Formulating with Retinaldehyde: Solubility, Oil-Free Gel/Cream, and Ingredient Compatibility

Based on the information provided:

• Adding anti-irritant ingredients for sensitive/dry skin: For sensitive or dry skin, it is recommended to add ingredients that help strengthen and moisturize the skin, such as Vitamin B5 (Panthenol) and Vitamin B3 (Niacinamide).
• Adding HA and Adenosine: Yes, you can add HA (Hyaluronic Acid) and Adenosine to the formula.
• Long-term use of Vitamin A and unsuitable skin types: Using Retinaldehyde at 0.05% is safe for continuous use. Avoid strong sun exposure (e.g., outdoor sports), but normal daily sun exposure is fine. Pregnant women should avoid using any type of Vitamin A.
• Gel formulation without oil and dissolving Retinaldehyde without oil: Retinaldehyde must be dissolved in oil for it to be effective. It cannot be dissolved in other solvents. Therefore, an oil-free gel formulation containing Retinaldehyde is not possible.
• Ratio of oil and suitable oil for acne-prone skin: The staff recommended using FloraSolve 5% and LipidSoft Dry 15% to dissolve Retinaldehyde, suggesting brief heating to 60°C can help. These are the recommended oils for dissolution.
• Luxury Cream Maker for oil-free cream and acne-prone skin: Since Retinaldehyde requires oil dissolution, an oil-free cream containing Retinaldehyde is not feasible based on the provided information.