Orphenadrine citrate is an N-methyl-D-aspartate receptor antagonist

Orphenadrine citrate is an N-methyl-D-aspartate receptor antagonist, which is possible of analgesic effects. Associated side effects with orphenadrine citrate use are partially related to its anticholinergic action and include dry mouth, urinary retention, confusion, blurred vision, agitation, and restlessness. 4. Orphenadrine citrate is available in a combined form with paracetamol, aspirin, and nonsteroidal anti-inflammatory drugs.The Combination of Orphenadrine citrate and paracetamol has appeared predominant pain relieving impacts, compared to each fixing when utilized alone. 5, 6
Several quantitative instrumental methods have been described for determination of orphenadrine citrate, zero-Crossing derivative spectrophotometry 7,three analytical methods ( potentiometry, atomic absorption spectrometry, and spectrophotometry) built on reaction with ammonium reineckate to form ion-pair complexes 8,ion-pair complexes with cobalt-thiocyanate in 2 M HCl medium9, bromophenol blue, bromocresol green, and methyl orange as ion-pair reagents at pH 4 10, alizarine , alizarine yellow G ,alizarine red S or quinalizarin – drug ion-pair complexes 11, screening for basic drugs in 2-mL urine samples by dual-plate overpressured layer chromatography and comparison with gas chromatography-mass spectrometry12, modelling of spectrophotometric data using partial least-squares method 13, 4-chloro-7-nitro-2,1,3-benzoxadiazole in the nonaqueous medium as ?-acceptor. 14,simultaneous determination of paracetamol and orphenadrine citrate in dosage formulations and in human serum by RP-HPLC 15,eosin –drug ion pair complex 16, ?-acceptors such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 3,6-dichloro-2,5-dihydroxy-p-benzoquinone (p-CA) 17 , and application of normalized spectra in resolving a challenging Orphenadrine citrate and Paracetamol binary mixture18.
In the present study, the chromogenic reagent is the acidic dye Eriochrome black T (EBT) Sodium 1-(1-hydroxy-2-naphthylazo)-6-nitro-2-naphthol-4-sulphonate (NaH2In) figure-2, it’s of class azo (-N=N-) compound, and contains –SO3Na group allowing it to be soluble in water.At low pH (e.g. 1.4) the basic drug protonated (positively charged), and EBT is a completely ionized forming anion (H2In- ).The electrostatic attraction between cationic drugs and the anionic dyes produce an ion-pair complex, which definitely extracted using organic solvents. 19.