介質研磨山藥之經皮吸收探討

Abstract

隨著年齡增長會產生皮膚老化現象，包括皮膚鬆弛、乾燥且有皺紋產生。目前有許多方法減少此問題，例如醫美手術、雷射治療或是使用含有天然成分的保養品。山藥 (Dioscorea spp.) 是廣泛種植且可作為食用的植物，山藥中的薯蕷皂配基 (diosgenin) 是固醇皂素酸水解去醣基後之產物，已有文獻指出diosgenin能減緩皮膚黑色素生成、促進皮膚纖維母細胞分泌膠原蛋白，而山藥中的植物固醇stigmasterol與β-sitosterol成分則具有保濕、增加傷口癒合的作用。奈米化妝品是奈米科技的創新應用，奈米/次微米山藥具有做為奈米化妝品的開發潛力。 本實驗使用基隆山藥，購自於瑞芳農會，探討介質研磨後山藥之物理特性及經皮吸收效果，並以山藥凍乾粉及粗碎山藥作為對照。山藥凍乾粉粒數平均粒徑為4.95 ± 0.01 μm，經介質研磨後可降低至0.1 ± 0.00 μm，細碎山藥則為4.93 ± 0.01 μm。細碎山藥與研磨山藥pH介於5 ~ 8之間，在此pH範圍內，表面電位介於 -20 ~ -40 mV之間，顯示經機器攪打破碎後，懸浮液仍處於穩定狀態，且是適合皮膚的酸鹼值。沉降試驗中，研磨山藥穩定性優於細碎組，在第五個小時後才緩慢沉降；山藥中活性物質diosgenin、β-sitosterol與stigmasterol經研磨後比起細碎組可增加4.44倍、4.98倍與2.20倍。將細碎山藥與研磨山藥放置皮膚上進行體外模擬穿透實驗，於12小時試驗後切片觀察，結果顯示細碎山藥與研磨山藥並不會對皮膚造成破壞，適合塗抹於皮膚上，但於表真皮與接受液分析中，無法測得山藥中的有效成分，可能受HPLC機器靈敏度、懸浮液粒徑、分子量影響與樣品濃度過低所導致。奈米尺寸的山藥懸浮液在經皮吸收後難以定量，因此需要仰賴更精密的儀器做偵測。

Skin aging is associated with skin thinning, atrophy, dryness, wrinkling. Nowadays, there are several methods to relieve this issue, such as plastic surgery, laser rejuvenation, and skincare products with natural compound. Yam (Dioscorea spp.) has been consumed as a food and medicine around the world. Diosgenin, an aglycon of the yam steroid saponin, has been found to exhibit health benefits, including reduction of pigmentation and enhancing WS1 cells to secrete more collagen. The phytosterols in yam are stigmasterol and β-sitosterol, which enhance water holding capacity and yield wound healing effect. Nanocosmetics is a novel application of nanotechnology. Nano/submicron yam can be potential material for nanocosmetics. In this study, Keelung yam (Dioscorea pseudojaponica Yamamoto) was purchased from Rueifang Farmer’s Association, and the aim of study was to investigate the physical properties of media-milled yam and its percutaneous absorption effect. Raw yam powder was used as a control and a blended yam were utilized for comparasion with media-milled yam. The number mean diameter of raw yam powder was 4.95 ± 0.01 μm, blended yam was 4.93 ± 0.01 μm, after two-steps media-milling, number mean diameter was decreased to 0.10 ± 0.00 μm. The pH value of blended yam and media-milled yam are both between 5 ~ 8, and in this range, with zeta-potential of -20 ~ -40 mV, indicating a stable media-milled suspension. In sedimentation test, media-milled yam was more stable than the blended group. The media-milled yam was precipitated slowly after 5 hours. Active compounds such as diosgenin, β-sitosterol and stigmasterol are increased after media-milling. Application of blended yam and media-milled yam to the skin for 12 hours did not result in any damage to skin. However, active compounds in yam were not detected in epidermis, dermis and receiver, probably due to the limitation of HPLC analytical sensitivity, particle size and the molecular weight of compounds.