pH对萘普生透皮速率的影响

目的：通过对萘普生在不同ｐＨ条件下透皮速率的研究，考察介质ｐＨ对药物透皮吸收的影响。方法：测定萘普生不同ｐＨ介质中的溶解度，使用Ｖａｌｉａ－Ｃｈｉｅｎ扩散池测定萘普生通过大鼠皮肤的体外透皮速率。结果：萘普生的稳态透皮速率随ｐＨ升高而增大，而表观渗透系数则ｐＨ升高而减少。根据分子型药物与离子型药物通过皮肤的途径不同，用平行扩散模型建立了稳态透皮速率和表观渗透系数与氢离子浓度的关系式。结论：当药物在介     

甘草次酸固体脂质纳米凝胶的制备及体外透皮效应

目的制备甘草次酸固体脂质纳米凝胶并考察其体外透皮效应。方法采用微乳液法制备甘草次酸固体脂质纳米粒并考察其包封率、粒径与表面电位,以研和法制备固体脂质纳米粒凝胶;采用改良Franz立式扩散池法进行体外透皮实验,HPLC法测定甘草次酸含量,评价甘草次酸固体脂质纳米粒凝胶的经皮渗透结果。结果甘草次酸固体脂质纳米粒外观为圆球形或椭球形;甘草次酸固体脂质纳米粒的包封率为64.75%±1.36%,粒径范围(46.13±20.10)nm,电位分布范围为(-53.4±7.11)mV。24h甘草次酸固体脂质纳米粒凝胶较甘草次酸固体脂质纳米粒的累积透过量提高66%。结论甘草次酸固体脂质纳米粒凝胶能提高甘草次酸的透皮速率,有望成为甘草次酸透皮给药的新型制剂。     

吲哚美辛理化性质的测定及研究pH对其经皮渗透活性的影响

目的 测定吲哚美辛(IND)的理化性质及研究pH对其经皮渗透活性的影响.方法 建立IND高效液相色谱法(HPLC)的体外分析方法,测定药物在水、不同pH缓冲液(PBS)中的溶解度;运用ACD/labs软件中的pKa DB模块计算药物分子的解离常数(pKa);摇瓶法测定药物的表观油水分配系数(logP);通过测定药物在不同溶媒中的溶解度,选择满足漏槽条件的接受液,同时选择离体豚鼠皮肤,用改良的Franz扩散池测定稳态渗透速率常数(Js)稳态渗透系数(Ps).结果 IND的pKa 为4.18,logP为4.10;IND在pH为9.0时溶解度最大,达到2428.45 mg/L;加入短分子醇类溶解度显著增大;IND的Js及Q随pH升高而增大,Ps随pH升高而降低.结论 IND为难溶性药物,pH可显著影响其溶解度;IND溶解度、pKa和logP的测定可为进一步研究IND的经皮渗透制剂提供基础.当药物在介质中饱和时,可以通过调节pH增加IND的经皮渗透速率.     

pH值对右旋布洛芬体外透皮性能的影响研究

目的:研究pH值对右旋布洛芬(DI)体外透皮性能的影响,为其透皮给药制剂的开发提供实验依据。方法:建立DI的高效液相色谱分析方法,测定其在水和不同pH的磷酸盐缓冲液(PBS)中的平衡溶解度;用摇瓶法测定DI的正辛醇溶液在正辛醇饱和蒸馏水与不同pH的PBS中的表观油水分配系数;以稳态渗透速率(Js)和渗透系数(Ps)为评价指标,检测不同pH的PBS对DI体外透皮性能的影响。结果:32℃时,DI在水中难溶;在pH7.4的PBS中平衡溶解度、Js、Ps均最大,表观油水分配系数极小,分别为5421.6μg·mL-1、339.97μg·cm-2·h-1、0.063cm·h-1、0.17。结论:pH值对DI体外透皮性能有很大影响,pH7.4时DI有较高的溶解度、脂溶性及较理想的皮肤通透性。     

pH对奥沙普秦渗透性的影响

研究 pH对奥沙普秦渗透性的影响。采用Valia Chien扩散池对奥沙普秦进行大鼠离体皮肤的体外渗透性实验 ,并测定奥沙普秦在不同 pH介质中的溶解度。随着供药池中饱和溶液 pH的增加 ,奥沙普秦的表观渗透系数从 1 7 85 4 4× 1 0 -6cm·s-1减小到 1 1 932× 1 0 -6cm·s-1,而稳态渗透速率却从 0 36 78× 1 0 -3 μg·cm-2 ·s-1增加到 1 2 5 96× 1 0 -3 μg·cm-2 ·s-1。因此在经皮给药制剂中 ,通过调节基质的 pH可以提高药物的稳态渗透速率。     

溶液pH对普萘洛尔透皮性能的影响

目的考察不同pH对普萘洛尔稳定性及离体透皮性能的影响。方法采用HPLC测定普萘洛尔浓度;以4 500 lx光照及100℃高温进行加速试验,研究其在pH5.0～9.0内的稳定性;以正辛醇-磷酸盐缓冲液为模拟系统,采用摇瓶法测定不同pH下的lgP(油水分配系数的对数值);并以大鼠腹部皮肤为模型,采用改良的Franz扩散池考察pH对药物透皮性能的影响。结果普萘洛尔对热稳定,但在光照条件下发生降解,降解反应符合一级动力学过程,且具有明显的pH依赖性,表现为当pH高于7.4时降解速率常数显著增加。另外,普萘洛尔lgP随pH升高而增大,当pH在7.0以上时,lgP值均大于1,并表现出良好的透皮性能;当pH在7.0以下时,lgP及透皮性能均急剧下降。结论本研究为普萘洛尔经皮给药制剂的设计与开发提供了实验依据。     

pH对盐酸利多卡因经离体大鼠皮肤渗透性的影响

为了考察pH对利多卡因经皮渗透性的影响,用水平扩散池测定了盐酸利多卡因在不同pH值下通过离体人鼠皮肤的稳态流量(Jss)等参数。结果表明利多卡因游离碱和盐酸盐的经皮渗透性有明显差别,前者的稳态流量为后者的14倍,且滞后时间较短,稳态流量对pH作图呈“S”形曲线,pH接近pKa时稳态流量突增。由此可见,介质的pH值影响利多卡因的经皮渗透性,制剂中应作为一个重要因素考察。     

纳洛酮醇质体凝胶复合物的经皮渗透研究

目的设计纳洛酮醇质体凝胶复合物,考察不同浓度的羟丙甲纤维素(HPMC)以及纳洛酮醇质体凝胶复合物与化学促渗剂联合应用对体外透皮速率的影响。方法采用注入法制备醇质体,HPMC制备凝胶,以SD雄性大鼠皮肤为媒介,改良Franz单室扩散池为体外模型,用HPLC法测定透过皮肤的纳洛酮含量。求算稳态透皮速率和皮肤中的滞留量。结果纳洛酮为2mg·mL-1时,HPMC作为纳洛酮醇质体基质时经皮渗透速率为1%HPMC>3%HPMC>5%HPMC>醇质体>10%HPMC。二甲基亚砜的促渗效果最好,且随二甲基亚砜浓度增加,稳态渗透速率增加。结论适当浓度的HPMC作为纳洛酮醇质体的基质时,能提高纳洛酮醇的透皮速率,增加药物在皮肤中的滞留量,醇质体凝胶复合物有望开发为纳洛酮经皮给药的新剂型。     

乙醇对萘普生经皮离子导入的影响

探讨了不同浓度乙醇对萘普生离子导入透过离体大鼠腹部皮肤的影响，乙醇对萘普生被动扩散具有一定的促渗作用，乙醇浓度为３０％到８０％的萘普生饱和溶液，离子导入时的透皮速率均比药物饱和水溶液离子导入的透皮速率有不同程度的增加，其中乙醇浓度为７０％时药物的透皮速率最大，达到１８５±２３．７ｕｇ／ｈ·ｃｍ２，为被动扩散的６．４倍，药物饱和水溶液离子导入透皮速率的３倍。     

电渗作用对替硝唑经皮离子导入的影响

考察了电扬下电渗作用对分子型药物替硝唑经皮渗透的影响。实验结果表明,替硝唑从饱和水溶液经正极导入时,透皮速率比其被动扩散增加12.8倍,负极导入也产生一定的促进作用。替硝唑的透皮速率随电流强度而增加。另外,NaCl的加入使用电场下替硝唑的透皮速率明显下降,而在NaCl浓度为0.05mol/L时药物在电场下的透皮率相对较大。     

Formulation of carbenoxolone for delivery to the skin

Carbenoxolone (CEX), a semi-synthetic derivative of glycyrrhetinic acid, has previously been used as a disodium salt for the management of dyspepsia and peptic ulcer because of its anti-inflammatory properties. Although glycyrrhetinic acid is available in pharmaceutical and personal care products for skin care, the topical use of the free acid form of CEX, has not previously been reported. In this work we investigated the percutaneous penetration of CEX. Solubility and permeability studies were conducted using a range of solvents or skin permeation enhancers (SPEs) commonly used for skin delivery. Binary combinations of dimethyl isosorbide (DMI) and Transcutol™ (TC) with isopropyl myristate (IPM) were effective in promoting skin permeation of CEX although individual solvents were not. Alternative fatty acid esters to IPM were subsequently investigated with the most promising formulation consisting of TC and propylene glycol laurate (PGL). Interestingly, propylene glycol monolaurate (PGML) did not demonstrate comparable efficacy when combined with TC. A ternary formulation consisting of TC, PGL and IPM demonstrated the best permeation enhancement of CEX compared with all other vehicles. The findings confirm (i) the feasibility of promoting CEX penetration across the skin (ii) the synergistic effect of combinations of solvents and SPEs on dermal and transdermal delivery (iii) the necessity for more fundamental studies to explain the differential effects of fatty acid esters on the skin barrier.     

Percutaneous penetration of ozagrel and the enhancement produced by saturated fatty acids

The effects of a series of fatty acids on the percutaneous penetration of ozagrel (OZ), a selective thromboxane A2 synthetase inhibitor, through rat skin and the mechanism by which fatty acids enhance the skin penetration of OZ were examined in vitro. Lauric acid, at the fatty acid: OZ molar ratio of 2 : 1, was the most potent agent as far as increasing the skin penetration was concerned, with a flux 24-fold higher than that without fatty acid. A molar ratio of 3 : 1 also produced a large enhancing effect, comparable with that of a molar ratio of 2 : 1. When the gel formulation with lauric acid (molar ratio of 2 : 1) was applied to the skin for 6 h, the amount of drug penetrating into the skin was significantly increased compared with that after the formulations without lauric acid and with capric and palmitic acids. However, lauric acid did not change the apparent partition coefficient of OZ between n-heptane and phosphate buffer (pH 7.4). The 13C-NMR spectra of OZ was also unaffected by the addition of lauric acid, indicating that a complex or ion pair with lauric acid was not formed. A possible mechanism for the enhancing effect is the increased incorporation of lauric acid with OZ into the bulk lipid phase of the stratum corneum, where the fatty acid would act as a co-penetrant enhancing passage through the stratum corneum.     

Dermal penetration enhancement profile of hexamethylenelauramide and its homologues: in vitro versus in vivo behavior of enhancers in the penetration of hydrocortisone

Several amides of cyclic amines were prepared and tested as penetration enhancers in the diffusion of various drugs through hairless mouse skin in vitro. Hexamethylenelauramide (hexahydro-1-lauroyl-1H-azepine) was selected as a broad spectrum penetration enhancer worthy of further study. Later, the duration of the effect of various enhancers on the penetration barrier in vivo was determined by evaluating the in vitro diffusion of hydrocortisone through skins that had been pretreated in vivo. We found that the longer the pretreatment, the smaller the amount of penetrated hydrocortisone. Furthermore, our results suggested that differences exist in the retention of various enhancers in living mouse skin. The in vitro pretreatment experiments revealed that the penetration through dead skin is slow compared with the penetration through living skin. Neither the nature of the receptor phase, nor the increased temperature of the in vitro experiments, explain the striking differences between the in vivo and the in vitro experiments. Finally, the penetration of hydrocortisone through the stratum corneum in the presence of enhancers, as well as the penetration of 1-dodecylhexahydro-2H-azepin-2-one (laurocapram), hexamethylenelauramide, and oleic acid, were determined using a stratum corneum stripping technique. More hydrocortisone penetrated through the stratum corneum during the first 3 h in the presence of hexamethylenelauramide than in the presence of laurocapram or oleic acid.     

复合透皮促渗剂对氨氯地平的促渗透作用

目的：研究不同透皮促渗剂对氨氯地平混悬液的体外兔皮渗透作用.方法：以30%乙醇为溶媒,分别配制含不同透皮促渗剂的氨氯地平饱和混悬液,采用自制改良Franz’s扩散池测量其对体外兔皮的促渗透作用.结果：促渗剂对氨氯地平均有促渗透作用,不同透皮促渗剂促透作用的大小顺序为：丙二醇＜油酸＜阿佐恩＜阿佐恩＋丙二醇＜油酸＋丙二醇.与不含促渗剂相比,油酸＋丙二醇渗透系统稳态透皮渗透速率约为不含促渗剂的2.7倍.结论：复合透皮促渗剂对氨氯地平有良好的促渗透作用.     

The effects of an alpha hydroxy acid (glycolic acid) on hairless guinea pig skin permeability.

The barrier integrity of hairless guinea pig skin after treatment with an alpha hydroxy acid was assessed through in vivo topical application of an oil-in-water emulsion containing 5 or 10% glycolic acid at pH 3.0. The control was a commercial moisturizing lotion, pH 7.8. A dosing regimen for the glycolic acid formulations that was tolerated by the hairless guinea pigs and significantly decreased stratum corneum turnover time was determined using the dansyl chloride staining technique. Once-daily dosing of hairless guinea pig skin for 3 weeks with the glycolic acid formulations resulted in approximately a 36-39% decrease in stratum corneum turnover time compared with the control lotion. After this treatment, hairless guinea pigs were sacrificed for the in vitro measurement of the percutaneous absorption of [14C]hydroquinone and [14C]musk xylol. No significant differences in the 24-hour absorption of either test compound were found for skin treated with the control lotion or the glycolic acid formulations. There were also no significant differences found in the absorption of [3H]water through skin from the different treatment groups. Although no increase in skin penetration occurred after treatment with the glycolic acid formulations, histology revealed approximately a twofold increase in epidermal thickness. Also the number of nucleated cell layers nearly doubled in skin treated with 5% and 10% glycolic acid compared with the control lotion and untreated skin. These studies demonstrate that substantial changes in the structure of hairless guinea pig epidermis can occur without significant effect on skin permeability of two model compounds.     

系列甘草次酸衍生物的合成与波谱测定

目的:合成一系列的甘草次酸衍生物,并对其进行波谱测定。方法:对甘草次酸30位羧基进行修饰,合成甘草次酸甲酯和甘草次酸乙酯;对甘草次酸3位羟基进行修饰,合成甘草次酸甲酯-3-O-乙酸酯和甘草次酸乙酯-3-O-乙酸酯;对甘草次酸11位羰基进行修饰,合成脱氧甘草次酸和脱氧甘草次酸甲酯;对合成物进行波谱测定。结果:合成的甘草次酸衍生物经紫外、红外、质谱、核磁共振氢谱与碳谱的鉴定,均为目标化合物。结论:合成的甘草次酸衍生物可为其后续抗炎活性及毒副作用的研究奠定基础。     

Transdermal delivery of levosimendan

The aim of this study was to determine if transdermal penetration of levosimendan, a novel positive inotropic drug, could be enhanced and controlled by formulation modifications. Penetration of levosimendan across human epidermis in vitro was determined using abdominal excised skin and diffusion cells. Predicted steady-state plasma concentrations of levosimendan were estimated using permeabilities and pharmacokinetic parameters of levosimendan. For penetration enhancement we used different pH values, co-solvents, cyclodextrins, surfactants, penetration enhancers, liposomes, and iontophoresis. Sodium lauryl sulfate, ethanol, oleic acid, and soya phosphatidylcholine or their combinations clearly increased levosimendan permeation across the skin in vitro. Iontophoresis was also an efficient method to increase transdermal permeation of levosimendan. A hydrophilic co-solvent/penetration enhancer is needed to achieve better permeability of levosimendan across the skin. In conclusion, transdermal delivery of levosimendan can be significantly increased by formulation modification. Based on kinetic calculations, therapeutic plasma concentrations may be achievable transdermally.     

Factors influencing hydrocortisone permeation into human hair follicles: use of the skin sandwich system

The aim of the present study was to use the in vitro human skin sandwich system in order to quantify the influence of formulation variables on intrafollicular hydrocortisone permeation. The investigated variables were the pH and the viscosity of the topical formulation as well as the presence of chemical enhancers (carvone, menthone, oleic acid and sodium lauryl sulphate). Furthermore, skin sandwich hydration was also varied in order to determine if the method itself can be run using only partially hydrated skin tissues. It was determined that the follicular contribution to hydrocortisone flux decreased marginally with increasing alkalinity in the pH range 3-8.8. Intrafollicular penetration was markedly reduced when HPMC gels were used instead of an aqueous solution. Pretreating the skin with chemical enhancers also reduced the follicular contribution to flux, probably due to permeabilisation of the continuous stratum corneum. Furthermore, it was not possible to satisfactorily modify the skin sandwich method so that it could be deployed using less hydrated skin.