To investigate theological properties of common hydrophilic gel excipients such as Carbopol based on viscosity, the viscosity was determined by rotation method and falling-ball method. Linear regression was made between ln(eta) and concentration, the slope of which was used to explore the relation between viscosity and concentration of different excipients. The viscosity flow active energy (E(eta)) was calculated according to Arrhenius equation and was used to investigate the relation between viscosity and temperature of different excipients. The results showed that viscosities measured by two methods were consistent. Concentration of guargum (GG) and hydroxypropylmethyl cellulose (HPMC) solution had a great influence on the viscosity, k > 5; while concentration of polyvinylpyrrolidone-K30 (PVP-K30) and polyethylene glycol 6000 (PEG6000) exerted a less effect on viscosity, k < 0.2; viscosity flow active energy of different excipients were close, which ranged from 30 to 40 kJ x mol(-1). Therefore, theological properties study could provide the basis for application of excipients and establish a foundation for the research of relation between excipients structure, property and function.
Excipients ; chemistry ; Gels ; chemistry ; Polyethylene Glycols ; chemistry ; Polyvinyls ; chemistry ; Povidone ; chemistry ; Rheology ; Temperature ; Viscosity

To build the evaluating method of the characteristic physical properties of the wetting mass, this study reported the preparation of wetting mass by adding water into microcrystalline cellulose, and using texture analyser texture profile analysis to test its physical properties, including hardness, adhesiveness, springness, cohesiveness, chewiness, resilience and so on, then finding out the better method and parameters. The method was evaluated and used to test wetting mass, which was made of microcrystalline cellulose of different types and polyvinylpyrrolidone. When running texture profile analysis whose trigger force was 1500 g, the relative standard deviation was under 10%, and the trend of every characteristic physical property tallied with the theory result by water ratio increase. Testing result of the same excipient with the same water ratio had a higher precision, while characteristic physical properties of wetting mass who was made of the same excipient with different water ratios and different excipients had a great difference. Using texture analyser to test physical properties of wetting mass could get a result which tallied with the theory by water ratio increase, and had a well precision, accuracy and sensitivity, and thus it could also evaluate the characteristic physical properties of wetting mass relatively well.
Adhesiveness ; Cellulose ; chemistry ; Excipients ; chemistry ; Hardness ; Povidone ; chemistry ; Surface Properties ; Technology, Pharmaceutical ; methods ; Water ; chemistry ; Wettability

OBJECTIVETo prepare a stable water-based magnetic fluid.

METHODSA water-based magnetic fluid was prepared by addition of polyvinylpyrrolidone (PVP) as the coating agent for the magnetic particles. After preparation of Fe3O4 by co-precipitation method, PVP was added for its coating, followed by ultrasonic agitation and purification.

RESULTSThe magnetic nanoparticles of homogeneously small size and water-based magnetic fluid were obtained, which had good dispersion in water with strong magnetism.

CONCLUSIONPVP can be used as a surfactant to stabilize the magnetic fluid.

Ferrous Compounds ; chemistry ; Magnetics ; Materials Testing ; Nanoparticles ; chemistry ; Povidone ; chemistry ; Surface Properties ; Surface-Active Agents ; chemical synthesis ; chemistry

Ischemic brain injury is a major disease which threatens human health and safety. (3, 5, 6-trimethylpyrazin-2-yl) methyl 3-methoxy-4-[(3, 5, 6-trimethylpyrazin-2-yl) methoxy] benzoate (VA-T), a newly discovered lead compound, is effective for the treatment of ischemic brain injury and its sequelae. But the poor solubility of VA-T leads to poor dissolution and limited clinical application. In order to improve the dissolution of VA-T, the pharmaceutical technology of solid dispersions was used in the present study. VA-T/polyvinylpyrrolidone (PVP) solid dispersion was prepared by the solvent method. The dissolution studies were carried out and solid state characterization was evaluated by differential scanning calorimetry (DSC), infrared spectroscopy (IR), x-ray diffraction (XRD) and scanning electron microscopy (SEM). The dissolution rate of VA-T was significantly improved by solid dispersion compared to that of the pure drug and physical mixture. The results of DSC and XRD indicated that the VA-T solid dispersion was amorphous. The IR spectra showed the possible interaction between VA-T and PVP was the formulation of hydrogen bonding. The SEM analysis demonstrated that there was no VA-T crystal observed in the solid dispersions. The ideal drug-to-PVP ratio was 1:5. In conclusion, the solid dispersion technique can be successfully used for the improvement of the dissolution profile of VA-T.
Benzoates ; administration & dosage ; chemistry ; Brain Ischemia ; drug therapy ; Chemistry, Pharmaceutical ; methods ; Drug Delivery Systems ; Povidone ; chemistry ; Solubility

Solid dispersions technique was used to solidify buagafuran and improve buagafuran in vitro dissolution and stability. Buagafuran solid dispersions were prepared separately using PVPK30, PEG6000 and Poloxamer188 at various weight ratios as carriers. The status of buagafuran in solid dispersions was determined by using DSC and IR. The solubility, content and in vitro dissolution of pure drug and the solid dispersions were detected by using HPLC. When buagafuran/carrier was 1:5 or less, the drug existed in a solid dispersion form. Three kinds of carriers all can improve buagafuran dispersibility and in vitro dissolution. Accelerating experiment showed that buagafuran/PVPK30 < or = 1:10 solid dispersions was ageing-resistant, and the aspect, content and in vitro dissolution did not change after storaged over 3 months, but PEG6000, Poloxamer188 and a lower ratio PVPK30 solid dispersions became aged. Buagafuran/PVPK30 < or = 1:10 solid dispersions can be developed as buagafuran oral drug delivery carrier.
Anti-Anxiety Agents ; administration & dosage ; chemistry ; Drug Carriers ; Drug Delivery Systems ; Drug Stability ; Drug Storage ; Poloxamer ; chemistry ; Polyethylene Glycols ; chemistry ; Povidone ; chemistry ; Powders ; Sesquiterpenes ; administration & dosage ; chemistry ; Solubility

AIMTo prepare nifedipine (NP) rapid release mini-tablet, sustained release mini-tablets, pulsed release mini-tablets and delayed-onset sustained release mini-tablets and develop multiplied pulsed drug delivery system (DDS), site-specific DDS, zero-order DDS and quick/slow DDS by various ways.

METHODSVelocity-time (v-t) equation of each mini-tablet was deduced by non-linear least square model fit. The difference of combinations in v-t profiles between theoretical value and test value was compared.

RESULTSAccording to the v-t equations, the combined release behaviors were observed directly from v-t profiles and the test values coincided with the theoretical profiles.

CONCLUSIONThe programmed DDS, which consist of a variety of mini-tablets with different dosages and combinations in capsules, could be predicted by summing up the v-t equation of each tablet.

Capsules ; Delayed-Action Preparations ; Drug Delivery Systems ; Models, Chemical ; Nifedipine ; administration & dosage ; chemistry ; Polyethylene Glycols ; administration & dosage ; chemistry ; Povidone ; administration & dosage ; analogs & derivatives ; chemistry ; Solubility ; Starch ; chemistry ; Tablets

The improving effect of electrospun drug-loaded nanofibers on the solubility of poorly water-soluble drug was investigated in the present research. Drug-loaded nanofibers were successfully prepared using electrospinning process with helicid as the poorly water-soluble model drug and polyvinylpyrrolidone K60 (PVP K60) as the filament-forming matrix. Scanning electron microscopy observation demonstrated that the nanofibers had a three-dimensional continuous web structure, and had well smooth surface and a diameter between 400-600 nm. X-ray diffraction results suggested that helicid lost its original crystal structure but highly distributed into the nanofibers in an amorphous state, resulting from the hydrogen bonding interactions between the carboxylic group of PVP K60 and the hydroxyl groups of helicid. The drug-loaded nanofibers obviously improved helicid's solubility, and were able to completely release the whole drug in 60 s. Electrospun drug-loaded nanofibers can improve the solubility and release profiles of poorly water-soluble drug.
Benzaldehydes ; administration & dosage ; chemistry ; Drug Carriers ; Drug Compounding ; Electrochemical Techniques ; methods ; Microscopy, Electron, Scanning ; Nanofibers ; chemistry ; ultrastructure ; Pharmaceutical Preparations ; chemistry ; Povidone ; chemistry ; Solubility ; Spectrophotometry, Ultraviolet ; X-Ray Diffraction

PURPOSE: The purpose of this study was to compare 1% chlorhexidine-gluconate/61% ethanol (CHG/Ethanol) emollient and 7.5% povidone-iodine (PVI) scrub for antimicrobial,residual effect, and skin condition. METHOD: CHG/Ethanol emollient hand hygiene was performed waterless, and brushless by operating doctors and nurses (N=20). PVI hand washing was performed with water and a brush (N=20) for 5 min. The subjects were asked to press their left hand in hand-shaped agar before a surgical scrub, immediately after a surgical scrub and after the operation. The amount of isolated microorganisms were calculated by counting the number of divided areas(1 X 1 cm, 160 cell) which were culture positive in the hand culture plate. The skin condition was evaluated. RESULT: The antimicrobial count of CHG/Ethanol emollient and PVI immediately post surgical scrub was 0.0 vs. 4.1 (p>.05), and after the operation was 0.1 vs. 37.8 (p>.05)respectively. The Residual effect of CHG/Ethanol emollient immediately post surgical scrub and after the operation were 0.0 vs. 0.1 (p>.05), and PVI were 4.1 vs. 37.8 (p>.05)respectively. The skin condition and satisfaction of CHG/Ethanol emollient was higher than PVI (p<.05). CONCLUSION: The antimicrobial effect between CHG/Ethanol emollient and PVI were the same. Considering skin condition, satisfaction and allergic reaction CHG/Ethanol emollient for surgical scrub is recommended in Korea.
Adult ; Anti-Infective Agents/*pharmacology ; Chlorhexidine/*analogs & derivatives/chemistry/pharmacology ; Colony Count, Microbial ; Ethanol/chemistry/*pharmacology ; Female ; Handwashing ; Humans ; Male ; Microbial Sensitivity Tests ; Povidone-Iodine/chemistry/*pharmacology

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

Oral solid rapidly-disintegrating dosage form has aroused general concern increasingly because of its characteristics about convenient taking, rapid absorption, high bioavailability and not serious adverse drug reaction. This article introduced its mechanism, which was rapid disintegration, fast dissolution or the promoting dissolving action of supplementary material. This dosage form included dispersible tablets, fast dissolving tablets, fast releasing tablets, droppills, granules and tablets by solid dispersible technology, quick-liquefying chewable tablets and dry elixir. It will become a new way for promoting bioavailability in traditional Chinese medicine difficultly-dissolving composition, create up a new dosage form for treating emergency case by traditional Chinese medicine and give a new thinking for studying new supplementary materials. In brief, oral solid rapidly-disintegrating dosage form will have good prospect in the field of traditional Chinese medicine.
Administration, Oral ; Capsules ; chemistry ; Cellulose ; Drug Delivery Systems ; Drugs, Chinese Herbal ; administration & dosage ; Polyethylene Glycols ; Porosity ; Povidone ; Solubility ; Tablets ; chemistry ; Technology, Pharmaceutical ; methods