Stable isotope techniques in early drug development: an economic evaluation.

Stable isotope labeled (SIL) drug methods are compared with standard methods for performing early (phases I and IIa) drug development studies (mass balance, bioavailability, single-dose volunteer and patient, multiple-dose volunteer and patient). SIL methods offer considerable reduction in the cost (> 50%) and number of subjects (67%) required for bioavailability and multiple-dose patient studies. Moreover, a complete early drug development program is described for optimally combining SIL and standard studies, which can reduce cost by 23% and number of subjects by 36% compared with a program using standard methods. These reductions should result in development time savings of at least one year.