Alot. Naprelan (naproxen) is specifically formulated so that 30% of the drug is released right away and the rest (70%) is slowly released throughout the day. Naprelan (naproxen) also offers the intestinal protective drug absorption system. This allows the drug to break apart and be absorbed throughout the digestive system. This helps prevent too much of the drug from settling in 1 area of the stomach or intestines.