166 JOURNAL OF COSMETIC SCIENCE 60000 -,------------------- - 4 ° C24h -+- 4 ° C 7 days - 4 ° C30days 40000 20000 0 +--+--+---+---+----+---+--..==•=::111 0.5 2.5 10 100 Speed (rpm) Figure 4. Viscosity vs speed of Argireline® gel maintained at 4°C as a function of storage time. Table V Chromatographic Parameters of Stability at Different Temperatures Temperature (°C) 25 40 60 RT 18.5 18.5 18.5 AUC 1899098 1119000 781954 µm/ml 500 294 205 % 100 58.80 41 Although the rate of absorption below 50% with both formulations may appear low, the results in general show that both the cream and the gel formulations satisfied the requirements for cosmetic products intended for topical application, since the cosmeti­ cally active substance, 8-acetyl hexapeptide, is targeted to treat the most superficial layers of the skin (23).

COSMETIC FORMULATIONS WITH ARGIRELINE® 5,00 /J.u 10,00 15.00 Figure 5. Chromatogram of Argireline® at initial time. 10,00 20,00 Minutes .l0,00 35,00 35,00 Figure 6. Chromatogram of Argireline® 24 hours after being subjected to temperature of 40°C. 167 40,00 40,00