Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy,
Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
Skin Pharmacol Physiol. 2020;33(6):323-330. doi: 10.1159/000512643. Epub 2021 Jan 25.
With the increasing diffusion of tattooing, the photolability of tattoo inks has become a critical issue, as available data indicated that several tattoo colorants are unstable under sunlight, generating potentially toxic photodegradation products. Therefore, it is desirable to enhance the photostability of coloring agents contained in tattoo inks.
Lipid microparticles (LMs) highly loaded with Acid Red 87 (C.I. 45380), a colorant used in tattoo inks, were evaluated for their effect on the colorant photoinstability. In addition, the capacity of the LMs to retain the incorporated C.I. 45380 colorant after their intradermal administration in excised porcine skin was investigated.
LMs loaded with C.I. 45380 were prepared using glyceryl tristearate as the lipidic material and phosphatidylcholine as the surfactant. Non-encapsulated C.I. 45380 or the colorant-loaded LMs were irradiated with a solar simulator for photodecomposition studies or introduced in the excised porcine skin mounted in Franz diffusion cells for stability evaluation in the dermal tissue.
The colorant content of the microparticles was 17.7%, and their size ranged from 25 to 170 μm. The light-induced degradation of C.I. 45380 was significantly decreased by its incorporation in the LMs from 20.2 ± 5.8% to 1.9 ± 2.1%. Moreover, after intradermal injection of free or microencapsulated C.I. 45380 in the excised pig skin, the LMs reduced by 93.7% (from 24.6 to 1.5%) the quantity of the colorant diffused and hence lost in the Franz cell receptor fluid. Hence, the LM carrier efficiently retained the entrapped C.I. 45380 following incubation in the dermal region of the isolated porcine skin, which is in favor of a long-lasting tattoo. Based on these data, the incorporation of C.I. 45380 in the LMs could represent a potentially useful strategy to reduce the photodecomposition of the tattoo colorant and its harmful interactions with the skin tissue.
随着纹身的普及，纹身墨水的光解性已成为一个关键问题，因为现有数据表明，几种纹身色料在阳光照射下不稳定，会产生潜在的有毒光降解产物。因此，提高纹身墨水所含着色剂的光稳定性是很有必要的。
用脂质微球（LM）高度负载酸性红 87（C.I. 45380），这是一种用于纹身墨水的着色剂，评估其对着色剂光不稳定性的影响。此外，还研究了 LM 在皮内给药于离体猪皮后保留其包封的 C.I. 45380 着色剂的能力。
使用三硬脂精作为脂质材料和磷脂酰胆碱作为表面活性剂制备负载 C.I. 45380 的 LM。未包封的 C.I. 45380 或负载着色剂的 LM 用太阳模拟器进行光降解研究照射，或引入安装在 Franz 扩散池的离体猪皮中，以评估在真皮组织中的稳定性。
微球的着色剂含量为 17.7%，粒径范围为 25-170μm。C.I. 45380 的光诱导降解率从 20.2%±5.8%显著降低至 1.9%±2.1%，当将 C.I. 45380 包封在 LM 中时。此外，在离体猪皮中皮内注射游离或微囊化的 C.I. 45380 后，LM 将 93.7%（从 24.6%降至 1.5%）的着色剂扩散并丢失到 Franz 细胞受体液中。因此，LM 载体在离体猪皮的真皮区域孵育后，有效地保留了包封的 C.I. 45380，这有利于纹身的持久效果。基于这些数据，将 C.I. 45380 包封在 LM 中可能是一种减少纹身着色剂光分解及其与皮肤组织有害相互作用的潜在有用策略。
