Oral mucosal drug delivery system based on nano technology / 药学学报

Oral mucosal drug delivery has the advantages of rapid drug absorption, no first-pass effect and good patient compliance. However, factors such as low drug dissolution, saliva carrying the drug into the gastrointestinal tract and the existence of physiological barriers in the mucosa may affect the mucosal permeation and bioavailability of the drug. Nanotechnology applied to drug oral mucosa delivery can overcome the above disadvantages and obtain efficient absorption effect. This paper describes the physiological structure of oral mucosa and the factors affecting the absorption of drugs in oral mucosa, reviews the application of nanotechnology such as liposomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, polymer nanoparticles, polymer micelles and nanohybrid suspensions in oral mucosal drug delivery and the mechanism of promoting drug absorption, summarizes the main problems of current research, and gives an outlook on the application of nano oral mucosal drug delivery system. The main problems of current research are summarized, and the prospects for the application of nano oral mucosal drug delivery systems are discussed.

Application research and design strategy on smart responsive mesoporous silica anti-tumor nanodelivery systems / 药学学报

Malignant tumors are major diseases that endanger human health. Due to their complex and variable microenvironment, most anti-tumor drugs cannot precisely reach the focal tissue and be released in a controlled manner. Intelligent responsive nano carriers have become a hot spot in the field of anti-tumor drug delivery systems. As an excellent nano material, mesoporous silica has the advantages of non-toxic, stable, adjustable pore volume and pore diameter, and easy functional modification on the surface. By virtue of its perceptive response to the tumor microenvironment or physiological changes, it can achieve the targeted drug release or controlled drug release of the drug delivery system in the tissue, making it an ideal carrier for intelligent response drug delivery system. In this paper, we review the design strategies and current research status of smart responsive anti-tumor drug delivery systems based on mesoporous silica, in order to provide a reference for the development of anti-tumor drug nanoformulations.

Preparation and in vitro release of quercetin nanocrystals self-stabilized Pickering emulsion / 中国中药杂志

A new quercetin nanocrystals self-stabilized Pickering emulsion(QT-NSSPE) was prepared by high-pressure homogenization combined with probe ultrasonic method. The influences of oil fraction, quercetin(QT) concentration, and pH of water phase on the formation of QT-NSSPE were investigated. On this basis, the QT-NSSPE prepared under optimal conditions was evaluated in terms of microstructure, stability, and in vitro release and the droplet size and drug loading were 15.82 μm and 4.87 mg·mL~(-1), respectively. The shell structure formed by quercetin nanocrystals(QT-NC) on the emulsion droplet surface was observed under a scanning electron microscope(SEM). X-ray diffraction(XRD) showed that the crystallinity of adsorbed QT-NC decreased significantly as compared with the raw QT. There were not significant changes of QT-NSSPE properties after 30 days of storage at room temperature. The in vitro release experiment confirmed that QT-NSSPE has a higher accumulative release rate than the raw QT. All these results indicated that QT-NSSPE has a great stability and a satisfactory in vitro release behavior, which is a promising new oral delivery system for QT.

Advances in formation and application of self-assembled nanoparticles from traditional Chinese medicine / 中国中药杂志

Due to the diverse sources and unique structures, the chemical components of Chinese medicinal materials are easy to self-assemble to form nanoparticles. The formation of self-assembled nanoparticles(SAN) can not only affect the absorption and distribution of the effective ingredients in Chinese medicinal materials but also may improve the biological activity of the effective ingredients or their simple mixtures, which is of great significance for revealing the compatibility mechanism of Chinese medicine prescription, developing new Chinese medicine products, and producing new nanomaterials. This paper reviews the formation, isolation, characterization, and application of SAN of Chinese medicines, and discusses the problems and development trends of the relevant research, which can provide reference for the further study and promote the innovation and application of such SAN.

Effect of self-assembled nanoparticles from Shaoyao Gancao Decoction on release and absorption of main components of Baishao / 中国中药杂志

To study the effect of self-assembled nanoparticles from Shaoyao Gancao Decoction(SGD-SAN) on the encapsulation, in vitro release and intestinal absorption of the main components of Baishao. Particle size analysis and morphological observation were used to verify the formation of SGD-SAN in the decoction. The entrapment efficiency(EE) of SGD-SAN on the main components of Baishao was determined by ultrafiltration centrifugation. The dialysis bag method was used to study the in vitro release of the main components of Baishao with pH 6.8 phosphate buffer solution as the release media. Single-pass intestinal perfusion study was performed to investigate the effect of SGD-SAN on the absorption of the main components of Baishao. The results showed that there were nanoparticles in the SGD, and the particle sizes and PDI of SGD-SAN were about 200 nm and 0.38, respectively. SGD-SAN was irregularly spherical under transmission electron microscope(TEM). The EEs of albiflorin, paeoniflorin and benzoylpaeoniflorin in SGD-SAN were 33.78%±1.03%,33.61%±0.90%,88.53%±0.58%, respectively. The release characteristics of albiflorin, paeoniflorin and benzoylpaeoniflorin from SGD-SAN showed a slow-release effect on pH 6.8 phosphate buffer solution media. SGD-SAN could significantly enhance the absorption of albiflorin, paeoniflorin and benzoylpaeoniflorin in the ileum. The results of this study indicated that SAN could be formed during the mixed decoction of Baishao and Gancao, and SGD-SAN could encapsulate the components of Baishao, with a certain slow-release effect, and the formation of SAN facilitated the absorption of drugs in the ileum.

Preparation and in vitro quality evaluation of self-microemulsion co-loaded with tenuifolin and β-asarone / 中国中药杂志

To prepare and optimize the self-microemulsion co-loaded with tenuifolin and β-asarone(TF/ASA-SMEDDS) and evaluate its quality. The prescription compositions of TF/ASA-SMEDDS were screened by solubility test, single factor test and pseudo-tern-ary phase diagram, and the prescriptions were further optimized by Box-Behnken response surface method, with the drug loading and particle size as the evaluation indexes. Then the optimized TF/ASA-SMEDDS was evaluated for emulsified appearance, particle size, morphology and drug release in vitro. The optimized prescription for TF/ASA-SMEDDS was as follows: caprylic citrate triglyceride polyoxyethylene castor oil-glycerol(10.8∶39.2∶50), drug loading of(5.563±0.065) mg·g~(-1) for tenuifolin and(5.526±0.022) mg·g~(-1) for β-asarone; uniform and transparent pan-blue nanoemulsion can be formed after emulsification, with particle size of(28.84±0.44) nm. TEM showed that TF/ASA-SMEDDS can form spherical droplets with a uniform particle size after emulsification; In vitro release test results showed that the drug release rate and cumulative release of tenuifolin and β-asarone were significantly improved. The preparation process of TF/ASA-SMEDDS was simple and can effectively improve in vitro release of tenuifolin and β-asarone.

Preparation and quality evaluation of orodispersible film containing ginkgolide B novel nanosuspension lyophilized powder / 中国中药杂志

To prepare a new dosage form that can improve the drug loading of the film--ginkgolide B nanosuspension lyophilized powder orodispersible film(GB-NS-LP-ODF) and to evaluate its quality. Firstly, ginkgolide B nanosuspension(GB-NS) was prepared by media milling method, and then ginkgolide B nanosuspension lyophilized powder(GB-NS-LP) was prepared with freeze-drying method. The mannitol was used as lyoprotectant and its dosage was also investigated. GB-NS-LP-ODF was prepared by solvent casting method and its formulation was screened by single factor test method and optimized by orthogonal test. The appearance, mechanical properties, content uniformity and in vitro dissolution of the optimized GB-NS-LP-ODF were investigated. The particle size of prepared GB-NS was about 201 nm, and the optimal dosage of mannitol was 8%. According to the optimal formula, the GB-NS-LP-ODF was prepared with GB-NS-LP 35.6%, PVA 0588 49.4%, PEG 400 10.7% and CMS-Na 4.3%, and completely disintegrated in about 30 s, and the particle size of reconstituted GB nanoparticles from ODF was about 210 nm. The film with smooth appearance and good mechanical properties was stable within 30 days and the content uniformity(A+2.2 S<15) conformed to the regulations. Scanning electron microscope(SEM) showed that GB-NS-LP-ODFs were evenly distributed and the particle size was about 200 nm. X-rays diffraction(XRD) showed that its crystallinity was significantly lower than that of GB raw drug and GB-ODF. The results of in vitro release test showed that the drug film was completely dissoluted within 10 minutes. These results indicated that nanosuspension lyophilized powder was prepared by freeze drying of nanosuspensions, and then loaded into the orodispersible film to effectively increase the drug loading of the ODF and have broad application prospects.

Preparation and in vitro anti-hepatic fibrosis evaluation of herpetone nanosuspensions / 中国中药杂志

Herpetone( HPT) is a bioactive lignan extracted from Herpetospermum pedunculosum,which can protect liver,lower aminotransferase and inhibit hepatitis B virus. However,HPT has a poor oral bioavailability due to its poor water solubility. And there is no report about whether HPT has an anti-hepatic fibrosis activity. To improve the dissolution of HPT and study its anti-hepatic fibrosis activity and mechanism,the study group prepared herpetone nanosuspensions( HPT-NS) by the miniaturized media milling method. The formulation and process of HPT-NS were optimized by the single factor experiment. Scanning electron microscopy was used to observe morphology of HPT-NS. Dialysis method was used to study dissolution of HPT-NS in vitro. CCK8 method was used to assess the effect of HPT-NS on proliferation of the rat hepatic stellate cells( HSC-T6). Flow cytometry was used to assess the effect of HPT-NS on apoptosis and cell cycle of HSC-T6. The mean particle size of optimized HPT-NS was( 196±7) nm with a polydispersity index of 0.279±0.009.SEM showed that HPT-NS was in a regular rod shape. The cumulative dissolution rate of HPT-NS reached 93% in 18 h,and was higher than that of herpetone coarse suspensions( HPT-CS,28%). CCK8 experiment showed that the inhibition rate of HPT-NS on HSC-T6 was higher than that of HPT-CS. Flow cytometry showed that HPT-NS could block HSC-T6 cells in G2/M phase and induce apoptosis of HSC-T6 cells,with a significantly stronger effect than HPT-CS. The results revealed that HPT-NS significantly increased the in vitro dissolution of HPT,and enhanced the inhibitive effect on HSC-T6 cell proliferation by blocking cells in the G2/M phase and inducing late apoptosis.

Study on preparation of volatile oil from Acorus tatarinowii self-nanoemulsion dropping pills and its protective effect on acute myocardial ischemia injury / 中国中药杂志

In this study, solid dispersion technology was used to develop volatile oil from Acorus tatarinowii self-nanoemulsion dropping pills(VOA-SNEDDS-DP) and its protective effect on acute myocardial ischemia injury was evaluated. Taking exterior quality, weight variation and the resolving time as comprehendsive evaluation indexes, the preparation process and formulation of the dropping pills were optimized by orthogonal design, and the dissolution rate in vitro of the optimized VOA-SNEDDS-DP was investigated. The rat model of acute myocardial ischemia was induced by intraperitoneal injection of isoproterenol hydrochloride and the serum levels of superoxide dismutase(SOD), malondialdehyde(MDA), creatine kinase(CK) and pathological changes of myocardial tissue were determined to evaluate therapeutic effect of the dropping pills on acute myocardial ischemia. The results showed that the optimal formulation and preparation process of VOA-SNEDDS-DP were as follows: PEG6000-PEG8000 was 1∶1, proportion of VOA-SNEDDS and matrix was l∶2.5, the temperature of drug fluids was 75 ℃, drop rate was 35 drops/min, drop distance was 5 cm, the condensing agent temperature was 2-10 ℃. The content of β-asarone in the dropping pills was 42.46 mg·g~(-1). The accumulated dissolution rate of the dropping pills reached 93.85% in 10 min. The results of pharmacodynamic experiments showed that VOA-SNEDDS-DP could significantly increase the SOD content(P<0.05), reduce the levels of MDA and CK(P<0.05) in serum, and effectively improve the pathological morphology of myocardial tissue. These results revealed that the preparation of VOA-SNEDDS-DP by solid dispersion technology was stable and feasible, and VOA-SNEDDS-DP had protective effect on acute myocardial ischemia injury.

Research progress on and behaviors of poorly soluble Chinese materia medica nanosuspension / 中国中药杂志

Nanosuspension (also called nanocrystal suspension or nanocrystal) could significantly enhance the saturated solubility and dissolution of insoluble drugs, and improve their bioavailability by reducing particle size and increasing the specific surface, which could then solve the delivery problems of the poorly soluble active ingredients and effective parts of Chinese materia medica (CMM). Based on the brief summaries of nanosuspension preparation methods, this paper would mainly review the and behaviors of poorly soluble CMM nanosuspension, discuss and analyze its problems, so as to provide reference and thinking for the further study of nanosuspension drug delivery system of poorly soluble CMM and promote the development and perfection of nanosuspension technology in CMM.

Preparation and quality evaluation of volatile oil from Acori Tatarinowii Rhizoma self-nanoemulsion / 中国中药杂志

In order to increase the solubility of volatile oil from Acori Tatarinowii Rhizoma, this study was to prepare self-nanoemulsion of volatile oil from Acori Tatarinowii Rhizoma . The prescriptions were preliminarily screened by miscibility studies, excipient compatibility tests, and pseudo-ternary phase diagrams, and then the optimal formulation was obtained by using the Box-Behnken response surface method, with particle size and drug-loading rate as the indicators. The self-nanoemulsion prepared by optimal prescription was characterized and evaluated for dissolution. The results showed that the optimal prescription for this volatile oil self-nanoemulsion was as follows: 41.7% volatile oil, 46.8% Tween-80, and 11.5% PEG-400. The prepared self-nanoemulsion was clear and transparent, with drug-loading of (192.77±1.64) mg·g⁻¹, particle diameter of (53.20±0.94) nm, polydispersity index of 0.230± 0.013, and Zeta potential of (-12.2±0.7) mV. The dissolution of self-nanoemulsion was higher than that of volatile oil. In this research, volatile oil served as the oil phase in self-nanoemulsion, so the prescription was simpler and the drug loading rate was higher. The prepared self-nanoemulsion complied with the relevant quality requirements, providing a reference for the preparation of volatile oil formulations.

Preparation of astilbin amorphous nanosuspension and its evaluation / 中国中药杂志

Astilbil nanosuspension (AT-NS) was prepared by an antisolvent precipitation method. The formula and process of AT-NS were optimized by the single factor experiment. AT-NS was prepared under the optimal conditions, and its morphology and crystallinity were characterized. In vitro release of AT-NS was also determined. The particle size of AT-NS stabilized by PVP K30 was (149±3) nm, and the polydispersity index (PDI) and stability index (SI) were 0.137±0.014 and 0.940±0.012, respectively. The results of SEM showed that AT-NS was spherical. Both XRD and DSC showed that AT was amorphous in nanosuspension. In the release test, AT-NS showed a significantly increased dissolution. This simple low-cost approach could prepare AT-NS successfully. AT-NS could significantly improve the dissolution of AT and provide the reference to break the limitation on the clinical application of AT.

Preparation of insoluble flavonoids nanosuspensions by miniaturized media milling / 中草药

Objective To study the feasibility of preparing insoluble flavonoids nanosuspensions (NS) by miniaturized media milling. Methods The miniaturized media milling method was constructed with the magnetic stirrer, vial and zirconia beads as the power plant, milling chamber and milling media to prepare the nanosuspensions of four flavonoids: quercetin (QCT), baicalin (BCN), puerarin (PRN), and silymarin (SLR). The process of stirring speed, the amount of milling medium and the milling time were optimized with average particle size, polydispersity index (PDI) and stability index (SI) as indicators. Results The optimized process of stirring speed, the amount of milling medium and the milling time of QCT-NS, BCN-NS, PRN-NS and SLR-NS were QCT-NS 800 r/min, 8 h, 1:1, BCN-NS 800 r/min, 24 h, 1:1, PRN-NS 800 r/min, 24 h, 2:1, SLR-NS 800 r/min, 12 h, 1:1. The average particle sizes of QCT-NS, BCN-NS, PRN-NS and SLR-NS prepared with the optimized process were below 400 nm. The PDI of QCT-NS, BCN-NS and SLR-NS was below 0.3 (PRN-NS) and SI was above 0.75, the PDI and SI of PRN-NS were 0.41 and 0, respectively. Conclusion The miniaturized media milling methods for preparation of insoluble flavonoids NS is simple, stable and feasible, and it is worth for further study.

Application progress on nanosuspension based gel in transdermal drug delivery of Chinese materia medica / 中草药

Nanosuspension based gel (NS-gel) is molecular gel based on nanosuspension system. NS-gel is developed by incorporating nanosuspension or nano powders obtained by solidification of nanosuspension with gel matrix and other excipients, which has dual advantages of nanosuspension and gel. This paper reviews the preparation and evaluation of NS-gel, the factors influencing the transdermal absorption of NS-gel and its application progress in transdermal drug delivery of Chinese materia medica (CMM), and analyzes the problems of NS-gel research, so as to provide reference and thinking for the further study and development of NS-gel in transdermal drug delivery of CMM.

Preparation of nanosuspension of quercetin with a miniaturized milling method / 中国中药杂志

The nanosuspension of quercetin (QT-NS) was prepared by a miniaturized milling method, and the process was optimized by Box-Behnken response surface method. Then the accumulative release rate of QT-NS in vitro was determined. The results showed that the optimal process parameters were as follows: ZrO2 4.5 mL, milling speed 690 r•min⁻¹ and milling time 1.5 h; the particle size of QT-NS was (169±5) nm, polydispersity index of 0.204±0.006 and stability index of 0.827±0.014, respectively. There was a little deviation between the theoretically predicted value and the measured value, indicating that this model had a good prediction effect. The accumulative release rate in vitro of QT-NS in 120 min was significantly higher than that of the raw drug and physical mixture. This simple low-cost miniaturization approach could prepare QT-NS successfully, and could provide reference for the formulation of the nanosuspension.

Preparation of isopsoralen loaded nanostructured carrier and its in vitro transdermal permeation characteristics / 中国中药杂志

To increase the permeation and retention of isopsoralen in skin, and improve its bioavailability.Isopsoralen loaded nanostructure liquid carrier (IPRN-NLC) was prepared by high pressure homogenization andoptimized by orthogonal experiment with the encapsulation efficiency, drug loading and average particle size as the evaluation indexes. The in vitro transdermal permeation of IPRN-NLC was evaluated by Franze diffusion cells.The results showed that solid-liquid lipid ratio of optimum IPRN-NLC formulation was 7∶3,drug-lipid ratio of 1∶30, 1% surfactant. Under these conditions, IPRN-NLC had an average encapsulation of （90.25±0.73）%,drug loading of （1.56±0.27）% and an average particle size of (305±1.57) nm.The in vitro transdermal permeation results showed that IPRN-NLC could increase the amount of IPRN permeated though skin, with 3 times of the epidermal retention as compared with IPRN solution. From the results we can know that the IPRN-NLC prepared by high pressure homogenization can improve the permeation andaccumulation of IPRN in the skin, with wide application prospects in the field of transdermal administration.

Formulation of dried lignans nanosuspension with high redispersibility to enhance stability, dissolution, and oral bioavailability / 中国天然药物

Herpetospermum caudigerum lignans (HTL), one of the potential drugs with anti-hepatitis B virus and hepatoprotective effects, has limited clinical applications because of poor aqueous solubility and low bioavailability. Both herpetrione (HPE) and herpetin (HPN) are the most abundant ingredients in HTL and exhibit weak acidity. The purpose of the present study was to produce dried preparations of HTL (composed of HPE and HPN) nanosuspensions (HTL-NS) with high redispersibility using lyophilization technology. The HTL-NS was prepared by utilizing precipitation-combined homogenization technology based on acid-base neutralization reactions, and critical formulation and process parameters affecting the characteristics of HTL-NS were optimized. The resultant products were characterized by particle size analysis, SEM, XRD, stability, solubility, dissolution and in vivo bioavailability. HTL-NS showed near-spherical-shaped morphology and the size was 243 nm with a narrow PDI value of 0.187. The dried preparations with a relatively large particle size of 286 nm and a PDI of 0.215 were achieved by using 4% (W/V) mannitol as cryoprotectants, and had a better stability at 4 or 25 °C for 2 months, compared to HTL-NS. In the in vitro test, the dried preparations showed markedly increased solubility and dissolution velocity. Besides, in the in vivo evaluation, it exhibited significant increases in AUC, CMRT and a decrease in T, compared to the raw drug. In conclusion, our results provide a basis for the development of a drug delivery system for poorly water-soluble ingredients with pH-dependent solubility.

Lignans-rich extract from Herpetospermum caudigerum alleviate physical fatigue in mice / 中国结合医学杂志

<p><b>OBJECTIVE</b>To ascertain anti-fatigue constituents and mechanisms of Herpetospermum caudigerum.</p><p><b>METHODS</b>The 80% ethanol extracts of Herpetospermum caudigerum were partitioned with chloroform, ethyl acetate and n-butanol, respectively. Male Kunming mice were divided into 13 groups with 16 mice in each group: a control group fed with water, 9 groups treated with 3 fractions of Herpetospermum caudigerum (chloroform fraction, ethyl acetate fraction and n-butanol fraction) at dose of 80, 160 and 320 mg/kg for the low-dose group, medium-dose group and high-dose group, 3 herpetrione (HPE) treated groups fed with HPE at dose of 15, 30, and 60 mg/kg for the low-dose group, medium-dose group and high-dose group. All animals were treated once per day for 30 days. Anti-fatigue activity was assessed through the forced swimming test and serum biochemical parameters including blood lactic acid (BLA), blood urea nitrogen (BUN), malondialdehyde (MDA), hepatic glycogen (HG), lactic dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GPx) determined following the recommended procedures provided by the commercial kits.</p><p><b>RESULTS</b>Compared with the control group, the lignans extract (ethyl acetate fraction) of Herpetospermum caudigerum and HPE could signifificantly prolonged the exhaustive swimming time (P<0.05 or P<0.01), and also increased the HG levels (P<0.05 or P<0.01) and the activities of antioxidant enzymes (SOD, GPx and LDH, P<0.05 or P<0.01); BLA and MDA levels were decreased considerably in lignans extract and HPE treated groups (P<0.05 or P<0.01). HPE also could significantly decrease the BUN contents compared with the control group (P<0.05). The chloroform and n-butanol fraction showed no effect on swimming time and biochemical parameters.</p><p><b>CONCLUSIONS</b>The lignans extract had antifatigue activities and HPE may be partly responsible for the anti-fatigue effects of Herpetospermum caudigerum. The possible mechanisms of anti-fatigue activity were related to the decrease of BUN and BLA, the increase of the HG storage and protecting corpuscular membrane by preventing lipid oxidation via modifying several enzyme activities.</p>

Analysis on intestinal absorption of paeoniflorin lipid liquid crystalline nanoparticles via everted intestinal sacs / 中国中药杂志

To study the absorption kinetics of paeoniflorin lipid liquid crystalline nanoparticles (Pae-LLCN) in different intestinal segments of rats and compare them with paeoniflorin(Pae) solution. Rat everted gut sac models were adopted for intestinal absorption test, and Pae content was determined by HPLC method to study the absorption characteristics of Pae-LLCN in rat duodenum, jejunum, ileum and colon, and investigate the effects of different drug concentrations on intestinal absorption. Results showed that Pae-LLCN and Pae were well absorbed at different intestine segments and different concentrations. The absorption constant Ka was increased with the increasing of the drug concentration, indicating possible passive absorption. The accumulative absorption volume Q and absorption constant Ka of Pae-LLCN were higher than those of Pae at each intestinal segment(P<0.05). The results revealed that Pae-LLCN and Pae could be well absorbed in whole intestinal segments and its mechanism may be passive absorption. LLCN can effectively improve the intestinal absorption of Pae.

Nanostructured lipid carrier based topical gel of Ganoderma Triterpenoids for frostbite treatment / 中国天然药物

The objective of this study was to prepare nanostructured lipid carrier (NLC)-based topical gel of Ganoderma Triterpenoids (GTs) and evaluate their effects on frostbite treatment. GT-NLCs was prepared by the high pressure homogenization method and then characterized by morphology and analyses of particle size, zeta potential, entrapment efficiency (EE), and drug loading (DL). The NLCs was suitably gelled for skin permeation studies in vitro and pharmacodynamic evaluation in vivo, compared with the GT emulgel. The GT-NLC remained within the colloidal range and was uniformly dispersed after suitably gelled by carbopol preparation. Transmission electron microscopy (TEM) study showed GT-NLCs was spherical in shape. The EE (%) and DL (%) could reach up to (81.84 ± 0.60)% and (2.13 ± 0.12)%, respectively. The result of X-ray diffractograms (XRD) showed that GTs were in an amorphous state in the NLC-gel. In vitro permeation studies through rat skin indicated that the amount of GTs permeated through skin of GT-NLCs after 24 h was higher than that of GT emulsion, and GT-NLCs increased the accumulative amounts of GTs in epidermis 7.76 times greater than GT emulsion. GT-NLC-gel was found to possess superior therapeutic effect for frostbite, compared with the GT emulgel. The NLC based topical gel of GTs could improve -their therapeutic effect for frostbite.