Blood levels of o,p'-DDD following administration in various vehicles after a single dose and during long-term treatment.

Plasma levels of o,p'-DDD were measured after ingestion of a single oral dose. At the onset of therapy o,p'-DDD was administered as commercially available tablets and granules and in milk, chocolate, and an oil emulsion to 9, 12, 14, 10, and 6 patients, respectively. Following administration in chocolate, emulsion, and milk significantly higher mean plasma levels were recorded in the first 5- and 10-h periods than after tablets. Granules gave significantly lower plasma levels than all other forms. Plasma levels were also measured during maintenance therapy, when a total of 200 g o,p'-DDD was administered to 22 patients with adrenocortical carcinoma. The plasma disappearance rate after termination of long-term therapy was found to be between 18 and 159 days. The recovery of o,p'-DDD from faeces was about five times higher after ingestion of tablets than after administration in oil emulsion and milk. As far as the rapid increase in plasma levels and patient compliance are concerned, the best results were obtained with the milk powder mixture.