Cranial bone regeneration with collagen type I and polyvinylpyrrolidone (Fibroquel®) combined with hyaluronic acid in Wistar rats: morphological study / Regeneración ósea craneal con colágeno tipo I y polivinilpirrolidona (Fibroquel®) combinado con ácido hialurónico en ratas Wistar: estudio morfológico

SUMMARY: The purpose of this study was to evaluate by morphological methods, if a mixture of Fibroquel® and hyaluronic acid implanted in an animal model of cranial bone injury could promote bone regeneration. 12 Wistar rats were divided in three groups, control group, bone injury without treatment and bone injury with treatment. After experimental period, bone samples were taken and stained with H & E, Masson trichrome, PAS-D, immunohistochemistry with anti-PCNA monoclonal antibody and applied a semiquantitative morphometric method. Treatment group showed extensive areas of collagen fibers in contact with normal bone tissue, areas of normal histology, PAS positive material and less cellular proliferation. We demonstrated for the first time that a mixture of Fibroquel® and hyaluronic acid implanted in an animal model of cranial bone injury promotes bone regeneration.

RESUMEN: El propósito de este estudio fue evaluar por métodos morfológicos, si una mezcla de Fibroquel® y ácido hialurónico implantado en un modelo animal de lesión del hueso craneal podría promover la regeneración ósea. Se dividieron 12 ratas Wistar en tres grupos, grupo control, lesión ósea sin tratamiento y lesión ósea con tratamiento. Después del período experimental, se tomaron muestras de hueso y se tiñeron con H & E, tricrómico de Masson, PAS-D, inmunohistoquímica con anticuerpo monoclonal anti-PCNA y se aplicó un método morfométrico semicuantitativo. El grupo de tratamiento mostró áreas extensas de fibras de colágeno en contacto con tejido óseo normal, áreas de histología normal, material PAS positivo y menor proliferación celular. Demostramos por primera vez que una mezcla de Fibroquel® y ácido hialurónico implantado en un modelo animal de lesión del hueso craneal promueve la regeneración ósea.

Comparación de la respuesta clínica a la aplicación de hilano G-F 20 y colágeno-PVP en pacientes con artrosis de rodilla / Comparison of the clinical response to the application of Hylan G-F 20 and collagen-PVP in patients with knee osteoarthritis

Resumen: Antecedentes: La osteoartritis de rodilla es una enfermedad articular caracterizada por degeneración, pérdida del cartílago y alteración del hueso subcondral asociadas a cambios en los tejidos blandos. En una muestra de 2,500 individuos se encontró una prevalencia de artrosis de 2.3% (IC 95% 1.7 a 2.9) en adultos. En nuestro hospital representa la segunda causa de consulta. Material y métodos: Se tomaron dos grupos de pacientes: el primero, de 70 pacientes a los que se les aplicó hilano G-F 20 en tres infiltraciones; al otro grupo, de 40 pacientes, se le aplicó colágeno-PVP en cuatro aplicaciones. Se les realizó un interrogatorio basado en el cuestionario de WOMAC, con el cual pudimos valorar dolor, rigidez y capacidad funcional antes y después de la aplicación de los medicamentos. Resultados: Nuestro estudio presentó que en ambos grupos hubo mejora de la calidad de vida al disminuir los síntomas tales como dolor, rigidez y limitación funcional; el colágeno fue más eficiente para la disminución del dolor y el hialino G-F 20, para la disminución de la rigidez y la limitación funcional. Conclusiones: Ambos tratamientos mostraron seguridad y eficacia. Su uso en nuestro instituto para los pacientes fuera de tratamiento quirúrgico puede disminuir de manera importante los internamientos por dolor, con lo que podemos hacer un uso más eficiente de los recursos con que contamos.

Abstract: Background: Knee osteoarthritis is a joint disease characterized by degeneration, loss of cartilage and subchondral bone alteration associated with changes in the soft tissues. In a sample of 2,500 individuals, the prevalence of osteoarthritis was found in 2.3% (IC 95% 1.7 a 2.9) in adults; it represents the second cause of consultation in our hospital. Material and methods: Two groups of patients were studied: the first included 70 patients who received hylan G-F 20 in three infiltrations; the other group, of 40 patients, received collagen-PVP in four applications. A subjective questionnaire based on the WOMAC evaluation was applied, with which we could assess pain, stiffness and functional capacity before and after the application. Results: Both hylan G-F 20 and collagen-PVP improved the quality of life of our patients by reducing symptoms such as pain, stiffness and functional limitation, collagen being more efficient for reducing pain and hylan G-F 20 for reducing stiffness and functional limitation. Conclusions: Both treatments were safe and effective; they can be used in our institute as a conservative treatment to decrease hospitalizations for pain management.

Lumbar fusion with collagen type I and polyvinylpyrrolidone in combination with autograft. An experimental study in New Zealand rabbits / Colágena tipo I y polivinilpirrolidona en combinación con autoinjerto para artrodesis lumbar. Estudio experimental en conejos de Nueva Zelanda

Abstract: Introduction: Multiple strategies have been developed looking for upgrading the consolidation rate of spine arthrodesis with autolog bone graft, but no evidence exists that adhesion with Collagen type 1 and polyvinylpyrrolidone (FibroquelMR) have application on this field. Objective: Determine if collagen type 1 + Polyvinylpyrrolidone are effective as bone enhancer in posterolateral arthrodesis on rabbits. Method: Posterolateral arthrodesis in 15 New Zealand rabbits on level L5-L6 using autolog bone graft in left side (control group) and autolog bone graft + 1 ml FibroquelMR (study group) in right side of arthrodesis. Euthanasia and block resection of lumbar segment eight weeks post surgery. Radiographic analysis, manual exploration and light microscopy of fussed segments. Results: Radiographic consolidation was observed in 80% in control group and 95% in study group, interleaved trabecular pattern with bone continuity and normal characteristics in 12 left sides and 14 right sides. Conclusion: Collagen type 1 and polyvinylpyrrolidone use is likely to have positive effect in bone consolidation process, therefore it can be recommended to use it as a bone enhancer.

Resumen: Introducción: Existen diversas estrategias para aumentar la tasa de consolidación de la artrodesis de columna en presencia de injerto óseo autólogo, sin aún comprobar si la adhesión de Colágena tipo I y polivinilpirrolidona (FibroquelMR) tienen aplicaciones en este campo. Objetivo: Determinar la efectividad de la colágena tipo I con polivinilpirrolidona como potenciador óseo en artrodesis posterolateral de conejos. Métodos: Artrodesis posterolateral en 15 conejos de Nueva Zelanda L5-L6 colocando injerto autólogo del lado izquierdo (Control) e injerto autólogo + 1 ml FibroquelMR (Estudio) en el lado derecho de la artrodesis. Eutanasia con resección en bloque del segmento lumbar a las ocho semanas del postoperatorio. Análisis radiográfico, palpación manual y por microscopia de luz de los segmentos fusionados. Resultados: Se observó consolidación radiográfica en 80% en grupo control y 93% en el estudio, continuidad ósea con patrón trabecular intercalado y hueso de características normales en 12 del lado izquierdo y 14 en el lado derecho. Conclusiones: La utilización de Colágena tipo I y polivinilpirrolidona puede tener efectos positivos en el proceso de consolidación ósea por lo que se puede recomendar su utilización como reforzador óseo.

Cytotoxicity of a new antimicrobial coating for surgical screws: an in vivo study

<p><b>INTRODUCTION</b>The risk of surgery-related infection is a persistent problem in orthopaedics and infections involving implants are particularly difficult to treat. This study explored the responses of bone and soft tissue to antimicrobial-coated screws. We investigated whether such screws, which have never been used to fix bony tissues, would result in a cytotoxic effect. We hypothesised that the coated screws would not be toxic to the bone and that the likelihood of infection would be reduced since bacteria are not able to grow on these screws.</p><p><b>METHODS</b>Titanium screws were inserted into the left supracondylar femoral regions of 16 rabbits. The screws were either uncoated (control group, n = 8) or coated with a polyvinylpyrrolidone-polyurethane interpolymer with tertiary amine functional groups (experimental group, n = 8). At Week 6, histological samples were obtained and examined. The presence of necrosis, fibrosis and inflammation in the bony tissue and the tissue surrounding the screws was recorded.</p><p><b>RESULTS</b>Live, cellular bone marrow was present in all the rabbits from the experimental group, but was replaced with connective tissue in four rabbits from the control group. Eight rabbits from the control group and two rabbits from the experimental group had necrosis in fatty bone marrow. Inflammation was observed in one rabbit from the experimental group and five rabbits from the control group.</p><p><b>CONCLUSION</b>Titanium surgical screws coated with polyvinylpyrrolidone-polyurethane interpolymer were associated with less necrosis than standard uncoated screws. The coated screws were also not associated with any cytotoxic side effect.</p>

Kinematic and spermatic recovery after selection by centrifugation in colloid solutions of ovine cryopreserved semen / Cinética e recuperação espermática após seleção por centrifugação em soluções coloidais de sêmen ovino criopreservado

Frozen and thawed ovine semen undergo morphological and functional changes that prevent or decrease the efficiency of fertilization. Sperm selection methods seek to improve the quality and viability of the fertilizing materials. Four sperm selection methods were employed, using two silica colloidal solutions coated with silane (silica colloidal-silane) or by polyvinylpyrrolidone (silica colloidal-PVP), and varying the volume of colloidal solution. Sperm kinematic and sperm recovery were evaluated by means of CASA. The protocols using silica colloidal-silane showed higher total motility (TM), progressive motility (PM) and percentage of rapid sperm (%RAP) compared to the methods employing silica colloidal-PVP and to the samples prior to sperm selection. The silica colloidal-PVP had greater sperm recovery compared to the silica colloidal-silane. Only the method using 4mL of silica colloidal-PVP was not efficient in selecting samples with better quality compared to the samples analyzed prior to sperm selection. The methods using lower volumes of colloidal solution did not differ from those using higher volumes and the best results were shown by the method with 1mL silica colloidal-silane. The results found in the study indicated greater efficiency of the silica colloidal-silane solution for sperm selection of thawed ovine semen when compared to selection using silica colloidal-PVP. The method using 1mL of silica colloidal-silane was equally efficient to the method with higher volume, presenting itself as an alternative to process samples with lower sperm concentration.(AU)

O sêmen ovino congelado e descongelado sofre alterações morfofuncionais que impossibilitam ou diminuem a eficiência na fecundação. Os métodos de seleção espermática visam melhorar a qualidade e a viabilidade do material fecundante. Foram utilizados quatro métodos de seleção espermática utilizando duas soluções de sílica coloidal revestida por silano (sílica coloidal-silano) ou por polivinilpirrolidona (sílica coloidal-PVP), variando o volume de solução coloidal. Foram testadas a cinética espermática no CASA e a recuperação espermática. Os protocolos utilizando sílica coloidal-silano apresentaram maior motilidade total (MT), motilidade progressiva (MP) e porcentagem de espermatozoides rápidos (% RAP) quando comparados aos métodos utilizando a sílica coloidal-PVP e às amostras antes da seleção espermática. A sílica coloidal-PVP teve maior recuperação espermática quando comparada à sílica coloidal-silano. Somente o método utilizando 4mL de sílica coloidal-PVP não foi eficiente na seleção de amostras com melhor qualidade quando comparado às amostras analisadas antes da seleção espermática. Os métodos utilizando menores volumes de solução coloidal não diferiram dos métodos de maior volume, sendo a sílica coloidal-silano com 1mL o método que apresentou os melhores resultados. Como conclusão, os resultados encontrados no trabalho apontaram a maior eficiência da sílica coloidal-silano em selecionar sêmen ovino congelado e descongelado quando comparado à seleção em sílica coloidal-PVP. O método utilizando 1mL de sílica coloidal-silano foi igualmente eficiente ao método com maior volume, sendo uma alternativa para processar amostras com baixa concentração espermática.(AU)

Morphological changes in experimental tuberculosis resulting from treatment with quercetin and polyvinylpyrrolidone

Research objective: Morphological study of tissue necrosis stages in experimental organpreserving tuberculosis pharmacotherapy using Quercetin and Polyvinylpyrrolidone [QP]

Background and methods: 32 laboratory mice of C57BL/6JLacSto strain were used in the experiment. The animals were divided into five groups, six to seven mice in each: group1- Mycobacterium tuberculosis [MBT] uninfected mice; group 2- MBT infected mice; group 3- MBT infected and treated with antituberculosis preparation [ATP]; group 4- MBT infected and QP treated; group 5- MBT infected and treated with ATP and QP. The mice were infected through caudal vein injection with MTB H37Rv strain. The preparation QP, which belongs to the capillary-stabilizing-remedy group, was used for the research. The ATP were izoniazid and streptomycin

Results: QP produced a strict delineation of caseous necrosis from the unaffected parts of the connective tissue with fibrosis in the center and a large number of Langerhans cells, which was not observed in the control groups without QP. The combination of QP and ATP had more pronounced effects. In MBT-infected mice, where QP was not used, unlike the group where QP was used, adipose dystrophy of hepatocytes was observed. Thus, the hepatoprotective effect of QP against TB can be suggested

Conclusion: QP produces a clear delineation of caseous necrosis from an uninfected tissue by connective-tissue formation, and by forming fibrotic tissue in the center of epithelioid cells that prevents further TB dissemination by enhancing TB pharmacotherapy

Preparation and physicochemical characterization of a solid dispersion of (3, 5, 6-trimethylpyrazin-2-yl) methyl 3-methoxy-4-(3, 5, 6-trimethylpyrazin-2-yl) methoxy benzoate (VA-T) and polyvinylpyrrolidone / 中国天然药物

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.

Effect of metal primers and tarnish treatment on bonding between dental alloys and veneer resin

PURPOSE: The aim of this study was to evaluate the effect of metal primers on the bonding of dental alloys and veneer resin. Polyvinylpyrrolidone solution's tarnish effect on bonding strength was also investigated. MATERIALS AND METHODS: Disk-shape metal specimens (diameter 8 mm, thickness 1.5 mm) were made from 3 kinds of alloy (Co-Cr, Ti and Au-Ag-Pd alloy) and divided into 4 groups per each alloy. Half specimens (n=12 per group) in tarnished group were immersed into polyvinylpyrrolidone solution for 24 hours. In Co-Cr and Ti-alloy, Alloy Primer (MDP + VBATDT) and MAC-Bond II (MAC-10) were applied, while Alloy Primer and V-Primer (VBATDT) were applied to Au-Ag-Pd alloys. After surface treatment, veneering composite resin were applied and shear bond strength test were conducted. RESULTS: Alloy Primer showed higher shear bond strength than MAC-Bond II in Co-Cr alloys and Au-Ag-Pd alloy (P<.05). However, in Ti alloy, there was no significant difference between Alloy Primer and MAC-Bond II. Tarnished Co-Cr and Au-Ag-Pd alloy surfaces presented significantly decreased shear bond strength. CONCLUSION: Combined use of MDP and VBATDT were effective in bonding of the resin to Co-Cr and Au-Ag-Pd alloy. Tarnish using polyvinylpyrrolidone solution negatively affected on the bonding of veneer resin to Co-Cr and Au-Ag-Pd alloys.

Cryopreservation of Human Wharton's Jelly-derived Mesenchymal Stem Cells Following Controlled Rate Freezing Protocol Using Different Cryoprotectants; A Comparative Study

OBJECTIVES: To compare the effect of three different cryoprotectants on basic stem cell characteristics for the possibility of using well defined, dimethyl sulfoxide (DMSO) and serum free freezing solutions to cryopreserve human Wharton's jelly-derived mesenchymal stem cells (WJMSCs) following controlled rate freezing protocol. METHODS: The mesenchymal stem cells isolated from human Wharton's jelly were cryopreserved using 10% DMSO, 10% polyvinylpyrrolidone (PVP) and a cocktail solution comprising of 0.05 M glucose, 0.05 M sucrose and 1.5 M ethylene glycol following controlled rate freezing protocol. We investigated the post-thaw cell viability, morphology, proliferation capacity, basic stem cell characteristics, in vitro differentiation potential and apoptosis-related gene expression profile before and after cryopreservation. RESULTS: The cryoprotectant 10% DMSO has shown higher post-thaw cell viability of 81.2+/-0.58% whereas 10% PVP and cocktail solution have shown 62.87+/-0.35% and 72.2+/-0.23%, respectively at 0 h immediately thawing. The cell viability was further reduced in all the cryopreserved groups at 24 h later post-thaw culture. Further, the complete elimination of FBS in cryoprotectants has resulted in drastic reduction in cell viability. Cryopreservation did not alter the basic stem cell characteristics, plasticity and multipotency except proliferation rate. The expression of pro-apoptotic BAX and p53 genes were higher whilst p21 was lower in all the cryopreserved groups when compare to the control group of WJMSCs. CONCLUSION: Although 10% DMSO has shown higher post-thaw cell viability compare to 10% PVP and cocktail solution, the present study indicates the feasibility of developing a well-defined DMSO free cryosolution which can improve storage and future broad range applications of WJMSCs in regenerative medicine without losing their basic stem cell characteristics.

Size Control of 99mTc-tin Colloid Using PVP and Buffer Solution for Sentinel Lymph Node Detection

Colloidal particle size is an important characteristic that allows mapping sentinel nodes in lymphoscintigraphy. This investigation aimed to introduce different ways of making a 99mTc-tin colloid with a size of tens of nanometers. All agents, tin fluoride, sodium fluoride, poloxamer-188, and polyvinylpyrrolidone (PVP), were mixed and labeled with 99mTc. Either phosphate or sodium bicarbonate buffers were used to adjust the pH levels. When the buffers were added, the size of the colloids increased. However, as the PVP continued to increase, the size of the colloids was controlled to within tens of nanometers. In all samples, phosphate buffer added PVP (30 mg) stabilized tin colloid (99mTc-PPTC-30) and sodium bicarbonate solution added PVP (50 mg) stabilized tin colloid (99mTc-BPTC-50) were chosen for in vitro and in vivo studies. 99mTc-BPTC-50 (100 nm) mainly accumulated in the liver. When a rabbit was given a toe injection, the node uptake of 99mTc-PPTC-30 decreased over time, while 99mTc-BPTC-50 increased. Therefore, 99mTc-BPTC-50 could be a good candidate radiopharmaceutical for sentinel node detection. The significance of this study is that nano-sized tin colloid can be made very easily and quickly by PVP.

Simultaneous separation of primary cardiomyocytes and cardiac fibroblasts from neonatal rats with density gradient centrifugation / 生理学报

To improve a fast and high-quality isolation method for culturing the primary cardiomyocyte and fibroblast in vitro, the neonatal Wistar rats were decapitated accordingly and left ventricles were isolated under the sterile condition. The ventricles were chopped and digested in the enzyme solution containing 0.5 mg/mL type II collagenase. During this process, the digesting time, frequency and stirring speed, centrifuging frequency and speed were strictly controlled. The cardiomyocytes were separated from the cardiac fibroblast by using the Percoll density gradient centrifugation. The cell viability was tested by staining with 0.2% trypan blue. The purity of cardiomyocytes and fibroblasts were determined by immunoflourescent staining with anti-cTnI, anti-Vimentin and anti-α-SMA antibodies. The results indicated that with this protocol, the viability and purity of cardiomyocytes were 92% and 95%. The automobile pulse of the adhered cardiomyocyte was visible. For fibroblasts, the cell viability and purity were 96% and 94%. Our results demonstrate that this advanced isolation method is reproducible, and can simultaneously produce high-quality primary cardiomyocytes and fibroblasts for the future study.

pH-sensitive polyvinylpyrrolidone-acrylic acid hydrogels: Impact of material parameters on swelling and drug release

In this study, we fabricated pH-sensitive polyvinylpyrrolidone/acrylic acid (PVP/AA) hydrogels by a free-radical polymerisation method with variation in the content of monomer, polymer and cross-linking agent. Swelling was performed in USP phosphate buffer solutions of pH 1.2, 5.5, 6.5 and 7.5 with constant ionic strength. Network structure was evaluated by different parameters and FTIR confirmed the formation of cross-linked hydrogels. X-ray crystallography showed molecular dispersion of tramadol HCl. A drug release study was carried out in phosphate buffer solutions of pH 1.2, 5.5 and 7.5 for selected samples. It was observed that swelling and drug release from hydrogels can be modified by changing composition and degree of cross-linking of the hydrogels under investigation. Swelling coefficient was high at higher pH values except for the one containing high PVP content. Drug release increased by increasing the pH of the medium and AA contents in hydrogels while increasing the concentration of cross-linking agent had the opposite effect. Analysis of the drug release mechanism revealed non-Fickian transport of tramadol from the hydrogels.

Nesse estudo, preparamos hidrogéis de polivinilpirrolidona/ácido acrílico(PVP/AA), sensíveis ao pH, por meio de método de polimerização de radical livre, com variações no conteúdo de monômero, de polímero e de agente de ligação cruzada. O inchamento foi realizado em soluções tampão fosfato USP pH 1,2, 5,5, 6,5 e 7,5, com força iônica constante. A estrutura reticular foi avaliada por diferentes parâmetros e o FTIR confirmou a formação de hidrogéis de ligação cruzada. A cristalografia de raios X mostrou dispersão molecular do cloridrato de tramadol. Realizou-se estudo de liberação do fármaco em soluções tampão fosfato pH 1,2, 5,5 e 7,5 para amostras selecionadas. Observou-se que o inchamento e a liberação do fármaco dos hidrogéis podem ser modificados mudando-se a composição e o grau de ligação cruzada dos hidrogéis em estudo. O coeficiente de inchamento foi alto em pH mais altos, exceto para um deles com alto conteúdo de PVP. A liberação do fármaco aumentou com o aumento do pH do meio e do conteúdo em AA nos hidrogéis, enquanto que o aumento na concentração do agente de ligação cruzada apresentou efeito oposto. A análise do mecanismo de liberação do fármaco revelou transporte não Fickiano do tramadol dos hidrogéis.

Comparison of different methods for total RNA extraction from sclerotia of Rhizoctonia solani

Background Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) is one of the most important pathogens of rice (Oryza sativa L.) that causes severe yield losses in all rice-growing regions. Sclerotia, formed from the aggregation of hyphae, are important structures in the life cycles of R. solani and contain a large quantity of polysaccharides, lipids, proteins and pigments. In order to extract high-quality total RNA from the sclerotia of R. solani, five methods, including E.Z.N.A.™ Fungal RNA Kit, sodium dodecyl sulfate (SDS)-sodium borate, SDS-polyvinylpyrrolidone (PVP), guanidinium thiocyanate (GTC) and modified Trizol, were compared in this study. Results The electrophoresis results showed that it failed to extract total RNA from the sclerotia using modified Trizol method, whereas it could extract total RNA from the sclerotia using other four methods. Further experiments confirmed that the total RNA extracted using SDS-sodium borate, SDS-PVP and E.Z.N.A.™ Fungal RNA Kit methods could be used for RT-PCR of the specific amplification of GAPDH gene fragments, and that extracted using GTC method did not fulfill the requirement for above-mentioned RT-PCR experiment. Conclusion It is concluded that SDS-sodium borate and SDS-PVP methods were the better ones for the extraction of high-quality total RNA that could be used for future gene cloning and expression studies, whereas E.Z.N.A.™ Fungal RNA Kit was not taken into consideration when deal with a large quantity of samples because it is expensive and relatively low yield.

In vitro dissolution and physicochemical characterizations of novel PVP-based solid dispersions containing valsartan prepared by a freeze-drying method

Valsartan [VAL] shows poor oral bioavailability mainly as a result of its low water solubility at low pH. This study is designed to investigate the dissolution properties and physicochemical characteristics of novel PVP-based solid dispersions [SDs] containing VAL. The SDs were prepared with polyvinylpyrrolidone [PVP-K30] as a hydrophilic polymer, sodium hydroxide [NaOH] as an alkalizer, and poloxamer 188 [F68] as a surfactant, without using any organic solvents by a freeze-drying method. The dissolution study was carried out and the physicochemical properties of SDs were also characterized by using differential scanning calorimetry [DSC], fourier transform-infrared [FT-IR] spectroscopy, X-ray diffractometry [XRD] and scanning electron microscopy [SEM]. The dissolution rates of SDs were significantly improved at pH 1.2 and pH 6.8 compared to that of pure drug. The results of physicochemical properties suggested that some interactions between VAL and carriers had occurred in the molecular level and the drug presented in the SDs was amorphous. It was concluded that the novel PVP-based SDs has been successfully prepared by a freeze-drying method, resulting in significant dissolution improvement of VAL

The rheology properties of common hydrophilic gel excipients / 药学学报

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.

Comparison of Wettability for Ocular Prosthesis Depending on Different Kinds of Artificial Tear Eye Drops

PURPOSE: In this study we compared the surface wettability of ocular prosthesis and depositions depending on different types of artificial tear eye drops. METHODS: The artificial tear eye drops contain sodium hyaluronate (HA) 0.1%, 0.18%, 0.3%, carboxylmethylcellulose sodium (CMC), hydroxymethylcelluose + dextran (HMC), propylene glycol + polyethylene glycol (PG), polysorbate 80 (PS) povidone (Pov) were evaluated. Flat rectangular parallelepiped blocks consisting of polymethylmethacrylate (PMMA) or silicone materials were made. One artificial tear eye drop was applied on the surface of two different blocks of artificial eyes using a 23-gauge needle. Then, the static method contact angle was measured by using a contact angle goniometer. To measure the deposits, a petri dish was covered with 3 mL of artificial tear eye drops and dried for 48 hours at room temperature. Then, the light transmittance at the center of the petri dish was measured to investigate the amount of the residue. RESULTS: The contact angles of HA 0.1%, 0.18%, 0.3%, CMC, HMC, PG, PS and Pov on PMMA were 78.69degrees, 84.29degrees, 75.46degrees, 80.93degrees, 66.29degrees, 71.26degrees, 58.40degrees and 70.24degrees, respectively. The contact angles on silicone were 53.68degrees, 60.87degrees, 64.46degrees, 62.78degrees, 38.89degrees, 63.58degrees, 30.68degrees and 51.41degrees, respectively. The largest decrease in transparency was observed in the artificial tear eye drops containing HMC. CONCLUSIONS: The wettability and deposits on the surface of ocular prosthesis can vary based on the components and concentration of artificial tear eye drops. The results from this study should be considered when choosing the right artificial tear eye drops for improving dry eye symptoms in patients wearing ocular prostheses.

Comparison of Wettability for Ocular Prosthesis Depending on Different Kinds of Artificial Tear Eye Drops

PURPOSE: In this study we compared the surface wettability of ocular prosthesis and depositions depending on different types of artificial tear eye drops. METHODS: The artificial tear eye drops contain sodium hyaluronate (HA) 0.1%, 0.18%, 0.3%, carboxylmethylcellulose sodium (CMC), hydroxymethylcelluose + dextran (HMC), propylene glycol + polyethylene glycol (PG), polysorbate 80 (PS) povidone (Pov) were evaluated. Flat rectangular parallelepiped blocks consisting of polymethylmethacrylate (PMMA) or silicone materials were made. One artificial tear eye drop was applied on the surface of two different blocks of artificial eyes using a 23-gauge needle. Then, the static method contact angle was measured by using a contact angle goniometer. To measure the deposits, a petri dish was covered with 3 mL of artificial tear eye drops and dried for 48 hours at room temperature. Then, the light transmittance at the center of the petri dish was measured to investigate the amount of the residue. RESULTS: The contact angles of HA 0.1%, 0.18%, 0.3%, CMC, HMC, PG, PS and Pov on PMMA were 78.69degrees, 84.29degrees, 75.46degrees, 80.93degrees, 66.29degrees, 71.26degrees, 58.40degrees and 70.24degrees, respectively. The contact angles on silicone were 53.68degrees, 60.87degrees, 64.46degrees, 62.78degrees, 38.89degrees, 63.58degrees, 30.68degrees and 51.41degrees, respectively. The largest decrease in transparency was observed in the artificial tear eye drops containing HMC. CONCLUSIONS: The wettability and deposits on the surface of ocular prosthesis can vary based on the components and concentration of artificial tear eye drops. The results from this study should be considered when choosing the right artificial tear eye drops for improving dry eye symptoms in patients wearing ocular prostheses.

Preparation, characterization and tableting of cilnidipine solid dispersions

Solid dispersion technique has been developed many years for improving solubility of water-insoluble drugs, aiming to achieve a better oral bioavailability. However, this technique exhibits many inconveniences when used for large-scale tableting procedures. The objective of current research work was to develop cilnidipine solid dispersions [SDs] to improve the dissolution behaviors of this water-insoluble drug. Moreover, an innovative granulation method was designed to simplify the traditional tableting technology used in solid dispersion technique. Three different kinds of polymers, polyethylene glycol [PEG], polyvinylpyrrolidone [PVP] and poloxamer, were used as carriers to prepare solid dispersions. The interactions in the solid state were characterized by differential scanning calorimetry [DSC], powder Xray diffraction [PXRD] and FT-IR spectroscopy. The designed granulation method was employed to prepare solid dispersion tablets and the formulation was optimized through investigating the dissolution behaviors. The results indicated PEG solid dispersion showed the best effect both on physical characterizations and dissolution studies. Furthermore, all type of solid dispersions significantly improved the dissolution rates when compared to pure drug and its corresponding physical mixture [PM]. The solid dispersion tablets prepared in simplified tableting method exhibited better operability, stability and dissolution behavior than the tablets prepared in traditional ways, which brought more opportunities to solid dispersion technique for industrial production

Preparation and application on compound excipient of sodium stearyl fumarate and plasdone S-630 / 药学学报

The compound excipient containing sodium stearyl fumarate and plasdone S-630 was prepared by applying spray drying method. The basic physical properties of compound excipient were studied by solubility test, scanning electron microscope, differential scanning calorimeter, X-ray diffraction and Fourier transform infra-red spectroscopy. The effect of compound excipient on moisture absorption and ferulic acid in vitro dissolution of spray drying power of angelica were investigated. The results showed that the chemical constituents of compound excipient did not change before and after spray drying. The water soluble compound excipient can improve significantly moisture absorption and has application prospect.

Evaluación reológica de dos polímeros derivados de la polivinilpirrolidona para uso oftálmico / Reological evaluation of two polymers derived from polyvinylpirrolidone for ophtalmological uses

Introducción: los kollidones K-12 PF y K-17 PF, al igual que el polímero hidrofílico derivado de la celulosa, hidroxipropilmetilcelulosa F4M, podrían ser parte de futuras formulaciones oftálmicas, que proporcionen una adecuada liberación del fármaco desde el sitio de aplicación para logar un mejor efecto terapéutico en la zona ocular. Objetivo: evaluar desde el punto de vista reológico los polímeros K-12 PF y K-17 PF y compararlos con los resultados obtenidos con la hidroxipropilmetilcelulosa F4M, estableciendo a su vez, parámetros de calidad y de vida útil adecuados a las futuras formulaciones farmacéuticas que contengan estos polímeros. Métodos: se determinó la viscosidad para cada una de las disoluciones de polímero. Con los resultados de la viscosidad se realizó un análisis de varianza de clasificación doble, efecto fijo, con tres observaciones por casilla, empleando la prueba de Bartlett, para diferenciar los tratamientos térmicos a los que se conservaron las disoluciones. Resultados: se obtuvieron por representación gráfica las curvas de mejor ajuste para cada polímero y a su vez la tendencia de flujo, las cuales resultaron similares a los fluidos newtonianos. Conclusiones: los resultados muestran que para alcanzar el valor de viscosidad del patrón de hidroxipropilmetilcelulosa F4M, con los kollidones, es necesario añadir grandes cantidades de estos últimos. Además, los kollidones evaluados mostraron excelentes velocidades de disolución sin requerir tratamiento térmico.

Introduction: like the hydrophilic polymer from cellulose called hydroxypropylmethylcellulose F4M, kollidons K-12 PF and K-17 PF could be included in the future eye formulations that will provide adequate drug release from the site of administration and better therapeutic effect in the ocular zone. Objective: to reologically evaluate polymers K-12 PF and K-17 PF, to compare them with the results of hydroxypropylmethylcellulose F4M and to set quality and useful lifetime parameters fit for the future drug formulations having these polymers. Methods: the viscosity of dissolution of each polymer was determined to make a variance analysis of double classification, fixed effect, with three observations per box. Barlett´s test served to identify the heat treatments that preserved the dissolutions. Results: the best fit curves for each polymer were shown in graphs and also the flow tendencies which were similar to those of Newton´s fluids. Conclusions: the results yielded that great quantities of kollidons are required to reach the viscosity of the hydroxypropylmethylcellulose F4M pattern. Additionally, the evaluated kollidons showed excellent dissolution speeds without using any heat treatment whatsoever.