[Ion pair-HPLC of a pharmaceutical multicomponent system]

A multicomponent system of non-ionic (methyl- and propylhydroxybenzoate) and ionic (theophylline, phenobarbital, atropine methobromide, demelverine hydrochloride) analytes, which are applied in therapy as bronchospasmolytically effective drug (Aminophyllin compositum tablets), was investigated by means of ion-pair-HPLC-technique on reversed phases. As ion-interaction-reagents (IIR) were tried alkylsulfonates and sodium cyclamate. The influence of some factors on retention was described. The use of "mixed" IIR for improvement of the separation was investigated.