Kinetics of the Liberation of Active Ingredients from Lyophilised Xerogel

Overview

From sterilised hydrogel containing 60 g/l of hydroxypropylmethylcellulose and graded amounts ofadded electrolyte, xerogel foils were lyophilised and shaped into samples of the size of ophthalmiclamellae. Under stationary conditions with modifications of the releasing solution of sodiumchloride, the release of pilocarpinium chloride, atropinium sulfate, scopolaminium bromide andtetracainium chloride from a comparable amount of 3.6 mg of hydroxypropylmethylcellulose in thestructure of xerogel was tested. A linear dependece of the rate of release on the amount of activeingredients was demonstrated. Finally, the rates of liberation of the individual active ingredientsfrom hydrated xerogel were compared.

Key words:
lyophilisation – hydroxypropylmethylcellulose – xerogel – liberation