Why do some dull pain relievers dissolve faster than others?

For my science fair project I testest Tylenol aspirin ibuprofen advil and aleve, adjectives pain relivers/fever reducers and Asprin dissolved the fastest but I call for to know why it dissolved faster than the others, other than because its outer coat be thinner.Why do some dull pain relievers dissolve faster than others?
That all have to do with what it's formulated contained by. Something like Aleve to be exact designed to be taken once every 12 hours must dissolve more slowly so that you are receiving prescription during that whole time time. Many pills actually enjoy layers, a immediately dissolving outer one, so the medicine will be hurriedly acting and a slower dissolving core, so the medicine will work long-term.
Also, save in mind for your project that these pills are usually dissolving surrounded by the stomach (an acidic environment) and this can affect their solubility compared to hose.
Google "excipients".
the reason why some niggle relievers dissolves faster than others because some pain relievers are smaller and smoother while some some are big if you compare both you will find out that the smaller pill will dissolve faster than the bigger ones .