## PKNCA Package usage [R for BE/BA]

Dear Forum members,

Greetings for the day....

I am trying to estimate the Pharmacokinetic parameters using PKNCA package with the help of documents in R.

i have installed the package PKNCA and while using i am facing the below difficulty.

conc_obj <- PKNCAconc(X003, Concentration~Time|Subject)

i am getting the error "Rows that are not unique per group and time (column names: Time) found within concentration data"

As we estimate the parameters based on period, i need to include the period parameter in the above code. but am nt able to do that. Where to place the Period in the above code?

And i have tried to estimate the PK parameters using BEAR package. but it is not getting the same results as that of the WinNonlin

Any help in this regards is highly appreciated