Comparative Pharmacokinetic Profiles of a Novel Low-dose Micronized-isotretinoin 32 mg Formulation and Lidose-isotretinoin 40 mg in Fed and Fasted Conditions: Two Open-label, Randomized, Crossover Studies in Healthy Adult Participants

Two open-label, crossover studies compared the bioavailability of Micronized-isotretinoin 32 mg and Lidose-isotretinoin 40 mg in healthy adults. In the fed bioequivalence/food-effect study, participants (n = 71) received single doses of fed-state Micronized-isotretinoin 32 mg, fed-state Lidose-isotretinoin 40 mg and fasted-state Micronized-isotretinoin 32 mg. In the fasting study, participants (n = 18) received single doses of fasted-state Micronized-isotretinoin 32 mg and fasted-state Lidose-isotretinoin 40 mg. Bioavailability was assessed by isotretinoin LnAUC(0–t), LnAUC(0–∞) and LnC(max) in blood samples taken pre-dosing and over 96 h post-dosing. The 90% confidence intervals for baseline-adjusted least squares geometric mean ratios for LnAUC(0–t), LnAUC(0–∞) and LnC(max) fell within the 80–125% range for bioequivalence for fed-state Micronized-isotretinoin 32 mg vs. fed-state Lidose-isotretinoin 40 mg. Fasted-state Micronized-isotretinoin 32 mg had ~2 times higher bioavailability than fasted-state Lidose-isotretinoin 40 mg. Food had no effect on the rate and a marginal effect on the extent of absorption of Micronized-isotretinoin 32 mg.