Education:

B.Sc., Pharmacy, 1963
M.Sc., Pharmaceutics, 1966
University of Toronto

Ph.D., Pharmaceutical Chemistry (Pharmacokinetics), 1972
University of California, San Francisco

Research Interests:

Dr. Sawchuk's research focuses on basic and applied pharmacokinetics. A significant part of this activity has dealt with absorption and elimination of anticonvulsants in human and animal studies. Clinical studies have been directed toward optimizing therapeutic response by using pharmacokinetics to individualize dosing regimens. A number of anticonvulsants that demonstrate nonlinear (time-dependent and/or concentration-dependent) pharmacokinetics have been the subject of this research.

A major research focus in Dr. Sawchuk's group is the investigation of drug delivery to the middle ear. One goal of this work is to enhance distribution of antibiotics in the treatment of otitis media.  His group is also examining the distribution of anti-infective drugs to lung tissue. Other research activities involve the targeting of centrally acting agents to brain tissue.  These investigations employ microdialysis coupled to online HPLC in freely moving, conscious animals to continuously monitor the concentration of drug and/or metabolites in tissue extracellular space.

Because of the reliance of pharmacokinetic studies on availability of sensitive and specific methods for analysis of drugs in biological fluids, significant time and effort is devoted to development of analytical methods.  The emphasis here is on HPLC and LC/MS/MS.  Dr. Sawchuk directs the Bioanalytic and Pharmacokinetic Services Laboratory.  This laboratory interacts with the pharmaceutical industry in the conduct of preclinical and clinical studies on new chemical entities and existing drugs.

Selected Publications:

B.W.Y. Cheung, L.L. Cartier, H.Q. Russlie and R.J. Sawchuk.  The application of sample pooling methods for determining AUC, AUMC and mean residence times in pharmacokinetic studies.  Fundamental & Clinical Pharmacology 19: 347-354 (2005).

Z.Yang, Y. Huang, G. Gan and R. J. Sawchuk.  Microdialysis evaluation of the brain distribution of stavudine following intranasal and intravenous administration to rats.  J. Pharm. Sci. 94: 1577-88 (2005).

J.Z. Peng, R.P. Remmel and R.J. Sawchuk.  Inhibition of murine cytochrome P4501A by tacrine: in vitro studies.  Drug Metab. Dispos. 32: 805-812 (2004).

T. Zhu, B.W.Y. Cheung, L.L. Cartier, G.S. Giebink and R.J. Sawchuk.  Simultaneous intravenous and intramiddle-ear dosing to determine cefditoren influx and efflux clearances in middle ear fluid in freely moving chinchillas.  J. Pharm. Sci. 92: 1947-1956 (2003).

G. Gan, L.L. Cartier, Y. Huang, Z. Yang and R.J. Sawchuk.  Intestinal absorption and presystemic elimination of the prokinetic agent, EM574, in the rabbit.  J. Pharm. Sci. 91: 218-228 (2002).

R.J. Sawchuk, D.J. Mulford and M.D. Mayer.  Pharmacokinetics of a new cephalosporin.  J. Resp. Dis. 22(8): Suppl. S43-S51 (2001).

Y. Huang, P. Ji, A. Inano, Z. Yang, G.S. Giebink and R.J. Sawchuk.  Microdialysis studies of the middle ear distribution kinetics of amoxicillin in the awake chinchilla.  J. Pharm. Sci. 90: 2088-2098 (2001).

W.F. Elmquist and R.J. Sawchuk.  Use of microdialysis in drug delivery studies.  Advanced Drug Delivery Reviews 45: 123-124 (2000).

R.J. Sawchuk and W.F. Elmquist.  Microdialysis in the study of drug transporters in the CNS. Advanced Drug Delivery Reviews 45: 295-307 (2000).