The stability of recombinant human epidermal growth factor (rhEGF) as a function of buffer pH, temperature, burn skin and the effect of various protease inhibitors were investigated by reverse-phase high-performance liquid chromatography. The results showed that the pH of maximum stability of rhEGF in Mcllvaine buffer solutions was 7.2. Based on the Arrhenius equation, the half-life of rhEGF at 25 degrees C was 6.93 h. Burn wound induced activity of acid proteolytic enzymes was the main explanation as the cause for rhEGF rapid degradation in first day post-burn skin homogenate. An aminopeptidase inhibitor (bestatin) had a better stabilizing effect on the degradation of rhEGF in normal skin than other protease inhibitors (aprotinin and leupeptin). (c) 2004 Elsevier Ltd. All rights reserved.