Determination Of Rofecoxib Research Articles

Development and validation of an HPLC method for determination of rofecoxib in bovine serum albumin microspheres.

A simple and reliable HPLC method was developed and validated for determination of rofecoxib in bovine serum albumin microsphere. The analyses were performed on a C18 column (150 x 4.6 mm, 5 μm particle size) at room temperature with UV detection at 272 nm. The mobile phase was composed of acetonitrile-0.1% o-phosphoric acid solution in water (1:1, v/v) mixture, and flow rate was set to 1 mL/min. The method was validated according to the international guidelines with respect to stability, linearity range, limit of quantitation and detection, precision, accuracy, specificity, and robustness. The detection and quantification limit of the method were 1.0 μg/mL and 2.5 μg/mL, respectively. The method was linear in the range of 2.5–25 μg/mL with excellent determination coefficients (R2 >0.99). Intra-day and inter-day precision (<1.76% RSD) and accuracy (<0.55 % Bias) values of the method also fulfilled the required limits. It was concluded that the developed method was accurate, sensitive, precise, and reproducible according to the evaluation of the validation parameters. The applicability of the method was confirmed for in vitro quantification of rofecoxib in bovine serum albumin microspheres.

Separation and determination of rofecoxib and its degradation products by TLC chromatography

A thin layer chromatography with densitometry method for the determination of rofecoxib and degradation products is described. The chromatographic separation was performed on silica gel TLC plates as a stationary phase and chloroform-acetone-toluene-glacial acetic acid (12: 5: 2: 0.1, v/v/v/v) as a mobile phase. Densitimetric detection was carried out at 256 nm. The method is of high sensitivity and low LOD and LOQ: from 0.35 μg/spot to 1.05 μg/spot. The recovery was satisfactory at 98.62%. In addition, the stability of rofecoxib in solutions was investigated, including an effect of solution pH, temperature and incubation time. The method is rapid, easy and selective, particularly for the analysis of rofecoxib formulations.

Stability-Indicating Methods for the Determination of Rofecoxib

Two stability indicating methods have been developed for determining rofecoxib in the presence of its degradation product. The first suggested method is high performance liquid chromatography (HPLC), in which analysis is carried out using hypersil BDS C18 column (250 × 4.6 mm I.D.) with mobile Phase consisting of 0.05 M phosphate buffer (pH 3.5) and acetonitrile (70:30 v/v). A linear relationship was obtained between the detector response at 225 nm and the corresponding concentration of the studied rofecoxib in the concentration range (1–6 μg / 10 μl) with mean % recovery of 99.80 ± 0.405. The second method depends on the quantitative densitometric evaluation of thin layer chromatograms (HPTLC) with mobil phase consisting of toluene: chloroform: methanol (60: 35: 5 v/v/v) by using fluorescent high performance silica gel 60 plate. A linear relationship was obtained between peak area and the concentration of the cited drug in the range 1–6 μg/spot with a mean % recovery of 99.79 ± 0.185. The suggested methods are precise, accurate, rapid and prove their specificity in the presence of its degradation products. Both procedures are successfully applied to determine the drug in the presence of its degradation product and also in their pharmaceutical formulations.

Determination of Rofecoxib in Serum with Pre-column Derivatization and Fluorescence Detection

Determination of Rofecoxib in Serum with Pre-column Derivatization and Fluorescence Detection

Pre-column derivatization of rofecoxib for determination in serum by HPLC

An HPLC method for determination of rofecoxib in human serum is presented. The method is based on pre-column derivatization of analyte to a phenanthrene derivative of the drug. Rofecoxib and the internal standard were extracted from serum using liquid-liquid extraction. Upon exposure to UV light, the drug was found to undergo a photocyclization reaction, giving a species with high absorbance. Validation of the method has been studied in the concentration range 10-500 ng ml(-1).

RP‐HPLC Assay of Rofecoxib from Pharmaceutical Dosage Forms and Human Plasma and Its Drug Dissolution Studies

ABSTRACT A high performance liquid chromatographic (HPLC) method is described for the determination of rofecoxib (RFC) in bulk drug, tablets, and human plasma samples. The methods are linear over the concentration ranges 0.005–30.0 and 0.010–10 µg mL−1 in mobile phase and human plasma, respectively. Chromatography was carried out on a reversed phase Spherisorb ODSI column using a mixture of acetonitrile:methanol: 0.067 M KH2PO4 (27:20:53, v/v/v) adjusted to pH 6.95 with 3 M NaOH. Detection was realized at 244 nm using a DAD detector. The retention time observed for RFC and etodolac (internal standard) at about 7.5 and 10.7 min, respectively. The proposed RP‐HPLC method was validated for precision, accuracy, ruggedness, and recovery. The limit of detection was found to be 0.00143 and 0.00301 µg mL−1 in mobile phase and human plasma samples, respectively. The proposed method allows a number of cost and time saving benefits. The described method can be readily applied for the analysis of tablets, drug dissolution studies, and human plasma samples. This method could be used without any interference from tablet matrix and endogenous substance from the plasma samples.

Determination of rofecoxib, in the presence of its photodegradation product, in pharmaceutical preparations by micellar electrokinetic capillary chromatography

A simple and rapid micellar electrokinetic capillary chromatographic (MEKC) method for analysis of rofecoxib (ROF) and its photodegradation product (PDP) in pharmaceutical preparations has been developed and validated. Analyses were conducted in a fused silica capillary (72 cm effective length, 50 microm i.d.) with a background electrolyte consisting of 25 mmol L(-1) borate buffer at pH 7.0 containing 15 mmol L(-1) sodium dodecyl sulfate (SDS) and 10% acetonitrile (ACN). The separation was performed by voltage-controlled system, applying 30 kV at 30 degrees C, detecting at 225 nm; injection was hydrodynamic at 50 mbar for 2 s. Nifedipine was used as internal standard (IS). Under the optimum conditions ROF, PDP, and IS were well separated with in 10 min. The method was validated with regard to linearity, limit of detection and quantitation, precision, accuracy, specificity, and robustness. The detection limit of the method was low, 0.8 microg mL(-1), and the linearity range was wide, 2.5 to 125 microg mL(-1). The method was highly efficient-5x10(5) plates m(-1) for ROF. The method was applied to the tablet form of ROF-containing pharmaceutical preparations. The data were compared with those from the voltammetric method described in literature. No statistically significant difference was found.

LC determination of rofecoxib in bulk and pharmaceutical formulations.

An isocratic reversed phase-liquid chromatographic (RP-LC) method has been developed for the determination and purity evaluation of rofecoxib in bulk and pharmaceutical dosage forms using photodiode array detection set at 225 nm. The method is simple, rapid and selective. The method is capable of detecting all process intermediates and other related compounds, which may be present at trace levels in finished products. Hence the method is very useful for process monitoring during the production of rofecoxib. Chlorophenyl methyl sulphone has been used as internal standard for the quantitative determination of rofecoxib. The method is linear in the range of 125-500 microg. The precision for inter- and intra-day assay variation of rofecoxib is below 1.6% relative standard deviation (R.S.D.). The accuracy determined as relative mean error (R.M.E.) for the intra-day assay is within +/-2.0%. The drug was extracted from tablets (Vioxx) using acetonitrile. The percentage recoveries from dosage forms were ranged from 98.2 to 102.6.

HIGH-THROUGHPUT LIQUID CHROMATOGRAPHIC DETERMINATION OF ROFECOXIB IN HUMAN PLASMA USING A FULLY AUTOMATED ON-LINE SOLID-PHASE EXTRACTION SYSTEM1‡

A fully automated on-line solid-phase extraction method combined with high-performance liquid chromatography-fluorescence detection for the determination of rofecoxib in human plasma is described. A Spark Holland PROSPEKT system was used to perform all the automated on-line sample extraction and quantitation tasks, including sample loading, cartridge conditioning and washing, analyte elution, and start of a data acquisition system. Under postcolumn ultraviolet–irradiation conditions, the analytes were photochemically converted to highly fluorescent products and then monitored by a fluorescence detector. The assay was validated in the concentration range of 0.5–100 ng/mL using 0.25 mL of human plasma. The utility of this method was demonstrated by analysis of plasma samples from human subjects receiving oral doses of rofecoxib. ‡ This work was presented at the Fifteenth Annual International Symposium on Laboratory Automation and Robotics, October 1997, Boston, MA, USA.

Determination of Rofecoxib (MK-0966), a cyclooxygenase-2 inhibitor, in human plasma by high-performance liquid chromatography with tandem mass spectrometric detection

A method for the determination of 4-(4-methanesulfonylphenyl)-3-phenyl-5H-furan-2-one (Rofecoxib, Vioxx, MK-0966, I) a cyclooxygenase-2 inhibitor, in human plasma has been developed. The method is based on high-performance liquid chromatography (HPLC) with atmospheric pressure chemical ionization tandem mass spectrometric (APCI-MS–MS) detection in negative ionization mode using a heated nebulizer interface. Drug and internal standard ( II) were isolated from basified plasma using liquid–liquid extraction. The organic extracts were dried, reconstituted in mobile phase and injected into the HPLC-MS–MS system. Compounds I and II were chromatographed on a narrow bore (100 mm×3.0 mm) C 18 analytical column, with mobile phase consisting of acetonitrile:water (1:1, v/v) at a flow-rate of 0.4 ml/min. The MS–MS detection was performed on a PE-Sciex API III Plus tandem mass spectrometer operated in selected reaction monitoring mode. The parent→product ion combinations of m/z 313→257 and 327→271 were used to quantify I and II, respectively, after chromatographic separation of the analytes. The assay was validated in the concentration range of 0.1 to 100 ng/ml of plasma. The precision of the assay (expressed as coefficient of variation) was less than 10% at all concentrations within the standard curve range, with adequate assay accuracy. The effect of HPLC mobile phase components on the ionization efficiency and sensitivity of detection in the positive and negative ionization modes, and the detailed description of all necessary steps involved in the assay for I in plasma are presented.