Biomedical subjects

S McClintock

Publications and source records attributed to S McClintock.

4 recordsLinked to original sources

PubMed2003

Computer-assisted method development and optimization in high-performance liquid chromatography.

This paper reports the use of DryLab, a computer simulation software package, to assist in the development and optimization of a reversed-phase high-performance liquid chromatographic (HPLC) method for the separation of a model drug candidate and its degradation products. Prior to the optimization process, columns with various bonded phases are evaluated for their chromatographic performance using the sample of interest. Simultaneous optimization of two separation variables and the use of resolution maps to predict the optimal conditions are illustrated. Options to optimize column conditions (column length and flow-rate) to further reduce run time are briefly discussed. The accuracy of DryLab-predicted retention times and resolution is compared with experimental values. The DryLab software used in this study provided satisfactory predictions for the selected model, with average errors of less than 3.5 and 11.8% for retention time and resolution, respectively.

Chromatography, High Pressure Liquid↗

PubMed2002

Application of pressurized liquid extraction technology to pharmaceutical solid dosage form analysis.

The technique of pressurized liquid extraction has been evaluated for the extraction of active ingredients from pharmaceutical dosage forms using montelukast sodium oral chewable tablets as a model. The extraction method was optimized for the number of extraction cycles, extraction time, extraction solvent composition and temperature. Samples were extracted using two cycles of water for 2 min with a cell temperature of 40 degrees C and a pressure of 1.0 x 10(4) kPa, to disintegrate the tablet, followed by three cycles of methanol for 3 min at 70 degrees C and 1.0 x 10(4) kPa, to solubilize montelukast sodium. The method demonstrated an extraction efficiency of 98.2% of label claim and an RSD of 1.3% (n=10), as compared to 97.6% and an RSD of 0.9% obtained using a validated mechanical extraction method.

Chromatography, Liquid↗

PubMed1995

Popliteal vein aneurysm: an unusual source of pulmonary embolus.

A 78 year old woman developed repeated major pulmonary emboli following nasal resection for recurrent basal cell carcinoma. Lower extremity venography performed prior to planned insertion of an inferior vena caval filter unexpectedly revealed a large thrombus-containing aneurysm of the proximal popliteal vein. The aneurysm was excised and the vein repaired by lateral suture. Anticoagulation was continued for 3 months postoperatively. There were no further episodes of pulmonary embolism and popliteal vein patency was confirmed by duplex ultrasound 3 months postoperatively. The literature pertaining to these rare popliteal venous aneurysms is reviewed.

Aged↗

PubMed1991

Myocardial and aerobic requirements for an upper body exerciser: implications for cardiac rehabilitation.

To assess the cardiorespiratory, hemodynamic, and electrocardiograph (ECG) responses to an upper body exercise device, we studied ten cardiac men (mean age +/- SD = 58.0 +/- 6.5 years) who performed three five-minute exercise bouts at metronome settings of 20, 50, and 80 clicks per minute. Operation of the device involved shuttling a plastic buoy on two 6-m waxed ropes between two persons. Aerobic requirements were generally appropriate for arm training, corresponding to mean values of 5.3, 7.0, and 10.1 ml.kg-1.min-1 at the three progressive metronome settings. Perceived exertion (Borg, 6 to 20 scale) at these work rates was 8.3, 10.4, and 14.6, whereas average heart rate and systolic blood pressure responses were 77, 85, and 114 beats.min-1 and 145, 158, and 175 mmHg, respectively. Continuous ECG monitoring during upper body exercise revealed no significant ST-segment depression or serious arrhythmias. The device appears to be a safe and effective complement to a cardiac exercise training program.

Aged↗