Cystografin® (USP30% or Cystografin®-Dilute USP 18%) is a radiopaque contrast agent for retrograde cystourethrography. Cystografin® is not intended for intravascular injection.

Different stages of the drug development and approval process in the USA, lead from preclinical trials (testing in animals), first application in humans through limited and broad clinical tests, to postmarketing studies.

	Years	Test Population	Purpose	Success Rate
Preclinical Testing	3.5	Laboratory and animal studies	Assess safety and biological activity	5,000 compounds evaluated
File IND at FDA
Phase I	1	20 to 80 healthy volunteers	Determine safety and dosage	5 enter trials
Phase II	2	100 to 300 patient volunteers	Evaluate effectiveness, look for side effects
Phase III	3	1000 to 3000 patient volunteers	Verify effectiveness, monitor adverse reactions from long-term use
File NDA at FDA
FDA	2.5	Review process / Approval		1 approved
	12 Total
Phase IV	Additional Post marketing testing required by FDA

By Dale E. Wierenga, Ph.D. and C. Robert Eaton
Office of Research and Development
Pharmaceutical Manufacturers Association

'In reviewing this report, it is important to keep in mind the realities of the drug discovery and development process. The U.S. system of new drug approvals is perhaps the most rigorous in the world. On average, it costs a company $359 million to get one new medicine from the laboratory to the pharmacist's shelf, according to a February 1993 report by the Congressional Office of Technology Assessment.'

See also Phase 1 2 3 4 Drug Trials, Clinical Trial, Food and Drug Administration, and European Medicines Agency.

E-Z-CAT Dry is a dry CT barium contrast powder for suspension and can be mixed and self-administered at home. This may improve examination throughput, reduces patient waiting time and help to minimize waiting room congestion. The light E-Z-Cat® Dry foil packets can also be mailed to patients in remote locations.
The oral contrast agent is well compatible with new scanner technologies and provides a fast transit time through the GI tract.

Gastrografin® is a water-soluble iodinated radiopaque contrast agent for x-ray examinations of the esophagus, stomach, proximal small intestine, colon and is also used for bowel visualization in abdominal computer tomograms.
The high opacification and delineation after oral or rectal administration is caused by a low absorption of the intact gastrointestinal tract. However, visualization of the distal small bowel is generally unsatisfactory, since the hypertonicity of the medium causes intraluminal diffusion of water with subsequent dilution.

Hexabrix is an ionic dimer contrast medium. Intravascular injection of Hexabrix enhances those vessels in the path of the flow, permitting radiographic visualization of the internal structures of the human body until significant hemodilution occurs. The contrast agent is transported through the circulatory system to the kidneys and is excreted unchanged in the urine. Hexabrix is used primarily for peripheral arteriography