AllantoinvsPetrolatum (Vaseline)

Allantoin (5-ureidohydantoin) stimulates cell proliferation and tissue regeneration by promoting fibroblast activity, keratinocyte proliferation, and extracellular matrix synthesis including collagen and glycosaminoglycans. It acts as a mild keratolytic by promoting the natural desquamation process—loosening corneocyte adhesion and facilitating shedding—without the irritation, pH disruption, or barrier compromise associated with alpha- or beta-hydroxy acids. Allantoin has anti-inflammatory properties through modulation of prostaglandin synthesis (inhibiting COX-2 and reducing PGE2) and may downregulate pro-inflammatory cytokines. Its moisturizing effect comes from increasing the water-binding capacity of the extracellular matrix and stratum corneum; it is highly soluble and forms hydrogen bonds with water. Allantoin also promotes wound epithelialization. Its safety profile—non-irritating, non-sensitizing, non-comedogenic—makes it suitable for compromised skin, post-procedure care, and infant formulations.

Petrolatum is a mixture of long-chain saturated hydrocarbons (C16-C32) that forms a semi-occlusive film—reducing transepidermal water loss (TEWL) by up to 99%. It penetrates intercellular spaces of the stratum corneum, filling gaps in the lipid lamellae and creating a hydrophobic barrier. This occlusive environment raises stratum corneum water content, activating endogenous repair: upregulation of antimicrobial peptides (defensins, cathelicidin LL-37), lamellar body secretion, and barrier lipid synthesis. The stratum corneum obtains oxygen from dermal circulation, not the atmosphere. Studies demonstrate accelerated wound healing and barrier recovery, contradicting infection myths.