Development of a lyophilized parenteral pharmaceutical formulation of the investigational polypeptide marine anticancer agent kahalalide F

Kahalalide F is a novel antitumor agent isolated from the marine mollusk El ysia rufescens; it has shown highly, selective in vitro activity, against a ndrogen-independent prostate tumors. The purpose of this study was to devel op a stable parenteral formulation of kahalalide F to be used in early clin ical trials. Solubility and stability, of kahalalide F were studied as a fu nction of polysorbate 80 (0.1%-0.5% w/v) and citric acid monohydrate (5-15 mM) concentrations using an experimental design approach. Stabilities of ka halalide F lyophilized products containing crystalline (mannitol) or amorph ous (sucrose) bulking agents were studied at +5 degreesC and +30 degreesC /- 60% relative humidity (RH) in the dark. Lyophilized products were charac terized by infrared (IR) spectroscopy, and differential scanning calorimetr y (DSC). Recovery studies after reconstitution of kahalalide F lyophilized product anti further dilution in infusion fluid were carried out to select an optimal reconstitution vehicle. It was found that a combination of polys orbate 80 and citric acid monohydrate is necessary to solubilize kahalalide F. Lyophilized products were considerably less stable with increasing poly sorbate 80 and citric acid monohydrate concentrations, with polysorbate 80 being the major effector. A combination of 0.1% w/v polysorbate 80 and 5 mM citric acid monohydrate was selected for further investigation. Lyophilize d products containing sucrose as a bulking agent it-ere more stable compare d to the products containing mannitol. The glass transition temperature of the sucrose-based product was determined to be +46 degreesC. The amorphous state of the product was confirmed by IR analysis. A solution composed of C remophor EL, ethanol, and water for injection (5%/5%/90% v/v/v CEW) kept ka halalide F in solution after reconstitution and further dilution with 0.9% w/v sodium chloride (normal saline) to 1.5 mug/m. A stable lyophilized form ulation was presented containing 100 mug of kahalalide F, 100 mg sucrose, 2 .1 mg citric acid monohydrate, and 2 mg polysorbate 80 to be reconstituted with a vehicle composed of 5%/5%/90% v/v/v CEW and to be diluted further us ing normal saline.