Biopharmaceutics: Topical Delivery of Keloid Therapeutic Drug,Tranilast, by Combined Use of Oleic Acid and Propylene Glycol as a Penetration Enhancer: Evaluation by Skin Microdialysis in Rats

Topical delivery of tranilast (N-(3,4-dimethoxycinnamoyl)anthranic acid), an inhibitor of collagen synthesis and a therapeutic drug for keloid and hypertrophic scar, was examined, in rats, with oleic acid alone or a combination of oleic acid and propylene glycol as penetration enhancer. Evaluation was by measurement of the concentration of tranilast in plasma and in the dialysate from skin microdialysis. When tranilast at a dose of 1.5 mg was applied topically as an ethanol solution containing 5% polyvinylpyrrolidone on a dorsal skin surface (2.25 cm²), the maximum concentration of tranilast in skin dialysate was approximately 2 μM. When 10 or 20% oleic acid was added to the same ethanol solution the maximum concentration of tranilast in the dialysate increased to 10–20 μM, and this value was further increased to 60 μM by the addition of a combination of oleic acid (10 or 20%) and propylene glycol (10%) to the solution. With the combination of oleic acid and propylene glycol the area under the plot of the concentration of tranilast in skin dialysate against time between 0 and 4 h (AUC_0–4) was more than 400-fold that after intravenous administration. The transdermal bioavailability of tranilast as assessed by the AUC_0–4 of tranilast in plasma, was 0.2% of the dose applied in the ethanol solution, 3–5% of that applied in the ethanol solution containing oleic acid, and 14–16% of that applied in the ethanol solution containing both oleic acid and propylene glycol. These results suggest that the topical delivery of tranilast with an absorption enhancer such as a mixture of oleic acid and propylene glycol might be a more effective medication than oral administration of tranilast for the treatment of keloid and hypertrophic scar.     

微渗析技术用于盐酸奥旦西酮的大鼠在体透皮吸收研究

本文进行了微渗析探针的体内、外校正,浓差法和反渗析法分别用于测定探针的体内和体外回收率。在探针校正的基础上,研究了盐酸奥旦西酮（ＯＮ）丙二醇（ＰＧ）溶液的大鼠在体经皮吸收及渗透促进剂油酸（ＯＡ）的作用。微渗析样品用高效液相法测定。结果证明：探针的体外回收率（３５．４６±４２％）和体内回收率（３２．５３±１．８％）没有显著的差别（Ｐ＞０．１）。以 ２％和５％ＯＡ的ＰＧ溶液为渗透促进剂时,ＯＮ在渗析液和真皮中达到坪浓度的时间分别为３．５及１．５ ｈ：后者的坪浓度约是前者的两倍。当ＯＡ的浓度从０提高到２％、 ５％时,药物的稳态传递速度从０．００１增大到０．０３０和０．０５８μｇ·ｈ~－１。实验证明 ＯＡ对于ＯＮ的大鼠在体透皮吸收是一种有效的促进剂。     

基质对甲硝唑透皮速率影响

甲硝唑为治疗各种厌氧菌感染的常用药物,近来又用于疥疮、丘疹性等淋疹、酒糟鼻和银屑病等皮肤病的治疗,外用制剂常用的是软膏。随着药物透皮吸收研究的深入,有越来越多的文献报导制剂处方对药物透皮吸收的影响。甲硝唑软膏虽然只产生局部治疗作用,但药物一定要通过角质层才能产生作用,因此有必要研究软膏类型等因素对甲硝唑通过皮肤速率的影响。本文以兔皮肤为皮肤模型考察了常用的三种类型的软膏制剂中甲硝唑的透皮速率,为甲硝唑软膏的基质选择提供依据。1 实验方法     

赖氨匹林软膏透皮吸收的研究

赖氨匹林离体大鼠皮体外经皮渗透试验，丙二醇对赖氨匹林有较强的促渗作用，赖氨匹林有可能经皮给药。     

HPLC法测定水杨酸软膏中主药及有关物质的含量

目的:建立以高效液相色谱法测定水杨酸软膏中主药及有关物质含量的方法。方法:色谱柱为Kromasil C18,流动相为甲醇-水(冰醋酸调节pH至2.5)=50∶50,检测波长为270nm,流速为1.0mL·min-1,进样量为20μL。结果:主峰与有关物质可完全分离,水杨酸检测浓度的线性范围为10.014～100.14μg.mL-1(r=0.9999),平均回收率为99.35%,RSD=0.99%,最低检测限为5ng·mL-1,有关物质标示量均小于1.01%。结论:本方法操作简便、结果准确、专属性强,可用于该制剂的含量测定。     

固体脂质纳米粒作为水杨酸经皮给药载体的研究

目的 考察固体脂质纳米粒作为经皮给药载体对水杨酸经皮吸收的促渗透作用.方法 采用薄膜超声法制备水杨酸固体脂质纳米粒,以改良的Franz扩散池考察其体外透皮特性;并与水杨酸软膏剂比较,考察其促渗作用.结果 制备的水杨酸固体脂质纳米粒均匀圆整,包封率为46.4%,体外透皮特性优于普通软膏剂,24 h后皮肤药物累积透过量为654.3 μg/cm2,皮肤中药物残留量为22.99 μg,均分别显署高于软膏剂组(128.0 μg/cm2和0.84 μg,P<0.05).结论 固体脂质纳米粒作为水杨酸经皮给药载体,可有效促进药物透皮吸收和增加药物在皮肤中储留量,而且可延缓药物的释放,从而有效提高药物疗效及患者依从性.     

紫外分光光度法测定水杨酸软膏中水杨酸含量

目的 建立水杨酸软膏的含量测定方法。方法 采用紫外分光光度法，测定波长为296nm。结果 水杨酸浓度在4～28μg／mL范围内与吸收度有良好的线性关系（r=0．9999），平均回收率为101．2％，RSD=1．22％（n=6）。结论 紫外分光光度法能简便、快速、准确地测定水杨酸软膏中水杨酸含量。     

微透析技术及其在经皮给药系统中的应用

综述了经皮微透析技术及其近年来在经皮给药系统中的应用,包括经皮吸收药物的药动学研究及生物利用度和生物等效性评价。     

HPLC法测定复方水杨酸冰片软膏中水杨酸和苯甲酸的含量

目的:用HPLC法测定复方水杨酸冰片软膏中水杨酸和苯甲酸的含量.方法:采用C18柱(4.6 mm×200 mm,5 μm),流动相为甲醇-水(40:60)(用磷酸调pH值为3.2),检测波长为227 nm.结果:水杨酸、苯甲酸分别在0.76～24.32,1.21～48.43 mg·L-1(r=1)范围内有良好的线性关系,平均回收率分别为95.8%,101.1%(n=9).结论:该方法简便、快速、准确,可以有效地控制药品质量.     

HPLC法同时测定华佗膏中水杨酸苯甲酸的含量

目的：建立高效液相色谱法同时测定华佗膏中水杨酸苯甲酸的含量。方法：采用Agilent Eclipse XDB-C18色谱柱（4．6mm×250mm,5μm）,流动相为甲醇-0．05mol·L^-1磷酸氢二钠溶液（用磷酸调pH至4．6）（52：48）,柱温：30℃,流速为1．0mL·min^-1,二极管阵列检测器（DAD）,检测波长240nm,以外标法峰面积定量。结果：水杨酸与苯甲酸、空白样品分离良好,线性范围水杨酸为20．77～519．2μg（r=1．0000）;苯甲酸为41．89—1047．3μg（r=1．0000）,样品溶液在24h内稳定,平均回收率水杨酸为100．3％,RSD（n=9）为0．77％;苯甲酸为100．4％,RSD（n=9）为0．76％。结论：该方法简便、快速,测定结果准确可靠,重现性好,可用于华佗膏的质量控制。     

高效液相色谱法同时测定复方苯甲酸软膏中两组分含量

目的 :建立以高效液相色谱法同时测定复方苯甲酸软膏中苯甲酸和水杨酸含量的方法。方法 :以HypersilODS为色谱柱 ,磷酸二氢钾溶液为流动相 -甲醇 (78∶22) ,检测波长为254nm。结果 :苯甲酸、水杨酸的线性范围分别为0 4～2 0mg/ml(r=0 9999)、0 2～1 0mg/ml(r=0 9999) ;回收率分别为98 74 % (RSD=0 55 % )、98 67 % (RSD=0 59 % ) ;日内相对标准差分别为0 56 %、0 73 % (n=5) ,日间相对标准差分别为0 75 %、0 82 % (n=5)。结论 :本法可用于复方苯甲酸软膏的含量测定和质量控制 ,且简便、快速、准确。     

Evaluation of In-vivo Transdermal Absorption of Cyclosporin with Absorption Enhancer Using Intradermal Microdialysis in Rats

The purpose of this study was to evaluate the effect of absorption enhancer on in-vivo transdermal absorption of cyclosporin using intradermal microdialysis in rats. Cyclosporin oily solutions (0.5, 2, 8% w/v) were prepared from Sandimmun (10% w/v oily oral preparation of cyclosporin) by diluting with olive oil. 1-[2-(Decylthio)ethyl]azacyclopentan-2-one (HPE-101) and glycerin were added to the cyclosporin formulation as an absorption enhancer at various concentrations between 1 and 20%. These formulations were applied to the shaved abdomen of rats treated with intradermal microdialysis at a flow rate of 2.5 μL min^?1 for 6 h. Cyclosporin was immediately detected and attained a plateau in the dermal dialysate after topical application of cyclosporin oily solution alone. Cyclosporin levels in the dialysate increased with increasing cyclosporin concentrations in the formulation from 0.5 to 8% (w/v). HPE-101 did not influence cyclosporin absorption at concentrations less than 6% (w/v). Addition of 10% (w/v) HPE-101 significantly enhanced an apparent absorption rate of cyclosporin by 4.9 times. However, 20% (w/v) HPE-101 did not show the enhancing activity. On the other hand, addition of glycerin at concentrations of 6, 10, and 20% (v/v) significantly enhanced an apparent absorption rate of cyclosporin by 3.0, 64, and 6.9 times, respectively. The time lag for cyclosporin absorption was less than 0.21 h in all tested cases. This microdialysis study shows that glycerin is a suitable enhancer for improving the in-vivo cyclosporin absorption from the skin.     

Dodecyl Amino Glucoside Enhances Transdermal and Topical Drug Delivery via Reversible Interaction with Skin Barrier Lipids

Purpose

Skin permeation/penetration enhancers are substances that enable drug delivery through or into the skin.

Methods

To search for new enhancers with high but reversible activity and acceptable toxicity, we synthesized a series of d-glucose derivatives, both hydrophilic and amphiphilic.

Results

Initial evaluation of the ability of these sugar derivatives to increase permeation and penetration of theophylline through/into human skin compared with a control (no enhancer) or sorbitan monolaurate (Span 20; positive control) revealed dodecyl 6-amino-6-deoxy-α-d-glucopyranoside 5 as a promising enhancer. Furthermore, this amino sugar 5 increased epidermal concentration of a highly hydrophilic antiviral cidofovir by a factor of 7. The effect of compound 5 on skin electrical impedance suggested its direct interaction with the skin barrier. Infrared spectroscopy of isolated stratum corneum revealed no effect of enhancer 5 on the stratum corneum proteins but an overall decrease in the lipid chain order. The enhancer showed acceptable toxicity on HaCaT keratinocyte and 3T3 fibroblast cell lines. Finally, transepidermal water loss returned to baseline values after enhancer 5 had been removed from the skin.

Conclusions

Compound 5, a dodecyl amino glucoside, is a promising enhancer that acts through a reversible interaction with the stratum corneum lipids.

     

Recent Developments in Ionic Liquid-Assisted Topical and Transdermal Drug Delivery

Pharmaceutical Research - Ionic liquids (ILs) have attracted growing interest as designer solvents/materials for exploring unrealized functions in many areas of research including drug formulations...     

Effect of Penetration Enhancers on the Transdermal Delivery of Bupranolol Through Rat Skin

Bupranolol (BPL) is a suitable drug candidate for transdermal drug delivery system development based on its favorable physicochemical and pharmacokinetic properties. The effect of different penetration enhancers on the permeation of BPL across rat skin was studied using side-by-side diffusion cells. 2-pyrrolidone (PY), 1-methyl-2-pyrrolidone (MPY), and propylene glycol (PG) at various concentrations were used as penetration enhancers along with 0.4% w/v aqueous suspension of BPL. Menthol at different concentrations in isopropanol-water (6:4) mixture also was used as an enhancer wherein BPL at 0.4% w/v was completely solubilized. Skin pretreatment studies were carried out with all the above enhancers to understand their role in the penetration enhancement effect. PY and MPY at 5% w/v concentrations increased the permeation of BPL by 3.8- and 2.4-fold, respectively, versus control (p < .01). PG at 10% and 30 w/v concentrations increased the flux of BPL by 2.5- and 5.0-fold, respectively, versus control (p < .001). Menthol at 2% w/v concentration increased the flux of BPL by 3.8-fold (p < .01) and further increase in menthol concentration significantly decreased the flux of BPL. Overall, pyrrolidones and menthol at low concentrations (5% w/v or less) and PG at 30% w/v concentration were effective as penetration enhancers for BPL.     

HPLC法测定经皮给药中阿司匹林和水杨酸的浓度

目的:建立在体外经皮给药接受液中同时测定阿司匹林和水杨酸的高效液相色谱方法。方法:色谱柱为C18柱(5μm,250 mm×4.6 mm),流动相为水-乙腈-磷酸(650:350:2),流速:1.0 mL·min-1,检测波长:228 nm。结果:阿司匹林和水杨酸在0.1-50.0μg·mL-1范围内,峰面积与浓度呈良好的线性关系,日内RSD为1.3％-3.6％和2.1％-2.7％,日间RSD为1.9％-5.2％和2.8％-4.3％,回收率为98.8％-99.7％和98.6％-100.3％。结论:方法简便、准确,可为阿司匹林经皮给药体外研究提供一理想的检测方法。     

Effect of Lipophilicity on Microneedle-Mediated Iontophoretic Transdermal Delivery Across Human Skin In Vitro

The effect of lipophilicity of drug on the microneedle (MN)-mediated iontophoretic delivery across dermatomed human skin was studied. Beta blockers with similar pK_a but varied log P values were selected as model drugs in this study. Iontophoresis (ITP) or MNs, when used independently, increased the transdermal flux of beta blockers as compared with passive delivery (PD). ITP across the MN-treated skin (MN + ITP) increased the permeation rate of all beta blockers as compared with PD (p < 0.001). The enhancement ratios (ER) for hydrophilic molecules (atenolol and sotalol) were 71- and 78-fold higher for ITP + MN as compared with PD. However, for lipophilic molecule such as propranolol, there was 10-fold increase in the ER as compared with PD. These observations were further substantiated by the skin retention data; an inverse relationship between the skin retention and the hydrophilicity of the drug was observed. The results in the present study point out that the lipophilicity of the molecule plays a significant role on the electrically assisted transdermal delivery of drugs across the microporated skin. Using the combination of ITP + MN, hydrophilic drugs (atenolol and sotalol) were delivered at a much higher rate as compared with lipophilic molecules (propranolol and acebutolol).     

Application of in Vivo Microdialysis to Transdermal Absorption of Methotrexate in Rats

Microdialysis was applied to determine the in vivo transdermal absorption of methotrexate (MTX) in rats with or without a new penetration enhancer, l-[2-(decylthio)ethyl]azacyclopentan-2-one (HPE-101). A solution composed of 2.5 mM MTX and 3% (w/v) HPE-101 was applied to the shaved abdomen, in which a semipermeable membrane cannula of 10-mm length was inserted intracutaneously with the use of an L-shaped needle. Intradermal microdialysis was performed at a flow rate of 1.0 µL/min for 12 hr. The concentration of MTX in the dialysate was measured by fluorescence polarization immunoassay (FPIA). HPE-101 (3%, w/v) significantly increased the dermal MTX concentration from 0.06±0.04 µM in the control to 56±26 µM in the dialysate from 8 to 12 hr. HPE-101 at concentrations of 0.75, 1.5, 2.25, and 3% (w/v) enhanced the total recovery of MTX in dermal dialysate from 0 to 10 hr by approximately 5, 18, 42, and 500 times compared with the control, respectively. The microdialysis system is useful for assessing in vivo transdermal drug absorption.     

Physicochemical Modulation of Skin Barrier by Microwave for Transdermal Drug Delivery

Purpose

To investigate mechanism of microwave enhancing drug permeation transdermally through its action on skin.

Methods

Hydrophilic pectin-sulphanilamide films, with or without oleic acid (OA), were subjected to drug release and skin permeation studies. The skins were untreated or microwave-treated, and characterized by infrared spectroscopy, Raman spectroscopy, thermal, electron microscopy and histology techniques.

Results

Skin treatment by microwave at 2450?MHz for 5?min promoted drug permeation from OA-free film without incurring skin damage. Skin treatment by microwave followed by film loaded with drug and OA resulted in permeation of all drug molecules that were released from film. Microwave exerted spacing of lipid architecture of stratum corneum into structureless domains which was unattainable by OA. It allowed OA to permeate stratum corneum and accumulate in dermis at a greater ease, and synergistically inducing lipid/keratin fluidization at hydrophobic C-H and hydrophilic O-H, N-H, C-O, C=O, C-N regimes of skin, and promoting drug permeation.

Conclusion

The microwave technology is evidently feasible for use in promotion of drug permeation across the skin barrier. It represents a new approach in transdermal drug delivery.     

混合促透剂对肤康涂膜剂中水杨酸和酮康唑透皮效果的影响

目的:考察混合促透剂月桂氮(廾卓)酮和薄荷脑对肤康涂膜剂中水杨酸和酮康唑透皮促进作用的影响.方法:采用简单小室法,以离体雄性大鼠皮肤为透皮屏障,用高效液相色谱法测定体外接受液中水杨酸和酮康唑的含量,计算各时间点的累积透皮率.结果:含2%月桂氮(廾卓)酮和2%薄荷脑的涂膜剂与不含月桂氮(廾卓)酮的涂膜剂相比较,其透皮促进作用在6 h后则呈显著性差异(P＜0.01).结论:不同浓度的混合促透剂均可不同程度地提高水杨酸和酮康唑的透皮促进作用,其中以2%月桂氮(廾卓)酮和2%薄荷脑组成的混合促透剂作用最显著.