共查询到20条相似文献,搜索用时 359 毫秒
1.
E. Yonemochi Y. Yoshioka Y. Yoshihashi K. Terada 《Journal of Thermal Analysis and Calorimetry》2006,85(3):693-697
We have
developed the vacuum dryer attached XRD-DSC system and monitored manufacturing
process of freeze-dried pharmaceutical product. The aim of this study is to
apply the XRD-DSC system for the preformulation of freeze-dried injections.
Gabexate mesilate was used as a model drug. Drug solution was frozen then
heated to annealing temperature according to the process-controlling program.
The XRD-DSC analyses were performed to monitor the crystallized spicies and
their crystallinity of sample. When the solution was cooled slowly, peaks
of gabexate mesilate and mannitol polymorph had been already observed during
the cooling process while those crystallinity were low at fast cooling rate.
As the drying underwent, intensity of ice peaks were getting weaker. At the
cooling rate of 0.1°C min–1, the XRD
profile of final product was revealed that the characteristic peaks of gabexate
mesilate, mannitol δ-form and β-form were appeared. When the cooling
rate was increased, the crystallinity of final products was decreased. From
these results, it was confirmed that the XRD profiles during freeze-drying
process significantly related to the final freeze-dried product. It is obvious
that monitoring by XRD-DSC system is a quite effective way to simulate the
manufacturing process and to optimize the qualified product. 相似文献
2.
S. Halas 《Journal of Thermal Analysis and Calorimetry》2006,83(1):31-33
Thermogravimetry
(TG), thermogravimetry/mass spectrometry (TG/MS), and loss-on-drying methodology
are used to provide residual moisture results for freeze-dried biological
products regulated by the US Food and Drug Administration. Residual moisture
specifications must be met in order to ensure freeze-dried biological product
potency and stability throughout the licensed product's shelf life.
TG, TG/MS, loss-on-drying and vapor pressure moisture measurements are compared
for a BCG Vaccine. Comparisons are made between residual moisture data for
the freeze-dried cake and vapor pressure moisture determinations in the space
above the freeze-dried cake in the final container. Vapor pressure moisture
precision data is presented for α-interferon and BCG vaccine. Impact
of residual moisture and vapor pressure moisture upon product stability is
presented. 相似文献
3.
A. Santiago A. González J. J. Iruin M. J. Fernández-Berridi L. Irusta 《Journal of Sol-Gel Science and Technology》2012,61(1):8-13
Hydrophobic silica nanoparticles were obtained by microwave assisted sol–gel method using a two-step procedure. In the first
step different size silica particles were generated from tetraethyl orthosilicate and in the second one the silica particles
were hydrophobized using hexadecyl trimethoxysilane (HDTMOS). Under microwave irradiation, high conversion degrees were obtained
at relatively short reaction times. The HDTMOS added in the second step instead of coating the silica nanoparticles generated
new ones and therefore the final product showed a bimodal size distribution. All the synthesized nanoparticles gave rise to
high water contact angles (≈150°) and low hysteresis values. 相似文献
4.
The solvent-detergent (S/D) method was applied for inactivation of lipid-enveloped viruses during the production of immunoglobulins. Amberlite XAD-7 resin was used for removal of solvent (tri-n-butyl phosphate, TnBP) and detergent (Triton X-100) after the performed S/D inactivation procedure. The S/D reagents from the immunoglobulin preparation were adsorbed on Amberlite XAD-7, while immunoglobulins passed through the column and retained their biological activity. Using the method developed here, the final immunoglobulin preparation contains less than 1 ppm of Triton X-100 and less than 2 ppm TnBP. 相似文献
5.
The human hemorphin LVV-H7 is an endogenous cleavage product of the hemoglobin β, γ, ε or δ chain exhibiting potential pharmaceutical
relevance for blood pressure regulation, the treatment of Alzheimer’s disease or learning deficiencies. Here we present the
development of a multi-component capillary zone electrophoretic method (CZE-UV), allowing the simultaneous quantification
of LVV-H7 and four N-terminal degradation products generated in EDTA plasma. Hemorphins in the supernatant of precipitated
plasma samples are quantified by external calibration. Validation of the procedure oriented towards international pharmaceutical
guidelines and demonstrated excellent linearity ( r
2 ≥0.999), good precision (repeatability and reproducibility below 11%), accuracy (−8.4%–4%), ruggedness and an appropriate
lower limit of quantification (LLOQ 1.0 μg mL−1). This procedure was applied to stability studies of LVV-H7 in human EDTA plasma attended by profiling metabolites using
qualitative MALDI-TOF MS analysis. We detected the activity of a soluble plasma form of aminopeptidase M causing successive
N-terminal truncation. This is the first time that LVV-H7 degradation as well as its metabolite production have systematically
been monitored by a quantitative CZE-UV procedure, underlining the growing importance of such techniques in peptide analysis.
In addition, our results give useful hints for future drug development of LVV-H7. 相似文献
6.
A. V. Borisov V. K. Belsky V. K. Osmanov G. N. Borisova Zh. V. Matsulevich 《Chemistry of Heterocyclic Compounds》2006,42(10):1346-1351
Reaction of perfluoro-1-ethyl-2-methyl-1-propenyliminochloromethanesulfenyl chloride with 1-allyl-2-methoxybenzene in methylene
chloride and nitromethane gives as the main products β-and β-chloro sulfides plus derivative of 2,3-dihydrobenzofuran. The
reaction in nitromethane in the presence of lithium perchlorate gave a product of addition of sulfur-containing electrophiles
to the double bond-a derivative of 1,3-thiazolidin-2-one-in preference to the cycloaddition product.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1558–1564, October, 2006. 相似文献
7.
Raz Gvishi 《Journal of Sol-Gel Science and Technology》2009,50(2):241-253
A novel method to prepare crack-free sol–gel materials without shrinkage is reviewed. The method allows fabrication of a viscous
sol–gel resin in a few minutes followed by either thermal-curing or UV-curing requiring several hours or several minutes,
respectively. The method is distinguished by the short time required to achieve a solid monolith. The fast sol–gel method
uses a combination of organically modified alkoxides with traditional alkoxides as precursors, to produce a final product
which is an organic-inorganic hybrid with properties that vary from silicone rubbers to silica glass. Optical and physical
properties, such as refractive index and thermal expansion, can be engineered by controlling the ratio between the precursors.
This class of materials is a promising candidate for preparation of optical elements such as waveguides and submicron structured
replicas and can also be used as an optical bonding material. This paper reviews the fast sol–gel technology, as well as methods
to characterize the process and its final products. Various applications of fast sol–gel materials are presented. 相似文献
8.
Alfonz Plško Anton Lukáč Jana Pagáčová Iveta Staňová Mária Svítková Petr Exnar Jana Müllerová Vladimír Kovačič 《Journal of Sol-Gel Science and Technology》2007,43(1):137-143
We have observed occurrence of fibrous products on gel surface in four-component system of KK (silicic acid sol)–H2O–HCl–NH3, KK–H2O–HCl–NaOH and KK–H2O–HCl–TEA (triethanolamine). Bundles of fibres occur in the system with NH3, sticks and needles in system with NaOH, and finally in the system with TEA we can mostly observe the occurrence of crystalline
products. Dependency of product morphology on initial sol composition is occurring in observed systems. In the case of system
with NH3, mostly the length of nascent fibres is influenced by the composition, and in the systems with NaOH and TEA it is also final
shape of nascent products. Morphology of nascent products in systems with NH3 and NaOH is controlled by quantity of added HCl, but in the system with TEA it is quantity of added TEA. It is characteristic
for all observed systems that “spontaneously” occurring products consist of crystalline phase, that is chloride of respective
alkali, and amorphous phase, that is SiO2. Beginning of respective chloride crystallization in observed systems probably initializes occurrence of products on gel
surface. Further growth of crystals is influenced by present colloid of SiO2 that interacts with surface of growing crystal leading to anisotropy of its growth and therefore to “spontaneous” occurrence
of fibrous products. 相似文献
9.
Residual moisture content and formulation are important parameters when preparing lyophilized reference materials containing
labile proteins. The protection of Factor VIII and Factor V activities were monitored in a lyophilized plasma preparation
following formulation with either no additional excipient, 40 mM Hepes (4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid),
10 mg/mL glycine or a combination of 40 mM Hepes and 10 mg/mL glycine. The preservation of Factor VIII activity during freeze-drying
was improved by the addition of either stabiliser and improved most, amongst the options studied, by the addition of both
glycine and Hepes. The predicted stability at −20 °C and 20 °C was estimated using accelerated degradation studies. Although
for plasma lyophilized alone there was some benefit from further desiccation over phosphorus pentoxide, resulting in very
low moistures, for suitably formulated samples the predicted stability was as good for freeze-dried only samples as for those
with further desiccation. This study emphasises the importance of optimum formulation on the stability of lyophilized proteins. 相似文献
10.
Y. P. Naik G. A. Ramarao Ajita Banthiya Deepika Chaudhary Charu Arora 《Journal of Thermal Analysis and Calorimetry》2012,107(1):105-110
GEL combustion technique was applied to obtain oxides of thorium and cerium from their respective nitrate solutions using
citric acid as the gelating agent. The dried samples were characterized by IR and TG studies. Intermediate and final products
during TG studies have been isolated and characterized by XRD studies. All the TG runs during heating of thorium and cerium
nitrate with citric acid dried Gels showed a two step process. The weight loss at each step and the X-ray data of the product
at each step, helped in suggesting a possible mechanism. Kinetic study was carried out independently for each step. The reaction
mechanism as observed during interactive procedure was found to be diffusion controlled. The kinetic parameters (activation
energy and pre-exponential factor) for each step in all reactions have been calculated. Observations from XRD studies show
that with increase in cerium concentration in the oxides, the lattice parameter values have shown a decreasing trend for all
the five compositions studied. It was observed that in TG studies with increase in cerium concentration, the final temperature
of the reactions have shown a decreasing trend. SEM studies of the powders reveal that synthesized oxides have a tendency
to form agglomerate of varying size ranging from 50 to 100 μm in case of mixed oxides but the size of thorium oxide powder
so synthesized have pore size 10–100 μm. SEM images shows that GEL combustion may result in agglomeration, if the temperature
is not properly controlled to the desired value. SEM studies also reveal that each agglomerate contains approximately 10–100
individual particles. Surface area of the mixed oxide powders were determined using Gas adsorption technique. The surface
area was found to be in the range of 3–17 m2/g in all cases. Specific surface area of thorium oxide was found to be lesser than cerium oxide but in case of mixed oxides
surface area decreases with increase in cerium content. Majority of pores, indicating the particle size are in the range of
0.01–0.04 cm3/g. 相似文献
11.
Donohoe TJ Harris RM Burrows J Parker J 《Journal of the American Chemical Society》2006,128(42):13704-13705
The double oxidative cyclization of dienes is a viable procedure for making complex natural products containing cis-THF units. A double deprotection/double oxidative cyclization strategy using catalytic osmium tetroxide was used to construct the bisheterocyclic core of cis-sylvaticin and ultimately confirm its structure. The natural product was then prepared by a short sequence of reactions that is exceptionally concise: the final route being just 13 linear steps and 19 chemical operations in total. 相似文献
12.
S. L. Litvinenko T. V. Bezbozhnaya V. V. Zamashchikov 《Theoretical and Experimental Chemistry》2007,43(6):396-398
The phenanthroline complex, Pt(phen)Cl2, catalyzes the coupling of aromatic hydrocarbons with p-iodonitrobenzene under phase transfer conditions using 50% aqueous
KOH and 18-crown-6. The yield of the asymmetric diaryl products is 10,000–12,000% relative to the catalyst. A mechanism was
proposed involving the oxidative addition of ArI to an Ar-PtII intermediate species with subsequent reductive elimination of the final product Ar-Ar′ from Ar-PtIV-Ar′.
__________
Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 6, pp. 364–366, November–December, 2007. 相似文献
13.
Barrett B Borek-Dohalský V Fejt P Vaingátová S Huclová J Nemec B Jelínek I 《Analytical and bioanalytical chemistry》2005,383(2):210-217
A validated, highly sensitive, and selective HPLC method with MS–MS detection has been developed for quantitative determination
of azithromycin (AZI) in human Na2EDTA plasma. Roxithromycin (ROX) was used as internal standard. Human plasma containing AZI and internal standard was ultrafiltered
through Centrifree Micropartition devices and the concentration of AZI was determined by isocratic HPLC–MS–MS. Multiple reaction
monitoring mode (MRM) was used for MS–MS detection. The calibration plot was linear in the concentration range 2.55–551.43 ng mL−1. Inter-day and Intra-day precision and accuracy of the proposed method were characterized by R.S.D and percentage deviation,
respectively; both were less than 8%. Limit of quantification was 2.55 ng mL−1. The proposed method was used to determine the pharmacokinetic profile of AZI (250-mg tablets). 相似文献
14.
Nagwa Burham Sami A. Azeem Mohamed F. El-Shahat 《Central European Journal of Chemistry》2009,7(4):945-954
A new solid — phase extraction sorbent was developed based on stepwise anchoring of two ligand molecules for the determination
of copper, zinc, lead and cadmium in drinking water by flame AAS. Amberlite XAD-2 functionalized with 4′-(2-hydroxyphenylazo)-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one
(HPAPyr) was utilized for preconcentration/separation of these elements. The sorbent was prepared by two successive azo coupling
reactions. First, 2-aminophenol was anchored to the amino groups in the resin resulted from nitration followed by reduction.
Then, the resulted 2-aminophenol functionalized resin was further diazotized and coupled to the pyrazolone compound and the
final product HPAPyr-XAD-2 was characterized by IR and elemental analysis. The optimum pH range for sorption, shaking time,
exchange capacity, sample flow rate, preconcentration factor and interference from co-existing ions were investigated. All
metal ions were quantitatively desorbed from the resin by 4.5 mol L−1 nitric acid solution. The sorbent provides limit of detection within the range 0.9–3.3 μg L−1 and concentration factor up to 250. The procedure was validated by analysis of certified material NIST-SRM 1577b. Application
to drinking water showed satisfactory results with relative standard deviation RSD ≤ 8.5%.
相似文献
15.
The kinetic regularities of the liquid-phase hydrogenation and isomerization of α- and β-pinenes over the Pd/C, Ru/C, Rh/C,
Pt/C, and Ir/C catalysts were studied at temperatures ranging from 20 to 100 °C and at hydrogen pressures of 1–11 bar using
n-octane as the solvent. The hydrogenation and isomerization of α- and β-pinenes occur simultaneously on the Ru/C, Rh/C, Pt/C,
and Ir/C catalysts, and the reaction mixture contains the products of double bond hydrogenation, viz., cis- and trans-pinanes. The Ru, Rh, and Pd metals have a higher catalytic activity in β-pinene isomerization than Ir and Pt. Among the VIII
Group metals studied, the Pd-based catalyst has the highest catalytic activity in double bond isomerization of α- and β-pinenes.
The general scheme of the mechanism of hydrogenation and isomerization of α- and β-pinenes on the Pd/C catalyst was proposed. 相似文献
16.
Rajeev Gupta Debalina Ghosh Rabindranath Mukherjee 《Journal of Chemical Sciences》2000,112(3):179-186
Activation of dioxygen on dicopper(I) centres was systematically investigated using a group of open-chain and a macrocyclicm-xylyl-based dinucleating ligand from a bioinorganic viewpoint. Even though intermediate peroxodicopper(II) species was not
detected (even at −80°C for the open-chain system), the putative intermediate reacted with C–H groups in ligands giving oxygenated
products (C–OH groups). Absorption, spectroscopic and magnetic properties of the final dicopper(II) complexes have been investigated. 相似文献
17.
For inactivation of lipid-enveloped viruses during the immunoglobulin production, the solvent-detergent (S/D) method was applied. Tri-n-butyl phosphate (solvent) and Triton X-100 (detergent) were removed from S/D treated immunoglobulins by ion-exchange chromatography on Q-Sepharose Fast Flow (FF). During the chromatographic procedure immunoglobulins remained bound on a Q-Sepharose FF, whereas solvent and detergent were eluted by washing with starting buffer. Elution of immunoglobulins was achieved by increasing the ionic strength of the starting buffer. The final immunoglobulin preparation contained less than 10 microg/ml of Triton X-100 and less than 2 microg/ml tri-n-butyl phosphate. It was confirmed that the S/D procedure did not cause a significant change in polymers and specific antibodies content. Immunoglobulin classes were also not affected by the same procedure. 相似文献
18.
I. G. Zenkevich 《Fresenius' Journal of Analytical Chemistry》1999,365(4):305-309
New methods for the precalculation of GC retention indices (RIs) are discussed. The first is based on a new modification
of the correlation equation log RI = a logTb + bA + c and is recommended for low boiling compounds of the general type R-X with known boiling points (Tb) analyzed on polymer sorbent Porapack Q. The second method permits one to predict RIs of products of organic reactions A
+ B → C +… with the correlation ΔRI = a ΔE + b (a < 0,|ρ| > 0.9), where ΔRI = RIC– RIA– RIB and ΔE = EC– EA– EB– are the differences in the internal molecular energies of reagents and products of organic reactions which are estimated
by molecular dynamics methods. In the final section new possibilities of the use of RIs in reversed phase HPLC, namely for
the determination of the number of hydroxyl groups in phenols, are illustrated.
Received: 9 November 1998 / Revised: 15 April 1999 / Accepted: 30 April 1999 相似文献
19.
It has been established that during the cyclization of 5β-acetoxyisocembrol under the action of HCOOH + D2O the D atom enters position 7α of the product molecules exclusively, which is in harmony with the proposed cyclization scheme.
Using model compounds, an alternative scheme for the formation of one of the products has been disproved.
Novosibirsk Institute of Organic Chemistry, Siberian Division of the Russian Academy of Sciences. Translated from Khimiya
Prirodnykh Soedinenii, No. 5, pp. 642–647, September–October, 1994. 相似文献
20.
E. Ricci 《Journal of Radioanalytical and Nuclear Chemistry》1971,9(2):273-277
The kinetic energy of charged particles is rapidly degraded into large amounts of heat in the target; if biological samples
are bombarded, chemical decomposition may result. A simple least-squares straight-line fitting procedure was applied to test
the chemical stability of freeze-dried, compressed samples of human lung, brain andE. coli, under bombardment with a 0.33–0.48 μA beam of 0.7 MeV protons. The method showed no significant damage in these conditions,
and also estimated the meximum length of ‘safe’ bombardment to be approximately 50 min. The samples were being subjected to
proton-reaction analysis for ratios13C/12C and N/C when the least-squares test was performed; however, this method may be easily adapted to check- and roughly predict
— sample stability in practically any activation, prompt-reaction, or related analysis based on charged-particle bombardment.
Research sponsored by the U.S. Atomic Energy Commission under contract with the Union Carbide Corporation. 相似文献