Formulation Advice for Acne, Scars, and Dark Spots

Based on the previous discussion, making a toner or gel base is indeed a better approach for acne-prone skin compared to a silicone-based serum, as silicones can potentially clog pores.

To address your sister's concerns including blackheads, clogged pores, inflammatory acne, acne scars, and dark spots, here are some ingredients you can add to a water-based toner or gel formulation:

• Complex Salicylic Acid (a type of BHA suitable for leave-on products): This is excellent for exfoliating the skin's surface and inside the pores, helping to unclog blackheads and whiteheads and reduce inflammatory acne. It also has mild anti-inflammatory properties.
• Licorice Extract: Known for its anti-inflammatory benefits, it can help reduce the redness and irritation associated with acne. It also helps control oiliness and can improve the appearance of dark spots (post-inflammatory hyperpigmentation).
• Tranexamic Acid: This ingredient is effective in reducing the appearance of dark spots and acne marks, which is a key concern for your sister.
• Pep®-Acne: This peptide has antimicrobial properties specifically targeting P. acnes, the bacteria that contributes to acne formation.

If you prefer a gel texture over a liquid toner, you can use a water-soluble thickener like Hydroxypropyl Methylcellulose (HPMC).

Regarding preservatives, as discussed, even though Salicylic Acid has some antimicrobial action, it is highly recommended to add a broad-spectrum preservative to any water-based formula to ensure stability and safety, especially for long-term use. A reduced concentration (around 0.3-0.5%) should be sufficient.

For pitted acne scars, the ingredients above will primarily help with active acne and dark marks. Pitted scars are structural changes in the skin that are more challenging to treat with topical products alone and may require other methods like derma rolling or professional treatments. However, improving overall skin health and preventing new breakouts can help minimize further scarring.

Remember to observe your sister's skin response when she starts using the product and adjust the frequency of use as needed. Starting with once a day might be advisable to see how her skin reacts.

We hope this helps you create a beneficial product for your sister!