The Study Of Surface Chemistry And Skin Penetration Of L-Ascorbyl Ibuprofenate

This paper mainly studied the surfactivity and transdermal absorption of double prodrug derivative L-Ascorbyl Ibuprofenate(L-AI) synthesized from ibuprofen and L-Ascorbic acid as raw material. We compared the skin penetration of L-AI coagel and L-AP coagel embedding ibuprofen in pig ear skin by tape stripping technique.We measured the surface tension of L-AI series concentration at 20 oC through the automatic surface tension instrument and the minimum value was 35.57 mN·m-1, far below the water’s surface tension 72.75 mN·m-1. So L-AI was a new kind of surface active agent. Its surface activity was characterized by many methods and the results were: The critical micelle concentration(CMC) of L-AI at 20 oC was measured by conductivity meter and the CMC was about 2.90×10-4 mol·L-1; Determination of the CMC of L-AI at 20 oC by the surface tension was about 5.39×10-4 mol·L-1. The critical micelle temperature(CMT) of L-AI was measured by electrical conductivity meter and differential scanning calorimeter(DSC) and and the CMT was about 70 oC; The particle size of L-AI micelle was measured by dynamic light scattering instrument, and the size of the micelle was about 20 nm. The formation of micelles can solubilize poorly soluble drugs.We found that with different temperatures, L-AI aqueous solution formed different micro structure and has a certain application value. In this paper, The crystal structure and morphology of different concentrations of L-AI coagel were measured by x- ray diffraction and optical microscopy. The results showed that L-AI was a lamellar lamellar crystal structure. Formation of L-AI coagels did not damage the crystal structure of anhydrous powder. In the paper, L-AI and L-Ascorbic acid were compared the antioxidant capacity by DPPH method and we found that L-AI remained the oxidation resistance of L- Ascorbic acid.we studied the in vitro percutaneous penetration of L-AI coagel using improved Franz diffusion cell and selected two kinds of transdermal permeation enhancer of propylene glycol and oleic acid. The results showed that after adding 5% propylene glycol or 2% oleic acid, the accumulation of excess per unit area in 12 h was better respectively were 1002.10μg·cm-2 and 927.18 μg·cm-2. So we used 5% propylene glycol as the permeation enhancing agent in vitro transdermal enhancers of L-AI coagel.In this paper, we compared the skin penetration of L-AI and ibuprofen by tape stripping technique. The results showed that the fluorescent spot of L-AI was not detected when they were stripped down to the eleventh layer and that the fluorescent spot of ibuprofen was not detected when they were stripped down to the seventh layer. The amount of ibuprofen through the stratum corneum of L-AI was larger than ibuprofen and the penetration depth was deeper than ibuprofen. So L-AI has a certain research value and application potential.