大鼠皮肤角质层对荧光素钠脂质体透皮吸收的影响

目的 探讨大鼠皮肤角质层对荧光素钠脂质体透皮吸收的影响。方法 采用Scotch胶带剥脱皮肤角质层,利用荧光光度计、Franz扩散池和荧光显微镜研究皮肤角质层和活性层中荧光素钠的含量;观察皮肤剥脱角质层后荧光素钠脂质体透皮吸收能力的变化和荧光素钠在皮肤中的分布。结果 应用脂质体后皮肤各层荧光素钠的分布量均较相应溶液和凝胶作用后增加(P<0.01);荧光素钠在皮肤各层的分布比例发生了变化;剥脱角质层后脂质体荧光素钠混悬液和荧光素钠溶液各时间点累积透皮浓度相比较,差异无显著性(P>0.05);脂质体荧光素钠凝胶和荧光素钠凝胶相比较,各时间段累积透皮浓度差异无显著性(P>0.05)。结论 脂质体能增加皮肤各层的荧光素钠含量,并能够改变皮肤角质层和去角质层皮肤之间的荧光素钠比例。剥脱角质层后脂质体制剂透皮量显著增加,与相应的普通制剂相比差异无显著性;剥脱角质层后脂质体制剂的毛囊扩散途径不发生改变。     

毫火针对荧光素钠乳膏透皮和皮肤贮留量的影响

目的 探讨毫火针点刺治疗对大鼠荧光素钠(NaFI)乳膏透皮和皮肤贮留量的影响。方法 采用远交群(sprague dawley, SD)大鼠,分为4组,阴性对照组(NCG)、阳性对照组(PCG)、毫火针组(FNG)及毫针组(AG),大鼠麻醉后以背部中线划分左右对称大小为2 cm×2 cm皮肤2块,阴性及阳性对照组直接取下标记的皮肤,毫火针组及毫针组先行针刺干预再取皮,以0.125%荧光素钠乳膏为模型药物,采用Franz扩散法,多功能酶标仪检测不同时间点接收液中荧光素钠浓度和透皮24 h后皮肤中荧光素钠的贮留量。SD大鼠分组分区同上,活体大鼠皮肤干预8 h后制成病理切片,观察皮肤结构及荧光分布。结果 毫火针组NaFI累积透皮量多,2 h时差异有显著统计学意义(P<0.01),4、6、8 h时差异有极显著统计学意义(P<0.001),12、24 h时差异有统计学意义(P<0.05),且比毫针组更具优势,4、6 h时差异有统计学意义(P<0.05);相同药物浓度下,毫火针组比毫针组NaFI皮肤贮留量多(P<0.05),皮肤荧光强。结论 毫火针和毫针点刺SD大鼠皮肤...     

不同剂型8-甲氧基补骨脂素柔性纳米脂质体的大鼠体外透皮研究

目的:对8-甲氧基补骨脂素(8-MOP)柔性纳米脂质体凝胶、8-MOP柔性纳米脂质体、8-MOP酊剂三种剂型药物的透皮差异进行比较,探讨三种不同剂型8-甲氧基补骨脂素柔性纳米脂质体的大鼠体外透皮性。方法:将三种不同剂型8-MOP通过含有离体鼠皮的扩散池,测定鼠皮以及接受池中8-MOP的含量,并进行比较,对不同时间点3种不同剂型8-MOP的累积渗透量作图,对各组皮肤滞留量两两进行t检验。结果:8-MOP脂质体凝胶组在接受液中的累积渗透量小于8-MOP脂质体组和酊剂组;8-MOP酊剂组渗透量从第3 h后开始急剧升高;比较各组皮肤内滞留的药量,8-MOP脂质体凝胶组高于8-MOP酊剂组,而8-MOP脂质体组又高于MOP脂质体凝胶组,差异均有统计学意义(t值分别为53.97、18.97,P值均<0.05)。结论:8-MOP不同剂型有着不同的特性,8-MOP柔性纳米脂质体更具有皮肤亲和性,更有利于药物在皮肤内滞留发挥药物作用。     

不同剂型8-甲氧基补骨脂素柔性纳米脂质体的大鼠体外透皮研究

目的:对8-甲氧基补骨脂素(8-MOP)柔性纳米脂质体凝胶、8-MOP柔性纳米脂质体、8-MOP酊剂三种剂型药物的透皮差异进行比较,探讨三种不同剂型8-甲氧基补骨脂素柔性纳米脂质体的大鼠体外透皮性。方法:将三种不同剂型8-MOP通过含有离体鼠皮的扩散池,测定鼠皮以及接受池中8-MOP的含量,并进行比较,对不同时间点3种不同剂型8-MOP的累积渗透量作图,对各组皮肤滞留量两两进行t检验。结果:8-MOP脂质体凝胶组在接受液中的累积渗透量小于8-MOP脂质体组和酊剂组;8-MOP酊剂组渗透量从第3 h后开始急剧升高;比较各组皮肤内滞留的药量,8-MOP脂质体凝胶组高于8-MOP酊剂组,而8-MOP脂质体组又高于MOP脂质体凝胶组,差异均有统计学意义(t值分别为53.97、18.97,P值均0.05)。结论:8-MOP不同剂型有着不同的特性,8-MOP柔性纳米脂质体更具有皮肤亲和性,更有利于药物在皮肤内滞留发挥药物作用。     

脂质体鬼臼毒素混悬液在大鼠表皮及真皮的分布规律初探

目的 探讨脂质体鬼臼毒素在大鼠皮肤各层的分布规律。方法 观察组大鼠涂抹0.5%脂质体鬼臼毒素混悬液,对照组涂抹0.5%鬼臼毒素酊剂,分别在涂药1、2、4、6、12及24h取皮肤标本,常规石蜡切片,采用激光共聚焦显微成像仪(CLSM)扫描,观察单位面积鬼臼毒素的荧光量。结果 鬼臼毒素24h荧光值曲线下面积(AUC),表皮层中观察组是对照组的1.5倍,真皮层中是2.3倍;对照组在涂药2h后,表皮和真皮的荧光量即达到峰值(分别为1585.52/μm²和2005.66/μm²),在4h后荧光量迅速降低;而观察组在4h前,表皮和真皮中的荧光量较低,6h后逐渐增高,在12h达峰值(分别为(750.28/μm²和1073.08/μm²)。结论 脂质体制剂使鬼臼毒素在皮肤中缓慢释放,并持续较长时间。     

纳米晶片促进药物经皮渗透作用的研究

目的 :将纳米晶片用于经皮给药,了解纳米晶片作用于皮肤后,在皮肤表面形成开放给药通道的存在及其闭合,及纳米晶片促进外用药物的经皮渗透作用。方法:(1)扫描电镜观察纳米晶片作用后,在皮肤表面形成孔道的存在和闭合;(2)以0.125%荧光素钠为模型药物,在荧光显微镜下对比观察纳米晶片与荧光素钠结合作用和单纯外用荧光素钠后,荧光在大鼠皮肤的分布情况。结果:(1)纳米晶片可在皮肤表层形成给药通道,该通道在20 min左右即可闭合;(2)经过纳米晶片处理过的大鼠皮肤可见耀眼的荧光(+++);而未经纳米晶片处理的大鼠皮肤仅在角质层可见明显的线状荧光(+),其他部位可见微弱荧光(-)。结论:纳米晶片对外用药物有明显促进渗透作用,纳米晶片在皮肤美容和药物缓控释放领域具有广阔的前景。     

毛囊皮脂腺在脂质体鬼臼毒素透皮吸收中的作用

目的　探讨脂质体鬼臼毒素混悬液透皮的机制。方法　实验大鼠涂抹 0 .5%脂质体鬼臼毒素混悬液 ,分别在涂药 1、2、3、4、6、8、12、16、2 4及 48h时取皮肤标本 ,常规石蜡切片 ,采用激光共聚焦显微成像仪 (CLSM )扫描 ,观察毛囊皮脂腺部位和非毛囊、皮脂腺部位单位面积鬼臼毒素的荧光量。结果　毛囊皮脂腺部位单位面积的荧光值在涂药后 8h达到高峰 ,而非毛囊皮脂腺部位达到高峰的时间是涂药后 12h ,并且毛囊皮脂腺部位的荧光值在各个时间点上均高于非毛囊皮脂腺部位 ,两者相比差异有显著性 (P <0 .0 0 1)。鬼臼毒素 48h荧光值曲线下面积 (AUC) ,毛囊皮脂腺部位是非毛囊皮脂腺部位的 1.63倍。结论　毛囊皮脂腺部位可能在脂质体鬼臼毒素制剂透皮过程中起主要作用     

长脉宽与Q开关1064 nm Nd:YAG激光对皮肤作用的比较

目的:比较长脉宽1064 nm Nd:YAG激光和Q开关1064 nm Nd:YAG激光照射对小鼠皮肤的影响.方法:分别使用长脉宽1064 nm Nd:YAG激光(脉宽为3 ms、50 ms)和Q开关1064 nm Nd:YAG激光(脉宽5 ns)对小鼠背部脱毛后的皮肤进行照射,共照射4次,每次间隔1周.检测照射后不同时间点的皮肤弹性、皮肤羟脯氨酸含量,真皮内胶原增生情况以及红斑指数和经表皮失水量的变化情况.结果:从首次照射后第3或4周至第7周,各实验组的皮肤弹性都明显好于对照组;首次照射7周后各组实验侧的皮肤羟脯氨酸含量和真皮内胶原厚度都较对照组显著增大(P＜0.01),但各实验组之间无显著差异;苦味酸一天狼猩红染色-偏振光法检查显示各组增生的胶原主要为I型胶原.首次激光照射后即刻,各实验组的经表皮失水量及Q开关1064 nm Nd:YAG激光实验组的红斑指数都较其对照组显著增高(P＜0.01),并于1周内恢复.结论:长脉宽1064 nm Nd:YAG激光可以取得与Q开关1064 nm Nd:YAG激光对皮肤相似的效果,且不良反应较轻.     

女阴血管角皮瘤

报告1例女阴血管角皮瘤。患者女，41岁。两侧大阴唇红色及黑色丘疹半年。皮肤科检查：两侧大阴唇可见较多直径0.1～0.5 cm的红色、紫红色及黑色丘疹，无糜烂破溃结痂。皮肤镜检查：镜下可见点球状及团状血管腔隙样结构，部分呈红色紫红色及紫黑色，腔隙周边可见白色面纱结构。病理检查：真皮乳头内见扩张的薄壁血管，管腔内见红细胞及部分血栓，周边表皮突向下延伸包裹。诊断：血管角皮瘤。治疗：电灼法将所有肉眼可见皮损汽化切除。     

不同肤色人种皮肤对硫酸月桂酯钠引发刺激性接触性皮炎反应差异的比较

目的评估不同肤色人种皮肤对化学刺激物的敏感性。方法用多个浓度的硫酸月桂酯钠对32例健康志愿者（黑种人8例,白种人16例,黄种人8例）背部皮肤进行斑贴试验。结果显示黑种人组最小红斑刺激量高于白种人组（P＜0.05）和黄种人组（P＞0．05）。然而在相同浓度的硫酸月桂酯钠刺激部位,黑种人、白种人和黄种人3组经表皮水分散失和真皮浅层微血管血流量值无显著性差异。黑种人、白种人和黄种人3组经表皮水分散失和真皮浅层微血管血流量值分别与硫酸月佳酯钠刺激浓度有明显的剂量应答关系,并且3组经表皮水分散失值与临床观察指数值之间呈显著正相关（黑种人组：r＝0．83,P＜0．01;白种人组：r＝0．92,P＜0．01;黄种人组：r＝0．89,P＜O．01）。结论与白种人和苗种人相比,黑种人皮肤对硫酸月桂酯钠刺激同样较敏感。     

The effect of liposomes on skin barrier structure.

The present work deals with the 'in vivo' stripping technique to evaluate the percutaneous absorption of sodium fluorescein (NaFl) vehiculized in two different liposome preparations formed by phosphatidylcholine (PC) and lipids mimicking the stratum corneum (SC; ceramides, cholesterol, palmitic acid and cholesteryl sulphate), respectively. Furthermore, the possible effect of these vesicles on the SC lipid alkyl chain conformational order were evaluated at different depths of SC by non-invasive biophysical techniques: Corneometer, Tewameter and especially ATR-FTIR. The results of NaFl percutaneous absorption indicate the highest penetration in the case of incorporation in PC liposomes, which could be related to the increase in SC lipid disorder detected by ATR-FTIR, i.e. a decrease in skin barrier function. On the other hand, SC lipid liposomes have been shown to have a higher affinity for SC owing to the high amount of NaFl found in this layer, suggesting a greater reservoir capacity of SC when similar lipid composition formulation is applied. A lipid order increase is observed by infrared spectroscopy, when these types of liposomes are topically applied, resulting in a strong barrier effect. These results could be useful in designing specific liposomal topical applications.     

Enhancement of hydrocortisone permeation of human and hairless mouse skin by 1-dodecylazacycloheptan-2-one

The influence of 1-dodecylazacycloheptan-2-one (Azone) on the in vitro permeation of hairless mouse skin and human epidermis by hydrocortisone was studied as a function of the amount of Azone solubilized and/or emulsified into aqueous media applied to the membranes using the infinite-dose technique. The permeability-enhancing effect of Azone increases with increasing Azone total concentrations until 0.1% is reached with mouse skin and 0.01% is reached for human epidermis. Thereafter, permeabilities for both tissues drop systematically. The maximally enhanced permeability in mouse skin approached that for mouse skin stripped of its stratum corneum. The peak permeability in human epidermis is an order of magnitude smaller than for mouse skin with the duration of Azone treatment required to achieve the full effect in human epidermis being twice that for mouse skin (approximately 20 h vs approximately 12 h). Thus, there is a profound difference in Azone's action on these two tissue types. It was also established that the affinity of an enhancer for a permeant drug can significantly offset its ability to enhance permeability. Specifically, hydrocortisone was found to partition significantly into the Azone-rich phase of the emulsion, lowering its concentration (and its thermodynamic activity) in the continuous aqueous phase and thereby reducing its flux through the skin. This physiochemical effect was profound enough to nullify the intrinsic permeability-enhancing effect of Azone as the total Azone concentration was raised to 10%.     

Enhanced transfollicular delivery of adriamycin with a liposome and iontophoresis

To find a better way to deliver drugs into hair follicles, we tried two approaches: single topical application using various liposomes; and iontophoresis combined with topical application of ionic liposome. After delivery of adriamycin (ADR) to wax-depilated rat skin, the transport of the drug was examined under fluorescence microscopy. Most liposomal ADR showed more effective transdermal and transfollicular penetration than free ADR. Among tested liposomes, the non-ionic GDL liposome (GDL/CH/POE-10 = glycerol dilaulate/cholesterol/polyoxyethylene-10) was the most selective to hair follicles against skin, while the cationic liposome (GDL/CH/POE-10/DOTAP, dioleoyl trimethylammonium propane) containing monocationic DOTAP was less selective; however, it was better at improving the delivery amount and penetration of ADR into the follicles and skin. The DMPC/DMPG (7/3) formulation of anionic PC liposome (DMPC/DMPG = dimyristoyl-phosphocholine/-phospoglycerol) showed results similar to the cationic liposome. The DMPC/DMPG (3/7) formulation yielded poor results, however, probably because of its increased viscosity and anionic property. Although ADR delivery was enhanced by liposomal formulations, topical applications had some limitations in delivery capacity and speed. To accelerate delivery, iontophoresis was combined with the cationic liposome at positive 0.2-0.4 mA/cm(2) for 20-30 min. The resulting delivery of ADR through follicular routes was excellent. This combination method diffused ADR 3.0-fold more efficiently, rapidly and deeply than single topical application of cationic liposomal ADR. This system also achieved a 3.5-fold higher diffusive follicular delivery than a free ADR/iontophoresis combination. Furthermore, it was demonstrated that the tetracationic lipid DOSPER and hydrophile spermine could serve as a cationic additive instead of the monocationic DOTAP in the liposome. These results suggest that the combinative system of the topically applied cationic liposome followed by iontophoresis has a significant synergistic effect on the transfollicular delivery of ADR.     

Semisolid formulations containing dimethyl sulfoxide and α-tocopherol for the treatment of extravasation of antiblastic agents

The topical treatment with dimethyl sulfoxide (DMSO) and/or α-tocopherol (α-T) is widely used in order to prevent the local complications of extravasation of cytostatic drugs and protect patients against skin ulceration. Till now, DMSO and α-T have been mainly used in solution. The goal of this study was to formulate semisolid preparations for cutaneous application differing in the hydrophilic and lipophilic properties and containing DMSO and α-T in combination. With respect to solutions, the use of semisolid preparations containing DMSO and α-T could be advantageous in patients having extravasation as DMSO and α-T can remain in contact with the skin over an extended period of time. As a consequence, the action of the active principles can be limited specifically on the injured skin area, reducing the cutaneous irritative effects of DMSO. The following types of semisolid formulations containing 50% m/m DMSO and 2.5% m/m α-T were prepared: hydrophilic ointment, o/w emulsion, hydrophilic gel and lipophilic gel. The ex vivo skin permeation of DMSO and α-T was evaluated by using modified Franz’s diffusion cells and human stratum corneum and epidermis (SCE) as a membrane. The permeated and retained amounts of DMSO and α-T were determined. The oleogel preparation, the hydrophilic gel and the o/w emulsion were uniform in colour and aspect, without any evidences of phase separation over the period of the study. Hydrophilic ointments were discarded as they showed phase separation after 12 h. All formulations had a different behaviour in terms of skin permeability. In particular, hydrogel and o/w emulsion showed the best control on the drug release considering the interactions of the vehicle components with the SCE and the drugs partition between the vehicle and the SCE. The DMSO permeated amount after 24 h was 4.1 mg/cm² for hydrogel and 2.5 mg/cm² for emulsion while the permeated amount of pure DMSO after 24 h was 47.5 mg/cm². Therefore, aiming to reduce side effects after the topical application of the antidotes DMSO and α-T, these results suggested that hydrogel and o/w emulsion could be considered the most promising formulations for further clinical evaluations in managing of extravasation of anthracyclines.     

Diffusion of [2-14C]diazepam across hairless mouse skin and human skin

The objectives of this study were to investigate the absorption of diazepam applied topically to the hairless mouse in vivo and to determine the diffusion of diazepam across isolated hairless mouse skin and human skin. [14C]Diazepam was readily absorbed after topical administration to the intact hairless mouse, a total of 75.8% of the 14C-label applied being recovered in urine and feces. Diazepam was found to diffuse across human and hairless mouse skin unchanged in experiments with twin-chambered diffusion cells. The variation in diffusion rate or the flux for both human and mouse tissues was greater among specimens than between duplicate or triplicate trials for a single specimen. Fluxes for mouse skin (stratum corneum, epidermis, and dermis) were greater than for human skin (stratum corneum and epidermis): 0.35-0.61 microgram/cm2/h for mouse skin vs 0.24-0.42 microgram/cm2/h for human skin. The permeability coefficients for mouse skin ranged from 1.4-2.4 X 10(-2)cm/h compared with 0.8-1.4 X 10(-2)cm/h for human skin. Although human stratum corneum is almost twice the thickness of that of the hairless mouse, the diffusion coefficients for human skin were 3-12 times greater (0.76-3.31 X 10(-6) cm2/h for human skin vs 0.12-0.27 X 10(-6) cm2/h for hairless mouse) because of a shorter lag time for diffusion across human skin. These differences between the diffusion coefficients and diffusion rates (or permeability coefficients) suggest that the presence of the dermis may present some barrier properties. In vitro the dermis may require complete saturation before the diazepam can be detected in the receiving chamber. [14C]Diazepam was not detected in the receiving chamber of the Franz cell apparatus in experiments with human skin. This indicated that the rate of diffusion was less than 0.09 microgram/cm2/h. Since this diffusion technique more closely resembles topical administration to humans, these results appear to indicate that achieving therapeutic concentrations in humans may be difficult. In addition, the hairless mouse may not be a suitable model for predicting percutaneous absorption of diazepam in humans.     

Irradiance and light dose influence histological localization of photodamage induced by photodynamic therapy with aminolaevulinic acid

BACKGROUND: Photodynamic therapy (PDT) with aminolaevulinic acid (ALA) is used in many countries for the treatment of actinic keratoses. OBJECTIVES: The objectives of the current study were to evaluate the influence of irradiance and light dose on the localization and extent of photodamage to mouse skin following ALA-PDT. METHODS: In this study we evaluated the influence of irradiance and light dose on epidermal photodamage following ALA-PDT. Groups of hairless mice received an intraperitoneal injection of ALA followed 2 h later by exposure to 12 J cm(-2), 24 J cm(-2) or 48 J cm(-2) of unfiltered light from a slide projector. For each of these fluences, groups of mice were exposed at the following irradiances: 5 mW cm(-2), 20 mW cm(-2) or 40 mW cm(-2). Skin biopsies were performed 24 h and 72 h later. RESULTS: Histological localization of photodamage was influenced by irradiance and light dose. At high irradiance and low fluence, PDT photodamaged cells were mostly located in the upper area of the epidermis whereas at lower irradiance and high fluence the complete epidermis was necrotic and often absent 24 h after light exposure. Protoporphyrin IX (PpIX) fluorescence intensity was similar in the upper and lower region of the epidermis 2 h after ALA injection. The decrease in PpIX fluorescence intensity immediately after light exposure was also similar in both regions of the epidermis. CONCLUSIONS: The localization of photodamage following ALA-PDT is influenced by irradiance and light dose. This phenomenon cannot be explained by differences in PpIX intensity in the epidermis either before or after light exposure.     

Altered binding of Ulex europaeus I lectin to psoriatic epidermis

We have used Ulex europaeus I (UEA I) lectin, specific for α-l -fucose-containing glycoconjugates, in fluorescence microscopy to stain cryostat sections of human skin from normal persons and patients with psoriasis and lichen simplex. In normal skin the upper layers of the stratum spinosum and the stratum granulosum were strongly reactive with UEA I, whereas the lower layers of the epidermis did not react. The staining intensity of the upper epidermis was similar to that of the endothelium of dermal blood vessels. Biopsies of the lesional skin of lichen simplex showed an intense UEA I-specific staining throughout the whole epidermis, similar in intensity to that seen in the upper epidermis of normal skin. In psoriatic lesions positive UEA I-specific fluorescence was seen throughout the whole epidermis, but the fluorescence was more faint and often granular. In uninvolved skin of psoriatic patients the whole epidermis showed a diffuse UEA I-specific fluorescence, differing in this respect from normal skin. In normal skin UEA I binds to epidermal cells which are at a certain state of differentiation. The results with psoriatic epidermis confirm that both uninvolved and lesional epidermis have a defect in epidermal maturation, as shown by the altered binding of UEA I lectin.