In this study we synthesized a micro- and mesoporous material, SBA-16. And later on we functionalized it with octyltrimethoxysilane and octadecyltrimethoxysilane, respectively. The materials of SBA-16 and its functionalized form were characterized by nitrogen adsorption isotherms at 77K, small angle X-ray scattering (SAXS), Fourier-transform infrared (FT-IR), thermal gravimetric analysis (TGA), and adsorption isotherms of single component n-heptane, toluene and water vapour. The data of FT-IR and TGA demonstrated the successful chemical modification of surface and porous wall of SBA-16 with different hydrocarbon chains. The results of SAXS, nitrogen adsorption at 77K, and adsorption isotherms of probe molecules revealed that the functionalized SBA-16 materials possessed relatively less regularity, smaller BET surface area and pore volumes, and lower adsorption capacities for the probe molecules compared to the original SBA-16. However, the functionalized SBA-16 materials showed much less affinity to polar molecules such as water. This work provides useful fundamental information for future study of novel mesoporous silica materials as potential drug delivery carriers.
Adsorption ; Drug Carriers ; chemistry ; Porosity ; Silicon Dioxide ; chemistry ; Surface Properties

The application of intraocular drug delivery is usually limited due to special anatomical and physiological barriers, and the elimination mechanisms in the eye. Organic nano-drug delivery carriers exhibit excellent adhesion, permeability, targeted modification and controlled release abilities to overcome the obstacles and improve the efficiency of drug delivery and bioavailability. Solid lipid nanoparticles can entrap the active components in the lipid structure to improve the stability of drugs and reduce the production cost. Liposomes can transport hydrophobic or hydrophilic molecules, including small molecules, proteins and nucleic acids. Compared with linear macromolecules, dendrimers have a regular structure and well-defined molecular mass and size, which can precisely control the molecular shape and functional groups. Degradable polymer materials endow nano-delivery systems a variety of size, potential, morphology and other characteristics, which enable controlled release of drugs and are easy to modify with a variety of ligands and functional molecules. Organic biomimetic nanocarriers are highly optimized through evolution of natural particles, showing better biocompatibility and lower toxicity. In this article, we summarize the advantages of organic nanocarriers in overcoming multiple barriers and improving the bioavailability of drugs, and highlight the latest research progresses on the application of organic nanocarriers for treatment of ocular diseases.
Drug Carriers ; Delayed-Action Preparations ; Drug Delivery Systems ; Nanoparticles/chemistry*

OBJECTIVETo prepare the sustained release solid dispersion of tripterine, using HPMC-stearic acid with the intention of improving drug dissolution and controlling drug releases moderate, so that the drug performances lower toxicity.

METHODTripterine sustained release solid dispersions was prepared by the solvent method with different weight ratios of HPMC-stearic acid and tripterine, which were dissolved in 95% ethanol. And in vitro dissolution experiment was conducted. Differential scanning calorimetry, scanning electron microscopy and X-ray powder diffraction can prove the formation of solid dispersions.

RESULTThe ideal tripterine sustained release solid dispersions were prepared under the condition as follows, the weight ratio of tripterine and HPMC-stearic acid was 1: 10, and the release rate of drug can keep moderate and controllable. In vitro cumulative release of tripterine sustained release solid dispersion is up to more than 90% after 8 h, and the tripterine exist as amorphous in the solid dispersion.

CONCLUSIONThe sustained release solid dispersion of tripterine, carried by HPMC-stearic acid, can improve the release of tripterine effectively and controls the release rate keep moderate and controllable, and the preparation process is simple, which has potential applications.

Chemistry, Pharmaceutical ; methods ; Delayed-Action Preparations ; chemistry ; Drug Carriers ; chemistry ; Kinetics ; Stearic Acids ; chemistry ; Triterpenes ; chemistry

To prepare beta-cyclodextrin (beta-CD)-deoxyrhaponti inclusion complex by the homogeneous method, and characterize the inclusion complex with ultraviolet-visible spectrum and fluorescence spectroscopy, in order to determine the inclusion rate, the ratio of subject-object, the binding constant of supra-molecular system and the thermodynamic function. The results showed that the designed method was so rational that the inclusion complex was successfully prepared. The ultraviolet-visible spectrophotometry method was adoptedto determine the inclusion rate of 38%, and the ratio of subject-object of 2: 1. The thermodynamic parameters of this inclusion complex: deltaH(0), deltaS(0) was all smaller than zero, which indicated that the main acting forces generated by the inclusion complex were hydrogen bonding and Vander Waals' force. deltaG(0) < 0 and deltaG(0) were directly proportional to the reaction temperature, which suggested that the reaction would spontaneously increase with the temperature rise. The polarization fluorescence method was used to quantitatively prove the non-covalent inclusion complex generated during the interaction between beta-CD interacting with DES. The results could also provide reference for studies on cyclodextrin supra-molecular system.
Drug Carriers ; chemistry ; Drugs, Chinese Herbal ; chemistry ; Nanoparticles ; chemistry ; Stilbenes ; chemistry ; beta-Cyclodextrins ; chemistry

OBJECTIVETo prepare the novel liposomes composed of hydrogenated soybean phosphatidylcholine (HSPC) and soybean phosphatidylcholine (SPC) containing the total alkaloids from seed of Strychnos nux-vomica, and to compare the pharmaceutical properties of the novel liposomes with the corresponding HSPC or SPC liposomes.

METHODThe total alkaloids were extracted from seeds of S. nux-vomica. and further purified. Novel liposomes containing the total alkaloids were prepared by ammonium sulfate transmembrane gradients and stealth liposome technique. Pharmaceutical properties such as encapsulation efficiency (EE), size, zeta potential and drug release profile of novel liposomes and corresponding HSPC or SPC liposomes were compared intensively.

RESULTFor novel liposomes, HSPC-SPC (1:3) was the best ratio which has the highest EE. At the drug/lipid weight ratio of 1:6, the EE of novel, SPC and HSPC liposomes were (73.6 +/- 2.9)%, (62.9 +/- 1.8)% and (54.7 +/- 1.0)% (n = 3), respectively. Compared with the corresponding SPC or HSPC liposomes, the size of novel liposomes was obviously decreased but the zeta potential was not different. The results of drug release showed that the novel liposomes were more stable than the SPC liposomes in the presence of rat plasma

CONCLUSIONTaken together, high encapsulation efficiency improved stability in blood, and relative low price of phospholipids of the novel liposomes, indicate that the novel liposomes may act as promising carriers for anti-tumor traditional Chinese medicine.

Alkaloids ; chemistry ; Animals ; Drug Carriers ; chemistry ; Liposomes ; chemistry ; Rats ; Seeds ; chemistry ; Strychnos nux-vomica ; chemistry

Lactoferrin (Lf) is one of the food protein belonged to the innate immune system. Apart from its main biological function of binding and transport of iron ions, lactoferrin also has many other functions and properties such as antibacterial, antiviral, antiparasitic, catalytic, anti-cancer, anti-allergic and radioprotecting. Lf is usually used as additives of food and cosmetics. The research of lactoferrin has been increasingly reported, and the application of lactoferrin as a drug carrier has drawn extensive attention over the recent year. In this paper, researches of lactoferrin as drug carriers are classified and summarized in brain targeting, liver tumor targeting, lung tumor targeting and oral delivery systems according to their different characteristics.
Administration, Oral ; Brain ; Drug Carriers ; Humans ; Lactoferrin ; chemistry ; Neoplasms

Nowadays, there are more and more researches on characters and applications of polycaprolactone (PCL). This paper reviews the researches of polycaprolactone, including its synthesis, physical and chemical properties, biodegradation, absorption properties, and its applications in clinical use and drug delivery systems. PCL can be from open ring polymerizaion. It is a kind of semi-crystalline polymer, and has good flexibility. The degradation reaction of PCL is hydrolysis. PCL is not cumulated in the body, and can be totally excreted. It can be used as suture, material for fixation of bone fracture, vector of drug, etc. PCL is widely used in medical area because of its safety, low toxicity, biodegradability.
Biodegradation, Environmental ; Drug Carriers ; Polyesters ; chemical synthesis ; chemistry ; metabolism ; Sutures

Glycerin containing carrageenan as a non-aqueous carrier for vitamin C (Vc) was prepared in this study. The stabilities of Vc at room temperature and after high temperature accelerating treatment were investigated. The effects of Vc as well as carrageenan on rheological properties were analyzed. The results showed that, with the increases of Vc, the viscosity of the non-aqueous system decreased and the shear-thinning phenomenon disappeared. Furthermore, the stability of Vc was kept well in this non-aqueous system, and the retention rate maintained at a high level-over 99% a month later in room temperature, and over 97% after high temperature accelerating treatment for 20 days. The retention rate of Vc was improved with the increasing of carrageenan. It was proved that this non-aqueous system was an ideal drug delivery system for Vc.
Ascorbic Acid ; chemistry ; Carrageenan ; Drug Carriers ; chemistry ; Drug Stability ; Glycerol ; chemistry ; Oxidation-Reduction ; Solutions

To establish an HPLC method for determining components in monocrotalinum liposomes. The results showed a good linear relationship in monocrotalinum liposomes within the concentration range between 1.6-102.4 mg x L(-1) (r = 0.999 8), with RSDs of intra-day precision, inter-day precision, stability and reproducibility of 0.61%, 0.92%, 1.7%, 1.6%, respectively. The recovery rate of monocrotaline was (99.96 +/- 0.50)%. These data indicated that the HPLC method could accurately determine components in monocrotalinum liposomes. Meanwhile, the microcolumn centrifugation method was established to determine the entrapment efficiency of components in monocrotalinum liposomes. As a result, the recovery rate and the blank liposome recovery of free components were (94.44 +/- 0.77)%, (95.86 +/- 0.68 )%, respectively. According to the parallel determination of the entrapment efficiency of three monocrotaline liposomes, their RSD was 4.0%. The data indicated that the microcolumn centrifugation method was an accurate and feasible method for determining the entrapment efficiency of monocrotaline liposomes.
Chromatography, High Pressure Liquid ; methods ; Drug Carriers ; chemistry ; Drug Compounding ; Liposomes ; chemistry ; Monocrotaline ; chemistry

Various geometric shapes and structures self-assembled of amphiphilic lipids when present in an aqueous environment, as active delivery vehicles, are becoming one of focuses of drug delivery system. Lipid-based cubic liquid crystalline nanoparticles (or Cubosomes) consisting of "honeycombed (cavernous)" structure spontaneously formed when a certain concentration of amphiphilic lipids dispersed in aqueous solution has curved bicontinuous lipid bilayer in three dimensions, separating two congruent networks of water channels. Its unique structure consists of internal double water channels and large interfacial areas, which reveal great flexibility in encapsulation efficiency of various polarities and amount of drugs, and has variegated range of drugs encapsulated. As a drug delivery vehicle, high drug payloads, stabilization of peptides or proteins and simple preparation process are also its advantages. The ability of cubic phase to incorporate and control release of drugs of varying size and polar characteristics, and biodegradability of lipids make it an interesting drug delivery system for various routes of administration, including oral, topical (or mucosal) and intravenous administrations, with extensive application in a multitude of dosage forms. Furthermore, a number of different proteins in cubic phase appear to retain their native conformation and bioactivity, and are protected against chemical and physical inactivation. In this paper, investigations of lipid-based cubic liquid crystalline nanoparticles are reviewed and summarized, with a hope to provide a reference for its in-depth study. At the end, the authors made a development prospect of this novel excellent candidate for active ingredients delivery vehicle.
Drug Carriers ; chemistry ; Drug Delivery Systems ; methods ; Lipids ; administration & dosage ; chemistry ; Liquid Crystals ; chemistry ; Nanoparticles