I Gave Medicine to My Childhood Friend and Now They Have Separation Anxiety

'''"I want you to develop a cure for magic rejection syndrome. The deadline is six months." An order from the princess has fallen, and I, an apothecary from a fallen noble family, am in a situation where I have to create a cure for an incurable disease. I managed to complete it, but the side effect is excitement...? There's no way I can give something like this to Her Highness the Princess! And to think that the one who came to deliver the request is Lucian Lithhardt, the heir to the Grand Duke's family, who I broke up with in the past. "But why aren't you leaving and sticking around?" "Poor Sasha. Why do you think I came all the way here?" Of all people, he's my test subject? * S...