The course enables students not only to identify medicines(active ingredients) but also to quantify them in their pure form, in pharmaceutical formulations and in biological liquids. Ultraviolet spectrophotometry is considered a very useful technique in Pharmaceutical Analysis because it is highly sensitive (due to electronic excitations).Theory of electronic spectroscopy- Orbitals involved in electronic transitions. Furthermore, identification of medicines is carried out on the basis of their various chromophore groups(the chromophore concept) because they provide (give) specific spectrum ( which is characterized from its fine structure: maxima, minima, diversions, shoulders, width of electronic excitations,that is,width in the spectrum where the electronic promotions occur, values of specific absorption coefficient, A 1%, 1cm, ratios of absorption intensities in specific maxima, minima or combination of the them, pH solution etc). This method, because of the above mentioned advantages, can be combined with High-Performance Liquid Chromatography in order to detect, identify and quantify the medicines in the presence of the various impurities and metabolites. Ultraviolet spectrophotometry is described extensively in various Pharmacopoeias (Greek, European etc) as a useful means for the identification, the purity control and the quantitative determinations of various medicines in pharmaceutical formulations.
This kind of knowledge is considered fundamental and essential for a possible future professional employment of a Pharmacy graduate in a Pharmaceutical Analysis Laboratory (in addition it includes instrumentation and sampling: dispersive instruments-photomultiplier detectors-rapid scan ultraviolet/visible spectrometers-linear photodiode arrays –Fourier Transform ultraviolet/visible spectrophotometers etc.)
Course Content (Syllabus)
Principles of instrumental methods. Classification of instrumental analytical methods. General characteristics of instrumental methods that are used in Pharmaceutical Analysis. Energy and the electromagnetic spectrum. The nature of the radiated energy(ultraviolet/visible is a form of energy ,which can be described by two complementary theories: the wave theory and the corpuscular theory. Neither of these theories alone can completely account for all the properties of light : some properties are best explained by the wave theory ,and others by the corpuscular theory.The wave theory supports the propagation of light by light waves involves both electric and magnetic forces). Interactions of electromagnetic radiation with matter. Classification of spectroscopic analytical techniques which can be applied in Pharmaceutical Analysis. Generally about spectroscopic methods. Ultraviolet spectrophotometry: Absorption and emission spectra. Principles methods.
Study of ultraviolet spectrum of various representative organic molecules(called chromophores) which are of particular interest in Pharmaceutical Analysis(spectra of benzene ,aniline, pyridine ,phenol and diphenols ,barbituric acid and its derivatives ,xanthines,hormones ,corticosteroids,anti-inflammatory ,anti-histamine).
Quantifications through ultraviolet spectrophotometry: The importance of specific absorption coefficient in quantitative analysis. Spectophotometric quantifications of active ingredients in different formulations. Polar and non- polar solvents. Stock solutions. Quantifications through derivatisation.
Flamespectrophotometry and spectrophotometry of individual absorption: flames, burner nebulisers. Transmission Flamespectrophotometry. Individual absorption spectrophotometry. Instrumentation, sensitivity and detection limit. Applications
The laboratory content of the module has been enriched with electronic educational material that is special software in CD-ROM format which contains the spectra of some representative medicines as well as their spatial configurations, that is, the chemical structure in space (bonds length, ring arrangement, various bonds angles) so that the relation of the structure of the medicine with the relevant spectrum to be obvious. Moreover, a large part of the laboratory practice is done by the students with the application of a special UVPC programme.
The lectures of the modules are enriched by multimedia use (power point presentations, videos etc).