e-mail: gt0335c@prism.gatech.edu or
gtironman@aol.com
Areas: Pharmeaceutical Separations and Supercritical Fluids
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Name: Jimmy C. Bonner, Jr. e-mail: gt0335c@prism.gatech.edu or gtironman@aol.com Areas: Pharmeaceutical Separations and Supercritical Fluids |
Paclitaxel is the most promising anti-cancer drug discovered to date, providing significant antineoplastic activity in ovarian and metastatic breast cancers. First found in the bark of the western yew Taxus brevifolia, the highly functionalized paclitaxel moiety acts as a mitotic spindle poison via enhancement of tubulin polymerization. Supercritical extraction with cosolvent enhanced carbon dioxide was studied as a means of separation of paclitaxel from renewable resources. High pressure carbon dioxide (10 to 60 MPa), modified with 10 mol% ethanol, was able to extract Paclitaxel from Taxus x media 'Hicksii' needles. Extraction efficiency increased with pressure, as did extraction rate.
The supercritical extracts were adsorbed onto activated carbon and desorbed with supercritical carbon dioxide to effect a post-extraction separation. The desorption step simplifies subsequent chromatographic purification. Final purification of the extracts was completed by HPLC. An isocratic methanol:water:acetonitrile mobile phase (24:40:36) separated paclitaxel from other needle extracts. The three step separation process is considerably simpler than the solvent intensive industrial process and is capable of meeting projected paclitaxel demand without tapping the limited supply of old growth Taxus brevifolia.
Supercritical Fluid technology is also being applied to the separation of Merck & Co. pharmaceuticals. A number of industrial issues, such as process upset rectification, impurity removal, standard purification, and impurity purification, are being investigated as potential applications of the technology as a separation unit operation.
Completed a summer quarter at University College, London, as part of the Georgia Tech London program.
Graduated with Highest Honors from Georgia Tech in 1989.
Interned at Merck during the summer of 1989.
Graduated from MIT's Practice School in September, 1990. (Completed MIT practice school projects at GE in Waterford, NY, and Dow in Midland, MI.)
Currently employed by Merck and Co.
Technical Operations (1990-1992) Staff Engineer. Completed new product demonstrations and process engineering assignments.
Factory Two (1992-1995) Process Supervisor. Directly supervised four supervisors and 24 operators. Plant operations included the production supervision of Zocor(tm), Prilosec(tm), and Cozaar(tm) and related personnel, yield, purity, environmental, GMP, safety, and financial issues.
Assigned to Georgia Tech in September, 1995, to earn a doctorate in Chemical Engineering.
