A novel spectrofluorimetric method for the assay of pseudoephedrine hydrochloride in pharmaceutical formulations via derivatization with 4‐chloro‐7‐nitrobenzofurazan

Abstract

A new highly sensitive and specific spectrofluorimetric method has been developed to determine a sympathomimetic drug pseudoephedrine hydrochloride. The present method was based on derivatization with 4-chloro-7-nitrobenzofurazan in phosphate buffer at pH 7.8 to produce a highly fluorescent product which was measured at 532 nm (excitation at 475 nm). Under the optimized conditions a linear relationship and good correlation was found between the fluorescence intensity and pseudoephedrine hydrochloride concentration in the range of 0.5-5 µg mL(-1). The proposed method was successfully applied to the assay of pseudoephedrine hydrochloride in commercial pharmaceutical formulations with good accuracy and precision and without interferences from common additives. Statistical comparison of the results with a well-established method showed excellent agreement and proved that there was no significant difference in the accuracy and precision. The stoichiometry of the reaction was determined and the reaction pathway was postulated.

A Novel Fluorimetric Method for Determination of Pseudoephedrine Hydrochloride in Pharmaceutical Formulations and Blood Serum

“…Table 5 compares the analytical figures of merit of the proposed method with those of some previously published methods. The proposed method offers analytical characteristics that are better than its fluorimetric predecessor [17]. As compared to some methods [1], it does not need any expensive equipment or laborious pretreatment step, and compared to others [10] it does not need sophisticated mathematical calculations.…”

“…Most of these methods are expensive, time-consuming, and use multiple techniques or need tedious and labor-intensive sample pretreatment prior to analysis. Although some HPLC- [16] and CE-based [9] methods of analysis use laser-induced fluorescence detection, to the best of our knowledge, no more than one fluorescence analysis method has been proposed for determination of PSH [17].…”

Chromogenic and Fluorogenic Probes for the Detection of Illicit Drugs

“…El‐Didamony and Gouda report on the development of a spectrofluorometric method for the detection of pseudoephedrine ( 41 ) in commercial pharmaceutical formulations in pure and dosage forms through its derivatization with 4‐chloro‐7‐nitrobenzofurazan ( 42 ) (Scheme ) . Compound 42 itself is nonemissive but upon reaction with thiols or amines, it forms highly fluorescent product 43 .…”

“…- [33] MA molecular recognition (perylene bisimidefluorophore, and two cholesterol subunits) vapor5.5 10 À6 amines, organic solvents, water,a pple pomace [34] MDMA NPs water0.95 cocaine, heroin, methadone, and morphine [ 35] MA molecular recognition (aminefunctionalized polyfluorene) THF 2.5 10 À5 pethidine and EPH [36] MDMA NPs water-AMP,g lucose, glycine, and sarcosine [37] AMPH,M ETH, MDMA; and DA molecular recognition (macrocyclic) H 2 O/MeOH (7:3, v/v, pH 7.4) 7.4 10 À6 , 1.3 10 À6 , 8.0 10 À6 ,and 6.7 10 À5 - [38] MDMA and MDA colorimetric reaction sulfuric acid aqueous (75 %, w/v) 0.19 - [39,40] MA NPs toluene and vapor -o-toluidine, hexylamine, diethylamine,dibutylamine, allylamine, trimethylamine, and aniline [41] catecholaminemolecularr ecognition water-biogenica mines, sugars, neurotransmitters, and aminoa cids [42] phenothiazinedrugs spectrophotometric methodsulfuric acid -- [43] ChemistryOpen 2018, 7,401 -428 www.chemistryopen.org 2018 The Authors. Publishedb yWiley-VCH Verlag GmbH &Co. KGaA, Weinheim STIMULANT DRUGS PEA UV n-hexane1 0 À4 phenylethanolamine [44] d-a nd l-a-phenylethylamines fluorescencechiral sensors MeCN -- [45] PEPH hydrochloride spectrofluorometricmethodPBS(pH 7.8) 0.5 additiveore xcipients present in the pharmaceuticalsf ormulations [46] cocaine, MDMA/MDA, and heroine/morphine spectralfluorescence signature (SFS) measurements water -- [47] MA aptasensor combined with AuNPs (colorimetric assay) human urine 1.2 10 À4 pethidine, triazolam, barbital, morphine, ketamine, and diazepam [49] MA aptasensorand oxidationr eaction of afluorophore water 7.4 10 À9 ketamine,norketamine, morphine, methadone, cocaine, mephedrone, cathinone, methcathinone, 3-trifluromethylphenyl piperazine,1 -3-trifluromethylphenyl piperazine, 3,4-methylenedioxy pyrovalerona, MDA, MDMA, EDDP,and mCPP [50] cocaineaptamern anomachine (FRET processa llowed or not depending on the analyte) water 1.5 10 À4 - [51] cocaineaptamern anomachine and amplified aptamer nanomachine (quenching off/on process) water 3.0 10 À5 for normal and 3.5 10 À17 for amplified process - [52] cocaineaptamern anomachine (quenching off/on process)…”

“…El-Didamonya nd Gouda report on the development of a spectrofluorometric method for the detection of pseudoephedrine (41)i nc ommercial pharmaceuticalf ormulations in pure and dosage forms through its derivatization with 4-chloro-7-nitrobenzofurazan (42)(Scheme6). [46] Compound 42 itself is nonemissive but upon reactionw ith thiols or amines,i tf orms highly fluorescent product 43.I np hosphate-buffered saline (PBS, pH 7.8), 41 reacts with 42 to yield as trongly emissive derivativewith ab and at l = 532 nm. The authors optimize several parameters such as pH, buffer,c oncentration, solvent, and temperature finally to proposeamethod that can measure concentrations of 41 down to 0.5 mg mL À1 with good accuracy and precision.…”