Objective: Difficulty swallowing pills can compromise pain control in painful musculoskeletal disorders. This open-label, 2-period crossover study assessed pharmacokinetics and safety of cyclobenzaprine extended-release (CER) 30-mg capsule contents sprinkled over applesauce compared with intact capsules in healthy subjects.
Materials and methods: 32 subjects were randomized to treatment sequences AB or BA (A = single CER intact capsule; B = single CER capsule contents sprinkled over applesauce (15 mL)). Treatments were separated by a ≥ 14-day washout. Pharmacokinetic assessments included maximum observed plasma drug concentration (Cmax), time to Cmax (tmax), time to first quantifiable plasma drug concentration (tlag), and area under the plasma drug concentration-vs.-time curve from time 0 to the last measurable drug concentration (AUC0-t) and extrapolated to infinity (AUC0-∞). Bioequivalence was established if the 90% confidence intervals (CIs) of the geometric least squares (LS) means ratios of B:A of Cmax, AUC0-t, and AUC0-∞ were 80 - 125%. Safety was also assessed.
Results: Mean plasma drug concentration-vs.-time profiles were similar for CER intact and sprinkled over applesauce. The 90% CIs of LS means ratios indicated bioequivalence: Cmax 91.96 - 100.76%, AUC0-t 96.18 - 103.50%, and AUC0-∞ 95.70 - 103.07%. Median tmax was not significantly different (p > 0.05), and median tlag was the same (1 hour). All adverse effects were mild and resolved during the study. No clinically meaningful changes were noted for clinical laboratory values.
Conclusion: CER capsules intact and sprinkled over applesauce are bioequivalent. Sprinkling CER capsule contents is not expected to affect efficacy or safety and can, therefore, be an option for patients with musculoskeletal pain and difficulty swallowing capsules. .