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At least 1,135 records · Page 63Linked to original sources
PubMed2006

Application of novel chitosan derivatives in dissolution enhancement of a poorly water soluble drug.

Solid dispersions of the poorly water soluble drug dexamethasone and newly synthesized chitosan derivatives (chitosan succinate, CS, and chitosan phthalate, CP) were prepared by spray drying. The resulting microspheres were evaluated in terms of their drug loading or encapsulation efficiency as well as drug release profile. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and infrared spectroscopy (IR) were used to evaluate the solid dispersion for possible interactions between drug and polymers. The pure drug was evaluated in the same manner for comparison purposes. High loading levels (>74%) were achieved using CP and CS as polymer matrices. Drug release rate was accelerated significantly upon the formation of the solid dispersions; the drug release rate was increased with increasing percentage of the chitosan derivatives in the microspheres. IR studies showed no chemical interaction while the X-ray studies showed a significant change in the crystallinity of the drug upon formation of solid dispersions.

Algorithms↗
PubMed2006

[Preparation and physicochemical properties for zirconia as high performance liquid chromatographic packing materials].

There has been an increasing importance in the application of zirconia as column packing material for high performance liquid chromatography (HPLC) because of its excellent chemical, thermal, and mechanical stabilities as well as bioanalysis suitability. Zirconia spheres could be synthesized by polymerization-induced colloid aggregation (PICA), oil emulsion methods (OEM), or spray-dry method. It has been found that preparative procedure of zirconia support can affect its chromatographic behavior significantly. The review analyzes the relationship between zirconia packings' physicochemical properties and their preparative procedures. Specific surface area, pore structure, pore volume, pore size distribution, and particle size distribution are discussed in detail. At present, zirconia has not become highly competitive because of its limitations such as small specific surface area and pore volume, broad pore size distribution and particle distribution, and unfavorable pore structure. The review also describes silica-zirconia composite HPLC materials prepared by sol-gel method, coating and co-precipitation procedure. However, their chemical stability as HPLC column packings was suspicious because of the residual silica on the material surface. Furthermore, the study showed that zircon (ZrSiO4) is present in all silica-coated zirconia or silica-zirconia composites. It could be deduced that co-existence of more than one crystallines on the material surface could produce chemical heterogeneity, resulting in complex chromatographic separation mechanism. It leads a conclusion that a new synthetic way is needed for preparing zirconia-based HPLC packings with ideal chromatographic parameters. A novel material with higher specific surface area and pore volume, good pore structure, narrower pore size distribution and more uniform particle size distribution was prepared by layer-by-layer self-assembly technique (LbL SA), consisting of micrometer-sized silica spheres as core and nanometer-size zirconia particles as surface coating. The chemical stability of the material is as good as that of zirconia, and its specific surface area is as high as that of silica.

English Abstract↗
PubMed2006

Postweaning mortality in Manitoba swine.

A case-control study to investigate the contribution of postweaning multisystemic wasting syndrome (PMWS) and Porcine circovirus type 2 (PCV-2) to deaths among piglets of nursery age (19 to 68 d) in Manitoba indicated a significant positive association between PCV-2 infection and an increased mortality rate in nursery pigs. The clinical syndrome PMWS was seldom recognized in case or control herds; however, PCV-2 infection was widespread at the herd level. Other factors more strongly associated with increased piglet mortality rate than herd level PCV-2 infection were Mycoplasma hyopneumonia infection, porcine reproductive and respiratory syndrome (PRRS), and diarrhea caused by Eschericia coli K88. Management factors associated with case herd status included close proximity to other herds, larger number of sows supplying pigs to the nursery, larger range in age and weight going into the nursery, the moving of lightweight pigs into another nursery room at the end of the nursery fill, and not using spray-dried plasma in the 1st nursery ration. These results highlight the host-agent-environment triad leading to high nursery-barn mortality rates.

Animal Husbandry↗
PubMed1991

Removal of inhaled 99mTc-labelled particles of disodium cromoglycate from the lungs.

Disodium cromoglycate particles were labelled with 99mTc by spray-drying technique. The in vitro dissolution profile as well as the leakage of radioactivity from the drug particles were determined using a through-flow cell method. The radioactive drug particles were mixed with a lactose carrier and inhaled from a dry powder device by five healthy volunteers. The removal of the inhaled drug particles from the lungs was evaluated by a gamma camera. A close relationship between the dissolution of the drug as such and the leakage of radioactivity was noted. Gamma scintigraphy indicated a biphasic exponential removal of radioactivity from the lung region. The slow component with the halftime of about 55 min was mainly due to the dissolution of drug particles in the lungs. The halftime of the fast component describing mucociliary clearance was less than 10 min. This process was the dominating one for the removal of the drug from the lungs. The experiment thus showed that the main fraction of the inhaled dose was deposited in the tracheobronchial region. Accordingly, only a small portion of the dose initially deposited in the lung can be absorbed and induce a therapeutic effect.

Aerosols↗
PubMed1991

Effects of inspirease holding chamber on the deposition of metered dose inhalation aerosols.

A modified cascade impaction method as well as a radiotracer technique has been used to assess the effects of the 700 ml collapsible holding chamber (InspirEase) on the in vitro and in vivo deposition of inhaled metered dose aerosols. The in vitro deposition of beclomethasone dipropionate 250 micrograms/dose aerosol administered either through the conventional aerosol actuator with the short plastic mouthpiece or through the InspirEase-device was evaluated with the modified cascade impactor which method imitated the human respiratory tract. For the in vivo study the disodium cromoglycate particles were labelled with pure gamma-radiator 99mTc using a coprecipitation technique based on spray drying. The deposition of the inhaled disodium cromoglycate particles in the human respiratory tract after administration of the drug doses from the devices tested was determined by means of gamma camera. InspirEase increased both in the in vitro and in vivo tests the fraction of the drug dose deposited into the therapeutically significant regions of the respiratory tract. In addition, the therapeutically insignificant fraction deposited in the upper passages and mouth clearly decreased. Thus using the InspirEase holding chamber not only a better lung penetration of the inhaled drug particles can be achieved but also the local side effects would be decreased.

Administration, Inhalation↗
PubMed1991

[Obtention of a protein concentrate of chickpea (Cicer arietinum) by ultrafiltration].

A protein concentrate was obtained from chick-pea (Cicer arietinum) flour aqueous extract. The factor involved in the recovery of protein were the flour: water ratio, and the pH. The best aqueous extract was subjected to infiltration in a Romicon HF1/2SSS unit equipped with hollow fiber membranes cartridges with a nominal molecular-weight cut-off point of 50,000 daltons. The concentrate was spray-dried and the product obtained had the following composition, expressed in g/100 g: 67.8 protein with 4.9 g/16 g N of reactive lysine; 17.3 fat, 10.0 carbohydrates, and 4.9 ash (dry basis). The nitrogen solubility index was 93 and the color, by Hunter, was L = 86.8.

Edible Grain↗
PubMed1990

Effect of the new spacer-device on the deposition of the inhaled metered dose aerosol.

The effect of the new spacer-device on the in vitro and in vivo deposition of inhaled drug particles was studied. The in vitro deposition of beclomethasone dipropionate 250 micrograms/dose aerosol administered either through the conventional aerosol actuator with the short plastic mouthpiece or through the new pear-shaped spacer-device was evaluated with the modified cascade impactor method. For the in vivo study the disodium cromoglycate particles were labelled with a pure gamma-radiator 99mTc using a coprecipitation technique based on spray drying. The deposition of the inhaled disodium cromoglycate particles in the human respiratory tract after administration of the drug doses from the devices tested was determined by means of a gamma camera. The new spacer-device increased both in the in vitro and in vivo tests the fraction of the drug dose deposited into the therapeutically significant regions of the respiratory tract. In addition, the therapeutically insignificant fraction deposited in the upper airways and mouth clearly decreased. Thus using the new spacer-device evaluated in this study the local side effects would be decreased.

Aerosols↗
PubMed1990

Antibodies from colostrum in oral immunotherapy.

An immunoglobulin preparation for oral use was prepared from pooled bovine colostrum from more than 100 animals. The preparation has high antibacterial antibody titres, and a high capacity for the neutralization of bacterial toxins. It is well tolerated and highly effective in the treatment of severe diarrhoea, e.g. in AIDS patients. The preparation is spray-dried and stable at 2-8 degrees C.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Dot-enzyme linked immunosorbent assay for the detection of antibodies in bovine brucellosis.

A dot-enzyme linked immunosorbent assay (dot-ELISA) for the detection of antibodies in bovine brucellosis using soluble antigens extracted from Brucella abortus S-99 is described in which antigen was deposited on a nitrocellulose sheet (0.5 x 0.5 cm) bound to a plastic strip and the unsaturated sites blocked by a solution of spray-dried milk powder. Sera were tested at dilutions of 1:800 and 1:1600, using rabbit anti-bovine-immunoglobulin or protein-A coupled to peroxidase as conjugates and diamino-benzidine as substrate. A positive reaction was clearly indicated by a brown dot on the nitrocellulose sheet. Using antigen-coated, pre-blocked strips, the test could be completed within 45 minutes.

Animals↗
PubMedDate not supplied

Effects of beta-carotene-rich algae Dunaliella on reproduction and body growth in mice.

Effects of beta-carotene-rich algae Dunaliella on reproduction and body growth were investigated in SHN mice. At 2-3 months of age, female mice were placed with males and fed different diets simultaneously throughout the experiment; Group I was provided with AIN-76TM diet containing 2.2 X 10(-4)% retinyl palmitate. Group II or III was given vitamin A deficient AIN-76TM diet supplemented with spray dried powder of Dunaliella or its oily solution. The final concentrations of beta-carotene in the diets were 5.1 X 10(-5)% and 3.0 X 10(-2)% in groups II and III respectively. Groups II and III were markedly lower and higher than group I in still-birth rate and litter size or rearing rate, respectively. Body growth was also enhanced in male offspring fed supplemental beta-carotene continuously (groups II and III). These results have demonstrated that, in mice, reproduction and body growth are improved by beta-carotene from Dunaliella.

Animals↗
PubMedDate not supplied

Inhibition by beta-carotene-rich algae Dunaliella of spontaneous mammary tumourigenesis in mice.

Effects of beta-carotene-rich algae Dunaliella on spontaneous mammary tumourigenesis were studied in SHN mice. In both breeder and virgin mice, mammary tumourigenesis was significantly inhibited in the experimental groups fed diets supplemented with spray dried powder of D. bardawil and oily solution of D. salina Teod. extract compared with the control. There was little difference between the experimental and the control groups in plasma prolactin level, endocrine organ weights and pattern of oestrous cycles. Moreover, mammary gland susceptibility to mammotrophic hormones was affected little by Dunaliella. These results suggest that the inhibition by Dunaliella of spontaneous mammary tumourigenesis of mice may not be through their modulation of endocrine systems.

Animals↗
PubMedDate not supplied

Interactive effects of duration of storage and addition of formaldehyde on levels of aflatoxin M1 in milk.

Spray-dried skim milk, naturally contaminated with aflatoxin M1, was added to either raw or pasteurized whole milk to a final concentration of 1.1 microgram aflatoxin M1/L milk. Formalin (37% w/w) was added to the milk solutions to final concentrations of 0, 0.025, 0.05, and 0.1% formaldehyde. Samples were stored in the dark at 21 degrees C in plastic and glass containers and were analyzed for aflatoxin M1 at 0, 1, 2, 3, and 4 weeks. This experiment was repeated using only raw milk and glass containers. Aflatoxin M1 analyses were done at 0, 1, and 2 weeks. Aflatoxin M1 losses increased over time and with increased formaldehyde concentration. With both experiments, aflatoxin M1, levels after 2 weeks were less than 0.05 micrograms/L in samples containing 0.1% formaldehyde.

Aflatoxin M1↗
PubMed1988

Development of an infant food product based on fermented milk, cereals and soybean.

The objective of this work was to develop an infant food product based on yogurt, cereals and soybean. The experimental conditions to obtain the yogurt using milk and lyophylized microorganisms, were: incubation period, 5 hours, a temperature of 41 +/- 1 degree C and innoculum concentration, 3%. Two protein mixtures were prepared: 1) corn-yogurt, with a protein supply relation of 65/35%, and 2) wheat-soy-yogurt with a protein supply relation of 20/60/20%, respectively. The mixtures were fermented during 24 hours at 37 degrees C and spray-dried thereafter. Artificial flavors, sugar and maltodextrins were added to the final product, in order to develop and instant purée. The protein content of the product was 11%, with a net protein utilization (NPU) of 80% in relation to casein. Banana was the most acceptable flavor. This type of product represents an alternative to preserve milk in developing countries, obtaining a suitable baby food product.

Edible Grain↗
PubMed1985

Molluscicidal properties of Acacia nilotica subspecies tomentosa and astringens II.

A screening programme of plants rich in plant phenolic tannins for molluscicidal activity against the snail species Bulinus truncatus and Biomphalaria pfeifferi is now under way. The spray-dried powders of the pods and stem bark of Acacia nilotica subspp. nilotica, tomentosa and astringens prove to be promising vegetable molluscicides.

Acacia↗
PubMed1977

[Development of a new testmethod for surface disinfection procedures. III. The impression method: influence of the test surface material and the types of microorganisms on the recovery rate (author's transl)].

The preceding test results appear to favour the impression method used for the testing of surface disinfection procedures. Further investigations were concerned with the selection of a suitable germ carrier. The high recovery rate of the bacteria and the invariably uniform quality of the germ carrier are the decisive criteria. Since a dependence on the type of germ was also to be expected, we checked Staph. aureus, Str. faecalis, E. coli, Kl. pneumoniae and P. aeruginosa for their behaviour on PVC, varnished wooden surfaces, V 2A, rough and smooth glass, resopal, ceramic tiles with dull and glazing finish as well as on plywood. The germ carriers were contaminated quantitatively, dried, sprayed with distilled water to stimulate disinfection and examined after they were allowed to react for a period of 6 hours. A set of 10 germ carriers was examined simultaneously with 10 Rodac impressions. The data were checked by variance analytical methods and evaluated on the mean (or median) values. It was found that while the initial germ number was kept equal OP tiles and V 2A steel produced the highest germ yield. Plywood proved largely unsuitable. Among the test germs, E. coli and Kl. pneumoniae had the lowest adhesion; it was inferior to that of staphylococci and pseudomonads. However, for these 4 germ types 3 impressions per germ carrier suffice for a reliable assessment based on computations. The yield amounts to more than 90 per cent. 94 per cent of the Streptococci were also recovered with 3 impressions, but the absolute germ quantity was low. The use of this type of germ can be recommended only with reservation.

Bacteriological Techniques↗
PubMed1978

Study of particulate matter in carbenicillin disodium using scanning electron microscopy and microbeam x-ray spectrography.

A scanning electron microscopy membrane filtration study was conducted to determine the particulate contamination of samples of carbenicillin disodium which had been manufactured by bulk filling and by lyophilization. The bulk-filled product contained more contaminating particles than the lyophilized product. In both products, the number of particles increased logarithmically with decreasing particle size in the range measured (exceeding 0.1 micron). X-ray spectrographic analysis of particles larger than 0.5 micron revealed that the major particulate contaminates in both products were composed primarily of elements below atomic number 10. It is concluded that packaging of carbenicillin disodium by lyophilization of a solution results in significantly less submicrometer particulate contamination than packaging by sterile bulk filling of spray-dried powder.

Carbenicillin↗