藥丸內是含有drug外有成泡劑---是anhydrous Sodium carbonate or bicarbonate , potassium carbonate or bicarbonare , binder & powder form citric , malic , tartaric or other food grade organic acid . Citric acid is the most popular one used. 將以上撈好壓成粒狀成tablet . 當藥丸放進水內carbonate + acid will produce a lot of bubble . 藥丸外coated了一層prevent moisture get in to start the reaction . 糖衣用處 .有胃藥有喉藥(以籮果子) .