With the proliferation of the internet, anyone can purchase basically anything they might want from any country on the globe. When it comes to medical devices, there are reasons that the FDA certifies the aerosol equipment we use. The reasons and rules are usually written in blood, this means that people have died from improper equipment or training. If your MDI manufacture is using equipment or supplies from anyone other than three cGMP/FDA suppliers, you are at very high risk of harm or death if your using their device.
The hard part is how do you tell if your manufacturer has the correct training and equipment to manufacture the device in a safe as possible manner. Ask questions, if they do not have answers, you should not buy the device.