Enhancing Bioavailability: Advances in Oral Isotretinoin Formulations

Oral isotretinoin continues to be unsurpassed in efficacy for acne. However, it is associated with potential adverse events including risk of fetal defects, necessitating appropriate mitigation strategies. Furthermore, the variance in bioavailability of the original formulation when ingested in fed versus fasted conditions can lead to differences in daily dosing and duration of exposure. Advances in formulation, with lidose encapsulation and subsequently with micronization, have led to iterative improvements in reducing bioavailability variation between fed and fasted conditions. Differences in bioavailability during fasting were 60% less for originator oral isotretinoin, 33% less for lidose-encapsulated form, and 20% less for micronized-isotretinoin formulation. The latter also demonstrated overall greater bioavailability such that a 20% dose reduction was required compared to the originator and lidose-encapsulated formulations. By reducing the effect of high-fat/high calorie food co-ingestion, this micronized formulation may facilitate clarity in determining appropriate oral isotretinoin dose requirements in achieving optimal patient outcomes.