Aspargine-glycine-arginine (NGR)-containing peptides are targeted peptides which can be integrated with CD13 receptors on tumor vascular endothelial cells. NGR peptides are connected to liposomes to obtain NGR peptide-modified liposomes. By intravenous injection of these liposomes, NGR peptides can be combined with CD13 receptors on tumor vascular endothelial cells, position liposomes in tumor tissues, and concentrate drug in liposomes in tumor, so as to enhance the antitumor effect. The article starts with NGR peptides, summarizes definition of NGR, NGR peptide-modified liposomes, strengths and weaknesses of NGR peptide-modified liposomes in antitumor and the latest study orientation of NGR peptide-modified liposomes, and looks into the future of studies on NGR peptide-modified liposomes.
Animals ; Antineoplastic Agents ; pharmacology ; CD13 Antigens ; administration & dosage ; pharmacology ; Humans ; Liposomes ; Oligopeptides ; administration & dosage ; pharmacology

Antineoplastic Agents ; administration & dosage ; pharmacology ; Drug Delivery Systems ; Humans ; Liposomes ; administration & dosage ; pharmacology ; Sesquiterpenes ; administration & dosage ; pharmacology

AIMA new proliposomal technology was used to trap several drugs, such as tegafur, silymarin, cistanosides, oleanolic acid. And then these proliposomal characters were studied.

METHODSThese proliposomes formed liposomes after mixing with water. And then the liposomal morphology was determined by electron microscope, and the liposomal particle size determined by particle sizes instrument. The trap efficiency was determined by the column chromatography, and then the influence factors on the trap efficiency were investigated.

RESULTSThe liposomes looked round, some with multiply layers, the particle was small, and the xi potential was about - 30 mV. The trap efficiency changed with the partition coefficient and pH. When the partition coefficient and pH increased, the trap efficiency increased. Furthermore, the trap efficiency was not influenced by the molecular weight.

CONCLUSIONThis kind of liposomal technology trapped the drugs efficiently, and the lipophilic drugs were trapped more easily. Some Chinese traditional drugs could be trapped too.

Hydrogen-Ion Concentration ; Liposomes ; chemistry ; Oleanolic Acid ; administration & dosage ; Particle Size ; Silymarin ; administration & dosage ; Technology, Pharmaceutical ; Tegafur ; administration & dosage

Bacterial endophthalmitis, which is a devastating complication of intraocular surgery or eye trauma, has a poor prognosis. Intravitreal injection of antimicrobial agents has become a part of the standard treatment of endophthalmitis. The authors investigate the pharmacokinetics of intravitreal liposome-encapsulated tobramycin as a possible method of prolonging the duration of therapeutic concentrations. Tobramycin was encapsulated into liposomes of phosphatidylcholine, phosphatidic acid, and alpha-tocopherol by the reverse phase evaporation method. The final liposomal suspension contained tobramycin, 7.0 mg/ml, 60.5% encapsulated. One eye received an intravitreal injection of either liposome-encapsulated tobramycin (LET), tobramycin phosphated-buffered saline (TS) or a mixture of tobramycin and liposome-encapsulated saline (TEL), and the results were as follows: 1. Concentrations of free tobramycin were significantly lower with LET than with TS or TEL at 1 hour after intravitreal injection. 2. Concentrations of free and total tobramycin were significantly higher with LET than with TS or TEL at 5 and 8 days after intravitreal injection. Concentrations of free tobramycin with TS were lower than the minimal inhibitory concentration(MIC) of tobramycin for Pseudomonas aeruginosa at 8 days after intravitreal injection, while those with LET were higher than the MIC of tobramycin for Pseudomonas aeruginosa 18 days after injection.
Animal ; Delayed-Action Preparations ; Injections ; Liposomes ; Rabbits ; Tobramycin/administration & dosage/*pharmacokinetics ; Vitreous Body/*metabolism

Nanoparticles had received much attention in the development of new kind of pharmaceutical formation because of the special nano-effectivity. Recently, some studies discovered the special functions of the nanoparticles in transdermal and transmucosal drug delivery systems. Even though the acting mechanism of the nanoparticles in these drug delivery systems are not known, these discoveries of the special function of the nanoparticles provide new developing prospect to the drug delivery systems. This paper mainly reviews the present studying results about the nanoparticles used in the transdermal and transmucosal drug delivery systems, including the lipid nanopaticles, natural polymer and the synthesized polymer nanoparticles.
Administration, Cutaneous ; Animals ; Chitosan ; Drug Delivery Systems ; Humans ; Lipids ; Liposomes ; Nanotechnology ; methods ; Polymers

Liposomes and nanoparticles have been used as drug carriers to increase solubility, prolong drug duration in vivo, target drug delivery, reduce toxicity and combat multi-drug resistance. With major advances in the preparation techniques, preparation material, and surface modifiers in recent years, liposomes and nanoparticles delivery systems have achieved success in fields including cancer therapy, overcoming biological barriers, and biological drugs and vaccine carriage.
Drug Carriers ; Drug Delivery Systems ; methods ; Humans ; Liposomes ; Nanoparticles ; Vaccines ; administration & dosage ; chemistry

OBJECTIVETo study the effect of buffer on separate capacity of macroporous resin. To evaluate the quality of ferulic acid liposome and determine its entrapment efficiency.

METHODDifferent type of macroporous resin counterpoised by buffer system of Na2 HPO3-NaH2, PO3 was used to separate the free ferulic acid from the preparation and HPLC was used to determine the concentration of the ferulic acid to calculate the entrapment efficiency.

RESULTThis method had good linearity in the range of 0.56 - 2.8 g x mL(-1) (r = 0.999 6). The precision RSD was less than 1.1%. The adsorption effect of macroporous resin on liposome was reduced while it had no effect on the absorption ability of macroporous resin on the ferulic acid by the usage of buffer. The recovery of HPD450 resin on blank liposome was between 97.2% - 100.8%, while the average recovery is 98.1%.

CONCLUSIONBuffer system can enhance the separate ability of macroporous resin on liposome and free drug.

Adsorption ; Buffers ; Coumaric Acids ; administration & dosage ; analysis ; Drug Carriers ; Liposomes ; Quality Control ; Resins, Synthetic

In order to increase the stability and solubility of essential oil in Jieyu Anshen Formula, this study was to prepare the essential oil into liposomes. In this experiment, the method for the determination of encapsulation efficiency of liposomes was established by ultraviolet spectrophotometer and dextran gel column. The encapsulation efficiency and particle size of liposomes were used as evaluation indexes for single factor investigation and Box-Behnken design-response surface method was used to optimize the design. Then the optimal formulation of volatile oil liposome was characterized using methyleugenol, elemin, β-asarone and α-asarone as index components. Finally, the in vitro transdermal properties of liposomes were studied by modified Franz diffusion cell. The results showed that the concentration of lecithin, the mass ratio of lecithin to volatile oil, and the stirring speed were the three most significant factors affecting the liposome preparation. The optimum formulation of volatile oil liposome was as follows: the concentration of lecithin was 7 g·L~(-1); mass ratio of lecithin to volatile oil was 5∶1; and the stirring speed was 330 r·min~(-1). Under such conditions, the prepared liposomes had blue emulsion light, good fluidity, half translucent, with particle size of(102.6±0.35) nm, Zeta potential of(-17.8±0.306) mV, permeability of(1.67±1.01)%, and stable property if liposome was stored at 4 ℃. 24 h after percutaneous administration, the cumulative osmotic capacity per unit time was(30.485 2±1.238 9),(34.794 8±0.928 3),(26.677 1±1.171 7),(3.066 2±0.175 3) μg·cm~(-2)respectively for methyleugenol, elemin, β-asarone and α-asarone. In vitro transdermal behaviors of methyleugenol, elemin, β-asarone and α-asarone in liposomes were all consistent with Higuchi equation. The prepared volatile oil liposomes met the relevant quality requirements, providing a reference for further research on preparation of multi-component Chinese medicine essential oil liposomes.
Administration, Cutaneous ; Drugs, Chinese Herbal ; analysis ; Liposomes ; Oils, Volatile ; analysis ; Particle Size ; Solubility

AIMTo prepare acyclovir liposome for improvement the entrapment efficiency and stability.

METHODSAcyclovir liposome was prepared by the reverse evaporating method. Surfactants such as sodium deoxycholate and oleic acid were added to optimize the conditions and technology of preparing acyclovir liposome. The entrapment efficiency and particle size of the acyclovir liposome were determined. The liposome stability was proved by centrifugal acceleration experiment.

RESULTSThe particle size of the acyclovir liposome was 219.8 nm with the polydispersity index of 0.158. The entrapment efficiency reached 65%. The liposome was stable.

CONCLUSIONThe results suggest that the conditions and technology are stable and practical to prepare the liposome with high entrapment efficient and stability.

Acyclovir ; administration & dosage ; Antiviral Agents ; administration & dosage ; Drug Carriers ; Drug Stability ; Liposomes ; chemistry ; Particle Size ; Technology, Pharmaceutical ; methods

Ethosomes, as a new vector for transdermal drug delivery, could obviously improve the transdermal penetration of drugs. In this study, we prepared testosterone undecanoate ethosomes, with TU ethosomes as the basic remedy, to determine its appearance, particle size, entrapment efficiency (EE) and membrane fluidity. Meanwhile, a transdermal test was conducted in mice, in order to determine the permeability characteristics of ethosomes as a vector for transdermal drug delivery, and compare transdermal behaviors of TU ethosomes, liposomes and their ethanol solutions.
Administration, Cutaneous ; Animals ; Drug Delivery Systems ; Liposomes ; chemistry ; Mice ; Skin Absorption ; Testosterone ; administration & dosage ; analogs & derivatives ; chemistry