Liquid crystalline polymer pouches for local anaesthetic emulsion
Abstract:In order to enhance the long-term properties of a high-pH local anaesthetic drug, emulsion tests were conducted where the emulsion was stored in pouches made of a compression moulded high-barrier liquid-crystalline polymer, Vectra A950. The oxygen permeability of the pouch material was too low to be detected at 23°C and 0% relative humidity with the instrument used. The water vapour transmission rate was 0.135 (g.mm/m2.day) at 38°C and 100% relative humidity. The emulsion, containing prilocain and lidocain as active substances, was stored in pouches which were sealed by the thermal impulse technique at 260°C for 1.08 s. It was possible to obtain good quality films and good quality seals by optimization of the compression moulding and sealing operations. The concentrations of prilocain and lidocain in the emulsion were studied for 14 weeks at two different temperatures, 40°C and 60°C, and at 100% relative humidity. The decrease in concentration was higher for prilocain (5.4–8.3%) than for lidocain (3.4–3.6%). The loss of the substances from the emulsion was due mainly to adsorption onto the polar surface of the liquid crystalline polymer. Copyright © 2001 John Wiley & Sons, Ltd.
Document Type: Research Article
Publication date: July 1, 2001
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