How calculate therapeutic index?

The therapeutic index (TI) is calculated by dividing the toxic dose (TD50) by the effective dose (ED50) of a drug. Specifically, the formula is TI = TD50 / ED50, where TD50 is the dose at which 50% of the population experiences toxic effects, and ED50 is the dose at which 50% of the population achieves the desired therapeutic effect. A higher TI indicates a wider margin of safety for the drug.