Formula Improvement Suggestions

Based on the ingredients you provided for your hair curl cream (Aqua, Cetyl Alcohol, Polyvinyl-pyrrolidone, Steareth-20, Fragrance, Phenoxyethanol, Silicone-Quaternium-22, Cetrimonium Chloride, Etidronic Acid, Methyl-Chloroisothiazolinone, Methylisothiazolinone), here are some suggestions for potential improvements:

Preservative System

The current formula uses Phenoxyethanol along with Methyl-Chloroisothiazolinone and Methylisothiazolinone. While effective, the combination of Methyl-Chloroisothiazolinone and Methylisothiazolinone (often found as Kathon CG) can be a sensitizer, especially in leave-on products like a curl cream.

• Suggestion: Consider replacing the Methyl-Chloroisothiazolinone and Methylisothiazolinone blend with a milder, broad-spectrum preservative system. Phenoxyethanol SA (a blend of Phenoxyethanol, Caprylyl Glycol, and Sorbic Acid) is a good alternative that offers broad protection and is considered safer and less irritating than the Methylisothiazolinone blend.

Enhanced Conditioning and Moisture

Curly hair often requires significant moisture and conditioning to prevent frizz and enhance curl definition. Your formula includes Cetyl Alcohol, Silicone Quaternium-16 (similar to Silicone-Quaternium-22), and Cetrimonium Chloride, which provide conditioning and detangling.

• Suggestion: To boost moisture and conditioning, you could add a humectant like Glycerin. Glycerin helps to draw moisture into the hair shaft. Incorporating emollients or natural oils/butters could also provide deeper nourishment and improve the feel and shine of the hair.

Adjusting Hold and Texture

The Polyvinyl-pyrrolidone (PVP) provides hold. Different molecular weights of PVP offer varying levels of hold and stiffness. You mentioned Polyvinyl-pyrrolidone in general.

• Suggestion: If you want to adjust the hold or feel, you could experiment with different grades of PVP, such as Polyvinylpyrrolidone K30 for a more natural hold or Polyvinylpyrrolidone K90 for stronger hold. Combining different grades can help fine-tune the desired styling effect.

Emulsification and Stability

Cetyl Alcohol and Steareth-20 (or Ceteareth-20, a similar emulsifier) form the base emulsion. The stability and texture depend on the ratio and processing.

• Suggestion: If you encounter issues with stability or achieving the desired texture, you may need to adjust the concentrations of Cetyl Alcohol and Ceteareth-20 or consider co-emulsifiers.

Chelating Agent

Etidronic acid is included as a chelating agent, which helps improve the stability and efficacy of preservatives by binding with metal ions in water.

• Suggestion: Ensure the concentration of Etidronic acid is appropriate for your water source to effectively chelate metal ions without negatively impacting the formula.

By considering these points and potentially incorporating alternative ingredients like Phenoxyethanol SA and Glycerin, you can likely improve the mildness and performance of your curl cream formula.