Tablet technology and Analytical Instruments - Overview

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They play a major role in drug development and are mainly
concerned regarding the mechanism of drug delivery. Incase of solid
dosage forms, disintegration is the first step in drug delivery. Rapid
disintegration results in faster dissolution, increased absorption and
finally better bioavailability.
Automation
Fiber-optic dissolution system
Flow injection analysis
These characterization techniques help in the determination of
Internal structure of the tablets
Microhomogeneity
Morphology of the API
The techniques include
Microscopy
Energy dispersive X-ray spectroscopy
X-ray powder diffraction
Thermal analysis
FTIR microspectroscopy
NMR imaging
Mass spectrometry
Raman spectroscopy
Microscopy
Nondestructive techniques like light microscopy, PLM, SEM,
transmission microscopy provides information regarding the composition
and homogeneity of the active drug throughout the dosage form.
Performance characteristics of the dosage form like dissolution
rate, potential flaws in the coating mainly incase of enteric coated
tablets can be determined.
PLM is used to determine the distribution of API within the granulation.
Energy dispersive X-ray spectroscopy
It is used along with SEM.
It also determines the distribution of active drug within the granulation.
Energy dispersive X-ray spectroscopy demonstrates that the API
exists hydrochloride salt in the granulation. In this process high
temperature and drying conditions donot affect the active drug. In this
the active drug is plainly visible within the cross-section of the
granulation matrix, and the energy dispersive X-ray spectroscopy is
used to detect the chlorine content and the overall distribution of the
active drug in the matrix.
X-ray powder diffraction
X-rays get diffracted when they come in contact with lattice
points of crystalline compounds. Lattice is the three-dimensional
arrangement of molecules in a crystal. The diffracted angles of various
rays are different because every crystal compound has its own
characteristic X-ray diffraction pattern.
This technique helps in differentiating various polymorphs, their
hydrates or solvates, and also the phase transitions occuring between
them. It is also useful for determining the changes in the drug
substance like, hydration or dehydration, change from a crystalline to
an amorphous form.
Thermal analysis
Thermal analysis comprises of a group of techniques in which
physical and chemical properties of a substance is measured as a
function of temperature by subjecting them to various controlled
temperature programme.
Thermoanalytical methods
(1) Thermogravimetric analysis ( TGA )
(2) Differential thermogravimetric analysis ( DTG )
(3) Differential thermal analysis ( DTA )
(4) Differential scanning calorimetry ( DSC )
Among these techniques DTA is useful for the characterization of solid pharmaceutical materials.
When the sample and the inert reference materials are subjected to
identical temperatures, the thermal effects associated due to physical
and chemical changes in the sample are measured by a differential
method. The temperature difference between the sample and the inert
reference is known as differential temperature.
DTA technique is used for studying physical changes such as
melting, freezing, crystallization, specific heat and adsorption of a
compound.
DTA is used to study the thermal characteristics of a compound, its stability, degradation, and reaction kinetics.
FTIR microspectroscopy
It is a non-destructive technique used to analyse small samples
and to locate chemical components present within the sample. FTIR
microspectroscopy with special resolution can be used to identify the
minute crystalline particles growing on the tablet.
NMR imaging
Nuclear magnetic resonance spectroscopy is the use of NMR
phenomenon to study the various physical, chemical, and biological
properties of matter. It is based on the physical phenomenon that
elementary particles such as protons and electrons carry an intrinsic
angular moment called spin. It uses radio frequency waves ( RF ) to
induce transitions between different nuclear energy states in a
magnetic field.
NMR is a powerful technique used for the examination of nuclear structure.
It is also used for the determination of molecular structure.
It is used for the identification of compounds using fingerprint technique.
Mass spectrometry
It is a powerful analytical technique that deals with the
determination of the elemental composition of the sample upon
converting it to rapidly moving charged particles.
When a compound is exposed to a high voltage electric current, it
loses electrons and gets converted to positively charged ions. The
basic electric or magnetic acting on these moving charged ions,
deflects them along circular path on a radius that is a function of
their mass to charge ratio i.e., m/e.
It is uesful in the determination of molecular weight, molecular formula and also the structure of compounds.
It is used in the detection of impurity and also in the identification of unknown compounds.
Raman spectroscopy
It deals with the determination of the solid phase physical properties of the active drug in various solid dosage forms.
It doesnot require any sample preparation.
Laser source confocal Raman spectroscopy is used to analyse solid
dispersions, required in the evaluation and determination of the
physical properties.
This technique can be used to measure the homogeneity in a rapid and non-destructive manner.
This page doesnot contain any plagiarised material.
References:
1.Satinder Ahuja and Stephen Scypinski, HANDBOOK OFMODERN PHARMACEUTICAL ANALYSIS, volume 3, 2001;chapter 6 ,pages252-256
2. Gilpin, R. K. and Pachla, L. A. Pharmaceutical and related drugs. Anal. Chem. 71:217R-233R,
1999.
3. Krstulovic, A. M. and Lee, C. R. Defining drug purity through chromatographic and related
methods: current status and perspectives. J. Chrom. B. 689(1):137-153, 1997.
4. Adamovics, J. A., Ed. Chromatographic Analysis of Pharmaceuticals, 2nd ed. Dekker, New
York, 1996.

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Comments

kranthi kumar's picture

Dear Mam, I am glad to know about Tablet technology and Analytical Instruments , the way you presented is simple and easy to understand. Thank you for sharing this information.
TK Indira's picture

Concise yet worthy information. Awaiting for further book pages.

T.K. Indira. http://www.pharmainfo.net/tkindira

-- "Our greatest glory is not in never falling, but in rising every time we fall..." Team 'Char'minar.

P.V.ABHIGNA's picture

Dear madam, Thanks for that simple and very easily understandable information on tablet technology. Do procede with the book pages i will be waiting for more info. Regards,

ABHIGNA.P.V.

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