To investigate the safety, tolerability, pharmacokinetics (including dose proportionality assessment), and pharmacodynamics of single rising oral doses of BI 1181181 (Single rising dose (SRD) part) Secondly, to investigate the relative bioavailability of the tablet versus the powder for oral solution (PfOS) and the effect of food on the pharmacokinetics of BI 1181181 (Bioavailability/Food effect (BA/FE) part)