HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF THE SILICON PHTHALOCYANINE PC-4 IN HUMAN BLOOD

A sensitive and reproducible method has been developed for the measure ment of the silicon phthalocyanine Pc4 in red blood cell concentrates (RBCC). The procedure involves extraction of the RBCC with acetonitril e, purification of the extracts with reversed-phase Sep-Pak C-18 cartr idges and determination of Pc 4 in the extracts by high-performance li quid chromatography (HPLC) using a reversed-phase C-18 column. The det ection limit with I-mi RBCC samples is 2 ng. This method is applicable to monitoring Pc 4 during its use as a photosensitizer for the inacti vation of viruses in RBCC prior to transfusion. It has the potential t o be adapted for measuring Pc 4 in tissues during its use in photodyna mic therapy of cancer.