This study is looking at how safe and tolerable a medicine called **salbutamol** is when used in an inhaler by people aged 12 and older with asthma. Salbutamol helps open up the airways in your lungs, making it easier to breathe. Inhalers use a gas called a **propellant** to help deliver the medicine, and this study is comparing two different propellants: **HFA-152a** and **HFA-134a**.

• The study lasts for 3 months and you'll need to use the inhaler during this time.
• If you join, you should not have had a severe asthma attack in the last 6 months.
• Make sure you haven't used certain asthma medications, like some inhalers called **LAMA**, in the past 3 months.

To join, you need to be 12 years or older and have had asthma for at least 6 months. You should not have other lung problems or recent infections. If you meet the criteria, you'll be given one of the inhalers and will be asked to come for regular check-ups during the study.