Luliconazole is the R enantiomer of a chiral molecule. The potential for interconversion between R and S enantiomers in humans has not been assessed. Information on the pharmacokinetics of luliconazole presented below refers to both R enantiomer and S enantiomer, if any, combined.

Luliconazole is >99% protein bound in plasma.

In a PK trial, 12 subjects with moderate to severe tinea pedis and 8 subjects with moderate to severe tinea cruris applied a mean daily amount of approximately 3.5 grams of LUZU Cream, 1% to the affected and surrounding areas once daily for 15 days. Plasma concentrations of luliconazole on Day 15 were measurable in all subjects and fluctuated little during the 24-hour interval. In subjects with tinea pedis, the mean ± SD of the maximum concentration (Cmax) was 0.40 ± 0.76 ng/mL after the first dose and 0.93 ± 1.23 ng/mL after the final dose. The mean time to reach Cmax (Tmax) was 16.9 ± 9.39 hours after the first dose and 5.8 ± 7.61 hours after the final dose. Exposure to luliconazole, as expressed by area under the concentration time curve (AUC0–24), was 6.88 ± 14.50 ng*hr/mL after the first dose and 18.74 ± 27.05 ng*hr/mL after the final dose. In subjects with tinea cruris, the mean ± SD Cmax was 4.91 ± 2.51 ng/mL after the first dose and 7.36 ± 2.66 ng/mL after the final dose. The mean Tmax was 21.0 ± 5.55 hours after the first dose and 6.5 ± 8.25 hours after the final dose. Exposure to luliconazole, as expressed by AUC0–24, was 85.1 ± 43.69 ng*hr/mL after the first dose and 121.74 ± 53.36 ng*hr/mL after the final dose.

PK data of luliconazole measured in adolescent subjects (12 to <18 years of age) with moderate to severe interdigital tinea pedis or moderate to severe tinea cruris as well as in subjects 2 to <18 years of age with tinea corporis are described in Specific Populations below.

Specific Populations

PK of luliconazole was assessed in 30 adolescent subjects 12 to <18 years of age with moderate to severe interdigital tinea pedis (N=15) or moderate to severe tinea cruris (N=15). Subjects with tinea pedis applied approximately 3 grams of LUZU Cream, 1% once daily to the affected area and adjacent skin for 15 days, while subjects with tinea cruris applied LUZU Cream, 1% once daily to the affected and adjacent skin for 8 days.

Generally, the systemic exposure of luliconazole was greater in the subjects with tinea cruris than tinea pedis. In subjects with tinea pedis, the systemic concentrations of luliconazole were quantifiable in all the subjects on Day 8 and Day 15. The mean ± SD Cmax was 1.80 ± 1.86 ng/mL after the first dose on Day 1, and 3.93 ± 1.67 ng/mL and 3.27 ± 1.71 ng/mL on Days 8 and 15, respectively. The mean ± SD AUC0-24 was 20.47 ± 14.47 ng*hr/mL after the first dose on Day 1, and 64.94 ± 32.47 ng*hr/mL and 60.38 ± 37.92 ng*hr/mL on Days 8 and Day 15, respectively. Like in adult subjects, the mean plasma concentrations of luliconazole in adolescent subjects on Days 8 and 15 were similar and fluctuated little during a 24-hour interval. 

In subjects with moderate to severe tinea cruris, the systemic concentrations of luliconazole were quantifiable in all the subjects on Day 8. The mean ± SD Cmax was 9.80 ± 5.94 ng/mL after the first dose (Day 1) and 15.40 ± 13.62 ng/mL after the last dose (Day 8). The mean ± SD AUC0-24 was 157.07 ± 92.18 ng*hr/mL and 266.06 ± 236.07 ng*hr/mL, after the first dose (Day 1) and the last dose (Day 8). 

In subjects with tinea corporis, the systemic concentrations of luliconazole were assessed at pre-dose and at 6 hours post-dose on the last day of treatment following once daily treatment with LUZU Cream, 1% for 7 days. The systemic concentrations were quantifiable in all the 12 subjects and the mean ± SD daily dose of LUZU Cream, 1% was 2.84 ± 1.82 g. The mean ± SD concentrations of luliconazole at 15 minutes prior to dosing and at 6 hours post-dose on Day 7 were 4.63 ± 2.93 ng/mL and 4.84 ± 3.33 ng/mL, respectively.

Drug Interactions

Results of in vitro studies indicated that therapeutic doses of LUZU Cream, 1% did not inhibit cytochrome P450 (CYP) enzymes 1A2, 2C9 and 2D6, but can inhibit the activity of CYP2B6, 2C8, 2C19, and 3A4. The most sensitive enzyme, CYP2C19, was further evaluated in an in vivo study using omeprazole as a probe substrate in adult subjects with moderate to severe interdigital tinea pedis and tinea cruris. The results showed that LUZU Cream, 1% applied at a daily amount of approximately 4 grams increased the omeprazole systemic exposure (AUC) by approximately 30% compared to the exposure of omeprazole administered alone. LUZU Cream, 1% is considered a weak inhibitor of CYP2C19. For tinea cruris, extrapolation from both in vitro inhibition studies and in vivo data in adults to the adolescent subjects showed that in some subjects, levels of luliconazole can approach or exceed those required to be a moderate inhibitor of CYP2C19.

Results of in vitro studies indicated that therapeutic doses of LUZU Cream, 1% did not induce CYP1A2, 2B6, and 3A4.