Search PubMedSearch

Biomedical subjects

G G Knapp

Publications and source records attributed to G G Knapp.

18 recordsLinked to original sources

Strategy and planning for chemopreventive drug development: clinical development plans. Chemoprevention Branch and Agent Development Committee. National Cancer Institute.

At the National Cancer Institute, Division of Cancer Prevention and Control, the Chemoprevention Branch and Agent Development Committee develop strategies for efficiently identifying, procuring, and advancing the most promising drugs into clinical trials. Scientific expertise is applied at each phase of development to critically review the testing methods and results, and to establish and apply criteria for evaluating the agents for further development. The Clinical Development Plan, prepared by the Chemoprevention Branch and the Agent Development Committee, is a summary of the status of the agent regarding evidence for safety and chemopreventive efficacy in preclinical and clinical studies. It also contains the strategy for further development of the drug that addresses pharmacodynamics, drug effect measurements, intermediate biomarkers for monitoring efficacy, toxicity, supply and formulation, regulatory approval, and proposed clinical trials. Sixteen Clinical Development Plans are presented here: N-acetyl-l-cysteine (NAC), aspirin, calcium, beta-carotene, 2-difluoromethylornithine (DFMO), DHEA analog 8354, 18 beta-glycyrrhetinic acid, N-(4-hydroxyphenyl)retinamide (4-HPR), ibuprofen, oltipraz, piroxicam, Proscar, sulindac, tamoxifen, vitamin D3 and analogs, and vitamin E. The objective of publishing these plans is to stimulate interest and thinking among the scientific community on the prospects for developing chemopreventive drugs.

Clinical Trials as Topic

Effect on dissolution of tablet storage in counting machines.

The effects of storage in an automatic counting and dispensing machine on dissolution rates on five drug products with known or suspected bioequivalence problems were studied. Amitriptyline hydrochloride, digoxin, prednisone, hydrochlorothiazide, and tolbutamide tablets exposed and unexposed to automatic counting machines were collected from 10 pharmacies located in various parts of the country. A 60-tablet unexposed sample was taken from a previously unopened container and placed in a tight, light-resistant container. Another 60-tablet sample of the same brand and lot number was collected 30 days after the initial filling of the counting machine or when it had to be refilled, whichever came first. Each sample was tested for dissolution rate and content uniformity. Twenty-seven paired samples representing 23 lots from 10 manufacturers were collected. There were no substantial differences in dissolution rate or content uniformity between the exposed and unexposed samples. Average temperatures in the pharmacies during the three-month sampling period ranged from 72 to 79 degrees F. Storage times of the drug product samples in the automatic counting machines varied from 9 to 46 days. The environmental conditions to which these tablets were exposed had no noticeable effect on the dissolution of these formulations.

Biological Availability