Abstract: A process for filling a canister for an inhaler is provided. The canister may be filled with components of a medicament. The canister may be suitable for use in a pressurised metered dose inhaler, such as a breath-actuate inhaler. The process may include sealing the canister with air at ambient conditions. A filling device may dispense a pressurised liquid or gas into the sealed, air-filled canister through a metering valve. The pressurised liquid or gas may comprise at least a propellant. While pressure-filled canisters were previously purged with propellant immediately before sealing to remove the air, the present process may exclude the purging step.