Simultaneous drug and metabolite POPPK

Dear NMusers, I have plasma concentration versus time data for a drug and its active metabolite. I would like to simulataneously fit this drug and its metabolite using NONMEM to obtain estimates of prameters and associated variability for both drug and its active metabolite. I am sure guys have done this nicely in past. I was wondering if someone can share a control stream and sample data for my guidance. Thanks _______________ Vijay V Upreti PhD Candidate Pharmacokinetics-Biopharmaceutics Laboratory Dept. of Pharmaceutical Sciences University of Maryland, School of Pharmacy Rm S509, 20 Penn St., Baltimore, MD 21201 Voice: 410.706.7388; Fax: 410.706.5017