Studies on pharmaceutical modification of anticancer agents. II. Enhanced delivery of bleomycin into lymph by emulsions and drying emulsions.

The enhanced delivery into lymph of bleomycin was studied by the intraperitoneal and intramuscular injection of oil emulsified preparations. A comparison of concentration of bleomycin in thoracic duct lymph showed that W/O emulsion was the most effective and followed by O/W emulsion. An application of spray drying powder was also attempted to the enhanced delivery, and the lymph concentration was increased as compared with the injection of the aqueous solution although lower than O/W liquid emulsion. A measuring of binding to oil particles indicated that approximately 40% of bleomycin was bound to the particles of O/W liquid emulsion and of reconstituted emulsions prepared from drying products. Furthermore the clearance rates of bleomycin from the muscle were delayed about one half by W/O, O/W and reconstituted emulsion. The possible mechanism of enhanced delivery into lymph was discussed in this paper.