Valrubicin (N-trifluoroacetyladriamycin-14-valerate) is a chemotherapy drug employed in the treatment of bladder cancer. It is currently available as Valstar®, a Cremophor-EL based formulation for intravesicular administration. At LipoMedics, we have developed a unique nanomedicinization process for water insoluble drugs using a combination of solvents and polymers we named quanticles. Here we report on the synthesis of valrubicin quanticles using phospholipid as polymer. Characterization includes particle size, drug incorporation, zeta potential and electrochemical analysis.

A series of stable phospholipid bound valrubicin quanticles were created using various combinations of PC6 (1,2-dihexanoyl-sn-glycero-3-phosphocholine), PC10 (1,2-didecanoyl-sn-glycero-3-phosphocholine), lysoPC10 (1-decanoyl-2-hydroxy-sn-glycero-3-phosphocholine) and cholesteryl oleate. Two methods of fabricating these quanticles were employed: high pressure homogenization and thin film evaporation. While characteristics like particle size and drug incorporation are similar, the methods result in formulations differing not only in their zeta potential but also in their voltammograms which indicate the formulations are either high capacitance material or low capacitance material.

As previously demonstrated with quanticles of paclitaxel, these quanticles can be distinguished by their zeta potentials and their voltammograms. Therefore, it appears to be the method of formulation that generates an ionic liquid capacitance material with distinctive high or low capacitive voltammic activity. In contrast to the previous work with paclitaxel, valrubicin adds its voltammic signature to the readings of the high capacitive material. A similar signature has not been detected in formulations of low capacitance material.