title: Simultaneous LC determination of tizanidine and rofecoxib in tablets.
abstract: A reverse phase high performance liquid chromatographic method to determine tizanidine (TZ) and rofecoxib (RF) in combination is proposed and applied to the pharmaceuticals. This method allows the determination of 0.1-0.5 microg/ml of TZ and 1.2-6.0 microg/ml of RF along with 10 microg/ml of nimesulide (internal standard), in a mobile phase consisting of 1% (v/v) triethylamine (pH adjusted to 2.5 using dilute orthophosphoric acid):acetonitrile in the ratio 55:45% (v/v). Detection wavelength of 303 nm and flow rate of 0.8 ml/min were fixed for the study. The limit of detection (LOD) for TZ and RF were found to be 10 and 1 ng/ml, respectively. The limit of quantification (LOQ) for TZ and RF were found to be 80 and 12 ng/ml, respectively. The amount of drug present in the tablet and the recovery studies were also carried out. The % R.S.D. of recovery studies for TZ and RF were found to be 0.0673 and 0.0146, respectively. The method is validated for accuracy, precision, ruggedness and robustness.
authors.affiliation: Department of Pharmaceutical Analysis, College of Pharmacy, Sri Ramakrishna Institute of Paramedical Sciences, Coimbatore 641044, Tamil Nadu, India. gands72@yahoo.co.in
authors.forename: M
authors.initials: M
authors.lastname: Gandhimathi
authors.forename: T K
authors.initials: TK
authors.lastname: Ravi
authors.forename: Susheel John
authors.initials: SJ
authors.lastname: Varghese
mesh_terms: D002626:Chemistry, Pharmaceutical; D002853:Chromatography, Liquid / Q000379:methods; D003000:Clonidine / Q000031:analogs & derivatives* / Q000032:analysis*; D004338:Drug Combinations; D007783:Lactones / Q000032:analysis*; D013450:Sulfones / Q000032:analysis*
chemical_list: D004338:Drug Combinations; D007783:Lactones; D013450:Sulfones; C116926:rofecoxib; C023754:tizanidine; D003000:Clonidine