Transdermal Delivery and the 500 Dalton Rule

The 500 Dalton Rule defines a molecular weight threshold below which compounds achieve passive transdermal penetration of intact stratum corneum. GHK (340 Da), KED (390 Da), and AEDG (432 Da) all fall below this threshold. Ethoxydiglycol (Transcutol) further enhances delivery efficiency.

The threshold

Bos and Meinardi's foundational dermatology research established 500 Daltons as the upper bound for passive transdermal penetration of compounds through intact stratum corneum. The 500 Dalton Rule is a standard reference in topical formulation science.

Where bioregulator peptides fall

GHK at 340 Daltons, KED at 390 Daltons, and AEDG at 432 Daltons all fall below the threshold. This places all three actives in HelioMend within the molecular weight range that supports passive transdermal delivery without invasive enhancement methods.

Penetration enhancement

Ethoxydiglycol — sold under the brand name Transcutol — is a well-characterized penetration enhancer used in topical pharmaceutical and cosmeceutical formulations. Estimates from published research suggest approximately 60% improvement over unaided delivery.

Empirical confirmation

LactiGo's University of Montana human biopsy study confirmed intramuscular delivery of transdermal peptides within 60 minutes of application using a comparable delivery vehicle. PLGA nanoparticle research on GHK confirmed 94% entrapment efficiency and 90% release within 48 hours.

Citations

  1. Bos JD, Meinardi MMHM. The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Exp Dermatol. 2000;9(3):165-9.
  2. LactiGo. University of Montana human biopsy study confirming intramuscular delivery of transdermal peptides within 60 minutes.
  3. PLGA nanoparticle entrapment of GHK: 94% efficiency, 90% release within 48 hours. Published formulation research.
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