title: Spectrophotometric method for the determination of nifedipine with 4-(methylamino)phenol and potassium dichromate.
abstract: A new simple, sensitive and reproducible spectrophotometric method for the determination of nifedipine in pure and dosage forms has been proposed. It is based on the reduction of nifedipine with Zn/NNH4Cl, followed by coupling with N-methyl-1,4-benzoquinoneimine--the oxidation product of 4-(methylamino)phenol, to give a chromophore which absorbed maximally at 525 nm. The experimental conditions were optimised and Beer's law was obeyed over the concentration range of 5-175 microg ml(-1). The molar absorptivity, detection limit, recovery and RSD were found to be 1.9 x 10(3) l mol(-1) cm(-1), 1.1 microg ml(-1), 99.7-100.5% and 0.3-0.8%, respectively. The proposed method was compared favourably with the official B.P. method.
authors.affiliation: Department of Chemistry, Aligarh Muslim University, India. cht17nr@amu.up.nic.in
authors.forename: Nafisur
authors.initials: N
authors.lastname: Rahman
authors.forename: Md Nasrul
authors.initials: MN
authors.lastname: Hoda
mesh_terms: D000627:Aminophenols / Q000737:chemistry*; D000643:Ammonium Chloride / Q000494:pharmacology; D004355:Drug Stability; D006358:Hot Temperature; D006898:Hydroxylamines / Q000032:analysis / Q000737:chemistry; D016014:Linear Models; D009543:Nifedipine / Q000032:analysis* / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D011192:Potassium Dichromate / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013054:Spectrophotometry, Atomic; D013607:Tablets / Q000032:analysis; D013997:Time Factors; D015032:Zinc / Q000494:pharmacology
chemical_list: D000627:Aminophenols; D006898:Hydroxylamines; D010636:Phenols; D013607:Tablets; D000643:Ammonium Chloride; C014112:N-methyl-4-aminophenol; D009543:Nifedipine; D015032:Zinc; D011192:Potassium Dichromate