Study of the influence of the auxiliary substances on the surface tension of the aqueous solutions of some substituted phenylcarbamic acid derivatives.

In the course of the drug form development of potential drugs the influence of auxiliary substances, namely glycerol (GL), propylene glycol (PG) and sorbitol (SO), used in the form of 5, 10, 15 and 20% solution on the surface tension (gamma) of some phenylcarbamic acid aqueous solutions was studied. Since this influence depends not only on the kind and concentration of the auxiliary substance used but also on potential drugs themselves, attempt was made to find optimal additives for particular drugs. The obtained results show that as optimal additives may be used: SO for IR-1 and H + B, for XIX M it is either PG or GL, for XIII it is GL, and finally for XIX it is either PG or SO.