, fleroxacin, levo-floxacin, sparfloxacin and tosufloxacin. J.Antimicrob.Chemother., 1994, 34, 446-448 Mueller, B.A. Brierton, D.G. Abel, S.R. Bowman, L. Effect of feeding with Ensure on oral bioavailabilities of ofloxacin and ciprofloxacin. Antimicrob.Agents Chemother., 1994,38, 2101—2105 [extracted ciprofloxacin plasma ultrafiltration fluorescence detection A-57084 (IS) LOQ 9.5 ng/mL pharmacokinetics]... 

All the considerations above apply especially to assay by NMR, that is, strength determinations, usually using a well-characterised internal standard. Minimisation of errors leads to strength precision of 1% [196]. Other literature too demonstrates that good precision can be obtained. For example, the fluoroquinolones pefloxacin, norfloxacin, ofloxacin have been assayed by both and F NMR in commercial preparations [201] with good recoveries for... 

---