Pharmacy Calculations: Days Supply PTCE PTCB CPhT Pharmacy Technician, NAPLEX PharmD and NCLEX Nursing Test Prep. Information that is useful for NAPLEX, PTCB PTCE, and NCLEX Exam Preparation. Covers common pharmacy days supply calculations including solid dosage forms, oral liquids, inhalers and nasal sprays, eye and ear drops, and injectables (insulin) days supply.