Skin Absorption vs. HLB Calculation in Cosmetic Formulation

Based on the information provided:

There is no single ingredient or "perfect formula" that guarantees the deepest or best absorption for all substances into the skin. Current scientific understanding allows for educated guesses and predictions based on existing data and theories, but it's not yet possible to predict absorption with 100% accuracy.

Here's a summary of the key points:

• No Perfect Formula: We don't have a complete theory to predict exactly how much a specific formula and its ingredients will absorb into the skin.
• Carriers: Substances like Ethoxydiglycol and other glycols (like Propylene Glycol) can help improve the absorption of ingredients that are difficult to dissolve in water or oil by acting as solvents or carriers.
• Base Type: The base of the formulation matters. Water-based formulas generally result in the least absorption compared to cream, alcohol, ointment, or emulsion bases.
• Whole Formula Matters: The absorption is influenced by all ingredients in the formula, and the interactions between them are complex and not fully understood.
• HLB Calculation: HLB (Hydrophilic-Lipophilic Balance) calculation is related to the stability of an emulsion (preventing separation), not to how well the ingredients absorb into the skin.

Therefore, while carriers like Ethoxydiglycol can help, and the base type is important, achieving optimal absorption often requires experimentation because the effect of the entire formulation is complex. HLB calculation is not the tool for optimizing absorption; it's for ensuring emulsion stability.