Search

Influences of cellulose derivatives (with and without additives of humectants) on two parameters, namely the liberation of the potential local anaesthetic XX Z and the structural viscosity of preparations were compared. The aim was to select a suitable base for topic application of the substance XX Z, chemically pyrrolidinoethylester of 3-heptyloxyphenylcarbamic acid. The rate of release of the substance XX Z from 2.5% methylcellulose base was higher then from 2% hydroxyethylcellulose base, and in both cases it was reduced after addition of humectants. It is concluded that among bases with additives of humectants is, for topic applications, more suitable the hydroxyethylcellulose base then methylcellulose base.

Chromatographic-spectrophotometric methods for the determination of vitamins K1, K3 and K4 in pharmaceuticals (tablets, dragees, injection solutions) in the presence of decomposition products have been elaborated. The TLC method on Kieselgel HF 254 (Merck) was applied to separation of the active substances from decomposition products, using the following solvent systems: benzene--ethyl acetate (9:1) for vitamin K1, cyclohexane--chloroform--metanol--acetic acid (2:15:3:1) for vitamin K3, and benzene--acetone (9:1) for vitamin K4. After elution from the plates, vitamin K1 was determined in ethanol at lambda = 251 nm, vitamin K3 in water at lambda = 234 nm and vitamin K4 in methanol at lambda = 225 nm. Maximum sensitivity of the elaborated methods came up to 7 X 10(-5) g, and standard deviations of single determinations ranged from 1.99% to 3.70%.