The Chaiken brothers are tackling one of health care’s biggest problems: the sky-high cost of prescription drugs. Blink’s strategy is to use e-commerce to score patients lower prices for their medicine. Their mission is to upend the byzantine and opaque pharmaceutical supply chain, in which middlemen often take a cut without passing savings on to consumers. So far, it seems to be working: Blink has partnered with drug giants Eli Lilly and Roche and has a participating pharmacy in most zip codes.