The purpose of the study is to evaluate the safety and tolerability of a single application of Ha44 Gel 0.74% w/v for the treatment of head lice under maximal use conditions.

Secondary objective is to evaluate pharmacokinetics of Ha44 and benzyl alcohol (contained in Ha44 vehicle) under maximal use conditions.

This is an open-label safety and pharmacokinetic (PK) study involving a single application of Ha44 Gel 0.74% administered under maximal use conditions.

All participants must have an active head lice infestation (at least 3 live lice) and be 6 months to 17 years of age. The study will enroll approximately 36 pediatric subjects between the ages of 6 months and 17 years.

Pediatric PK samples will be collected at 0 (predose), 30 and 60 mins and 2 and 8 hrs time points.

More than one household member with an active lice infestation may participate in the study. Eligible subjects will be consented and screened for study eligibility on Day 0 (Visit 1). All subjects will return to the study site for three follow-up clinic visits at Days 1, 7 and 14. The maximum study duration for a subject is 16 days.

Inclusion Criteria:

1. Male or female

2. 6 months to 17 years of age

3. Be in good health, as determined by medical history and physical examination

4. Has an active head lice infestation at screening as determined by an experienced evaluator. An active infestation is defined as the presence of at least 3 live lice.

5. Female subjects must be:

   • Of non-childbearing potential (no history of menstrual periods, post-hysterectomy, or post-menopausal for at least 2 years) OR,
   • If of childbearing potential, must have a negative urine pregnancy test prior to treatment and agree to use a highly effective method of contraception from Day 0 through the Day 14 visit. Acceptable methods of contraception include abstinence, vasectomized partner, tubal ligation, combined oral hormonal contraceptive, contraceptive injection, contraceptive patch, or IUD. If a hormonal contraception is the only method, the subject must have been on a stable dose for at least 3 months.

6. The parent/guardian agrees to allow serial blood samples collected from subject for PK analysis during study.

7. Has signed an informed consent and/or assent form (ICF).

Exclusion Criteria:

1. Has a condition or illness that, in the opinion of the Investigator, may interfere with the study results.
2. Has current dermatological disease or inflammation on the face, scalp, ears, neck or back, including eczema, atopic dermatitis, alopecia, psoriasis or any other chronic skin disease that, in the opinion of the Investigator, would interfere with the safety or PK evaluation.
3. Had a prior reaction to products containing piperonyl butoxide, pyrethrin, or pyrethrum extract.
4. Has been using hormonal contraception for less than 3 months.
5. Is pregnant or currently nursing.
6. Receiving systemic or topical medication, which in the opinion of the Investigator, may interfere with the study results.
7. Has received an investigational agent within 30 days prior to Day 0.

From the time of IP application on Day 0 until Day 14

Adverse events were systematically collected from the time of IP administration on Day 0 until Day 14.