Development and evaluation of nitrendipine loaded solid lipid nanoparticles: influence of wax and glyceride lipids on plasma pharmacokinetics

Nitrendipine is an antihypertensive drug with poor oral bioavailability ranging from 10 to 20% due to the first pass metabolism. For improving the oral bioavailability of nitrendipine, nitrendipine loaded solid lipid nanoparticles have been developed using triglyceride (tripalmitin), monoglyceride (glyceryl monostearate) and wax (cetyl palmitate). Poloxamer 188 was used as surfactant. Hot homogenization of melted lipids and aqueous phase followed by ultrasonication at temperature above the melting point of lipid was used to prepare SLN dispersions. SLN were characterized for particle size, zeta potential, entrapment efficiency and crystallinity of lipid and drug. In vitro release studies were performed in phosphate buffer of pH 6.8 using Franz diffusion cell. Pharmacokinetics of nitrendipine loaded solid lipid nanoparticles after intraduodenal administration to conscious male Wistar rats was studied. Bioavailability of nitrendipine was increased three- to four-fold after intraduodenal administration compared to that of nitrendipine suspension. The obtained results are indicative of solid lipid nanoparticles as carriers for improving the bioavailability of lipophilic drugs such as nitrendipine by minimizing first pass metabolism.     

姜黄素-PLGA纳米粒提高口服给药生物利用度的研究

目的 研究乳酸/羟基乙酸共聚物（PLGA）纳米粒子提高姜黄素口服生物利用度。方法 采用乳液挥发法制备姜黄素-PLGA纳米粒;通过透射电镜（transmission electron microscope,TEM）观察纳米粒形态;采用动态光散射法（dynamic light scattering,DLS）测定纳米粒大小、表面电位（Zeta电位）;考察药物的体外稳定性以及药物释放行为;以大鼠口服灌胃给药方式考察姜黄素和姜黄素-PLGA纳米粒的体内药物生物利用度。结果 姜黄素-PLGA纳米粒粒度分布均匀,平均粒径大小约200 nm;姜黄素-PLGA纳米粒具有较高的载药量和包封率以及稳定性,体外药物释放实验结果显示具有一定的缓释效果;口服灌胃100 mg·kg^-1姜黄素和姜黄素-PLGA纳米粒,给药30 min之后,姜黄素-PLGA纳米粒给药组的血药浓度水平显著高于姜黄素组（P〈0.05）,药物生物利用度提高到原来的5.2倍。结论 姜黄素-PLGA纳米粒可以有效的提高姜黄素稳定性和口服给药生物利用度。     

Effective in-vivo utilization of lipid-based nanoparticles as drug carrier for carvedilol phosphate

Objectives Lipid nanoparticles as carrier for oral drug administration improve gastrointestinal solubility of poorly soluble drugs and thus enhance bioavailability. However, basic drugs may undergo rapid dissolution from such solid dispersions in the stomach and precipitate in the intestine due to their higher solubility in acidic medium. Therefore, the objective of this work was to study the enhancement in bioavailability of carvedilol phosphate (basic drug) by providing an alkaline gastric environment to drug‐loaded solid lipid nanoparticles. Methods An alkaline gastric environment in rats was created and maintained with oral administration of an antacid suspension 5 min before and 30 min post dosing. Key findings The formulation administered orally exhibited enhanced bioavailability (～27%) when compared with drug suspension and sustained release behaviour when compared with formulation under ideal gastric conditions. The enhanced bioavailability is due to the presence of lipid nanoparticles as drug carrier while the sustained‐release characteristic may be attributed to the presence of antacid, which resulted in elevation of gastric pH and reduced the drug's solubility. Conclusions It may be concluded that although lipid nanoparticles can be instrumental in improving bioavailability, additional sustained release may be achieved by targeting intestinal release of basic drugs from lipid vehicles, which is possible by incorporating them into suitable enteric‐coated formulations.     

Fabrication and in vivo evaluation of Nelfinavir loaded PLGA nanoparticles for enhancing oral bioavailability and therapeutic effect

Nelfinavir mesylate (NFV) is an anti-viral drug, used in the treatment of Acquired Immunodeficiency Syndrome (AIDS). Poor oral bioavailability and shorter half-life (3.5–5 h) remain a major clinical limitation of NFV leading to unpredictable drug bioavailability and frequent dosing. In this context, the objective of the present study was to formulate NFV loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), which can increase the solubility and oral bioavailability along with sustained release of the drug. NFV loaded PLGA-NPs were prepared by nanoprecipitation method using PLGA and Poloxomer 407. The prepared NPs were evaluated for particle size, zeta potential, morphology, drug content, entrapment efficiency (EE) and in vitro dissolution studies. Oral bioavailability studies were carried out in New Zealand rabbits by administering developed NFV PLGA-NPs and pure drug suspension. PLGA-NPs prepared by using 1:4 ratio of drug and PLGA, with a stirring rate of 1500 rpm for 4 h. The prepared NPs were in the size of 185 ± 0.83 nm with a zeta potential of 28.7 ± 0.09 mV. The developed NPs were found to be spherical with uniform size distribution. The drug content and EE of the optimized formulation were found to be 36 ± 0.19% and 72 ± 0.47% respectively. After oral administration of NFV PLGA-NPs, the relative bioavailability was enhanced about 4.94 fold compared to NFV suspension as a control. The results describe an effective strategy for oral delivery of NFV loaded PLGA NPs that helps in enhancing bioavailability and reduce the frequency of dosing.     

Candesartan cilexetil loaded solid lipid nanoparticles for oral delivery: characterization,pharmacokinetic and pharmacodynamic evaluation

Abstract

Candesartan cilexetil (CC) is used in the treatment of hypertension and heart failure. It has poor aqueous solubility and low oral bioavailability. In this work, CC loaded solid lipid nanoparticles (CC-SLNs) were developed to improve the oral bioavailability. Components of the SLNs include either of trimyristin/tripalmitin/tristearin, and surfactants (Poloxamer 188 and egg lecithin E80). The CC loaded nanoparticles were prepared by hot homogenization followed by ultrasonication method. The physicochemical properties, morphology of CC-SLNs were characterized, the pharmacokinetic and pharmacodynamic behaviour of CC-SLNs were evaluated in rats. Stable CC-SLNs having a mean particle size of 180–220?nm with entrapment efficiency varying in between 91–96% were developed. The physical stability of optimized formulation was studied at refrigerated and room temperature for 3 months. Further, freeze drying was tried for improving the physical stability. DSC and XRD analyses indicated that the drug incorporated into SLN was in amorphous form but not in crystalline state. The SLN-morphology was found to be nearly spherical by electron microscopic studies. Pharmacokinetic results indicated that the oral bioavailability of CC was improved over 2.75-fold after incorporation into SLNs. Pharmacodynamic study of SLNs in hypertensive rats showed a decrease in systolic blood pressure for 48?h, while suspension showed a decrease in systolic blood pressure for only 2?h. Taken together, these effects are due to enhanced bioavailability coupled with sustained action of CC in SLN formulation. Thus, the results conclusively demonstrated the role of CC-SLNs for a significant enhancement in oral bioavailability along with improved pharmacodynamic effect.     

The pharmacokinetics of artemisinin after oral, intramuscular and rectal administration to volunteers

The pharmacokinetics after oral, intramuscular and rectal administration of artemisinin, a new potent antimalarial drug, to healthy volunteers has been examined. The study was set-up as a four-way cross-over design with a wash-out period of one week between the test days. In ten volunteers artemisinin concentrations in serum were monitored using a reversed phase HPLC assay with UV detection after derivatization. After oral administration, artemisinin was rapidly but incompletely absorbed, the mean absorption time was 0.78 h and the bioavailability relative to the intramuscularly injected suspension in oil 32%. The mean residence time of the latter (10.6 h) was 3 times that of the oral formulation (3.4 h). This seems to enable a twice daily dosage regimen for the intramuscular oil injection, while the oral formulation necessitates a more frequent dosing interval. After intramuscular injection and rectal administration of an aqueous suspension, very low and variable artemisinin concentrations in serum were observed, probably indicating a poor and erratic absorption.     

淫羊藿苷固体脂质纳米粒的大鼠体内药动学研究

目的:考察淫羊藿苷固体脂质纳米粒(ICA-SLN)在大鼠体内的药动学行为,以及利用固体脂质纳米粒技术提高ICA口服生物利用度的可行性。方法:对2组大鼠分别灌胃ICA混悬液和ICA-SLN混悬液后,采用HPLC-MS/MS法测定大鼠体内ICA的血药浓度,比较ICA混悬液和ICA-SLN混悬液在大鼠体内的吸收情况。结果:ICA在体内的药-时曲线呈现双峰,tmax为1 h,t1/2为3 h。载药纳米粒组与对照组的AUC0-∞分别为(233.6±71.2)ng.h.mL-1和(107.4±15.7)ng.h.mL-(1P<0.05)。结论:与单纯口服ICA相比较,ICA-SLN在大鼠体内的生物利用度更高。     

Polymeric nanoencapsulation of zaleplon into PLGA nanoparticles for enhanced pharmacokinetics and pharmacological activity

Zaleplon (ZP) is a sedative and hypnotic drug used for the treatment of insomnia. Despite its potent anticonvulsant activity, ZP is not commonly used for the treatment of convulsion since ZP is characterized by its low oral bioavailability as a result of poor solubility and extensive liver metabolism. The following study aimed to formulate specifically controlled release nano‐vehicles for oral and parenteral delivery of ZP to enhance its oral bioavailability and biological activity. A modified single emulsification–solvent evaporation method of sonication force was adopted to optimize the inclusion of ZP into biodegradable nanoparticles (NPs) using poly (dl‐lactic‐co‐glycolic acid) (PLGA). The impacts of various formulation variables on the physicochemical characteristics of the ZP‐PLGA‐NPs and drug release profiles were investigated. Pharmacokinetics and pharmacological activity of ZP‐PLGA‐NPs were studied using experimental animals and were compared with generic ZP tablets. Assessment of gamma‐aminobutyric acid (GABA) level in plasma after oral administration was conducted using enzyme‐linked immunosorbent assay. The maximal electroshock‐induced seizures model evaluated anticonvulsant activity after the parenteral administration of ZP‐loaded NPs. The prepared ZP‐PLGA NPs were negatively charged spherical particles with an average size of 120–300 nm. Optimized ZP‐PLGA NPs showed higher plasma GABA levels, longer sedative, hypnotic effects, and a 3.42‐fold augmentation in oral drug bioavailability in comparison to ZP‐marketed products. Moreover, parenteral administration of ZP‐NPs showed higher anticonvulsant activity compared to free drug. Oral administration of ZP‐PLGA NPs achieved a significant improvement in the drug bioavailability, and parenteral administration showed a pronounced anticonvulsant activity.     

Effect of particle size on oral bioavailability of darunavir-loaded solid lipid nanoparticles

The present investigation aimed to study the effect of particle size of solid lipid nanoparticles (SLNs) on oral bioavailability of darunavir. High pressure homogenisation technique was used to prepare SLNs. Three different sized SLNs loaded with darunavir were developed with mean particle sizes of around 100?nm, 200?nm and 500?nm, respectively. The in vivo pharmacokinetics in rats showed a significant increase in oral bioavailability of darunavir from all the three formulations in comparison to plain drug suspension and reference tablet. The results revealed insignificant difference between SLNs of 100 and 200?nm and these had significantly higher bioavailability in comparison to SLNs of 500?nm. However, more number of homogenisation cycles is required for obtaining 100?nm and thus we selected 200?nm as an optimum size for oral bioavailability enhancement of darunavir. The optimised SLN formulation was stable for a period of 6 months at 25?±?2?°C/60?±?5% relative humidity (RH).     

胰岛素乳酸/羟基乙酸共聚物纳米粒的制备及口服药效学研究

目的探索可生物降解乳酸/羟基乙酸共聚物［poly(lactic-co-glycolic acid),PLGA］纳米粒作为大分子蛋白质类口服给药系统的可能性。方法用复乳溶剂挥发法制备了胰岛素乳酸/羟基乙酸共聚物纳米粒(INS-PLGA-NPs);光子相关光谱法测定了平均粒径;HPLC法测定了胰岛素的包封率;放射免疫法研究了纳米粒的载药方式;考察了INS-PLGA-NPs的体外释放特性;评价了口服给予纳米粒对糖尿病大鼠降血糖作用。结果以1% poloxamer 188为乳化剂制备的纳米粒,平均粒径为149.6 nm,多分散度为0.09,包封率为42.8%;同时抗体捕捉实验发现纳米粒主要以吸附方式载药;胰岛素的体外释放分为两相;以10 u·kg^-1的剂量给予该纳米粒,4 h后血糖浓度显著降低(P<0.05),10 h血糖降至最低,药理相对生物利用度(10.3±0.8)%。结论PLGA-NPs可能成为大分子蛋白质药物口服给药的新型载体。     

Ocular drug delivery of progesterone using nanoparticles

The objective of this study was to evaluate ocular delivery of a lipid-soluble drug, [3H]progesterone, using nanoparticles. Polybutylcyanoacrylate nanoparticles loaded with [3H]progesterone were prepared by an emulsion polymerization technique using a hydrophilic continuous phase. The resulting nanoparticle suspension contained 2 x 10(-5) M progesterone. It was found that, at equilibrium, 99 per cent of the progesterone resided in the nanoparticles and the remainder in the aqueous phase indicating an excellent encapsulation efficiency. In addition, an appropriate control solution of progesterone was prepared, which did not contain polybutylcyanoacrylate. Concentrations of [3H]progesterone in various ocular tissues of the albino rabbit were monitored at various times following topical administration of either the nanoparticle suspension or the control solutions. Comparison of the concentration-time profiles indicates that tissue concentration of progesterone following topical administration of nanoparticles is generally four to five times less than that obtained with control solutions. This decreased concentration suggests that, due to the high affinity of progesterone for the nanoparticles, the drug is being made less available for absorption during its residence time in the precorneal area. The utility of nanoparticles as an ocular drug delivery system may depend on optimizing lipophilic-hydrophilic properties of the polymer-drug system, in addition to increasing retention efficiency in the precorneal pocket.     

Biocompatibility,absorption and safety of protein nanoparticle-based delivery of doxorubicin through oral administration in rats

Abstract

Doxorubicin, a potent anticancer drug associated with cardiotoxicity and low oral bioavailability, was loaded into apotransferrin nanoparticles to improve its pharmacological performance. Here, doxorubicin (doxo)-loaded apotransferrin nanoparticles were termed as Apodoxonano, and they were prepared by sol-oil chemistry. The pH-dependent stability of nanoparticles in simulated fluids was evaluated, and the in vitro release was investigated in phosphate-buffered saline. The pharmacokinetic and toxicity studies were conducted in Wistar rats. Nanoparticles have an average size of 75?nm, with 63% entrapment efficiency, at 10?mg w/w of apotransferrin. The particles displayed good pH-dependent stability in the pH range 1.1–7.4, but sensitive at endosomal pH of 5.5, thus facilitating intracellular drug release in endosomes. Multiplex assay showed high transport ability of nano form across epithelial cells (caco-2) when compared to doxo. Moreover, during oral administration, Apodoxonano localizes significantly in esophagus, stomach and small intestine, suggesting that it was absorbed in GI tract through epithelial lining. The drug localization was shown to be significantly lower in the heart reflecting its decreased cardiotoxic nature. The Apodoxonano with a longer bioavailability and a negligible cardiotoxicity can serve as an effective and safe vehicle of drug delivery.     

Self nanoprecipitating preconcentrate of tamoxifen citrate for enhanced bioavailability

We disclose a self nanoprecipitating preconcentrate (SNP) of tamoxifen citrate (TMX), which forms TMX loaded polymeric nanoparticles, on dilution with aqueous media. SNP comprised TMX, polymer (Kollidon SR) and surfactant/s dissolved in a pharmaceutically acceptable vehicle. Binary surfactant mixtures of Aerosol OT (AOT) with Tween 80 revealed synergistic reduction in surface tension to enable both high entrapment efficiency (EE) and low particle size (PS). Synergism of the surfactants was confirmed by molecular interaction parameter(β(σ)). Combination of AOT and Tween 80 resulted in EE (～85%) and PS (<250nm). Formation of TMX-KSR nanoparticles in situ was reproducible under most experimental conditions and exhibited pH independent behavior. Dilution volume (>80mL) influenced both PS and EE while dilution temperature influenced only PS. Marginal increase in size was evident at the end of 1h nevertheless was not of concern as TMX SNP exhibited near complete release in 1h. DSC and XRD studies revealed amorphous nature of TMX in nanoparticles. FTIR imaging confirmed uniform distribution of TMX in nanoparticles. ESEM and TEM revealed spherical nanoparticles. Biodistribution studies of (99m)Tc labeled TMX SNP in rats revealed no significant absorption however oral pharmacokinetics revealed enhanced oral bioavailability of TMX (165%) compared to TMX suspension. SNP presents a new in situ approach, for design of drug loaded polymeric nanoparticles.     

雷公藤甲素聚乳酸纳米粒的制备及毒性

目的探索可生物降解聚乳酸［poly(D,L-lactic acid)，PLA］纳米粒口服给药后降低毒性的可能性。方法 采用改良的自乳化溶剂蒸发法制备雷公藤甲素聚乳酸纳米粒；透射电子显微镜(TEM)观察纳米粒的形态；动态激光粒度分析仪测定其平均粒径大小和分布；采用反相高效液相色谱法(RP-HPLC)测定纳米粒的包封率及载药量；X-射线粉末衍射(X-ray)初步研究纳米粒中药物的物理状态；考察雷公藤甲素的体外释放特性；评价口服给予纳米粒对大鼠的降毒性作用。 结果确定适合处方的工艺为：水相-有机相为40∶15(v/v)，表面活性剂浓度为1% (w/v)，药物在有机相中的浓度为0.3% (w/w)，TP-PLA为1∶15 (w/w)。处方条件下制备的纳米粒平均粒径为149.7 nm，多分散指数为0.088，平均包封率及载药量分别为74.27% 和1.36%；雷公藤甲素的体外释放分为两相；纳米粒非常显著降低肝的毒性(P<0.01)，显著降低肾的毒性(P<0.05)。结论聚乳酸纳米粒可能成为雷公藤甲素口服给药的新型载体。     

Non-phospholipid vesicles as carriers for peptides and proteins: production, characterization and stability studies

Liquid crystalline phases that are stable in excess water, formed using lipids such as glyceryl monooleate (GMO) and oleyl glycerate (OG), are known to provide a sustained release matrix for poorly water soluble drugs in vitro, yet there has been no report of the use of these materials to impart oral sustained release behaviour in vivo. In the first part of this study, in vitro lipolysis experiments were used to compare the digestibility of GMO with a second structurally related lipid, oleyl glycerate, which was found to be less susceptible to hydrolysis by pancreatic lipase than GMO. Subsequent oral bioavailability studies were conducted in rats, in which a model poorly water soluble drug, cinnarizine (CIN), was administered orally as an aqueous suspension, or as a solution in GMO or OG. In the first bioavailability study, plasma samples were taken over a 30 h period and CIN concentrations determined by HPLC. Plasma CIN concentrations after administration in the GMO formulation were only sustained for a few hours after administration while for the OG formulation, the plasma concentration of cinnarizine was at its highest level 30 h after dosing, and appeared to be increasing. A second study in which CIN was again administered in OG, and plasma samples taken for 120 h, revealed a T_max for CIN in rats of 36 h and a relative oral bioavailability of 344% when compared to the GMO formulation (117%) and the aqueous suspension formulation (assigned a nominal bioavailability of 100%). The results indicate that lipids that form liquid crystalline structures in excess water, may have application as an oral sustained release delivery system, providing they are not digested rapidly on administration.     

Bioadhesion and enhanced bioavailability by wheat germ agglutinin-grafted lipid nanoparticles for oral delivery of poorly water-soluble drug bufalin

Wheat germ agglutinin (WGA)-grafted lipid nanoparticles has been prepared and its in vitro association with Caco-2 cells has been studied previously. The purpose of this study was to further investigate the potential of WGA-grafted lipid nanoparticles for oral delivery of bufalin, a poorly water soluble drug, by evaluating its ex vivo bioadhesion with intestinal mucosal segments and in vivo bioavailability. A significant higher adhesion between WGA-grafted lipid nanoparticles and intestinal mucosa was found compared with that of WGA-free lipid nanoparticles (p<0.05). The in vivo pharmacodynamic studies were performed by oral administration of WGA-grafted lipid nanoparticles and suspensions to fasted rats. Compared with suspensions, WGA-grafted lipid nanoparticles showed much larger AUC and C(max), and a 2.7-fold improvement in oral bioavailability. These results illustrate the potential utility of WGA-grafted lipid nanoparticles for oral delivery of a poorly water-soluble drug such as bufalin.     

Co-delivery of rapamycin- and piperine-loaded polymeric nanoparticles for breast cancer treatment

P-glycoprotein (P-gp) efflux is the major cause of multidrug resistance (MDR) in tumors when using anticancer drugs, moreover, poor bioavailability of few drugs is also due to P-gp efflux in the gut. Rapamycin (RPM) is in the clinical trials for breast cancer treatment, but its P-gp substrate property leads to poor oral bioavailability and efficacy. The objective of this study is to formulate and evaluate nanoparticles of RPM, along with a chemosensitizer (piperine, PIP) for improved oral bioavailability and efficacy. Poly(d,l-lactide-co-glycolide) (PLGA) was selected as polymer as it has moderate MDR reversal activity, which may provide additional benefits. The nanoprecipitation method was used to prepare PLGA nanoparticles with particle size below 150?nm, loaded with both drugs (RPM and PIP). Prepared nanoparticles showed sustained in vitro drug release for weeks, with initial release kinetics of zero order with non-Fickian transport, subsequently followed by Higuchi kinetics with Fickian diffusion. An everted gut sac method was used to study the effect of P-gp efflux on drug transport. This reveals that the uptake of the RPM (P-gp substrate) has been increased in the presence of chemosensitizer. Pharmacokinetic studies showed better absorption profile of RPM from polymeric nanoparticles compared to its suspension counterpart and improved bioavailability of 4.8-folds in combination with a chemosensitizer. An in vitro cell line study indicates higher efficacy of nanoparticles compared to free drug solution. Results suggest that the use of a combination of PIP with RPM nanoparticles would be a promising approach in the treatment of breast cancer.     

Enhanced oral bioavailability of etodolac by self‐emulsifying systems: in‐vitro and in‐vivo evaluation

Objectives The objective of this study was to prepare a self‐emulsifying drug delivery system (SEDDS) for oral bioavailability enhancement of a poorly water‐soluble drug, etodolac. The SEDDS formulations were optimized by evaluating their ability to self‐emulsify when introduced to an aqueous medium under gentle agitation, and by determination of the particle size of the resulting emulsion. Methods An optimized formulation of SEDDS (composed of 20% etodolac, 30% oil Labrafac WL1349, 10% Lauroglycol 90 and 40% Labrasol) was selected for bioavailability assessment in rabbits. The anti‐inflammatory effect was also determined in rats, and compared with powder drug and etodolac suspension in water (50 mg/kg). Key findings The peak plasma concentration of 16.4 ± 1.1 μg/ml appeared after 1.3 ± 0.2 h, whereas with powder drug and etodolac suspension the values were 7.5 ± 0.5 and 10.6 ± 0.7 μg/ml at 4.2 ± 0.4 and 2.4 ± 0.2 h, respectively. The AUC_0–8 of the etodolac SEDDS formulation was 2.3 times that of the pure drug and 1.4 times that of the suspension form. SEDDS formulation exhibits a 21% increase in paw thickness compared with a 39% increase on oral administration of etodolac suspension after 4 h at the same dose of the drug (20 mg/kg). Conclusions The result indicates the utility of SEDDS for the oral delivery of etodolac and potentially other lipophilic drugs.     

Preparation and characterization of betulin nanoparticles for oral hypoglycemic drug by antisolvent precipitation

Abstract

Betulin, a kind of small molecular compound, was reported that has hypoglycemic effect. Due to its low aqueous solubility and high permeability, betulin has low and variable oral bioavailability. In this work, betulin nanoparticles were thus prepared by antisolvent precipitation for accelerating dissolution of this kind of poorly water-soluble drugs. Ethanol was used as solvent and deionized water was used as antisolvent. The effects of various experimental parameters on the mean particle size (MPS) of nanocrystallization betulin were investigated. The MPS of betulin nanoparticles suspension basically remain unchanged when precipitation time was within 60?min and then increased from 304?nm to 505?nm later. However, the MPS of betulin nanoparticles suspension decreased with increased betulin solution concentration. On the contrary, the MPS of betulin nanoparticles suspension decreased along with the increase of temperature. Stirring intensity and the speed ratio of solvent adding into antisolvent had no significant influences on the MPS of betulin nanoparticles suspension. Betulin nanoparticles suspension with a MPS of approximately 110?nm was achieved under the optimal precipitation conditions. FTIR, Liquid chromatography coupled with tandem mass spectrometry (LC-MS), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to analyze the characteristic of betulin nanoparticles powder. These results show that betulin nanoparticles powder has the same chemical structure as raw drug, but a smaller size and lower crystallinity. The dissolution rate and solubility of betulin nanoparticles powder were separately 3.12 and 1.54 times of raw drug. The bioavailability of betulin nanoparticles powder increased 1.21 times compared with raw betulin. The result of in vivo evaluation on diabetic animals demonstrates that the betulin nanoparticles powder show an excellent hypoglycemic effect compared with raw betulin. In addition, the residual ethanol is less than the ICH (International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human) limit for class 3 solvents of 5000?ppm or 0.5% for solvents.