Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Spray drying”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,531 records · Page 85Linked to original sources
PubMed2002

Manufacture of slow-release matrix granules by wet granulation with an aqueous dispersion of quaternary poly(meth)acrylates in the fluidized bed.

Slow-release matrix granules were manufactured in the fluidized bed using an aqueous dispersion of quaternary poly(meth)acrylates (Eudragit RS 30 D) as binder for granulation. A factorial design was carried out to investigate the influence of the following parameters, spraying rate, applied polymer amount, and inlet air temperature, on various granule properties. Prerequisites for a slow release of the model drug theophylline are high spraying rate, high amount of polymer, and low inlet air temperature. No considerable decrease of the drug release rate can be achieved without a subsequent curing of the dry granules. A clear correlation exists between the moisture content of the fluidized bed, indicated by the terminal moisture content (TMC), and the mean dissolution time for 80% of the drug (MDT80).

Delayed-Action Preparations↗
PubMed2004

Management practices from questionnaire surveys in herds with very low somatic cell score through a national mastitis program in France.

French dairy herds (n = 534) were enrolled in the National 'Zero Mastitis Objective' Program to highlight management practices characterizing very low somatic cell score (SCS) herds. The herds studied were stratified into 2 groups. The first group (LOW) included herds within the first 5 percentiles and the second group (MED) herds within the 50 to 55 percentiles of herds on the basis of mean SCS for the 36 mo preceding the program. Potential explanatory variables, collected through questionnaire surveys, were analyzed using multistep logistic regression models. Twenty-six variables were significant factors in the final models, in which 18 were considered as primary factors for very low SCS. The probability for a herd belonging to the LOW group was associated with: (1) regular use of teat spraying; (2) herdsman precise in his techniques; (3) less than 1 person-year used at activities other than dairy herd; (4) teat dipping after mammary infusion at dry off; (5) heifers kept in a calving pen around parturition; (6) cows locked in feed-line lockups after milking; (7) dry cows with prepartum Ca restriction; (8) heifers on a nondamp pasture; (9) cows culled when at least one damaged teat; (10) heifers at pasture not drinking water from a river; and (11) disinfecting teat ends with alcohol before intramammary infusion at dry off. The probability for a herd belonging to the MED group was associated with: (1) milking cows housed in a straw yard; (2) checking heifers for mastitis only beginning at 2-wk prepartum; (3) no mastitis treatment when at least one clot was observed in milk at successive milkings; (4) distance of herdsman's house to cowshed >300 m; (5) only dirty teats washed before milking; (6) free access of cows from pasture to cowshed during bad weather; and (7) more than 18% of spring calvings. The variables associated with very low SCS should be applied as part of a thorough mastitis-control program adapted to each herd.

Animal Husbandry↗
PubMed1990

Effect of water isolation and early finishing on hardness of glass ionomer cements.

Glass ionomer cements have the disadvantage of being vulnerable to moisture. We would like to overcome this problem by clinical procedures. Three glass ionomer cements were tested in vitro with the goal of protecting these materials from moisture during clinical operations. To observe the effectiveness of various surface protective measures, we divided each cement sample into six groups, each of which underwent 24-hour surface treatment. The first group was a control where the cement was covered with a glass slab for 24 hours. The remaining five groups were subjected to no treatment or treatment with varnish, cocoa butter, Teethmate-A, or Ketac-Glaze. Two additional groups were prepared for comparison of early finishing with and without water spray. When the Vickers hardness number (HVN) for each sample was measured at 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, and 40 days, it tended to increase after 24 hours, reaching a maximum value at different times with different cements. Analysis of variance revealed that during the first few days the hardness of the control was significantly different from that without treatment or with treatment by varnish or cocoa butter. However, treatment with Teethmate-A or Ketac-Glaze produced results close to those for the control. Significant differences in hardness during the first few days were noted when early finishing was carried out under wet and dry conditions. These findings indicate that a light-cured unfilled resin should be applied to the surface of glass ionomer cement immediately after the initial set to allow complete setting without interference by oral fluids. Also, water spray should be avoided during contouring of the cements if they have not fully hardened.

Glass Ionomer Cements↗
PubMed2001

Ultrasonic nebulization system for respiratory drug delivery.

An ultrasonic spray system was tested for the production of aerosols for ultimate use in the respiratory delivery of drug to animals. A Sono-Tek ultrasonic spray system was mounted on top of a baffle to entrain aerosol particles within the carrier gas. Solvent was removed from the aerosol cloud by passing the droplets through drying columns composed of either charcoal or silica. The efficiency of removing ethanol and water were determined by measuring the outflow concentrations. Sodium fluorescein and sodium cromolyn dissolved in water were tested, and the effect of the liquid flow rate and drug concentration entering the atomizer on the output, and particle size distribution, were determined by the filter capture method, and by cascade impactor, respectively. Similar studies were conducted with budesonide and indomethacin dissolved in ethanol. The theoretical count median size distribution was calculated and compared with the experimental values calculated from the observed mass median aerodynamic diameter. The output rate expressed as the mass of aerosol collected in unit time increased nearly proportionately with the liquid flow rate (0.18-0.7 ml/min) and with the concentration of drug (0.19-12 mg/ml) entering the nebulizer. The mean particle size increased with solute concentration, but not by liquid flow rate. The calculated count median diameters were dependent on the type of solvent, but were independent of solute. At the high dose of cromolyn, there was very good agreement between the theoretical and observed. At lower doses, the observed size was larger than predicted, which was also true for the ethanol soluble solutes. The system has the potential of providing a wide range of dose levels for testing of drug delivery to animals including high doses with a controlled and relatively narrow particle size distribution.

Administration, Inhalation↗
PubMed2006

Auxin-enhanced root growth for phytoremediation of sewage-sludge amended soil.

A technology to increase root growth would be advantageous for phytoremediation of trace metal polluted soil, because more roots would be available for metal uptake. The objective of this study was to determine if the auxin, indole-3-acetic acid (IAA), would increase root growth in soil with metals from sewage sludge, when the tetrasodium salt of the chelate EDTA (ethylenediamine-tetraacetic acid) was added to solubilize the metals. Sunflower (Helianthus annuus L.) plants grew in large pots containing either soil from a sludge farm or composted sludge. The EDTA salt was added at a rate of 1 g kg(-1) soil 37 days after planting. IAA at the rate of 3 or 6 mg l(-1) was sprayed on the leaves (500 ml) and added to the soil (500 ml) three times: 41, 50, and 74 days after planting. At harvest 98 days after planting, oven-dry weights were measured, and plant organs were analyzed for Cd, Cu, Fe, Mn, Ni, Pb, and Zn. Metal uptake was determined as the product of metal concentration in an organ and weight. IAA increased root growth of plants grown in the soil with sludge when no EDTA was present. With no EDTA, Mn and Ni in leaves of plants grown in the soil were higher at 3 and 6 mg l(-1) IAA compared to 0 mg l(-1) IAA. With and without EDTA, Cd and Pb in leaves of plants grown in the compost were higher with 3 and 6 mg l(-1) IAA compared to 0 mg l(-1) IAA.

Biodegradation, Environmental↗
PubMed2003

Coating of pellets with micronized ethylcellulose particles by a dry powder coating technique.

Pellets were coated with ethylcellulose powder to achieve extended release. The film forming ability of ethylcellulose powder and the effect of formulation factors (plasticizer type and concentration) and curing conditions (curing temperature and time) were investigated. The coating formulation was divided into two components consisting of a powder mixture (polymer plus talc) and a mixture of liquid materials (plasticizer plus binder solution), which were sprayed separately into the coating chamber of a fluidized bed coater (Glatt GPCG-1, Wurster insert). The coated pellets were oven-cured under different conditions (60-80 degrees C, 2-24 h) without and with humidity (100% relative humidity). Propranolol hydrochloride was used as a model drug, and drug release was studied in 0.1 N HCl at 37 degrees C (USP XXV paddle method). Despite the high glass transition temperature of ethylcellulose (133.4 degrees C), micronized ethylcellulose powder can be used for dry powder coating by adjusting the coating temperature, amount and type of plasticizer applied, and curing conditions. 40% plasticizer and a curing step (80 degrees C, 24 h) were required to achieve complete coalescence of the polymer particles and extended drug release of coated pellets. Although ethylcellulose-coated pellets had an uneven surface, extended drug release could be obtained with coating level of 15%. Because of its high glass transition temperature, ethylcellulose-coated pellets showed unchanged drug release profiles upon storage at room temperature for 3 years.

Cellulose↗
PubMed1984

The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep. 1. Voluntary intake.

Voluntary intake was determined with vegetative Lotus pedunculatus cut and fed fresh to growing sheep of 42-46 kg live weight. Effects attributable to condensed tannins were assessed by growing the plant under high and low levels of soil fertility, inducing low and high concentrations of tannin (Expt 1), or by binding the tannins through spraying the herbage with polyethylene glycol (molecular weight 3350, PEG; Expt 2). Primary-growth lotus was used in Expt 1 and secondary-growth lotus in Expt 2. Concentrations of total and free condensed tannin were determined in fresh lotus, free tanning being defined as that not bound by mascerates of the plant. In Expt 1 the herbages fed contained respectively 46 and 106 g total condensed tannin/kg dry matter (DM) and 3 and 14 g free condensed tannin/kg DM. Mean metabolizable energy (ME) intakes were 0.89 and 0.77 MJ/kg live weight0 .75 per d (P less than 0.05) respectively. The lotus used in Expt 2 contained 63 and 5 g total reactive condensed tannin and free condensed tannin/kg DM respectively. After spraying with PEG at 2.4 g/g total condensed tannin, these values were reduced to 7 and 0.5 g/kg DM respectively. PEG addition increased apparent digestibility (proportion of each nutrient ingested) of cellulose, hemicellulose and nitrogen by 0.05, 0.08 and 0.26, and increased ME intake from 0.48 to 0.69 MJ/kg live weight0 .75 per d. It was concluded that high concentrations of condensed tannins depressed ME intake, due to depressions in both the voluntary intake and digestion of organic matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed2005

Effect of embedded metal compound on porosity of silica colloids prepared by spray reaction of silicon tetrachloride.

Attempts to prepare macroporous silica particles and metal-compound-nanoparticle-embedded silica microspheres were carried out using reactions between silicon tetrachloride and ultrasonic generating microdroplets including metal (Na, K, Al, Ni, Ti, Pt) compounds. Samples were collected by dry and wet processes. In the case of using nickel and aluminum compounds, acid-treated samples were also prepared. The obtained samples were characterized by scanning electron microscopy, X-ray fluorescence spectroscopy, powder X-ray diffractometry, mercury porosimetry, and the nitrogen adsorption method. The macroporous silica particles were prepared by removing the salt crystals, such as NaCl and KCl, formed in the silica frame. For acid-resistant metals, platinum- and titanium-compound nanoparticles are easily embedded in silica microspheres using these metal-compound solutions. For acid-soluble metals, aluminum- and nickel-compound-nanoparticle-embedded silicas were prepared by applying neutralization of the collection water. Micropores and mesopores were produced in wet-process samples. Acid treatment induced the increase of micropore volumes.

Journal Article↗
PubMed1989

Cutaneous absorption and decontamination of [3H]T-2 toxin in the rat model.

Cutaneous absorption and decontamination of [3H]T-2 mycotoxin using various treatment modalities incorporating water, detergent, sprays, and scrubbing of application sites were examined in the rat model at 5, 30, 60, and 1440 min (24 h) postexposure. Rats were killed immediately after treatment and radiolabeled T-2 remaining in full-thickness skin samples were determined. Absorption and decontamination were followed over time, and decontaminating treatment modalities were evaluated for efficacy. Less than 1% of the applied dose was absorbed in 5 min, and 50% was absorbed in 24 h. At 5 min, 99.5 +/- 0.05% of nonabsorbed (residual) [3H]T-2 was removed, and 58 +/- 5.2% of residual toxin was removed at 24 h with a 2.5% detergent/water spray. When treatment modalities were evaluated at 60 min, a 2.5% detergent/water scrub followed by a detergent/water spray produced optimal decontamination by removing 81 +/- 2.2% of residual toxin. All treatment modalities using detergent and/or water removed significant amounts of toxin (p less than or equal to .0001); a dry scrub was not efficacious. Treatment should be initiated as soon as possible after exposure for best results. However, the stratum corneum acts as a reservoir for the toxin, and decontamination should be carried out even if delayed several hours or days after exposure. Dermal absorption pharmacokinetics found in these studies are similar to those described for other low-molecular-weight compounds, and the decontamination results from T-2 toxin should be applicable to other, similar toxic substances.

Animals↗
PubMed1988

A rapid and sensitive microassay for bacterial collagenase and other proteolytic activities on collagenous substrates.

Many of the common substrate digestion assays have the disadvantage of being tedious and expensive, thus aggravating serial determinations of collagenase activity. In the assay presented here, the proteolytic reaction proceeds on a sheet of chromatographic paper bearing spots of dried gelatin or collagen solutions. After application of the enzyme sample, the sheets are incubated in a water-saturated atmosphere for 45 min and the reaction products are visualized by spraying with chromatographic, ninhydrin-containing peptide reagents. By its specific yellow staining, the activity of bacterial collagenase can be discriminated from the gray, brown, red, or violet spots which are produced by eight tested noncollagenolytic proteases. The detection limit for collagenase activity reaches down to 0.002 U in a sample volume of 1-2 microliters dropped onto a spot of 25 microliters gelatin solution (3%), thus corresponding with the sensitivity of a conventional radioassay. The sensitivity for noncollagenolytic proteases is better than 2 ng per sample, herewith exceeding a common casein-agar diffusion test. The method is also evaluated for native collagen. Within 1.5 h, 100 samples can be assayed. An example for the application in a collagenase purification step (ion exchange chromatography) is also presented.

Bacteria↗
PubMed2005

An in vitro evaluation of microleakage in class I preparations using 5th, 6th and 7th generation composite bonding agents.

The intent of this study was to evaluate microleakage of newer generations of dentinal bonding systems of Class I restorations filled with the same resin based composites. Eighty extracted human premolar and molar teeth were randomly assigned to four groups for bonding: the 5th generation bonding system (Optibond Solo), the 6th generation bonding system (Prompt-L-Pop) and the 7th generation bonding system (iBond), and a control group that was used with no dentinal bonding system. Cavities were prepared 3 mm in width, 2 mm in depth and 2 mm in length. Margins of the cavities were chamfered using a high-speed hand piece with water spray and a #1/2 round diamond bur. The cavities were restored with resin based composites after the application of the dentinal bonding systems according to the instructions of the manufacturer. Upon drying of the teeth, two coats of nail varnish were applied covering the surface of the tooth, excluding the tooth-restoration interface. Samples were thermocycled and immersed in methylene blue dye (0.05%). Each sample was sectioned with an Isomet and evaluated, for microleakage using light microscopy under a measuring microscope at 50x magnification Statitical significance was determined using the Chi-Square Test. Among the three dentinal adhesive systems used in this study the 5th generation outperformed both the 6th and 7th generation bonding systems.

Acrylic Resins↗
PubMed2002

Freeze-dried bone for maxillary sinus augmentation in sheep. Part II: biomechanical findings.

This study examines the biomechanical loading capacity of dental implants placed in the posterior maxilla in conjunction with subantral augmentation with either homogeneous demineralized freeze-dried bone from sheep (s-DFDB) or heterogeneous demineralized freeze-dried human bone (h-DFDB) as grafting material in sheep. In 36 adult female mountain sheep, the Schneiderian membrane was elevated extraorally in both maxillary sinuses, and two titanium plasma-flame-sprayed cylindrical implants were inserted in each lateral antral wall. Three groups of 18 maxillary sinuses each were augmented with s-DFDB, h-DFDB and autogenous bone from the illiac crest, respectively. In the remaining 18 sinuses, the subantral hollow space was left empty. Pull-out tests were carried out after intervals of 12, 16 and 26 weeks. The mean pull-out force needed, irrespective of time, was 259.3 N in the empty control group, 356.7 N in the group augmented with autogenous bone, 278.1 N in the test group augmented with h-DFDB and 365.2 N in the group augmented with s-DFDB, revealing no significant difference between the individual groups (P > 0.05). The implants of the group augmented with autogenous bone showed an increase in the mean pull-out force from 223.8 N after 12 weeks to 523.7 N after 26 weeks. The nonaugmented control group yielded values of 248 N after 12 weeks, which rose to 269.8 N at the last test, while the values of the h-DFDB group increased from 275.4 N to 325.4 N. The highest initial pull-out values were obtained in the s-DFDB group. They amounted to 310.5 N after 12 weeks and rose to 481.4 N after 26 weeks. Time thus proved to have a significant influence on the pull-out forces (P = 0.014) with a statistically proven linear trend (P = 0.007). The findings of this experimental study indicate that the use of homogeneous DFDB in one-stage sinus lift procedures results in a mechanical loading capacity of implants comparable to that achieved by autogenous cancellous bone from the iliac crest. In contrast, the use of heterogenous-DFDB resulted in only slightly higher pull-out forces than those observed in the nonaugmented control group after 26 weeks.

Alveolar Ridge Augmentation↗
PubMed1995

Failure of exit-race teat spraying to control Corynebacterium bovis colonisation.

When an automated exit-race teat sprayer replaced a conventional teat dip cup for the application of a disinfectant containing 0.5 per cent iodine, there was an increase in the level of intramammary infection by Corynebacterium bovis at drying off from approximately 25 per cent of quarters to approximately 75 per cent of quarters. When the peak level of infection had been reached half of the clinical mastitis in the herd was caused by C bovis, and these were recurrent and chronic infections. There was some evidence that the increase in C bovis infection increased the bulk milk cell count. There were no changes in the rates of infection by major pathogens or by coagulase-negative staphylococci, another important secondary pathogen. The reintroduction of teat dipping rapidly reduced the rate of mastitis infection and the level of infection was reduced to approximately 20 per cent of quarters in about 12 months.

Animals↗
PubMed1966

Stomata and transpiration of droopy potatoes.

A diploid potato (Solanum tuberosum) mutant called droopy wilts easily. Excised leaves of the mutant lost weight, and hence water, more rapidly and had many more open stomata than leaves of a normal sibling. Further, the stomata of abnormal plants remained open in wilted leaves. When the stomata of the abnormal mutant were closed by a chemical spray, its excised leaves lost water no more rapidly than normal. Thus, the wilting of the mutant must be caused by wide stomata. The wilting of the abnormal leaves and the small dry weight of the plants indicate the advantage of the stomatal hydrostat in the normal plants.

Journal Article↗
PubMed1991

Effects of a proprietary topical medication on wound healing and collagen deposition in horses.

Full-thickness skin wounds were created on the dorsum of both metacarpi in 8 horses. Three topical treatment regimens were studied. All wounds were bandaged with a nonadherent dressing, which was held in place with a snug elastic wrap. Group-A wounds were treated with a proprietary topical wound medication that consisted of a spray and an ointment. Group-B wounds were treated with the same regimen, except the putative active ingredients in the ointment were omitted. Group-C wounds were treated with a dry nonadherent bandage only. Wound dressings were changed every day and the limbs were photographed every other day until the wounds were healed. Specimens of normal skin and biopsy specimens of healed wounds were examined histologically and were assayed for hydroxyproline content. Wound healing measurements quantitated for each wound were number of days to healing, maximal wound size attained, day wound contraction commenced, day epithelium first noticed, rate of wound contraction, final wound size, and fraction of the wound that healed by contraction. The cosmetic appearance of the healed wounds was also graded. Significant differences were not noticed in hydroxyproline content, histologic appearance, or any of the wound healing measurements between treatment groups. The cosmetic appearance of healed group-A and -B wounds was significantly better than the appearance of group-C wounds. The topical treatment regimens studied neither enhanced nor inhibited wound healing in this study.

Administration, Topical↗
PubMed1988

Fabrication and characterization of small-diameter vascular prostheses.

We have developed a process to fabricate polyurethane vascular grafts of various dimensions and porosities in our laboratory. A primary feature of the presented fabrication technique is the ability to control surface porosity and roughness, and bulk mechanical properties. The method is based on the spray application of a fine mixture of polymer solution and nitrogen gas bubbles onto a lathe-mounted mandrel. The technique was successfully tested with Tecoflex, a linear segmented aliphatic polyurethane. Other urethane polymers can be used as well. Several polymer coats are applied in a semiautomated process, at the end of which the polymer coating is dried and the tube is slipped off the mandrel. It is the purpose of this paper to describe the fabrication process and present results of the evaluation of grafts. Wall structure was evaluated using scanning electron microscopy and compliance was measured in a specially designed testing apparatus. We developed methods to quantify kink resistance and suture retention capacity of the grafts. These characteristics were correlated with graft fabrication variables: mandrel rpm, horizontal speed of the spray nozzle, gas and polymer solution flow rates. We were able to routinely produce 3-6-mm-ID grafts with 0.5-1.2-mm wall thickness and average bulk pore sizes of 10-250 microns; the wall porosity could be varied between 30 and 70%. Compliance values of the grafts were comparable with corresponding values of carotid and femoral arteries of dogs.

Biocompatible Materials↗
PubMed2002

A marked seasonality of malaria transmission in two rural sites in eastern Sudan.

The ecology of Anopheles arabiensis and its relationship to malaria transmission was investigated in two villages in eastern Sudan. Seasonal malaria case incidence was compared with the number of vectors detected and with climatic variables. Following the end of the short rainy season in October the number of A. arabiensis detected dropped gradually until February when neither outdoor human bait trapping nor indoor spray catches revealed any mosquitoes. Vectors re-appeared in June as humidity rose with the onset of rain. Despite the apparent absence of the vector at the height of the long, hot dry season between February and May, sporadic asymptomatic malaria infections were detected in the two villages. The low endemicity of malaria in the area was reflected by the relatively low total September-December parasite and sporozoite rates (15 and 1.4%, respectively) measured in the villages. The entomological inoculation rate (EIR) was estimated to be around two to three infective bites per person per year, although heterogeneity in the transmission indices of malaria between the two villages was observed. The implications of these patterns of anopheline population dynamics for the epidemiology and control of malaria in eastern Sudan are considered.

Animals↗
PubMed2002

New-types of apparatus for producing microcapsules and microgranules.

Two types of simple compact apparatuses for microencapsulation and microgranulation have been developed. The vibration-type apparatus is a better fit for producing gel-like microgranules of 1.5-3.0 mm in diameter to be used in production of food (fodder) products and additives and microgranulated cell culture. The spray apparatus is fit for operation in two modes: drop-forming (particles of 100-500 microm in diameter) and spray modes (particles of 10-50 microm in diameter). The apparatus is most efficient when used in the mode of forming the particles directly in the medium of liquid nitrogen with successive lyophilic drying (without preliminary defrosting). It is used for microgranulating the live virus materials with their virulence being preserved.

Acrylic Resins↗