Alternative Solvents for Minoxidil

Regarding your question about alternative solvents for minoxidil for a clear, low-viscosity scalp spray with moisturizing properties:

• 1,3-Propanediol: Yes, 1,3-Propanediol (such as the one with Product ID 1337) can be used as a solvent and a humectant. The description indicates it can replace Propylene Glycol and Glycerin, offering a better skin feel and enhancing moisturizing effects. This aligns well with your goal of a non-sticky, moisturizing solution. It is a clear liquid and dissolves in water. The suggested usage rate is 1-20%.
• Ethyl Alcohol: Yes, Ethyl Alcohol (Product ID 706 and 35354) is a common and effective solvent for minoxidil and can help achieve a clear, low-viscosity solution suitable for a spray. Both 99.9% and 96% grades are described as clear liquids that act as solvents and are miscible with water and oil. Using Ethyl Alcohol first to dissolve minoxidil is a standard approach in many formulations.
• "Double Glycerin" (PEG/PPG/Poly Butylene Glycol -8/5/3 Glycerin): A specific product matching this exact name and composition was not found in the database search results. Therefore, I cannot provide specific information about its suitability or usage from the available data.

Formulation Approach:

A common approach for minoxidil solutions is to use a combination of solvents. Ethyl Alcohol is often used as the primary solvent to dissolve minoxidil effectively and help create a clear solution with low viscosity. Adding a humectant like 1,3-Propanediol can then help improve the skin feel, reduce dryness often associated with alcohol-based solutions, and provide moisturizing benefits without significantly increasing viscosity compared to traditional glycerin.

The strategy of dissolving minoxidil in Ethyl Alcohol first and then adding other ingredients like 1,3-Propanediol for moisture and skin feel is a viable approach.

Proportions:

The optimal proportions of minoxidil and solvents (Ethyl Alcohol, 1,3-Propanediol, and potentially water) depend on the desired concentration of minoxidil in the final product and the specific solubility characteristics of the minoxidil source you are using. Achieving a stable, clear solution requires careful formulation and testing. The product descriptions provide general usage rates for the individual ingredients (e.g., 1-100% for Ethyl Alcohol, 1-20% for 1,3-Propanediol), but these are not specific to dissolving minoxidil.

Therefore, I cannot provide exact proportions. You would need to determine the appropriate ratio through experimentation, starting with a known effective solvent system for minoxidil (often involving alcohol and a glycol) and then adjusting based on your desired concentration, clarity, viscosity, and skin feel, incorporating 1,3-Propanediol as a solvent and humectant.