PEG-2 Caprylylamine: A New Adjuvant Surfactant to Boost Lather Rate

Consumers judge a cleanser within seconds of pumping it into their palms, and much of that judgment rests on how quickly foam appears. A study covered by Cosmetics & Toiletries examined an adjuvant surfactant, PEG-2 caprylylamine (abbreviated P2C8), that formulators added in small amounts to primary surfactant systems to address exactly that gap between application and visible lather.

Researchers screened many candidate materials using an internally developed sensory evaluation method before narrowing the field, according to the article. The selection criteria combined preliminary in-house lather assessments with further testing, a process aimed at finding surfactants that could specifically raise lathering rate rather than overall foam volume or stability, which are properties more commonly optimized in shampoo and body wash formulation.

The finding that stood out involved primary surfactants with weak initial lather. When researchers added a small amount of P2C8 to these systems, the mixtures showed a marked improvement in how fast foam built up, even though the base surfactants alone underperformed on that metric. That interaction, a modest adjuvant compensating for a shortfall in the primary surfactant's own lathering speed, is the crux of the reported result.

To place P2C8 in context, the study compared it against two established foam-increasing agents: cocamide MEA and cocoyl methylethanol amide, also known as cocamidemethyl MEA or CMEA. Both are amide-type additives long used in cleansing formulations specifically to boost foam. The comparison let researchers see whether P2C8 offered a distinct performance profile rather than simply replicating what these amides already deliver.

Formulation chemistry rarely rewards a single fix, and the article frames P2C8's role as one piece of a larger consumer preference puzzle. Adequate lather is a factor cited as important to consumers selecting toiletries, alongside separate preferences such as long-lasting effects and a mildly acidic skin pH in the 4.5 to 6.0 range after rinsing. An adjuvant that only speeds foam onset, without addressing rinse-off feel or final skin pH, solves part of that equation.

Commercial interest in similar lather-boosting adjuvants is already visible elsewhere in the surfactant supply chain. Kawaken Fine Chemicals markets a related non-ionic surfactant, Foamite 2E8, which the company describes as an effective lather booster compared with ethylhexylglycerin and other additives, suited to shampoo, body wash, soap, shower gel and facial wash. That product's positioning, rinsing off easily and foaming quickly, echoes the functional niche P2C8 is being tested against.

Regulatory and ingredient databases list PEG-2 caprylylamine among the broader class of polyethylene glycol derivatives used in cosmetics for their range of viscosity and solubility properties, according to COSMILE Europe. That versatility is part of why PEG-based adjuvants keep surfacing in cleanser reformulation work, even as the surfactant landscape shifts toward biosurfactants and other sustainability-driven alternatives that companies are now positioning as mainstream replacements for legacy foam boosters.

What the comparative data suggest, at this stage, is a narrower claim than a wholesale replacement for cocamide MEA or CMEA. P2C8's advantage appears concentrated in the earliest moments of lather formation, precisely the window a shopper notices before ever finishing a wash. Whether that speed advantage holds up across a wider range of primary surfactant systems, and at what inclusion levels it stops helping and starts diluting other formulation goals, remains the open question the initial screening data do not yet answer.