Determination of Selected Active Substance in the Preparation VII.

Determination of Selected Active Substance in the Preparation VII Thesis Anna Šalamounová Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Chemistry and Drug Control Suitable HPLC methods for the determination of cinchocaine and for the determination of purity of dexamethasone in liquid pharmaceutical preparation were searched. The monolithic column Chromolith Speed ROD RP-18e 50-4.6 was used. A mixture of water:acetonitrile; 50:50; 1,575 ml of triethylamine in 250 ml of water; was chosen as the mobile phase for cinchocaine hydrochloride; pH of the mobile phase was adjusted to 7.0 by orthophosphoric acid. Flow rate was 3 ml/min, column temperature 25 žC, injected volume 5 µl and UV detection at 325 nm. Linearity, specificity, precision and accuracy were tested under these conditions. For purity of dexamethasone gradient elution was chosen. Mobile phase A: water, acetonitrile (80:20) and mobile phase B in the rate of 93:7; pH of the mobile phase was adjusted to 7.0 by orthophosphoric acid. Mobile phase B: water, acetonitrile (75:25); 1,05 ml triethylamine in 250 ml water; pH of the mobile phase was adjusted to 7.0 by orthophosphoric acid. Flow rate was 4 ml/min, column temperature 25 žC, injected volume 50 µl and UV detection at 238 nm. The method was..