To Investigate Primary Irritation Potential of Four Skin Serum Products on Human Subjects Assessed by 24 Hour Patch Test

To assess the irritation potential of four prototype daily defense serum formulations after 24 (± 2) hours under semi-occlusive patch application to the skin of healthy volunteers.

This is an evaluator (single) blind, test site randomized and intra-subject comparison patch test study to evaluate the cutaneous irritation potential of four experimental daily defense serum formulations, including a saline solution as a negative control.

Eligibility Criteria:
Inclusion Criteria:

* Demonstrates understanding of the study procedures, restrictions and willingness to participate as evidenced by voluntary written informed consent and has received a signed and dated copy of the informed consent form.
* General health: Good general and mental health with, in the opinion of the investigator or medically qualified designee no clinically significant and relevant abnormalities in medical history or upon physical examination and participants must have intact skin on the proposed application site; dorsum (scapular region).
* Fitzpatrick photo type I to IV.
* Agreement to comply with the procedures and requirements of the study and to attend the scheduled assessment visits.

Exclusion Criteria:

* Women who are known to be pregnant or who are intending to become pregnant over the duration of the study.
* Women who are breast-feeding.
* Any history of significant dermatological diseases or conditions or medical conditions known to alter skin appearance or physiologic response (e.g. diabetes,) which could, in the opinion of the Investigator, preclude topical application of the investigational products and/or interfere with the evaluation of the test site reaction.
* Presence of open sores, pimples, or cysts at the application site.
* Active dermatosis (local or disseminated) that might interfere with the results of the study
* Considered immune compromised.
* History of diseases aggravated or triggered by ultraviolet radiation.
* Participants with dermatographism.
* Currently using any medication which in the opinion of the investigator, may affect the evaluation of the study product, or place the participant at undue risk.
* Use of the following topical or systemic medications: immunosuppressants, antihistamines, non-hormonal anti-inflammatory drugs, and corticosteroids up to 2 weeks before Screening visit.
* Oral or topical treatment with vitamin A acid and/or its derivatives up to 1 month before the screening visit.
* Intention of being vaccinated during the study period or vaccination within 3 weeks of the Screening visit.
* Currently receiving allergy injections, or due to receive an injection within 7 days prior to Visit 1, or expects to begin injections during study participation.
* Previous history of atopy, allergic reactions, irritation or intense discomfort feelings to topical-use products, cosmetics or medication.
* Known or suspected intolerance or hypersensitivity to any of the study materials (or closely related compounds) or any of their stated ingredients, including any component of the patches.
* History of sensitization in a previous patch study.
* Participation in another clinical study (including cosmetic studies) or receipt of an investigational drug within 30 days of the Screening visit.
* Previous participation in this study.
* Recent history (within the last 5 years) of alcohol or other substance abuse.
* Intense sunlight exposure or sun tanning sessions up to 30 days before the Screening evaluation Intention of bathing, sauna, water sports, or activities that lead to intense sweating.
* Any participant who, in the judgment of the Investigator, should not participate in the study.
* Any skin marks on the test site that might interfere with the evaluation of possible skin reactions (e.g. pigmentation disorders, vascular malformations, scars, tattoos, excessive hair, numerous freckles).
* Prisoner or involuntary incarcerated participant.
* Participant from an indigenous tribe.
* An employee of the sponsor or the study site or members of their immediate family.