Curcumin-ethyl-cellulose (EC) sustained-release composite particles were prepared by using supercritical CO2 anti-solvent technology. With drug loading and yield of inclusion complex as evaluation indexes, on the basis of single factor tests, orthogonal experimental design was used to optimize the preparation process of curcumin-EC sustained-release composite particles. The experiments such as drug loading, yield, particle size distribution, electron microscope analysis (SEM) , infrared spectrum (IR), differential scanning calorimetry (DSC) and in vitro dissolution were used to analyze the optimal process combination. The orthogonal experimental optimization process conditions were set as follows: crystallization temperature 45 degrees C, crystallization pressure 10 MPa, curcumin concentration 8 g x L(-1), solvent flow rate 0.9 mL x min(-1), and CO2 velocity 4 L x min(-1). Under the optimal conditions, the average drug loading and yield of curcumin-EC sustained-release composite particles were 33.01% and 83.97%, and the average particle size of the particles was 20.632 μm. IR and DSC analysis showed that curcumin might complex with EC. The experiments of in vitro dissolution showed that curcumin-EC composite particles had good sustained-release effect. Curcumin-EC sustained-release composite particles can be prepared by supercritical CO2 anti-solvent technology.
Carbon Dioxide ; chemistry ; Cellulose ; administration & dosage ; analogs & derivatives ; chemistry ; Curcumin ; administration & dosage ; chemistry ; Delayed-Action Preparations ; Solubility ; Solvents ; Technology, Pharmaceutical

Hot-melt extrusion was applied to prepare mesoporous silica/ethylcellulose mini-matrix for sustained release, and fenofibrate was used as a model drug, ethylcellulose and xanthan gum were chosen as sustained-release agent and releasing moderator, respectively. This novel matrix obtained the controlled release ability by combining mesoporous silica drug delivery system and hot-melt extrusion technology. And mesoporous silica particle (SBA-15) was chosen as drug carrier to increase the dissolution rate of fenofibrate in this martix. Scanning electron microscope, transmission electron microscope, small angle X-ray powder diffraction and N2 adsorption-desorption were introduced to determine the particle morphology, particle size and pore structure of the synthesized SBA-15. The results showed that SBA-15 had a very high Brunauer-Emmett-Teller specific surface area, a narrow pore size distribution, large pore volume and a ordered two-dimensional hexagonal structure of p6mm symmetry. Differential scanning calorimetry and X-ray powder diffraction results demonstrated that fenofibrate dispersed in an amorphous state inside the pores of the mesoporous silica which contributed to the improvement in the dissolution rate. The drug release of mini-matrices was influenced by ethylcellulose viscosity grades and xanthan gum concentration, which increased with the increasing of xanthan gum concentration and decreasing of ethylcellulose viscosity. Mini-matrix containing 22% xanthan gum exhibited a good sustained release performance, and the drug release behavior followed the first-order kinetics.
Adsorption ; Calorimetry, Differential Scanning ; Cellulose ; analogs & derivatives ; Delayed-Action Preparations ; Drug Carriers ; chemistry ; Particle Size ; Porosity ; Powder Diffraction ; Powders ; Silicon Dioxide ; Solubility ; X-Ray Diffraction

In this study, solvent evaporation method was used to preparing baicalin ethylcellulose microspheres for intranasal administration. The prepared microspheres were round with certain rough surface. The average drug loading and entrapment efficiency was (33. 31 ± 0. 045)% , (63. 34 ± 0. 11)% , respectively. As the characteristic crystalline peaks of baicalin were observed in the microspheres sample, the result of X-ray diffractometric analysis indicated that the baicalin was present in crystalline form after its entrapment in ethylcellulose matrix. By investigating the thermogram of microspheres sample, it was found that endothermic peak of baicalin was shifted from 211. 8 °C to 244. 2 °C and associated with the first broad endothermic peak of ethylcellulose. This could confirm that baicalin was loaded into ethylcellulose, nor simply physical mixture. The powder flowability test exhibited that the specific energy of microspheres was 3. 57 mJ . g-1 and the pressure drop was 2. 22 mBar when air kept the speed of 2 mm . s-1 through the powder bed with the force was 15 kPa. The consequence of the baicalin in vitro released from microspheres showed that the pure baicalin sample displayed faster (90%) release than microspheres sample (75%) in 7 h. Fitting model for release curve before 7 h, the results showed that the pure baicalin sample and the microsphere sample accorded with first order model (R2 = 0. 990 4) and Riger-Peppas model(R2 = 0. 961 2), respectively. Ex vivo rabbit nasal mucosa permeability experiment revealed that the value of cumulative release rate per unit area of the microsphere sample was 1. 56 times that of the pure baicalin sample. This provided the foundation for the in vivo pharmacokinetic study.
Administration, Intranasal ; Air Pressure ; Animals ; Cellulose ; analogs & derivatives ; chemistry ; Drug Compounding ; methods ; Flavonoids ; administration & dosage ; chemistry ; pharmacokinetics ; Male ; Microspheres ; Mucous Membrane ; metabolism ; Particle Size ; Powders ; Rabbits ; Solvents ; X-Ray Diffraction

To develop estradiol transdermal film-forming spray (TFS), various polymers were screened using solvent appearance, spray ability, film-forming rate and appearance as indices. The influence of polymer type, plasticizer and penetration enhancer on the transdermal flux were investigated by selecting porcine skin as model, and transdermal flux of TFS was compared with commercial patch and gel. The drug existing state in the formed film was investigated by differential scanning calorimetry (DSC). The solvent appearances, spray abilities, film-forming rates and appearances of eudragit E PO, RL PO, hydroxypropyl cellulose EF, polyvinylpyrrolidone K30, Plasdone S630 and Agrimer VA64 were suitable for the preparation of TFS. TFS prepared by Eudragit RL PO had the biggest transdermal flux of estradiol among all the polymers investigated. Triethyl citrate, the plasticizer, decreased the transdermal flux. Azone increased the transdermal flux, while oleic acid, isopropyl myristate and menthol had opposite effects. TFS had a higher transdermal rate and a higher accumulative penetrated estradiol of 24 h than commercial patch and gel. The DSC result showed that estradiol was spread as molecule in the formed film of TFS. It was indicated that TFS could be expected to be an effective transdermal drug delivery system.
Administration, Cutaneous ; Aerosols ; Animals ; Azepines ; chemistry ; Calorimetry, Differential Scanning ; Cellulose ; analogs & derivatives ; chemistry ; Citrates ; chemistry ; Drug Delivery Systems ; Estradiol ; administration & dosage ; pharmacokinetics ; Plasticizers ; chemistry ; Polymers ; chemistry ; Skin Absorption ; Swine

Ibuprofen/ethyl-cellulose (EC)-polyvinylpyrrolidone (PVP) sustained-release composite particles were prepared by using supercritical CO2 anti-solvent technology. With drug loading as the main evaluation index, orthogonal experimental design was used to optimize the preparation process of EC-PVP/ibuprofen composite particles. The experiments such as encapsulation efficiency, particle size distribution, electron microscope analysis, infrared spectrum (IR), differential scanning calorimetry (DSC) and in vitro dissolution were used to analyze the optimal process combination. The orthogonal experimental optimization process conditions were set as follows: crystallization temperature 40 degrees C, crystallization pressure 12 MPa, PVP concentration 4 mgmL(-1), and CO2 velocity 3.5 Lmin(-1). Under the optimal conditions, the drug loading and encapsulation efficiency of ibuprofen/EC-PVP composite particles were 12.14% and 52.21%, and the average particle size of the particles was 27.621 microm. IR and DSC analysis showed that PVP might complex with EC. The experiments of in vitro dissolution showed that ibuprofen/EC-PVP composite particles had good sustained-release effect. Experiment results showed that, ibuprofen/EC-PVP sustained-release composite particles can be prepared by supercritical CO2 anti-solvent technology.
Calorimetry, Differential Scanning ; Carbon Dioxide ; chemistry ; Cellulose ; administration & dosage ; analogs & derivatives ; chemistry ; Crystallization ; Delayed-Action Preparations ; Drug Carriers ; Drug Compounding ; Ibuprofen ; administration & dosage ; chemistry ; Microscopy, Confocal ; Particle Size ; Povidone ; administration & dosage ; chemistry ; Solubility ; Spectrophotometry, Infrared ; Technology, Pharmaceutical ; methods

This paper report the development of a new dosage form - self-microemulsifying mouth dissolving films, which can improve the oral bioavailability of water insoluble drugs and have good compliance. A three factor, three-level Box-Behnken design was used for optimizing formulation, investigated the effect of amounts of microcrystalline cellulose, low-substituted hydroxypropyl cellulose and hypromellose on the weight, disintegration time, cumulative release of indomethacin after 2 min, microemulsified particle size and stretchability. Optimized self-microemulsifying mouth dissolving films could fast disintegrate in (17.09 +/- 0.72) s; obtain microemulsified particle size at (28.81 +/- 3.26) nm; and release in vitro at 2 min to (66.18 +/- 1.94)%. Self-microemulsifying mouth dissolving films with broad application prospects have good compliance, strong tensile and can be released rapidly in the mouth through fast self-microemulsifying.
Administration, Oral ; Biological Availability ; Cellulose ; analogs & derivatives ; chemistry ; Drug Compounding ; methods ; Drug Delivery Systems ; methods ; Emulsifying Agents ; chemistry ; Emulsions ; Hypromellose Derivatives ; Indomethacin ; administration & dosage ; Methylcellulose ; analogs & derivatives ; chemistry ; Particle Size ; Solubility ; Surface Properties ; Tensile Strength

Sodium cellulose sulfate (NaCS)/Ploy-dimethyl-dially-ammonium-chloride (PDMDAAC) microcapsules were used as a novel pseudo "Cell Factory" to immobilize mixed bacteria for hydrogen production under anaerobic conditions. Compared to free cells, the hydrogen production was increased more than 30% with NaCS/PDMDAAC microcapsules as the pseudo "Cell Factory". The biomass was increased from 1.5 g/L in free cell culture to 3.2 g/L in the pseudo "Cell Factory". This pseudo "Cell Factory" system showed the excellent stability during 15 repeated-batches. The hydrogen yield maintained 1.73-1.81 mol H2/mol glucose. The fermentation cycle was shortened from 48 h to 24 h, resulting in an increase of 198.6% in the hydrogen production rate. There were high percentage of butyric acid and acetic acid in the culture broth, which meant that the pseudo "Cell Factory" established in the present work could be used for the multi-product system.
Bacteria ; classification ; genetics ; metabolism ; Capsules ; Cells, Immobilized ; metabolism ; Cellulose ; analogs & derivatives ; chemistry ; Fermentation ; Hydrogen ; metabolism ; Polyethylenes ; chemistry ; Quaternary Ammonium Compounds ; chemistry

Ranolazine hydrochloride sustained-release tablet (RH-ST) was prepared and its release behavior in vitro was studied. The pharmacokinetic characteristics and bioavailability in six Beagle dogs after oral administration of RH-ST and ranolazine hydrochloride common tablets (RH-CT) as reference were compared. Three kinds of matrix, hydroxypropylmethylcellulose (HPMC K4M), ethylcellulose (EC 100cp) and acrylic resins (Eudragit RL100) were selected as functional excipients to keep ranolazine hydrochloride (RH) release for 12 hours. Through orthogonal designs, the polymers were quantified and the optimized cumulative release profile was obtained. The single oral dose of RH-ST 500 mg and RH-CT 333.3 mg was given to six dogs using a two way crossover design. Plasma levels were determined by LC-MS and the absorption fractions were calculated according to Loo-Riegelman formula. The steady-state concentration of RH in plasma of six dogs and its pharmacokinetics behaviors after continuous oral administration of RH-ST and RH-CT at different time intervals were studied by LC-MS. The steady-state pharmacokinetic parameters were computed by software program BAPP2.0. With the increase of the amount of the matrix, the drug release was decreased. The most important factor influencing drug release is the quantity of HPMC K4M. Drug release within the period (from 0 h to 12 h) fitted well into Higuchi model. The correlation coefficient (r) between the dissolution in vitro in release media of the distilled water and the absorptin fraction in vivo was 0.9550. To compare with RH-CT, RH-ST in vivo has a steady and slow release behavior, Tmax was obviously delayed (3.00 +/- 0.50) h and the relative bioavailability was over 80 percentage. The combined use of multiple polymers can decrease the tablet weight effectively, and the drug release rate can be decreased both in vitro and in vivo.
Acetanilides ; administration & dosage ; pharmacokinetics ; Acrylic Resins ; chemistry ; Administration, Oral ; Animals ; Area Under Curve ; Biological Availability ; Cellulose ; analogs & derivatives ; chemistry ; Cross-Over Studies ; Delayed-Action Preparations ; Dogs ; Excipients ; Female ; Hypromellose Derivatives ; Male ; Methylcellulose ; analogs & derivatives ; chemistry ; Piperazines ; administration & dosage ; pharmacokinetics ; Ranolazine ; Tablets

This paper is to study the inhibitory effect of water soluble polymers--methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose (HPC-M), poloxamer (F68) and polyvidon (PVP) on osthole (OST) crystallization and investigate the impact of polymer concentration and viscosity on crystallization behavior. Also, UV spectrophotometry method was used to determine the drug concentration at different time point to draw the OST concentration-time curve. Results show that HPMC has the most significant inhibition effect on OST crystallization, and drug concentration level is 1.61 times higher than that in control solution within 8 h followed by PVP (1.54) and MC (1.45) respectively. The kinetics of OST recrystallization can be described using first-order reaction, and the crystallization rate constants obtained by analyzing the regression equation indicate that HPMC-60SH-4000 and HPMC-60SH-10000 can greatly influence OST crystal formation. The dissolution rate of drugs precipitated from water-soluble polymer solutions is faster compared with controls in pH 1.2 HCl and pH 6.8 phosphate buffers, which demonstrated that water-soluble polymers can not only change the behavior of drug crystallization but markedly improve the dissolution rate of water insoluble drugs.
Cellulose ; analogs & derivatives ; chemistry ; Cnidium ; chemistry ; Coumarins ; chemistry ; isolation & purification ; Crystallization ; Hypromellose Derivatives ; Kinetics ; Methylcellulose ; analogs & derivatives ; chemistry ; Plants, Medicinal ; chemistry ; Poloxamer ; chemistry ; Polymers ; chemistry ; Povidone ; chemistry ; Solubility ; Viscosity

Albendazole is an orally administered broad-spectrum benzimidazole anthelmintic used against helminthiasis, hydatid cyst disease and neurocysticercosis. The objectives of this investigation are to develop a sustained release drug delivery system for albendazole, and to target its delivery to colon. Albendazole matrix tablets containing varying proportions of single and binary blends of four polymers; polyacrylic acid (carbopol 971), ethylcellulose (Etcell), eudragit L100-55 (EUD), and sodium carboxymethyl cellulose (CMC) were prepared by a modified wet granulation technique of kneading, extrusion and compaction. In vitro release profiles of albendazole was sequentially determined in simulated gastric fluid (SGF), simulated intestinal fluid (SIF) without enzymes and in rat caecal content medium (RCCM) at 37 degrees C. The in vitro drug release from matrix tablets containing CMC and Etcell as single polymers showed initial burst effect in the first 2 h (>20% and 50% respectively), followed by a slow release in SIF. However, matrix tablets containing polymer blends showed that no appreciable drug release occurred up to 5 h. Drug release from tablets containing polymer blends in the dissolution medium containing rat caecal material suddenly increased to > or =30% after 5 h (RCCM), and reaching up to 90% in 24 h. Albendazole matrix tablets containing carbopol 971, Etcell, EUD, and CMC as single polymers and as blends were formulated for oral use. Drug release from the tablet matrices containing carbopol alone, binary blends of carbopol/Etcell, and CMC/EUD were found to be very slow and dependent on polymer concentration. Matrix tablets containing blends of these polymers formulated using kneading, extrusion and compaction technique could provide sustained drug release and can be utilized in the colonic delivery of albendazole.
Acrylic Resins ; chemistry ; Administration, Oral ; Albendazole ; administration & dosage ; pharmacokinetics ; Animals ; Anthelmintics ; administration & dosage ; pharmacokinetics ; Carboxymethylcellulose Sodium ; chemistry ; Cellulose ; analogs & derivatives ; chemistry ; Colon ; metabolism ; Delayed-Action Preparations ; Drug Carriers ; chemistry ; Drug Compounding ; Drug Delivery Systems ; In Vitro Techniques ; Male ; Rats ; Tablets ; Technology, Pharmaceutical ; methods