I’ve had some success with BYU online. They have various science classes completely online where you just have to have your tests proctored at a local college. 3 credit classes are only $750 and are self-paced, so you can start at any time. I’m in anatomy right now, and it’s very doable. I would also look into taking a graduate pharmacology or pathophysiology class because many schools will allow you to apply the credits towards the DNP classes, and it shows you can handle the graduate level classes. I’m also taking a graduate level pharmacology course right now through University of Massachussets. It’s completely online including exams, but it’s a bit pricier at $1800 for 3 credits.