[The effect of bioadhesiveness of viscous solutions with naphazoline hydrochloride on the elimination of the drug from the eye of swine]. / Einfluss der Bioadhäsivität von Schleimen auf die Elimination von Naphazolinhydrochlorid vom Auge des Hausschweines.

Solutions of sodium carboxymethylamylopectine, tragant, hydroxyethylcellulose, polyvinylalcohol, polyacrylic ester D 339, polyacrylic ester D 340 and polyacrylic acid, all of the same viscosity and with the same concentration of naphazoline hydrochloride, were applied on the isolated eye of pig. After sink the eye in a solution of sodium chloride the elimination of the drug from the eye was investigated. The results were compared with the bioadhesion of the viscous solutions measured ex vivo on the intestine of pigs. There were correlations between the eliminated mass after 5 min, after 30 min and the bioadhesion. Furthermore the calculated initial elimination constant was indirect proportional to the bioadhesion. The elimination of the drug between 5 and 30 min was independent on the bioadhesion.

[The effect of mucous excipient concentration on bioadhesion ex vivo]. / Einfluss der Schleimstoffkonzentration auf die Bioadhäsion ex vivo.

The bioadhesion of aqueous solutions of polyacrylics (1-3), hydroxyethylcellulose (4), sodium carboxymethylamylopectin (5), polyvinylalcohol (6) and tragant (7) was investigated using a tensiometer and fresh intestine of pigs. It was dependent on the concentration of the excipient as described by a quadratic equation and found in the maximum from 244 Pa (7) to 554 Pa (4). The maximum of bioadhesion corresponds to the concentration of the excipient from 0.15% (2) to 23.7% (4) and to the viscosity of the solutions from 0.11 Pa.s (3) to 3.6.10(6) Pa.s (4). There was not a correlation between the viscosity and the bioadhesion.