TABLE 1.

Comparison of isotretinoin formulations

FORMULATION	STANDARD ISOTRETINOIN	LIDOSE ISOTRETINOIN	MICRONIZED ISOTRETINOIN
Novel features of technology	Use a conventional delivery system isotretinoin, a form of retinoid, by targeting all components involved in the development of acne30	Presolubilized (in a lipid matrix) Encapsulated carrier with a hard gelatin capsule + active drug + lipid excipients29	Lipid carrier system Particle reduction to micrometer (µm) size or nanostructured Superior solubility and absorption31
Advantages	Revolutionized the treatment of acne Used widely as an effective oral therapy for severe, recalcitrant nodular acne5	Significantly greater intestinal solubilization Faster absorption Greater bioavailability Less food dependency8	Faster dissolution Prolonged drug release Most bioavailable without food7 Achieves therapeutic blood levels at a 20% lower dose 7
Limitations or challenges	Low solubility and bioavailability Food-dependent absorption26	Complex formulation	Complex formulation requiring improved nanotechnology
Bioavailability	25% (reported)40	Approximately 2 times higher in fasting state compared with standard isotretinoin8	Micronized isotretinoin 32mg is absorbed approximately twice as well as lidose isotretinoin 40mg in fasted patients7
Recommended dosing regimen	0.5–1.0 mg/kg/day, in 2 divided doses with food to a cumulative dose of 120–150 mg/kg5	0.5–1.0 mg/kg/day given in 2 divided doses without regard to meals34	0.4–0.8 mg/kg/day in 2 divided doses without regard to meals34

AE: adverse event;