Best study material is "
Texas and Federal Pharmacy and Drug Law - 10th edition" by Pharmacy Regulatory Advisors, Brinkley and Cacciatore.
Easy to read, written as a study guide for the Texas MPJE. Written by a former TSBP Executive Director and a Pharm.D./J.D.
Pricy but 100% worth it. But you have to put in the work. There is no easy way to pass the MPJE. Read carefully and digest the information. Be prepared to apply it to a practical situation.
Read it in 2 weeks making flash cards/notes along the way, and referencing the actual law or rule (in the Lexis Nexis book or on TSBP
https://www.pharmacy.texas.gov/rules/, especially the "DEA Pharmacist's Manual"). And then another 2 weeks to review your notes/flash cards.
Print out and read the "Candidate's Guide To The Jurisprudence Examination" and make sure by the end of studying you hit each point (
https://www.pharmacy.texas.gov/files_pdf/CandidatesGuide.pdf )
Keep a good pace on the exam, there is plenty of time, 1:15 per question. Don't go too fast. And when you come across those ambiguous questions/situations, simply use your best judgement and imagination.