Journal of pharmaceutical and biomedical analysis
-
J Pharm Biomed Anal · Feb 2009
Determination of suxamethonium in a pharmaceutical formulation by capillary electrophoresis with contactless conductivity detection (CE-C(4)D).
A simple method based on capillary electrophoresis with a capacitively coupled contactless conductivity detector (CE-C(4)D) was developed for the determination of suxamethonium (SUX) in a pharmaceutical formulation. A hydro-organic mixture, consisting of 100mM Tris-acetate buffer at pH 4.2 and acetonitrile (90:10, v/v), was selected as background electrolyte (BGE). The applied voltage was 30kV, and the sample injection was performed in the hydrodynamic mode. ⋯ The presence of acetonitrile in the BGE allowed a reduction of SUX adsorption on the capillary wall. The CE-C(4)D method was validated, and trueness values between 98.8% and 101.1% were obtained with repeatability and intermediate precision values of 0.7-1.3% and 1.2-1.6%, respectively. Therefore, this method was found appropriate for controlling pharmaceutical formulations containing suxamethonium and degradation products.
-
J Pharm Biomed Anal · Jan 2009
Determination of paclitaxel and other six taxoids in Taxus species by high-performance liquid chromatography-tandem mass spectrometry.
A method of high-performance liquid chromatography-tandem mass spectrometry (LC-MS-MS) has been developed for the trace analysis of paclitaxel and other six taxoids in three Taxus species including Taxus cuspidata, Taxus media and Taxus chinensis var. mairiei. Seven taxoids were separated using a gradient mode on an Eclipse XDB-C18 column (4.6x150 mm; i.d., 5 microm) at 20 degrees C. The compound separations were detected by an API 3000 mass spectrometer equipped with a TurboIonSpray interface. ⋯ Linearity was confirmed over the whole calibration range (0.07-45, 0.058-37.5, 0.058-37.5, 0.056-36.3, 0.053-33.8, 0.057-37.5, and 0.06-38.8 microg/mL for 10-DAB III, baccatin III, 7-xyl-10-DAT, 10-DAT, cephalomannine, paclitaxel, and 7-epi-10-DAT, respectively) with coefficients higher than 0.9903. The inter- and intra-day precision of taxoids ranged from 2.86% to 6.31% for retention time and ranged from 3.91% to 7.33% for peak area. The recovery rates of this method were higher than 94.32% for 10-DAB III, 94.68% for baccatin III, 93.65% for 7-xyl-10-DAT, 93.29% for 10-DAT, 92.91% for cephalomannine, 93.41% for paclitaxel, and 93.06% for 7-epi-10-DAT, respectively.
-
J Pharm Biomed Anal · Jun 2008
Comparative StudyLiquid chromatography-atmospheric pressure ionization electrospray mass spectrometry determination of "hallucinogenic designer drugs" in urine of consumers.
A procedure based on liquid chromatography-mass spectrometry (LC-MS) is described for determination of 3,4-methylenedioxymethamphetamine (MDMA), 2,5-dimethoxy-4-methyl-phenethylamine (2C-D), 4-bromo-2,5-dimethoxy-beta-phenethylamine (2C-B), 1-(8-bromo-2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b'] difuran-4-yl)-2-aminoethane (2C-B-Fly), 4-ethylthio-2,5-dimethoxy-beta-phenethylamine (2C-T-2), 4-iodo-2,5-dimethoxy-beta-phenethylamine (2C-I), and 4-ethyl-2,5-dimethoxy-beta-phenethylamine (2C-E), 1-(m-chlorophenyl)piperazine (m-CPP), 4-hydroxy-N,N-diisopropyltryptamine (4-OH-DIPT) and 4-acetoxy-N,N-diisopropyltryptamine (4-acetoxy-DIPT) in urine of consumers using 3,4 methylendioxypropylamphetamine (MDPA) as internal standard. Sample preparation involved a solid-phase extraction procedure at pH 6 of both non-hydrolyzed and enzymatically hydrolyzed urine samples. Chromatography was performed on a C(18) reversed-phase column using a linear gradient of 10mM ammonium bicarbonate, pH 7.3 and acetonitrile as a mobile phase. ⋯ Calibration curves were linear to 2000 ng/mL for all the substances under investigation, with a minimum r(2)>0.99. At three concentrations spanning the linear dynamic range of the assay, mean recoveries ranged between 55.4 and 95.6% for the different analytes. Higher analytes concentrations in hydrolyzed samples showed the presence of conjugated compounds in urine.
-
J Pharm Biomed Anal · Jan 2008
Myrmecia pilosula (Jack Jumper) ant venom: validation of a procedure to standardise an allergy vaccine.
Ant sting allergy is relatively common within south-eastern Australia and is predominantly due to Myrmecia pilosula (Jack Jumper Ant, JJA). Venom immunotherapy has been shown to be effective in preventing anaphylaxis to the sting of the JJA, but analytical techniques to standardise the venom have not been validated. The purpose of this study was to develop assays to analyse JJA venom and apply these to the standardisation of venom prior to new batches being used for the diagnosis and treatment of JJA sting allergy. ⋯ SDS-PAGE and SDS-PAGE immunoblot were used as qualitative tools to determine the protein profile and presence or absence of additional high molecular weight allergens not quantifiable by HPLC-UV. A standardisation procedure has been developed that complies with the requirements described in the European Pharmacopoeia. Techniques used to determine the content of some of the other minor allergens could be developed, which would further improve the standardisation methodology.
-
J Pharm Biomed Anal · Jul 2007
A rapid and simple HPLC method for the analysis of propofol in biological fluids.
A selective and sensitive high-performance liquid chromatographic method for the analysis of propofol in biological samples was developed. Propofol and thymol (internal standard) were analysed on a Purospher RP-18 endcapped (75 mmx4 mm, 3 microm) stationary phase using acetonitrile and water (65:35, v/v) as eluents at a flow rate of 0.6 mL/min. The excitation and emission wavelengths were 276 and 310 nm, respectively. ⋯ The intra-day and inter-day precisions were lower than 5.5% for three concentrations assessed (0.05, 1.0 and 10.0 mg/L). Considering the column size and the flow rate, the separation was achieved with an analysis time less than 6 min with a reduced consumption of solvent. This rapid HPLC method using a simple treatment procedure is sensitive enough for monitoring propofol in human biological samples.