Compared with conventional transdermal drug delivery systems, dissolving microneedles significantly enhance drug bioavailability by penetrating the stratum corneum barrier and achieving intradermal drug delivery. In order to improve the transdermal bioavailability of dexmedetomidine hydrochloride, in this study, a novel microneedle delivery system was developed for dexmedetomidine hydrochloride based on 3D printing combined with micro-molding. By systematically optimizing the microneedle geometrical parameters, array arrangement, and preparation process parameters, we determined the optimal ratio of drug-carrying matrix as 15% PVP (polyvinyl pyrrolidone) K90. The microneedles exhibited significant drug loading gradients, with mean content of (209.99±27.56) μg/patch, (405.31±30.31) μg/patch, and (621.61±34.43) μg/patch. They showed a regular pyramidal structure under SEM and handheld electron microscopy, and their mechanical strength allowed effective penetration into the stratum corneum. The surface contact angles were all < 90°, indicating excellent hydrophilicity. The microneedles dissolved completely within 10 min after skin insertion, achieving a cumulative release rate of 90% (Higuchi model, r=0.996) during 2 hours of in vitro transdermal permeation. The cytotoxicity test and hemolysis test verified good biocompatibility. Pharmacodynamic evaluation showed that the microneedle group demonstrated pain-relieving effect within 15 min, with the pain threshold at the time point of 60 min being 3 times that in the transdermal cream group. The microneedle system developed in this study not only offers an efficient drug delivery option for patients but also establishes an innovative platform for rapid percutaneous delivery of hydrophilic drugs, demonstrating significant potential in perioperative pain management.
Dexmedetomidine/pharmacokinetics* ; Printing, Three-Dimensional ; Needles ; Drug Delivery Systems/methods* ; Administration, Cutaneous ; Animals ; Microinjections/instrumentation* ; Skin Absorption ; Skin/metabolism*

Atopic dermatitis (AD) is a chronic inflammatory skin condition. Natural products have gained traction in AD treatment due to their accessibility, low toxicity, and favorable pharmacological properties. However, their application is primarily constrained by poor solubility, instability, and limited permeability. The transdermal drug delivery system (TDDS) offers potential solutions for transdermal delivery, enhanced penetration, improved efficacy, and reduced toxicity of natural drugs, aligning with the requirements of modern AD treatment. This review examines the application of hydrogels, microneedles (MNs), liposomes, nanoemulsions, and other TDDS-carrying natural products in AD treatment, with a primary focus on their effects on penetration and accumulation in the skin. The aim is to provide valuable insights into the treatment of AD and other dermatological conditions.
Animals ; Humans ; Administration, Cutaneous ; Biological Products/pharmacokinetics* ; Dermatitis, Atopic/drug therapy* ; Drug Delivery Systems ; Hydrogels/chemistry* ; Skin/metabolism* ; Skin Absorption

Huoluo Xiaoling Dan is a classical prescription commonly used for blood circulation and pain relief in clinic with obvious effects. To make it directly treat lesion and improve the effect, this research optimized the preparation process of Huoluo Xiaoling gel paste and further evaluated its in vitro transdermal absorption performance, so as to provide a scientific basis for its development and utilization. Using primary viscosity, holding viscosity, and sensory score as evaluation indexes, the matrix amount of gel paste was determined by the single factor test and Box-Behnken response surface method. The ultra-performance liquid chromatography(UPLC) method was established to determine the content of eight active ingredients, including Danshensu, ferulic acid, salvianolic acid B, salvianolic acid A, ligustilide, tanshinone Ⅱ_A, 11-keto-β-boswellic(KBA), and 3-acetyl-11-keto-β-boswellic acid(AKBA). A mo-dified Franz diffusion cell method was used to evaluate and compare the absorption properties of the gel paste without volatile oil and with volatile oil microemulsion. The results showed that the optimal prescription for Huoluo Xiaoling gel paste matrix was NP700(1.35 g), glycerol(7.00 g), micropowder silica gel(1.25 g), sodium carboxymethyl cellulose(0.20 g), tartaric acid(0.06 g), and glyceryl aluminum(0.04 g). The mass fractions of eight active ingredients in the paste were successively 0.48, 0.014, 0.95, 0.39, 0.57, 0.055, 0.35, and 0.97 mg·g~(-1). The results of the in vitro transdermal absorption test showed that the addition of the volatile oil or the volatile oil microemulsion promoted the transdermal absorption of the active ingredients, and the law of drug penetration conformed to the zero equation or the Higuchi equation. The gel paste prepared by the optimal prescription has good appearance and adhesion, with no residue, and has the characteristics of skeletal slow-release preparation, which is easy to reduce the number of administration, la-ying a foundation for the development of new external dosage forms of Huoluo Xiaoling Dan.
Administration, Cutaneous ; Skin Absorption ; Chromatography, Liquid ; Oils, Volatile ; Viscosity

This study aims to establish a method for determination of paeonol(Pae), eugenol(Eug), and piperine(Pip) content in receptor liquid and research on the permeability and pharmacokinetics of Huoxue Zhitong gel patch and microemulsion gel. The Franz diffusion experiment was conducted to assess the percutaneous permeability, and the microdialysis method was employed to assess pharmacokinetics of Huoxue Zhitong gel patch and microemulsion gel. The content of Pae, Eug, and Pip in receptor liquid in vitro and in vivo was determined by HPLC and UPLC-MS. The Q_n and J_(ss) of Pae, Eug, and Pip in the gel patch were significantly higher than those in the microemulsion gel, indicating that the drug release was faster in the gel patch. The C_(max), AUC_(0-760), and MRT of Pae, Eug, and Pip in the gel patch were higher than those in the microemulsion gel, indicating that the gel patch can promote the penetration and prolong the skin residence of the drug. The results of this study provide reference for improving the dosage form of Huoxue Zhitong patch.
Administration, Cutaneous ; Chromatography, Liquid ; Emulsions ; Permeability ; Skin/metabolism* ; Skin Absorption ; Tandem Mass Spectrometry

To compare the effect of hot or warm property of Chinese medicine(CM) on the skin toxicity of essential oils(EOs) as penetration enhancer in vitro and in vivo, and explore the mechanism. EOs were extracted from WIM of Bichengqie(Litseae Fructus), Dingxiang(Flos Syzygii Aromatici), Huajiao(Pericarpium Zanthoxyli Bungeani), and Xiaohuixiang(Fructus Foeniculi) with warm property, and Ganjiang(Rhizoma Zingiberis), Gaoliangjiang(Rhizoma Alpiniae Officinari), Hujiao(Fructus Piperis), and Wuzhuyu(Fructus Evodiae Rutaecarpae) with hot property, respectively. Then the in vitro toxicity was evaluated by human keratinocyte cytotoxicity. In vivo skin irritation potency was also evaluated through pathological observation after topical administration. The components, especially those located in stratum corneum, were analyzed by GC-MS. The main components, namely monoterpenes and sesquiterpenes, of EOs extracted from CM with hot property,were detected for the interaction with keratino-lipid ceramide 3 by molecular simulation technology; and the interaction energy value was calculated based on the optimal conformation. It was found that the skin cell toxicity of EOs from CM with hot property was significantly higher than that of EOs from CM with warm property. However, there was no significant difference between them by in vivo skin irritation evaluation. Whether from CM with hot property or warm property, EOs showed a significant reduced toxicity compared with azone. Sesquiterpenes(33.56%±19.38%) were found to be one of the main components in EOs from CM with hot property, while almost no sesquiterpenes was found in EOs from CM with warm property. After topical administration of EOs from CM with hot property, sesquiterpenes were demonstrated to be prone to locate in stratum corneum. The results of molecular simulation also revealed that the interaction between sesquiterpenes and ceramide 3 was significantly stronger than that of monoterpenes(P<0.01). In conclusion, the location of sesquiterpenes in stratum corneum resulted in the significant difference between in vitro skin cell toxicity and in vivo skin irritation potency. The EOs from CM with hot property shall be taken into account for further development of potent penetration enhancer.
Humans ; Monoterpenes/metabolism* ; Oils, Volatile/toxicity* ; Sesquiterpenes/metabolism* ; Skin/metabolism* ; Skin Absorption

This study aimed to investigate the enhancing effect of muscone on the transdermal penetration of traditional Chinese medicine ingredients and explore its possible mechanism of action. The Franz diffusion cells were employed to investigate the effect of muscone on the transdermal permeation of a series of model drugs with a wide range of log P values. The solubilities at saturation and the stratum corneum(SC)/vehicle partition coefficients of model drugs were measured to evaluate the effect of muscone on drug thermodynamic activities and partition of drugs into SC. Attenuated total reflectance-Fourier transform infrared spectroscopy(ATR-FTIR) was employed to explore the effect of muscone on the molecular structure of SC. The results showed that muscone significantly promoted the transdermal penetration of hydrophilic and lipophilic drugs, and the enhancement ratio(ER) increased with the decrease in the log P. Muscone could interact with the SC lipids to increase the disorder and fluidity of lipid bilayer packing, which improved skin permeability and promoted transdermal absorption of drugs. This study provides a scientific basis for the application of muscone in traditional Chinese medicine topical preparations.
Administration, Cutaneous ; Animals ; Cycloparaffins ; Medicine, Chinese Traditional ; Permeability ; Rats ; Rats, Sprague-Dawley ; Skin/metabolism* ; Skin Absorption

Based on the previous study of compound liquorice microemulsion, this paper aims to prepare the compound liquorice microemulsion gel and investigate its pharmacodynamics of chronic eczema. The type, dosage and adding method of gel matrix, and formula dosage of humectant were optimized by single factor method to obtain the formula and preparation technique of the gel. With glycyrrhizic acid, glycyrrhetin and oxymatrine used as evaluation indexes, the Franz diffusion cell method was adopted to monitor the in vitro release profile of the gel. Eczema model of delayed-type hypersensitivity in mice was chosen to detect the ear swelling rate, degree of inflammatory cell infiltration of ear pieces, and pathological changes of ear pieces, so as to investigate the therapeutic effect of the microemulsion gel. The preparation process of the compound liquorice microemulsion gel was stable. The release of glycyrrhizin and oxymatrine was most consistent with the Hixcon-Crowell kinetic model, while the release of glycyrrhizic acid was most consistent with the Ritger-Peppas kinetic model. The pharmacodynamics studies proved that compound liquorice microemulsion gel could significantly reduce the ear swelling rate in mice, with good anti-inflammatory effect as well as the ability to resist the pathological changes of chronic eczema and inhibit the infiltration of dermal inflammatory cells. Therefore, the preparation process of compound liquorice microemulsion gel is feasible, with stable drug release and a significant therapeutic effect on chronic eczema.
Administration, Cutaneous ; Animals ; Drug Liberation ; Emulsions ; Gels ; Glycyrrhiza ; Mice ; Skin Absorption

L_9(3~4) orthogonal experiment design was used to optimize the preparation of the patches,and investigate its affecting factors and skin irritation. Eugenol was taken as the index component to study the release behavior in vitro and percutaneous penetration of Cangai oil transfersomes patches by HPLC.The results showed that the optimal prescription for preparing Cangai oil transfersomes patches were Eudragit E100 0.6 g, succinic acid 0.08 g,triethyl citrate 0.25 g,glycerol 0.2 g.Patches prepared by the preferred preparation had a flat appearance without obvious bubbles.The initial adhesion was 18.33±2.52, the stickiness was(30.01±2.45) min,and the peel strength was(5.62±0.95) kN·m~(-1).The results of affecting factors experiment showed the order of factors affecting its adhesion was humidity>temperature>lighting,and the skin irritation test results showed no significant skin irritation after 24 h of single administration. The results of drug release behavior in vitro showed that the release and the percutaneous penetration of both Cangai oil patches and Cangai oil transfersomes patches conformed to the Higuchi equation.The release amount of eugenol were 80.66% and 82.25% at 72 h, with no significant difference. The cumulative permeation area of eugenol per unit area reached(0.195 6±0.065 9),(0.131 0±0.045 5) mg·cm~(-2) at 72 h, with significant differences(P<0.05).The experiment results proved that the preparation process of Cangai oil transfersomes patches was stable,and the prepared patches had a good adhesion. At the same time,the preparation of transfersomes patches could alleviate and control the release of the drug to a certain extent, and provide a certain experimental basis for clinical pediatric drug safety.
Administration, Cutaneous ; Drug Carriers ; Drug Liberation ; Humans ; Plant Oils/pharmacology* ; Polymethacrylic Acids ; Skin/drug effects* ; Skin Absorption ; Transdermal Patch

To establish a determination method for the contents of ammonium glycyrrhetate,nardosinone,and curcumin in transdermal receptor liquid of Baimai Ointment,and investigate the percutaneous permeability of Baimai Ointment and the effects of two kinds of penetration enhancers on percutaneous absorption of three components. The contents of ammonium glycyrrhetate,nardosinone,and curcumin in transdermal receptor liquid were determined by high pressure liquid chromatography( HPLC). The vertical modified Franz diffusion cell was used to perform a transdermal experiment in vitro with the abdominal skin of mice( treated and untreated). The transdermal receptor liquid was preferably used to investigate the transdermal absorption rule of the Baimai Ointment and the effect of the penetration enhancer. The results showed that the comprehensive solubility of PEG-ET-NS( 3 ∶3 ∶4) was best among three types of receptor liquid PG-ET-NS( 3 ∶3 ∶4),PEG-ET-NS( 3 ∶3 ∶4),ET-NS( 3 ∶7). PEG-ET-NS was used as the receptor liquid for in vitro transdermal experiments. The cumulative permeation area of ammonium glycyrrhetate,nardosinone and curcumin within 24 h was 5. 73,18. 99,0. 38 μg·cm~(-2)respectively. Taking QEFand ER as comprehensive evaluation indicators of permeation performance,the comprehensive penetration-promoting performance of ammonium glycyrrhizinate: 3% PEG 400-ethanol-normal saline ≈ 1. 19 times( 3%azone) = 1. 94 times( blank); comprehensive penetration-promoting performance of nardosinone: 3% PEG 400-ethanol-normal saline≈1. 28 times( 3% azone) = 1. 37 times( blank); the comprehensive penetration performance of curcumin: 3% PEG 400-ethanol-normal saline≈1. 77 times( 3% azone) ≈3. 42 times( blank). The comprehensive penetration enhancement properties of the two penetration enhancers were as follows: 3% PEG 400-ethanol-normal saline>3%azone>blank. The transdermal absorption curve of ammonium glycyrrhetate,nardosinone and curcumin in Baimai Ointment were consistent with the zero-order equation,indicating that the transdermal absorption process was irrelevant to the concentration of three components,and its was a diffusion process. This experiment provides reference for the study of ointment transdermal preparations.
Administration, Cutaneous ; Animals ; Mice ; Ointments ; pharmacokinetics ; Permeability ; Skin ; Skin Absorption

To investigate the effects of essential oil from three kinds of pungent herbs,namely Menthae Haplocalycis Herba,Atractylodis Rhizoma and Cnidii Fructus,on the transdermal absorption in vitro of alkaloids from Sophorae Flavescentis Radix. The modified vertical Franz diffusion cell was used to conduct a transdermal experiment in vitro with the isolated abdominal skin of the SD rats as the transdermal absorption barrier. The effects of such three kinds of pungent essential oil on percutaneous absorption of alkaloids from Sophorae Flavescentis Radix were investigated by determining the content of 6 alkaloids( oxymatrine,oxysophocarpine,N-methylcytisine,sophoridine,matrine,and sophocarpidine) in the transdermal acceptor with ultra-performance liquid chromatography-triple quadruple mass spectrometry( UPLC-TQ-MS) technique simultaneously. With enhancement ratio( ER) as the index,their effects on promoting penetration was as follows: 1% Atractylodis Rhizoma oil > 1% Cnidii Fructus oil > 3% Azone ≈ 3% Atractylodis Rhizoma oil > 5%Atractylodis Rhizoma oil > 3% Cnidii Fructus oil ≈ 5% Cnidii Fructus oil > 3% Menthae Haplocalycis Herba oil > 5% Menthae Haplocalycis Herba oil > 1% Menthae Haplocalycis Herba oil > Blank. The results showed that these three kinds of pungent essential oil could be used as enhancers for alkaloids of Sophorae Flavescentis Radix,providing scientific guidance for improving percutaneous absorption of alkaloids from Sophorae Flavescentis Radix.
Alkaloids ; metabolism ; Animals ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; metabolism ; Oils, Volatile ; pharmacology ; Plant Roots ; chemistry ; Rats ; Rats, Sprague-Dawley ; Skin Absorption ; Sophora ; chemistry