Wells Fargo analyst David Maris "completely" disagrees with the view that shares of Emergent BioSolutions (EBS) are weak today on news of Purdue Pharma's nalmefene injection receiving fast track designation from the FDA. Maris notes that none of his clients have raised this as a potential issue and that, as an injection, Purdue's pproduct is not comparable to Emergent's nasal naloxone. An injection is not practical for the emergency medical technician and at home market, where most of Narcan is used, Maris tells investors in a research note. For example, Amphastar (AMPH) is a leader in the injectable market, and the vast majority of its use is in the hospital setting, the analyst points out. Rather, Maris attributes the recent selloff in Emergent BioSolutions to worries about the potential introduction of a generic version of Narcan. Teva (TEVA) has had a tentative approval for generic Narcan for some time, and its 30 month stay is over today, meaning that Teva could launch at risk from this point forward, Maris writes. As of now, there is no clear indication whether Teva will launch or not, he adds. While the analyst is not expecting an at-risk Narcan launch, he believes the risk of such an event is largely reflected in the shares given today's decline. Nonetheless, Maris keeps a Market Perform rating on Emergent with a $68 price target. The stock in afternoon trading is down 9%, or $4.98, to $52.00.