Salvage parenteral antibiotics for multidrug‐resistant (MDR) Gram‐negative bacteria; a fluorescamine‐based technique for ultrasensitive spectrofluorimetric measurement of Polymyxins; human plasma application

Abstract

Polymyxins (PMS), namely Colistin (CS) and polymyxin B (poly B), are antimicrobial drugs that have been recently used to treat multiresistant Gram-negative bacteria infections and their resurgence, owing to a lack of new antibiotics. A speedy, simple, and ultrasensitive spectrofluorimetric screening of PMS in pharmaceutical formulations and biological fluids was urgently required from this point forwards. A reaction between fluorescamine and the aliphatic amino moiety found in both drugs was performed in a slightly alkaline borate buffer (pH 8.5) resulted in highly fluorescent products measured at λ em 460 (after λ ex 390.5 nm). Linear calibration curves were constructed over the concentration range 70-1800 ng ml À1 and 100 to 1400 ng ml À1 , with slope values of 0.273 and 0.286, correlation coefficients of 0.9998 and 0.9997, and determination coefficient of 0.9997 and 0.9994 for poly B and CS, respectively.The ultrasensitivity of the proposed method was demonstrated by the very low limit of quantification values of 67.56 ng ml À1 and 94.89 ng ml À1 for poly B and CS, respectively. The cited drugs were successfully determined in their intravenous market preparations by the prescribed method. Moreover, due to the high sensitivity, the suggested method was used to assay the investigated drugs in biological fluids.

Condensation methodology for quantification of Polymyxin B fluorimetrically: application to pharmaceutical formulations and greenness assessment

“…H 2 SO 4 [ 26 ] Fluorescamine Reaction 0.07–1.8 Room temperature for 10 min. Not cost-effective Not utilized [ 27 ] Ninhydrin & phenylacetaldehyde 0.2–3 80 ºC for 15 min. Cost-effective Not utilized Current work …”

“…The previously reported fluorimetric methods had limitations such as utilizing drastic conditions (boiling for a long time, 35 min.) [ 28 ] or employing an expensive reagent [ 27 ], or using hazardous chemicals [ 26 ]. So the described approach aimed to overcome these drawbacks by establishing a fast, cost-effective, and environmentally friendly methodology to be easily applied in routine quality control assay.…”

“…Belongs to published papers, more than one chromatographic approach as HPLC [2][3][4][5][6][7] and LC-Mass [8][9][10][11][12][13][14][15][16][17][18][19] also microbiological articles were reported [20,21]. On the other hand, spectroscopic techniques were listed, including spectrophotometric [22][23][24][25] and spectrofluorimetric [26][27][28] approaches. Owing to its simplicity, sensitivity, and no need for a complex apparatus or sample preparation, the spectrofluorimetry technique is frequently employed in recent drug analyses.…”

“…H 2 SO 4 [26]Fluorescamine Reaction 0.07-1.8 Room temperature for 10 min. Not cost-effective Not utilized[27]…”