Because the Federal Food, Drug, and Cosmetic Act (FFDCA) does not provide a statutory definition of functional foods, the Food and Drug Administration has no authority to establish a formal regulatory category for such foods. The primary determinant of the regulatory status of a food is its intended use, which is determined largely by the label and labeling information accompanying the product. This information includes nutrient information, nutrient content claims, and various types of health claims. In marketing these foods, manufacturers may come under one of several existing regulatory options. The first decision manufacturers will make that will help determine their product's regulatory status is whether the product is a food or a drug. Thus, manufacturers and retailers have a range of legal and regulatory categories in which their products may be classified. This article describes the definitions provided in the FFDCA for a drug and a food, the safety and labeling requirements of various food categories, and types of possible claims for dietary supplements.

Piroxicam kinetics were studied after a single, oral, 20-mg capsule was taken by 12 young (six women, six men) and 13 elderly (seven women, six men) healthy subjects. Plasma samples were drawn for 216 hr after dosing. Plasma protein binding was studied in vitro by equilibrium dialysis and piroxicam concentrations were measured by HPLC with ultraviolet detection. The apparent volume of distribution was smaller in elderly women (7.8 +/- 0.4 l) than in young men (11.3 +/- 0.3 l) and elderly men (10.8 +/- 0.8 l). There were no such differences when the apparent volume of distribution was normalized for total body weight. There was a strong correlation between total body weight and apparent volume of distribution in all subjects (r = 0.83). Plasma protein binding of piroxicam ranged from 98.90% to 99.54% bound and was not affected by age or sex. Piroxicam body clearance in elderly women (0.026 +/- 0.002 ml/min/kg) was approximately 33% lower than in young women (0.039 +/- 0.003 ml/min/kg). This difference was reflected in different t1/2s of 61.7 and 44.9 hr. Predicted steady-state plasma piroxicam concentrations were 5.7 micrograms/ml in young women, 5.4 micrograms/ml in young men, 5.7 micrograms/ml in elderly men, and 9.3 micrograms/ml in elderly women. The high value in elderly women results from the lower piroxicam body clearance and total body weight. Our data suggest that healthy elderly women eliminate piroxicam at a slower rate than healthy young women. The clinical significance of these data needs to be assessed in patients.

1 The effect of dose (100 mg, 250 mg, 500 mg, 750 mg and 1000 mg) on the glucuronidation and sulphation of diflunisal was studied in six healthy volunteers. 2 Total urinary recovery ranged from 78.9 ± 11.9% to 91.5 ± 18.7% of the administered dose. Urinary recovery (normalized for total urinary recovery) of diflunisal sulphate (DS) significantly increased with dose from 9.3 ± 3.7% to 18.1 ± 4.8%.3 Normalized urinary recovery for diflunisal phenolic glucuronide (DPG) was unaffected by dose (range: 30.6 ± 3.8% to 40.6 ± 6.6%). Normalized urinary recovery for the acyl glucuronide (DAG) significantly decreased from 52.3 ± 4.6% to 40.2 ± 3.4% as the dose increased.4 Total plasma clearance of diflunisal significantly decreased from 14.4 ± 1.4 ml min-lto 8.7 ± 1.4 ml min-t as the dose increased from 100 mg to 750 mg. A further increase in dose to 1000 mg resulted in an unexplained increase in total plasma clearance to 10.3 ± 1.8 ml * -1 mmn 5 Dose-dependent plasma clearance of diflunisal was caused mainly by saturation of the formation of DAG, whereas the formation of DS and DPG were relatively unaffected by dose.

netics of tilmicosin in equine tissues and plasma. J. vet. Pharmacol. Therap. 31, 66-70.The macrolide antibiotic tilmicosin has potential for treating bacterial respiratory tract infections in horses. A pharmacokinetic study evaluated the disposition of tilmicosin in the horse after oral (4 mg ⁄ kg) or subcutaneous (s.c.) (10 mg ⁄ kg) administration. Tilmicosin was not detected in equine plasma or tissues after oral administration at this dose. With s.c. injection, tilmicosin concentrations reached a maximum concentration of approximately 200 ng ⁄ mL in the plasma of the horses. Tilmicosin concentrations in plasma persisted with a mean residence time (MRT) of 19 h. Maximum tissue residue concentrations (C max ) of tilmicosin measured in equine lung, kidney, liver and muscle tissues after s.c. administration were 2784, 4877, 1398, and 881 ng ⁄ g, respectively. The MRT of tilmicosin in these tissues was approximately 27 h. Subcutaneous administration of tilmicosin resulted in severe reactions at the injection sites.(Paper