Pharmaceutical compositions of a benzimidazole or a benzimidazole derivative are disclosed. For example, in certain embodiments the pharmaceutical compositions include a benzimidazole, PEG 400, and a dipolar aprotic solvent. In other embodiments, pharmaceutical compositions include a benzimidazole, an oil, a dipolar aproptic solvent, and a surfactant. In certain embodiments, the benzimidazole is mebendezole. The pharmaceutical compositions are formulated for delivery to a subject by any means, and include formulations for oral and parenteral delivery.