Theo-Asthalin SR (slow release) contains two medicines, Salbutamol 4 mg and Theophylline 300 mg and is to be taken by oral route. There is no advantage in taking two medicines in one pill. In fact, it is better and safer to take them individually and separately. You can ask for these drugs at a local pharmacy. With the availability of salbutamol for inhalation, it is much more effective and far safer to use this drug in the form of puffs from inhalers. These are widely available all over the world. The benefit of inhalational salbutamol is that it reaches lungs directly without passing through stomach, liver etc. and hence causes far less side effects. If at all you require two drugs, then the second drug should always be a steroid via inhalation.