10% Lactobionic Acid-Containing Moisturiser Reduces Skin Surface PH Without Irritation, Reveals Study

In the search for innovative solutions for managing inflammatory dermatoses, acidifying the stratum corneum has emerged as a promising approach. Acidifying emollients are commonly used to regulate skin pH; however, lower pH levels are often linked to increased irritation.

A study published by the National Institutes of Health (NIH) studied whether lactobionic acid (LA), a "superacid" from the alpha-hydroxy acid (AHA) family, can effectively lower skin surface pH without irritating.

Study methodology

Researchers evaluated the safety and effectiveness of a 10% LA-containing emulsion formulated with alkyl polyglucosides (APGs), sugar-based emulsifiers known for their mildness. The study used both in vitro and in vivo methodologies:

• In vitro safety assessment: Cytotoxicity assays were conducted to evaluate acute skin irritation potential.

• In vivo study: Human participants underwent 24-hour occlusive treatment with the LA-containing emulsion, followed by an assessment of key biophysical skin parameters:

  • Transepidermal water loss (TEWL)

  • Stratum corneum hydration (SCH)

  • Skin erythema index (EI)

• pH measurement: The pH of the skin surface was measured before and one hour after the application of the 10% LA-containing moisturiser.

What did the study reveal?

The study revealed promising findings regarding the effects of lactobionic acid:

• The emulsion with 10% LA effectively reduced the skin’s surface pH.

• No signs of irritation or skin barrier impairment were observed in either the in vitro or in vivo assessments.

• TEWL and SCH remained stable, indicating that the moisturizer did not disrupt the skin barrier function.

• The APG-based emulsion vehicle itself was found to have a satisfactory safety profile, further supporting the gentle nature of this formulation.

This study supports the use of lactobionic acid as a safe and effective alternative to low-molecular AHAs in acidifying emollients. The findings suggest that a 10% LA-containing moisturiser can reduce skin pH without causing irritation or compromising the skin barrier, making it a promising addition to dermatological and cosmeceutical formulations.