How is otc racepinefrin/asthmanefrin same basic medication as former avail epinefrin/primetine mist. how does the race added to standard inhaled epi ?

Racemization: The racemic or combination form of Epinephrine makes the product more stable and has a longer shelf life. The d-form has less side effect than the natural r-form in terms of rapid heart rate and increase in bp. The d-form has a lower side effect as mentioned but has a more sustained effect. The side effect precludes frequent use so need sustained effect, and the combo is more stable.