Part 1 is a randomized, double-blinded 3 period crossover and 1 period parallel study of single dose administration of NOC-110 via dry powder inhaler, preceded by a reference period of NOC-100 administered via nebulizer. A total of 12 healthy participants will be enrolled to ensure that 9 participants complete this part of study.~Part 2 is a randomized, double-blinded, placebo-controlled, multiple-dose, parallel design study in patients with refractory chronic cough. A total of 12 participants will be enrolled to ensure that 8 participants complete this part of study.
Part 1 will evaluate the safety, tolerability and PK of single doses of three dose levels of NTX-1175 drug substance administered by dry powder inhaler (NOC-110) compared to a single dose reference nebulizer (NOC-100) treatment in healthy participants.~Part 2 will evaluate the safety, tolerability and PK of multiple doses of NTX-1175 drug substance administered by dry powder inhaler (NOC-110) to participants with refractory chronic cough. Part 2 will also evaluate the treatment effect of multiple doses of one dose level of NTX-1175 drug substance administered by dry powder inhaler (NOC-110).