Utility of the fluorogenic characters of benzofurazan for analysis of tigecycline using spectrometric technique; application to pharmacokinetic study, urine and pharmaceutical formulations

Abstract

Tigecycline (TIGE) is the newest tetracycline derivative antibiotic with low toxicity, it is used for management of infectious diseases caused by Gram-positive and Gramnegative bacteria. Hence, an efficient, selective and sensitive method was developed for analysis of TIGE in commercial formulations, human plasma and urine. The spectrofluorimetric technique based on the reaction of secondary amine moiety in TIGE with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in slightly alkaline medium producing a highly fluorescent product measured at 540 nm (λ ex at 470 nm) after heating for 15 min at 75°C. The proposed strategy was upgraded and approved by ICH rules and bio-analytical validated using US-FDA recommendations. A linear relationship between fluorescence intensity and TIGE concentration was observed over the concentration range 40-500 ng mL −1 with limit of quantification (LOQ) 21.09 ng mL −1 and limit of detection (LOD) 6.96 ng mL −1 .The ultra-affectability and high selectivity of the proposed strategy permits analysis of TIGE in dosage form, human plasma and urine samples with good recovery ranged from 97.23% to 98.72% and from 99.36% to 99.80% respectively, without any interfering from matrix components. Also, the developed strategy was used to examine the stability of TIGE in human plasma and applied for pharmacokinetic investigation of TIGE.

Development of sensitive benzofurazan‐based spectrometric methods for analysis of spectinomycin in vials and human biological samples

“…Stoichiometry between SPEC and NBD-Cl was checked using a continuous variation method (Job's method), [22] as described previously [20,23,24] by preparing 1 × 10 −4 M SPEC and NBD-Cl.…”

Bio‐analytically fluorimetric method for estimation of ertapenem in real human plasma and commercial samples; application to pharmacokinetics study

“…During the reaction of EPM with NBD‐Cl reagent, a bi‐product, 4‐hydroxy‐7‐nitrobenzo‐2‐oxa‐1,3‐diazole (NBD‐OH), was formed. [ 3,5 ] Therefore it was necessary to acidify the medium used in the reaction before dilution to decrease the fluorescence intensity of NBD‐OH without affecting the reaction product. [ 3,5 ] The fluorescence of NBD‐OH was quenched using 1 ± 0.25 ml of 2 M HCl without affecting the fluorescence of the reaction product.…”

“…[1,2] In recent years, fluorimetric techniques have been the most applicable approach for estimation of varying pharmaceutical products in biomedical analysis because they are simple, sensitive, cost-effective, easily applied in a clinical laboratory, and selective. [1,[3][4][5][6] Varying methods have been reported for estimation of EPM such as spectrofluorimetry, [7] high performance liquid chromatography (HPLC) [8] and spectrophotometry. [9,10] Many drawbacks have been observed in the reported methods such as the use of highly expensive reagents, complicated equipment, and limited application.…”

Hydrogen Sulfide and Carbon Monoxide Tolerance in Bacteria

“…Some bacteria contain another type of CO regulator, namely RcoM, that upon binding of CO to its heme moiety controls transcription of coo and cox genes [ 107 , 108 ]. CooA responds only to CO, but other heme-based CO sensors also bind oxygen, namely Sinorhizobium meliloti FixLJ , Acetobacter xylinum AxPDEA1, B. subtilis HemAT, and E. coli Dos [ 109 , 110 , 111 , 112 ].…”

“…CooA is a homodimeric protein that upon CO binding to the heme undergoes a conformational change that triggers DNA ligation to the coo promoter, regulating the CO oxidation system [7,106]. Some bacteria contain another type of CO regulator, namely RcoM, that upon binding of CO to its heme moiety controls transcription of coo and cox genes [107,108]. CooA responds only to CO, but other heme-based CO sensors also bind oxygen, namely Sinorhizobium meliloti FixLJ, Acetobacter xylinum AxPDEA1, B. subtilis HemAT, and E. coli Dos [109][110][111][112].…”