Rationale for Use of Micronized Isotretinoin for Treatment of Acne Vulgaris: Practical Considerations and Therapeutic Advantages.

Objective: Isotretinoin is a widely used and clinically efficacious treatment for severe, recalcitrant, nodular acne vulgaris (AV). Clinicians are generally familiar with safety concerns regarding isotretinoin use, especially teratogenicity. However, there are specific "real-world" challenges with use of conventional formulations based on the original isotretinoin formulation, including poor solubility and food-dependent absorption requiring high fat intake with each dose. This review describes the development and use of new isotretinoin formulations and their potential to improve long-term outcomes in patients with AV. Methods: PubMed was searched using the terms "acne," "isotretinoin," "micronized," "lidose," and "efficacy." Results: Micronized isotretinoin received US Food and Drug Administration approval in 2019 for the treatment of severe recalcitrant nodular acne in patients aged 12 years or older. This isotretinoin formulation utilizes micronization technology to reduce drug particle size, thereby increasing its dissolution rate and bioavailability, combined with a lipid-based carrier system that enhances gastrointestinal absorption without the need for dietary fat ingestion. Together, these features allow for an approximately two-fold or greater increase in isotretinoin absorption despite a lower administered dose compared with prior formulations, without dependency upon high-fat food intake. Limitations: Evidence supporting reduction in relapse with micronized isotretinoin is based on studies with the lidose formulation and pharmacokinetic data supporting greater systemic exposure to micronized isotretinoin without food. Conclusion: The lack of any specific dietary requirements or need for food intake and the enhanced bioavailability of micronized isotretinoin may increase both patient compliance and the rate of prolonged remission of AV after completion of therapy.