Study of local anaesthetics. Part 139. Preformulation study of N-[2-(2-heptyloxyphenylcarbamoyloxy)-ethyl] dimethylammonium chloride.

In the course of the drug form development of substance XIX B (N-[2-(2-heptyloxyphenylcarbamoyloxy)-ethyl] dimethylammonium chloride [1]) the influence of auxiliary substance, namely glycerol (GL), propylene glycol (PG) and sorbitol (SO), used in the form of 5, 10, 15 and 20% solution, on the surface tension, partition coefficient, viscosity and liberation from aqueous solutions was studied. These parameters can influence the bioavailability. The obtained results show that as an optimal additive 5% SO may be used since this ensured maximal amount of liberated substance XIX B.