K-V Pharmaceutical (KV.A -16.8%) tanks after saying it's filed a lawsuit against the FDA for failing to crack down on compounded versions of its premature birth drug Makena. Pharmacies have been using the active ingredient hydroxyprogesterone, which does not have a formal FDA clearance, to compound cheaper versions of Makena, an injectable hormonal medicine that reduces the risk of pre-term birth in pregnant women with a history of early deliveries.