How to analyse PK in WinNonlin with limited sampling times

Hi all,

I would like to request your insight on analyzing a new data set for drug A that will be used for prophylaxis. I am also new to this forum and I’m not sure if this would be the correct place to ask my question. I am a trainee at NIH and I’ve been learning to use WinNonlin for about 1 year now, and would really appreciate your feedback.

Drug A was administered in healthy volunteers monthly for 3 months on Days 1 and 2 each month, as a single dose. The study group only collected PK samples for day 2 of each dosing interval. How would I input this in WinNonlin to best characterize the PK of drug A?