Pharmacokinetics and safety of 0.5% ivermectin lotion for head louse infestations.

The safety of a novel 0.5% ivermectin lotion (IVL) and potential for ivermectin absorption after application was investigated in an open-label study in young children, and a human repeat insult patch test (HRIPT) and cumulative irritation test (CIT) assessed any potential for cumulative dermal irritation and contact sensitization. In the pharmacokinetic and safety study, 30 head louse-infested children ages 6 months to 3 years received a 10-minute application of IVL on day 1. Blood was collected before application; 0.5, 1, and 6 hours after rinsing; and on days 2 and 8. Samples from 20 subjects were assayed for ivermectin (test sensitivity 0.05 ng/mL). Liver panel and complete blood counts were completed for all subjects. For the HRIPT/CIT, occlusive patches containing IVL or vehicle control lotion (CL) were repeatedly applied to 220 healthy adult subjects to assess contact sensitization; for cumulative dermal irritation testing, additional patches with normal saline and sodium dodecyl sulfate (SDS) were applied to 36 subjects. In the open-label study, all detected ivermectin plasma concentrations were <1 ng/mL. No safety signals emerged, and treatment was well tolerated. In the HRIPT/CIT, IVL was significantly less irritating than normal saline and SDS, with no evidence of dermal irritation or sensitization in human skin. IVL was safe when applied topically, absorption was de minimus, there was no evidence of irritation or sensitization from repeated exposures, and results support the safety of topical IVL use in children as young as 6 months.

Cumulative irritation potential and contact sensitization potential of tazarotene foam 0.1% in 2 phase 1 patch studies.

We performed 2 phase 1 patch studies to evaluate tazarotene foam 0.1% for cumulative irritation potential (study A) and contact sensitization potential (study B). Study A participants wore patches containing active study product, vehicle foam, and positive and negative controls for 24 +/- 1 hours for 21 consecutive days. Irritation scores were statistically higher with tazarotene foam 0.1% than vehicle foam and both controls. Fourteen participants (36%) experienced product-related, application-site adverse events (AEs); all of the AEs were mild and transient. Study B participants were exposed to active product and vehicle foam for an induction and challenge phase. At the investigators discretion, participants were administered a rechallenge to evaluate for contact sensitization. Three participants demonstrated questionable sensitization reactions and underwent a rechallenge; none of the participants displayed conclusive contact sensitization. Three application-site AEs were considered to be product related; none of the AEs led to study discontinuation. Tazarotene foam 0.1% showed potential to induce irritation but a low potential for contact sensitization and an acceptable tolerability and safety profile.

A practical UV source to induce Herpes simplex labialis lesions in the clinic.

BACKGROUND: Ultraviolet (UV) sources have been used to clinically induce herpes simplex lesions in the lips of susceptible individuals. METHODS: This study reports the optimization of a UV source for studies involving multiple clinical laboratory sites and subsequent clinical UV induction of cold sore lesions. We describe novel adaptations of a commercially available broadband UV phototherapy lamp that facilitate determination of individual's minimal erythemal dose (MED) and expose the lips with minimal risk of viral transmission to or between the volunteers and technicians. CLINICAL RESULTS: The source performed well in a clinical setting, with 171 of 386 subjects (44%) developing lesions, an induction rate similar to spectrally similar UV sources. CONCLUSIONS: The advantages of consistent and reproducible exposure geometry, additional UV shielding and biological hygiene achieved by our method significantly enhance the execution of UV-induced herpes simplex labialis studies.