title: Spectrophotometric determination of gabapentin in pharmaceutical formulations using ninhydrin and pi-acceptors.
abstract: Simple, rapid and sensitive spectrophotometric procedures are developed for the analysis of gabapentin in pure form as well as in their pharmaceutical formulations. The methods are based on the reaction of gabapentin as n-electron donor with ninhydrin and pi-acceptors namely, 2,3,5,6-tetrachloro-1,4-benzoquinone, chloranilic acid, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, tetracyanoethylene and 7,7,8,8-tetracyanoquinodimethane. The obtained complexes were measured at 568, 230, 314, 304, 335 and 439 nm for ninhydrin, chloranil, Chloranilic acid, DDQ, TCNE and TCNQ respectively. The proposed procedures could be successfully applied to the determination of gabepentin with good recovery; percent ranged from 99.3 to 100.7 The association constants and free energy changes using Benesi-Hildebrand plots are also studied.
authors.affiliation: Department of Chemistry, University of Karachi, Karachi 75270, Pakistan. farhanchemist@hotmail.com
authors.forename: Farhan Ahmed
authors.initials: FA
authors.lastname: Siddiqui
authors.forename: M Saeed
authors.initials: MS
authors.lastname: Arayne
authors.forename: Najma
authors.initials: N
authors.lastname: Sultana
authors.forename: Faiza
authors.initials: F
authors.lastname: Qureshi
authors.forename: Agha Zeeshan
authors.initials: AZ
authors.lastname: Mirza
authors.forename: M Hashim
authors.initials: MH
authors.lastname: Zuberi
authors.forename: Saima Sher
authors.initials: SS
authors.lastname: Bahadur
authors.forename: Nawab Sher
authors.initials: NS
authors.lastname: Afridi
authors.forename: Hina
authors.initials: H
authors.lastname: Shamshad
authors.forename: Nadia
authors.initials: N
authors.lastname: Rehman
mesh_terms: D000588:Amines / Q000032:analysis* / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D003509:Cyclohexanecarboxylic Acids / Q000032:analysis* / Q000737:chemistry*; D000077206:Gabapentin; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry; D007700:Kinetics; D057230:Limit of Detection; D016014:Linear Models; D009682:Magnetic Resonance Spectroscopy; D009555:Ninhydrin / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D013816:Thermodynamics; D005680:gamma-Aminobutyric Acid / Q000032:analysis* / Q000737:chemistry*
chemical_list: D000588:Amines; D003509:Cyclohexanecarboxylic Acids; D006841:Hydrocarbons, Aromatic; D007202:Indicators and Reagents; D004364:Pharmaceutical Preparations; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D009555:Ninhydrin