Sensitivity of dissolution rate to location in the paddle dissolution apparatus.

The aim of the present study was to determine the apparent diffusion boundary layer and dissolution rate constant for various surfaces of compacts and at various locations in the USP paddle dissolution apparatus. Benzoic acid compacts were coated with paraffin wax leaving only the surface under investigation free for dissolution. The dissolution rates for various surfaces at varying locations in the paddle dissolution vessel were determined from the slope of the dissolution profile (amount dissolved (mg) versus time (min)). The apparent diffusion boundary layer and dissolution rate constant were calculated and were found to vary depending on the surface of the compact from which dissolution took place and also on the location and size of the compact. It may be concluded that, in developing models to describe the dissolution from solid dosage forms, it is not accurate to assume constant hydrodynamics and mass transfer rates at all surfaces of the system, or in different locations within the test device. A more exact description of the hydrodynamics would be necessary in order to precisely model drug dissolution in the paddle dissolution apparatus.

Diquat intoxication.

Reported is the case of a 23-year-old man who ingested 300 mL of Reglone. He developed vomiting five to 10 minutes after ingestion. Shortly thereafter, he developed renal and central nervous system manifestations of toxicity, followed by cardiovascular collapse and death 14 hours after admission. Autopsy findings revealed esophagitis, tracheitis, gastritis, and ileitis. Prompt, aggressive therapy that included fluid replacement and removal of the toxin was unsuccessful.

Haemophilus influenzae associated with periappendiceal abscess.

A case of haemophilus influenzae infection in a periappendiceal abscess is reported with clinical history and bacteriologic data. Other reports of similar infections are few. The mode of transmission is discussed.