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M E Royer

Publications and source records attributed to M E Royer.

13 recordsLinked to original sources

Medicinal chemistry of imidazoquinolinone dopamine receptor agonists.

(R)-5-(Dipropylamino)-5,6-dihydro-4H-imidazo[4,5,1-ij]-quinolin-2( 1H)-on e (1a, U-86170), a potent high intrinsic activity dopamine (D2) agonist, has been prepared in eleven steps from quinoline. In several tests, the compound showed dopamine autoreceptor agonist activity at low doses. It showed postsynaptic agonist activity at somewhat higher doses, reversing the effects of reserpine in mice and increasing striatal acetylcholine levels. The compound showed some serotonergic (5HT1A) activity, but was inactive at other receptors. The related monopropylamine 2 (U-91356), also showed good dopaminergic agonist activity, and had improved metabolic stability and oral bioavailability in the rat and monkey when compared to 1a. Compounds 1a and 2 have been prepared in tritiated form, and [3H]1a (69 Ci/mmol) has found use as a D2 agonist radioligand in binding assays. The dopaminergic (D2) and serotonergic (5HT1A) activities of a series of compounds related to 1a have been evaluated using this ligand, [3H]raclopride, and [3H]8-OH DPAT.

Aminoquinolines↗

Pharmacokinetic and tolerance studies of cefpodoxime after single- and multiple-dose oral administration of cefpodoxime proxetil.

Cefpodoxime proxetil, a third generation, broad-spectrum, oral cephalosporin, was administered in single doses of 100, 200, 400, 600, and 800 mg (dose expressed as cefpodoxime equivalents) and multiple doses of 100, 200, and 400 mg twice daily to healthy volunteers. The pharmacokinetics of the active metabolite, cefpodoxime, and tolerance of cefpodoxime proxetil were determined. Results from the single-dose study indicate that cefpodoxime exhibits nonlinear pharmacokinetics over the dose range of 100 to 800 mg. This nonlinearity is primarily due to differences in dose-normalized AUC and Cmax, urinary recovery, and half-life between one or more of the higher-dose treatment groups and the 100-mg dosing group. After multiple-dose (twice daily) administration for 15 days, steady state is achieved on the second day of dosing, and there is no drug accumulation. Cefpodoxime pharmacokinetics are linear with dose over the clinically relevant dosing range of 100 to 400 mg. Microbiologic and HPLC plasma assay results are highly correlated, with close agreement between HPLC- and microbiologic-determined pharmacokinetic parameter estimates. Cefpodoxime proxetil was well tolerated in both studies. The most frequent medical events were related to gastrointestinal problems and consisted of transient loose stools in three subjects in the single-dose study and antibiotic-associated diarrhea in one subject in the multiple-dose study.

Administration, Oral↗

Radioimmunoassay of minoxidil in human serum.

A simple, sensitive, and specific radioimmunoassay for determining minoxidil was developed. Antiserums to two minoxidil haptens were compared for cross-reactivity and assay levels on human serums. One antiserum had little cross-reactivity with minoxidil metabolites. The radioimmunoassay is specific for determining minoxidil directly in serum without extraction. Human serum minoxidil levels were determined from a single oral dose.

Animals↗

Stability studies on horse antithymocyte globulin.

Two equine antithymocyte globulin preparations were studied with respect to their relative rosette inhibition activity after storage at 4 and 25 C. After storage at 4 C for 48 months no activity loss was observed; 25 C storage resulted in fragmentation and eventual loss of relative rosette inhibition activity. A third preparation was studied by monkey skin graft prolongation. During a 1-year period, there was no loss of immunosuppressive activity as measured by this method and the rosette inhibition assay.

Animals↗