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Current
Pharmaceutical Analysis
ISSN: 1573-4129
Current Pharmaceutical
Analysis
Volume 4, Number 3, August 2008
Contents
Trends in the Design and Application of Optical Chemosensors
in Pharmaceutical and Biomedical Analysis Pp. 106-117
M. Antonia Martín, Ana I. Olives, Benito del Castillo
and J. Carlos Menéndez
[Abstract]
Imaging Techniques and their Role in Dosage form Design
and Drug Delivery Research Pp. 118-125
Susanne Franke, Carole Malcolmson, Craig
R. Bunt, Ilva Rupenthal and Raid G. Alany
[Abstract]
13C NMR Spectroscopy
to Determine Structure and Composition of Waxes and Glycerides
Pp. 126-136
Giovanna Vlahov
[Abstract]
Recent Trends in High Throughput Analysis and Antioxidant
Potential Screening for Phenolics Pp. 137-150
Paula B. Andrade, David M. Pereira, Federico
Ferreres and Patrícia Valentao
[Abstract]
Computer-Assisted Optimization of Liquid
Chromatography Separations of Drugs and Related Substances
Pp. 151-161
Tomasz Baczek
[Abstract]
New Perspectives in the Analysis of Ecdysteroids:
A Promising Group of Biologically Active Compounds Pp.
162-175
Attila Ványolós and Maria
Báthori
[Abstract]
Inclusion Complexation Behaviors of 3-Tigloyl-Azadirachtol
With
β-Cyclodextrin
Derivatives Pp. 176-182
Bo Yang, Yong Chen, Jun Lin and Yu Liu
[Abstract]
Nitric Dioxide as Biologically Important Radical and
its Role in Molecular Mechanisms of Pancreatic Inflammation
Pp. 183-196
Aleksandra Dabrowska, Dagmara Jacewicz,
Agnieszka Chylewska, Michal Szkatula, Narcyz Knap, Jolanta
Kubasik-Juraniec, MichalWozniak and Lech Chmurzynski
[Abstract]
Abstracts
[Back to top]
Trends in the Design and Application of Optical
Chemosensors in Pharmaceutical and Biomedical Analysis
M. Antonia Martín, Ana I. Olives, Benito del Castillo
and J. Carlos Menéndez
During the last two decades the design of devices for the
sensing of pharmaceutically and biologically important compounds
has acquired great interest. The miniaturization of these
devices in instrumental analytical techniques allows the manipulation
of small sample volumes (submicroliter). The chemical nature
of the chemosensor and the nature of the molecular analyte-chemosensor
interaction determine the response to be measured or detected.
Some instances are the changes in the colour or fluorescence
properties of the chemosensor as a consequence of the interaction
with the analyte or the changes in the near-infrared electromagnetic
radiation that facilitate the quality control in manufacturing
of pharmaceutical compounds by near-infrared analysis (NIRA).
Molecular recognition of different inorganic and organic analytes
involves different mechanisms. The spectroscopic properties
of the signalling subunit of the sensor may change after interaction
with the analytes, or alternatively the spectro-scopic properties
of the chemo- or bio-sensor are modified as a consequence
of the displacement of the sensor by the ana-lytes. In such
cases the sensor bound to the receptor exhibits different
properties than the free sensor. In this field the rapid development
of different approaches such as molecularly imprinting polymers
and other cavitands (cyclodextrins and calixarenes), has led
to the specific determination of biologically interesting
compounds and chiral recognition processes. The evaluation
of the levels of clinically interesting compounds by conventional
approaches requires frequent blood sampling and therefore
the possibility of using different devices for the continuous
monitoring of physiological compounds is an attractive subject
in which the use of fiber optical chemo- or bio-sensors is
being considered with growing interest.
[Back to top]
Imaging Techniques and their Role in Dosage form Design
and Drug Delivery Research
Susanne Franke, Carole Malcolmson, Craig
R. Bunt, Ilva Rupenthal and Raid G. Alany
The development and registration of pharmaceuticals often
requires some degree of certainty around their in vivo
performance. Many commonly used diagnostic and therapeutic
imaging techniques have been attracting increasing interest
to monitor the performance of dosage forms and drug delivery
systems in vivo. The use of imaging and micros-copy
methods in dosage form design and drug delivery research is
still in its infancy with only gamma scintigraphy being widely
accepted by drug regulatory bodies as the method of choice
for monitoring the gastrointestinal transit of oral dosage
forms. The emerging use of ultrasonography and magnetic resonance
imaging may potentially bring these techniques further to
the scene with a more established role in the assessment of
pharmaceutical dosage forms. This review compares and contrasts
the scientific operation principles as well as advantages
and disadvantages of some of these imaging techniques, including
gamma scintigraphy, single photon emission computed tomography,
positron emission tomography, radiology/computed tomography,
ultrasonography magnetic resonance imaging and microscopy.
Scientific articles are reviewed to give a broad overview
of these techniques, their current applications and their
future potential use in dosage form design and drug delivery
research.
[Back to top]
13C NMR Spectroscopy
to Determine Structure and Composition of Waxes and Glycerides
Giovanna Vlahov
13C nuclear magnetic resonance
spectroscopy has been successfully applied to determine the
structures of natural derivatives of long-chain fatty acids
and in particular, waxes and glycerides.
The term wax is used to indicate esters of aliphatic acids
with alcohols other than glycerol. 13C
chemical shifts of unsaturated carbons in long-chain esters
and acids were explained in terms of long-range σ-inductive
interactions through saturated C-C bonds in polymethylene
chains. A mathematical model was proposed to predict NMR shifts
at sp2 carbons of
mono- and non-conjugated polyenoic acids and esters.
13C NMR was also applied
for studying the structure of glycerides. Unsaturation degree,
cis-trans isomerization, and positional isomerism
of fatty acids were determined along with their distribution
between the 1,3- and 2-positions of glycerol backbone. The
compositional data of the two fatty acid pools which esterify
1,3- and 2-glycerol positions, opened a new frontier in the
knowledge of glyceride structures. Positional data of triglycerides
enabled the set-up of new analytical methodologies which apply
quantitative 13C NMR spectroscopy
to determine the composition of natural mixtures of triacylglycerols,
i.e. vegetable oils.
[Back to top]
Recent Trends in High Throughput Analysis and Antioxidant
Potential Screening for Phenolics
Paula B. Andrade, David M. Pereira, Federico
Ferreres and Patrícia Valentao
The use of natural products as therapeutic agents goes back
to the first civilizations. A large percentage of the drugs
prescribed worldwide come from plants, as compounds can be
used unaltered or applied to the semi-synthesis of more potent
ones. Phenolic compounds are secondary plant metabolites widely
distributed in nature. They are known for their several health
promoting properties, such as vasoprotective, anti-inflammatory,
antimicrobial and antioxidant. Their antioxidant capacity
has been the object of intensive research towards their application
in cancer, cardiovascular and neurodegenerative diseases,
as well as in antiaging cosmetic products. In this review
we present the recent advances in the methodology used for
the extraction, purification and analysis (separation, detection
and structural elucidation) of these compounds, from species
largely consumed and with ethno-pharmaceutical relevance,
as they are applied in the quality/authenticity control of
vegetal matrices. The biochemical assays usually employed
to assess their antioxidative potential will also be included.
These comprise those testing their ability to scavenge both
reactive oxygen and reactive nitrogen species and those evaluating
their capacity to prevent the formation of these species.
[Back to top]
Computer-Assisted Optimization of Liquid
Chromatography Separations of Drugs and Related Substances
Tomasz Baczek
Nowadays, liquid chromatography (LC) has an established place
among other analytical techniques. This separation technique
is commonly used in pharmaceutical laboratories. LC method
optimization is usually realized by a trial-and-error method
based on the knowledge of the chromatographic process. Therefore,
LC method development is often time-consuming and involves
intensive exploitation of equipment and a substantial consumption
of chemicals. Over the last few years, the progress in computer
program development has assisted chromatographers in method
development also. The rational selection of optimized experimental
conditions for the chromatographic separation of analytes
can also be realized nowadays by means of specialized algorithms
(especially applying those used in the commercially available
DryLab and ChromSword software). The aim of the study is to
present recent achievements associated with the optimization
of chromatographic separations of drugs and related compounds
realized in reversed-phase liquid chromatography (RP-LC) systems.
Considering applications in pharmaceutical analysis, several
examples are provided. Optimization based just on experimental
chromatographic measurements and additionally employing the
quantitative structure-retention relationships (QSRR) is discussed
in view of the opportunity to obtain practically useful separation
information.
[Back to top]
New Perspectives in the Analysis of Ecdysteroids:
A Promising Group of Biologically Active Compounds
Attila Ványolós and Maria
Báthori
The plant kingdom has remained an inexhaustible reservoir
of compounds with a potential of further therapeutic use.
Ecdysteroids are such biologically active compounds which
were discovered in insects, and later their presence was confirmed
in many plant species. They have a tremendous potential in
the most modern therapy (gene-switch systems).
Ecdysteroids occur in plants together with several other types
of natural compounds with similar chromatographic behavior.
On the other hand, plants usually contain a series of ecdysteroids
with related chemical structures. Sophisticated ana-lytical
methods are therefore needed to identify and quantify these
compounds in complex biological samples.
This paper gives an up-to-date overview on the detection,
identification and quantification of ecdysteroids and discusses
the advantage and disadvantage of the various methods used
in the ecdysteroid analysis. HPLC, TLC and their coupled techniques
play an important role in their analysis, with the use of
which, the complete resolution of wide structural diversity
of ecdysteroids can be attained. This review also offers a
well-elaborated, valuable strategy for ecdysteroid screening.
[Back to top]
Inclusion Complexation Behaviors of 3-Tigloyl-Azadirachtol
With
β-Cyclodextrin
Derivatives
Bo Yang, Yong Chen, Jun Lin and Yu Liu
A series of β-cyclodextrin/3-tigloyl-azdirachtol
inclusion complexes were prepared from β-cyclodextrin,
heptakis(2,3,6-tri-O methyl)-β-cyclodextrin,
mono(6-ethylene-diamino-6 deoxy)-β-cyclodextrin
and mono(6-diethylene- triamino-6 deoxy)-β-cyclodextrin
with 3-tigloyl-azdirachtol (azadirachtin B, AZ-B) in ca.
90%, and their inclusion complexation behaviors were investigated
by means of UV/Vis, 1H NMR
and 2D NMR spectroscopy. The results showed that the AZ-B
could be efficiently encapsulated in the cyclodextrin cavity
in aqueous solution to produce complexes that were more stabilized
than free AZ-B. Furthermore, the water solubility of AZ-B
was obviously increased to high levels up to 4-6.3 mg/ml (calculated
as AZ-B) after inclusion complexation with cyclodextrins.
This satisfactory water solubility and high stability of the
cyclodextrin–AZ-B complexes will be potentially useful,
for their application as biopesticide and herbal medicine
or healthcare products. The enhanced binding ability of cyclodextrins
toward AZ-B was discussed from the viewpoint of the size/shape–fit
concept and multiple recognition mechanism between host and
guest.
[Back to top]
Nitric Dioxide as Biologically Important Radical and
its Role in Molecular Mechanisms of Pancreatic Inflammation
Aleksandra Dabrowska, Dagmara Jacewicz,
Agnieszka Chylewska, Michal Szkatula, Narcyz Knap, Jolanta
Kubasik-Juraniec, MichalWozniak and Lech Chmurzynski
This review addresses a few vital issues pertaining to the
chemical aspect of inflammatory stress mediated by •NO2.
Consequently, in this paper we have presented a short description
of different instrumental methods for the detection of nitrogen
dioxide (•NO2)
in biological material and have demonstrated new instrumental
method focusing on the reaction between an •NO2
and the two novel coordination ions of cis-[Cr(C2O4)(L-L)(OH2)2]+
[with L-L denoting either methyl 3-amino-2,3-dideoxy-α-D-arabino-hexopyranoside
(AaraNH2) or methyl 3-amino-2,3-dideoxy-β-D-arabino-hexopyranoside
(BaraNH2)] studied by the
stopped-flow technique. In order to investigate the
biochemistry of •NO2
mediated inflammatory stress, we developed our method for
specific detection of this radical in biological samples from
pancreatic extracts and managed to identify •NO2
as an agent nitrating membrane localized proteins, as well
as a selective oxidant of critical SH groups within membrane
buried proteins. We have proved that the method is applicable
to •NO2
assessment in tissue samples from rats with acute pancreatitis
induced by L–arginine, where oxidative and nitrosative
stress are supposed to play a key role in the pathomechanism
of the disease.
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