October 31, 1997
Contact:
Kristy Wooley
Phone: 410/706-0914 / Pager: 410/909-9459
Email: [email protected]
NEWS TIPS -- Annual Meeting of the American Association of Pharmaceutical Scientists November 2-6, 1997, Boston, MA
Search and Destroy Molecular Cancer Drug Delivery System Shown to Reduce Toxicity
Chemotherapy works because it kills cancer cells. Unfortunately, the drugs can also kill healthy cells as they pass through the body on their way to the cancerous target. Many are so toxic they never make it to market. But researchers at the University of Maryland School of Pharmacy are developing a new drug delivery system that greatly reduces toxicity.
Parshant Chikhale, Ph.D., assistant professor, and colleagues report that their system delivers anti-cancer drugs directly to tumor sites, controls the delivery speed, and will not harm brain tissue.
The researchers are reporting on three studies that indicate the novel delivery system will release the drugs only in the presence of a tumor. Drug release can be controlled with this system because the bond between a novel carrier molecule and the drug can only be broken in the environment found in the presence of cancerous tissue. By modifying the structure of the molecule, the researchers also were able to decrease and increase the speed of the chemical reaction releasing the drug. Chikhale also reports that binding amino acid-based anti-cancer agents to their molecule rendered the drugs unable to permeate the blood-brain barrier, avoiding toxicity to the brain.
Chikhale's posters will be presented at the annual meeting during three morning sessions on November 4, 5, and 6 at the meeting.
G.I. Jane -- A Coffee Achiever Pharmacokinetic Study Shows Ovulation Has No Effect on Stimulant or Sleep Aids
Long flights to the Middle East were often followed by 24 to 36 sleepless hours of work for military personnel deployed during Desert Storm. Many relied on caffeine pills to stay awake, and later, sleeping pills when given a break, but are these aids effective for G.I. Jane?
Natalie Eddington, Ph.D., associate professor, University of Maryland School of Pharmacy, reports that
absorption and clearance of two sleep aids and a stimulant commonly used by military personnel are not affected by three phases of a woman's menstrual cycle.
Eddington and her colleagues administered a single oral dose of caffeine to women before, during and after the ovulatory cycles and collected 12 blood samples over 24 hours to determine absorption and clearance in blood plasma. In tests of sedatives -- triazolam and indocyanine green -- the researchers also administered the doses before, during and after ovulation and collected blood plasma samples.
They found no differences in absorption and elimination for caffeine. The researchers did find slight differences in clearance and distribution for the sleep aids, but these were not statistically significant.
Eddington and two School of Pharmacy graduate students, Nattee Sirisuth and Angela Joubert, will present two posters on Wednesday, November 5, from 9:30 a.m. to 12:30 p.m. at the annual meeting.
Cancer Drug Detection Method Laser Used to Measure Camptothecin Levels in Human Blood
Researchers at the University of Maryland and the University of Kentucky have developed a laser detection method for monitoring levels of a new cancer treatment drug in human blood and plasma.
Topotecan is a newly approved ovarian cancer treatment from the camptothecin group of drugs. Some patients apparently have an affinity for the drug, absorbing and eliminating the topotecan at differing rates for reasons that remain unclear to scientists. Using a direct detection method will allow clinicians to make sure the drug remains within a therapeutic range, which is critical for preventing overdoses.
The researchers have found that camptothecins fluoresce when excited with a long wavelength Ti:Sapphire laser. Joseph Lakowicz, Ph.D., professor, University of Maryland School of Medicine, Center for Fluorescence Spectroscopy, has a patent pending on the laser process. Thomas G. Burke, Ph.D., associate professor, University of Kentucky College of Pharmacy, will report that the method may also allow them to determine the amount of free vs. bound drug in direct measurements of blood samples.
Burke will make a podium presentation on Tuesday, November 4, at 2:55 p.m.
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