They are asking you to interview, so there is clearly something about your app that made them interested in you. 22 credits is a hefty load, especially considering labs are usually only 1 credit, but often requires ~3 credit hours of work. However, it is completely doable, and if you are able to demonstrate that you can handle that kind of course load, then that is a good sign that you will be able to handle the work load in pharmacy school.
That being said, I would be prepared to talk about why you didn't complete these prereqs sooner if you were aware that their program required them. I'm not trying to be presumptuous; I know some people apply while they are still in school to avoid having to take a gap year. Again, 22 credits is a decent amount of work, and if they are all required coursework, it is difficult to say that they would want to offer you a spot since failing any one of these classes would make you ineligible to attend in the fall. My suggestion would be to show that you are being proactive about the situation and try to bring physical evidence of your organizational efforts to your interview. This way, in addition to being able to answer their questions orally, you have some sort of proof that you have been cognizant of your additional responsibilities and have been taking steps to ensure your academic success. I have no experience whatsoever as an admissions officer (hell, I'm trying to get into school myself), but I know that if I were in that role, it would help put my mind at ease when considering to offer you a spot. Think of it from their perspective - why should they offer you a spot over a candidate with equal stats but with all prerequisite work completed? If you have a good answer prepared, then I think you have a fighting chance. Good luck!