This study is being conducted to obtain information on the safety and tolerability of repeated doses of GW823296 for 28 days in healthy male and female subjects. In addition, the pharmacokinetics of GW823296 will be evaluated to confirm the doses to be used in Phase II efficacy studies. The effect of repeat dose (RD) of GW823296 on CYP3A4 enzyme activity will be investigated evaluating the pharmacokinetics of midazolam and urine 6-?-hydroxycortisol/cortisol ratio.