OBJECTIVETo prepare polylactic acid microspheres containing total alkaloid extracts of Caulis sinomenii and study their release characteristics in vitro.

METHODPolylactic acid microspheres containing total alkaloid extracts of C. sinomenii were prepared by O/W emulsification solvent-evaporation process. The microspheres were characterized in terms of morphology, encapsulation efficiency, and particle size distribution. The effect of different conditions on release property of microspheres was studied.

RESULTThe formed microspheres were spherical with smooth surfaces. The encapsulation efficiency and rate of drug loading were (83.4 +/- 5.63)% and (8.7-0.35)%, respectively. The distribution of particle size was uniform and the average size was (21.5 +/- 1.22) microm. In vitro release study revealed that the 32-hour accumulative release percentage reached 80%.

CONCLUSIONPolylactic acid microspheres containing total alkaloid extracts of C. sinomenii were prepared successfully. Microspheres with good sustained-release characteristics can be produced by controlling different process parameters.

Drugs, Chinese Herbal ; administration & dosage ; chemistry ; Lactic Acid ; chemistry ; Microspheres ; Polyesters ; Polymers ; chemistry ; Sinomenium ; chemistry

It has been one of important issues in nanomedicine research field to prepare drug-loaded nanoparticles. Optimization of the preparation parameters plays a key role in obtaining drug-loaded nanoparticles with homogeneous particle size and controlled drug release property. In this paper, gentamicin-loaded PLLA nanoparticles was prepared by means of double emulsion and solvent evaporation technique. Statistical software SPSS was employed to deal with the orthogonal design for optimizing the parameters of the formulation. The in vitro release of gentamicin from nanoparticles was determined by ultra-violet spectroscopy. Analysis of the experimental data based on orthogonal design demonstrated that the concentration of PLLA solution and the molecular weight of PLLA had significant influence on the size of nanoparticles, and the ratio of oil phase to water phase exhibited determined role in the gentamicin release property. Gentamicin-loaded PLLA nanoparticles prepared with the optimized parameters showed homogeneous particle size of 277 nm and sustained release property, which displayed a promising potential of clinical applications.
Delayed-Action Preparations ; chemical synthesis ; Drug Carriers ; Gentamicins ; administration & dosage ; pharmacokinetics ; Lactic Acid ; administration & dosage ; pharmacokinetics ; Nanoparticles ; administration & dosage ; chemistry ; Polyesters ; Polymers ; administration & dosage ; pharmacokinetics

V(E) acetate-loaded methoxy poly(ethylene glycol)-b-poly(lactic acid) amphiphilic diblock copolymer nano-dispersion (PMV) was prepared by self-emulsification/solvent evaporation method. The drug-loaded amount, size distribution of PMV nanoparticles, and entrapment efficiency of V(E) acetate (V(E)A) were determined by UV and laser particle analyzer. Drug release in vitro was primarily investigated by UV. The results indicate that the size of PMV nanoparticles is less than 300 nm and PMV is largely influenced by preparation methods, property of solvents, V(E)A-fed amount, and the concentration of dispersion. The initial burst release is not observed and the accumulated release is more than 79% after 14 h. This study develops a new formulation for V(E)A and provides an experimental basis for the novel drug delivery systems of V(E)A.
Delayed-Action Preparations ; chemical synthesis ; Drug Carriers ; administration & dosage ; chemistry ; Hydrophobic and Hydrophilic Interactions ; Nanoparticles ; Polyesters ; administration & dosage ; Polyethylene Glycols ; administration & dosage ; Vitamin E ; administration & dosage

To synthetize 3-carboxypropyl-triphenylphosponium bromide-polycaprolacton-CTPP-PEG-PC, and prepare curcumin CTPP-PEG-PCL micelles by using the self-assembled emulsion solvent evaporation method, in order to determine the critical micelle concentration (CMC) with the pyrene fluorescent probe technology, detect the particle size, entrapment efficiency (%), morpheme and in vitro release rate, and evaluate the cytotoxicity of hepatic stellate cells with MTT assay. The structure of CTPP-PEG-PCL had been identified by 1H-NMR spectra. Specifically, the CMC of polymer was 2.25 mg x L(-1), the average size was 190 nm, the drug content was (0.66 +/- 0.008) g x L(-1), and the entrapment efficiency was (94 +/- 0.6)%. The in vitro release results showed curcumin micelles had a significant higher inhibition ratio in the growth of hepatic stellate cells than crude curcumin (P < 0.05). This suggested that CTPP-PEG-PCL micelles feature low CMC, high encapsulation efficiency and notable inhibition effect in growth of hepatic stellate cells.
Cell Line ; Cell Proliferation ; drug effects ; Curcumin ; administration & dosage ; chemistry ; pharmacology ; Hepatic Stellate Cells ; drug effects ; Micelles ; Polyesters ; administration & dosage ; chemistry ; Polyethylene Glycols ; administration & dosage ; chemistry

AIMTo develop a less toxic alternative for sandimmun neoral (Neoral). To study the preparation conditions and to compare its pharmacokinetic characteristics with Neoral.

METHODSPolylactide nanoparticles loaded cyclosporine A was prepared by solvent-nonsolvent method. Polylactide nanoparticles were administered by oral in a dosage of 15 mg.kg-1. The CyA concentration in whole blood sample was determined by HPLC.

RESULTSThe quantities of CyA, PLA and volume of acetone added had significant influence on the NP diameters. Under proper condition, the nanoparticles with diameters of 57.5 nm were obtained. The relative bioavailability in rats was 101.6%, with a smaller absorption rate (P < 0.05) and a smaller elimination rate (P < 0.1).

CONCLUSIONThe nanoparticles (diamater < 100 nm) with relative high bioavailability were prepared using solvent-nonsolvent method. It is suitable for further study.

Administration, Oral ; Animals ; Biological Availability ; Cyclosporine ; administration & dosage ; pharmacokinetics ; Delayed-Action Preparations ; Immunosuppressive Agents ; administration & dosage ; pharmacokinetics ; Male ; Nanotechnology ; Polyesters ; Random Allocation ; Rats ; Rats, Wistar

Taking α-asarone as model drug, mono methoxy polyethylene glycol-polylactic acid copolymer (mPEG-PLA) as the drug carrier material to prepare drug-loading nanoparticles by premix membrane emulsification for nasal administration. The prepared nanoparticles were spherical with smooth surface and average particle size of 360 nm. Polydispersity index (PDI) was 0. 030, average drug loading of (11.5 ± 0.045) % (n = 3), and the encapsulation efficiency of (86.34 ± 0.11) % (n = 3). X-ray diffraction and differential scanning calorimetry results showed that, α-asarone existed in mPEG-PLA carrier in amorphous or molecular state, different from simple physical mixture. In the in vitro release test in simulated human nasal cavity, α-asarone apis can be released quickly at close to 94% at 102 h, in line with the first-order kinetics (R² = 0.981 9). mPEG-PLA drug-loading nanoparticles release only 54%, with slow release effect, in line with Riger-Peppas model (R² = 0.967 9, n = 0.630 2), for non-fick diffusion, released by the spread of drugs and skeleton dissolution dual control. This provided the foundation for nasal drug delivery in vivo pharmacokinetic study.
Administration, Intranasal ; Anisoles ; chemistry ; Calorimetry, Differential Scanning ; Nanoparticles ; chemistry ; Polyesters ; chemistry ; Polyethylene Glycols ; chemistry ; Solubility ; X-Ray Diffraction

The objective of this study was to prepare a biodegradable poly (DL-lactide) injectable gel of tinidazole. The formulation parameters evaluated in this study included polymer molecular weight, polymer concentration, solvent and drug loading, and orthogonal design was used to optimize the formulation. The preferable formulation was that 30% (w/w) poly(DL-lactide) (MW is 5 700) dissolved in 70% (w/w) N-methyl-2-pyrrolidone with 4%-6% (w/w) tinidazole.
Delayed-Action Preparations ; Drug Carriers ; chemistry ; Gels ; Lactic Acid ; chemistry ; Polyesters ; Polymers ; chemistry ; Technology, Pharmaceutical ; methods ; Tinidazole ; administration & dosage

Paclitaxel-loaded methoxy poly (ethylene glycol )-b-poly (L-lactic acid) diblock copolymer nanoparticles (PMT) were prepared by a self-emulsification/solvent evaporation method. The PMT morphology, size and its distribution, and drug release in vitro were investigated by DLS, UV, TEM and HPLC. The results indicate that PMT show a spherical morphology with inner core and outer shell. The diameter (nm) of PMT increases with the increase of the drug-loaded amount. The initial burst release is not observed, the drug releasing rate in vitro is lower, and the accumulated release increases with the increase of replacement amout of the pH7. 4 medium. This study develops a new formulation for paclitaxel and provides an experimental basis for the intravenous administration of paclitaxel.
Antineoplastic Agents, Phytogenic ; administration & dosage ; Delayed-Action Preparations ; Drug Carriers ; administration & dosage ; chemistry ; Humans ; Injections, Intravenous ; Nanoparticles ; Paclitaxel ; administration & dosage ; Polyesters ; administration & dosage ; chemistry ; Polyethylene Glycols ; administration & dosage ; chemistry ; Polymers ; administration & dosage ; chemistry

Methoxypolyethylene glycol-poly lactic acid (PELA) was synthesized by ring-opening copolymerization of lactide in the presence of mPEG and its structure was characterized by 1H NMR. The novel hypomicrons were prepared by solution-casting method using PELA block copolymer as a matrix and 7-ethyl-10-hydroxycamptothecin (SN-38) as an antitumor agent. The morphology, size and size distribution, drug loading, entrapment efficiency, and release characteristics in vitro of the SN-38 loaded hypomicrons were studied. The results showed that the obtained hypomicrons showed spherical shape with the core-shell structure, the sizes are in the range of 157-238 nm, and the drug loading content varied from 1.35%-3.58% depending on the copolymer composition and the SN-38 fed amount. The in vitro release behavior in phosphate-buffered saline, pH 7.4, exhibited a sustaining release manner and was affected by the copolymer composition. The drug-loaded amount and entrapment efficiency decreased with increasing the molecular weight of the copolymer. With the increasing of the SN-38 fed amount, the drug-loaded amount and the size of hypomicrons increased, the entrapment efficiency decreased. The SN-38 hypomicrons increased the solubility of SN-38 in water and were valuable for the development of the novel dosage form of SN-38.
Antineoplastic Agents, Phytogenic ; administration & dosage ; Camptothecin ; administration & dosage ; analogs & derivatives ; Drug Carriers ; Lactic Acid ; chemistry ; Microspheres ; Particle Size ; Polyesters ; Polyethylene Glycols ; chemistry ; Polymers ; chemistry ; Solubility ; Technology, Pharmaceutical

OBJECTIVETo determine the efficacy of polylactic acid glue in preventing epidural scar adhesion after laminectomy in rabbits.

METHODSTwenty-four Japanese white rabbits underwent laminectomy (including the attached ligaments) at L(2 ) and L(5). After laminectomy at L(5), polylactic acid glue was sprayed on the dura and nerve roots and this segment was taken as the experimental group. After laminectomy at L(2), nothing was used and this segment was enrolled as the self control group. Four rabbits were killed every two weeks postoperatively till the end of the experiment at 12 weeks. Then the operated spine was observed grossly, histologically and ultrastructurally to check the degree of scar formation, the status of epidural scar adhesion, the absorption of the glue, and the intracellular structure of fibroblasts.

RESULTSThe glue coagulated immediately after spraying and showed excellent hemostatic effect. The glue membrane was easy to be taken away from the dura mater of the samples for 2 weeks and there were no cells in the epidural space in the experimental group. But the dura mater was covered by hematoma in the control group, which formed mild adhesion, with fibroblasts proliferating actively. In the 4th week, some glue shivers remained in the epidural space with fibroblasts increasing a little, and the dura mater was smooth in the experimental group. However, in the control group, the formed scar was fragile and conglutinated with the dura mater diffusely and fibroblasts were much more than those in the experimental group. In the 6th-12th weeks, there was a potential interspace between the scar and the dura mater, and the polylactic acid glue was absorbed completely in the experimental group. Much tough scar was found in the control group, which was very difficult to dissect from the dura mater and the surrounding tissues. From the ultrastructural observation of the fibroblasts, the nucleus became much bigger and the rough endoplasmic reticulum was much more plentiful in the control group than that in the experimental group.

CONCLUSIONSPolylactic acid glue can effectively reduce epidural cicatrization and adhesion.

Animals ; Biocompatible Materials ; Cicatrix ; prevention & control ; Lactic Acid ; administration & dosage ; pharmacology ; Laminectomy ; Membranes, Artificial ; Polyesters ; Polymers ; administration & dosage ; pharmacology ; Postoperative Complications ; prevention & control ; Rabbits ; Tissue Adhesions ; prevention & control