In our laboratory, 64 autopsy cases of Japanese encephalitis patients were examined by immunofluorescence. Three patients showed some evidences of double infection of Japanese encephalitis virus and herpes simplex virus. Experiments were done to see the mechanisms of double infection. In doubly infected mice, Japanese encephalitis virus antigen was localized in the herpes simplex virus infected areas in the brain. These results suggested that "blood brain barrier" was broken by herpes simplex virus infection and Japanese encephalitis virus gained access to the susceptible cells.

Animals↗

PubMed1976

Controlled drug permeation I: controlled release of butamben through silicone membrane by complexation.

The effects of caffeine, beta-cyclodextrin, and povidone on the permeation behavior of butamben from saturated solutions in these complexing agents through a dimethyl polysiloxane membrane were investigated at 30 degrees. In all systems, these agents increased the rate of release over the plain saturated drug solution. The effect was more pronounced with caffeine and beta-cyclodextrin than with povidone. Interpretation of these results with the aid of solubility data for the corresponding systems led to the following generalization. For a fixed total (free and complexed) amount of drug available for release, sustained release is associated with systems containing more stable complexes. The practical value of this approach to the controlled release of drug is discussed.

Aminobenzoates↗

PubMed1976

Dissolution behavior and bioavailability of phenytoin from a ground mixture with microcrystalline cellulose.

The ground mixture of phenytoin and microcrystalline cellulose was prepared by grinding in a vibrational ball mill. The X-ray diffraction patterns indicated the amorphous nature of the ground mixture. Comparative studies were made concerning the in vitro dissolution and in vivo absorption of fine phenytoin powder, phenytoin sodium powder, and the ground mixture. The ground mixture showed a greater dissolution rate than the fine powder and attained supersaturation in the pharmacopeial disintegration media at pH 1.2 and 7.4. In vivo absorption studies of each preparation were carried out in five subjects, using a crossover design, by measuring the urinary excretion rate of a main metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin. The blood levels of phenytoin and the corresponding urinary excretion patterns of the metabolite were determined in two subjects. The ground mixtures significantly improved the bioavailability of phenytoin. The drug was completely and rapidly absorbed after oral administration of the ground mixture. The vibrational ball milling technique for a poorly water-soluble drug with microcrystalline cellulose provides a promising way of improving the in vivo drug absorption.

Adult↗

PubMed1976