Panel 6 (9 adult volunteers), will receive 800 mg Darunavir (DRV) on day 7 combined with TMC55844 that has been given for 7 days at 200 mg once daily dosis. After a wash out period of 14 days the participants will receive Darunavir 800 mg alone. TMC558445, TMC310911 or placebo will be formulated as oral drinkable solution. Part 1 will consist of single dose TMC558445/placebo from 40 up to 1600mg on Day 1 of each session with a volume between 2 and 20ml. Part 2 will consist of TMC558445/placebo twice daily from Day 1 to Day 7 with max dose of 200mg and volume of 5 ml + a single intake of 300 or 600mg TMC310911(12/24ml)/ DRV 800mg on morning of Day 7 in one session and single dose of TMC310911/ DRV on Day 1 in the second session.