Instrumental In Vivo Assessment of Cosmetic Emulsions Containing Platelet-Rich Fibrin (PRF) or Recombinant Epidermal Growth Factor (EGF): A Pilot Compatibility Study

<b>Background:</b> This study evaluates short-term skin compatibility and biophysical changes in new cosmetic preparations containing PRF and EGF, conducted through in vivo studies. <b>Material and Methods:</b> The study involved 20 healthy volunteers (aged 20-40) who received three identically packaged creams to be applied for a period of four weeks to specific facial areas: formulation 1: base formulation (control); formulation 2: base formulation human epidermal growth factor (EGF) loaded; and formulation 3: base formulation platelet-rich fibrin (PRF) loaded. Skin assessments were conducted at baseline (week 0) and at weeks 1, 2, and 4. Transepidermal water loss (TEWL), skin hydration using corneometry to determine the moisture content of the stratum corneum, skin elasticity using a cutometer to measure the skin's ability to return to its original state after deformation, and dermal bioavailability were measured. EGF concentration in the stratum corneum will be measured using the tape-stripping method followed by HPLC (high-performance liquid chromatography) analysis. <b>Results:</b> A significant decrease in TEWL was observed for all tested formulations (24%, 37%, and 34%, for formulations 1, 2, and 3, respectively), indicating improved skin barrier function. Formulation 3 showed the highest increase in skin hydration (by 95%), followed by formulation 2. Both formulations 2 and 3 demonstrated improvements in skin elasticity, with formulation 3 showing the greatest enhancement. EGF concentration in the stratum corneum increased over the four-week period, reaching equilibrium with the product concentration by week four. <b>Conclusions:</b> The in vivo instrumental compatibility studies confirmed that the new cosmetic formulations were well tolerated and associated with short-term improvement in selected skin parameters.