In pre-clinical studies, Eli Lilly tested four lead compounds for efficacy as selective serotonin reuptake inhibitors, using both in vitro and in vivo assays in rodents.

Initial studies investigated in vitro efficacy and selectivity.

Table 1: Assessment of in vitro efficacy of lead compounds in rodents

Inhibition of 5-HT uptake was assessed using synaptosomal preparations of rat brain, and affinity of binding to α₁-adrenoceptors was assessed using membrane preparations of rat cerebral cortex.

IC₅₀ = half maximal inhibitory concentration