PHARMACEUTICAL ANALYSIS
Learning outcomes of the course unit
The course aims to provide students with the knowledge and understanding of the chemical methodologies and instrumental techniques used in the qualitative identification and quantitative determinations of drug purity. The course also aims to provide students with the ability to use the knowledge and understanding gained in solving experimental problems through individual practical training in the laboratory. At the end of the course the student will be able to demonstrate knowledge and understanding in relation to: a) safety in the chemico-pharmaceutical laboratory; b) experimental protocols for the qualitative identification of an unknown inorganic, organic or organo-metallic compound, by means of its general reactivity, of the reactivity of its functional groups and the analysis of the physico-chemical and spectral properties; c) set up and development of extraction procedures and quantitative dosage of a drug in a mixture or in a complex matrix, d) experimental methods for the determination of physico-chemical properties of pharmaceutical interest; d) main spectroscopic techniques, with particular reference to instrumentation and applications to the quantitative identification of the pharmaceutical active ingredients. The student will be able to apply the knowledge and understanding acquired through the qualitative identification of unknown substances of pharmaceutical interest by evaluating the general reactivity and the reactivity of the embedded functional groups, the extraction and quantitative dosage of active ingredients in final dosage forms, the experimental determination of physico-chemical and spectral properties of unknown substances.
Prerequisites
Knowledge of Organic Chemistry and Analytical Chemistry
Course contents summary
Theory: Safety procedures in the pharmaceutical laboratory. Drug
characters. Solubility and its expressions. Purification Methods.
Experimental measurements of physico-chemical constants. Qualitative
and quantitative elemental analysis. Functional groups analysis.
Identification assays of sample compounds included in the European
Pharmacopeia. Limit assays.
UV-Visible and Infrared spectroscopy: Instrumentation. Applications to
pharmaceutical analysis, identification of reference functional groups.
Mass Spectrometry: ion sources and Mass Analyzers . Mass Spectrometry
applications to pharmaceutical analysis.
Chromatography. Instrumentation. Theory of chromatographic
separations. Analytical method validation: linearity, accuracy, precision,
repeatability and reproducibility, detection and quantitation limit.
Calibration standards and quality controls. Reference guidelines. Impurity
profiling.
Practise: Qualitative organic analysis following the procedures described
in European Pharmacopeia identification assays (Last available Edition). Quantitative
analysis of active pharmaceutical ingredients by UV-VIS spectroscopy.
Experimental determination of physico-chemical properties (pKa)
Course contents
Safety and first aid procedures in the chemical and pharmaceutical
laboratory. Symbols, risk and safety phrases. Hazard chemicals handling
procedures.
Drug organoleptic characters: physical state, color, odour. Solubility and
its expressions. Solvent classification: polarity, hydrogen-bonding, Van
der Waals forces; structure-solubility relationship; ionisation state-solubility
relationship.
Liquid state: boiling point determination, Raoult's law, liquid-gas
diagrams. Solid state: Amorphous and crystalline solids, melting point,impurities influences on melting point. Crystallisation as purification
method: state diagrams, eutectic mixtures. Polymorphism: enantiotropic
and monotropic polimorphs.
Sample treatment. Solvent extraction: liquid-solid, liquid-liquid extraction,
partition coefficient, single and multiple extractions. Variables influencing
extraction yields. Applications to pharmaceutical preparations.
Physical constants determination. Refractive index: measurement,
qualitative and quantitative analysis of liquids. Specific rotation index:
measurement; polarimeter. Optical purity of chiral drugs. Density.
Relative and Absolute density measurement.
Qualitative and quantitative elemental analysis: combustion; Na fusion;
elemental analysers. Functional groups analysis. Crystalline derivatives
preparation. Analytical profiles of classes of drugs . Identification assays
of sample compounds included in the European Pharmacopeia. Limit
assays.
Molecular absorption spectroscopy. UV-Visible. Instrumentation.
Qualitative analysis: UV spectrum-chemical structure correlations.
Identification of reference simple and conjugated chromophores: pH and
solvent effects. Quantitative analysis: Lambert-Beer law; calibration
curve. Infrared Spectroscopy: instrumentation, applications to
pharmaceutical analysis, identification of reference functional groups.
Mass Spectrometry: ion sources (EI, CI, FAB, ESI, APCI, MALDI); Mass
Analyzers (magnetic sector, quadrupole, ToF, 3D and linear ion trap);
Detectors; GC and LC coupling. Mass Spectrometry applications to
pharmaceutical analysis.
Chromatography. Classification: gas and liquid chromatography.
Instrumentation. Theory of chromatographic separations: retention time,
efficiency, selectivity, capacity factor, resolution. Van Deemter equation.
Chromatography separation techniques: liquid/liquid partition; liquid/solid
absorption: TLC, HPLC, GC. HPLC detectors: UV-Vis, Photodiode Array;
Fluorescence, Mass spectrometer).
Analytical method validation: linearity, accuracy, precision, repeatability
and reproducibility, detection and quantitation limit. Calibration
standards and quality controls. Reference guidelines.
Recommended readings
A. CARTA, M.G. MAMOLO: “Analisi Farmaceutica Qualitativa” – EdiSES,
Napoli
V. CAVRINI, V. ANDRISANO: “Analisi Farmaceutica” – Esculapio, Bologna.
F.CHIMENTI: “Identificazione sistematica di composti organici” – Grasso,
Bologna.
D.A. SKOOG, J.J.LEARY: “Chimica Analitica Strumentale” – EdiSES, Napoli.
F. SAVELLI, O. BRUNO: “Analisi Chimico Farmaceutica” – PICCIN, Padova
R.M. SILVERSTEIN, F.X. WEBSTER: "Identificazione spettroscopica di
composti organici" - Ambrosiana Editrice, Milano.
A. VOGEL: “Chimica Organica Pratica” – Ambrosiana Editrice, Milano.
D. SICA, F. ZOLLO: "Chimica dei composti eterociclici farmacologicamente
attivi" - PICCIN, Padova
EUROPEAN PHARMACOPEIA, Last available Edition.
Teaching methods
During the lessons, the general issues related to the chemical methods and experimental techniques employed in the quali-quantitative pharmaceutical analysis will be discussed. The course will be supported by laboratory practical exercises. The exercises will be individual and will aim to provide each student the opportunity to solve experimental problems related to the themes of the course. Practical activities will be planned so that the student can independently work towards solving those chemical problems previously exposed during the theory lessons.
Assessment methods and criteria
The assessment of the achievement of the course's objectives will include an individual practical test in the laboratory performed at the end of the course and a written exam. Through the individual practice test it will be ensured if the student has achieved the goal of applying the knowledge gained in the qualitative identification of unknown substances of pharmaceutical interest as described in the European Pharmacopoeia. By means of the written exam, the student will have to demonstrate that he/she has achieved the goal of the knowledge and understanding of the content of the course. In particular, in the final grade, thirty out of thirty, it will be taken into account the student's ability: a) to report and/or correctly balance the organic or reduction/oxidation chemical reactions (up to a maximum of 8 points out of 30); b) to understand and to properly report the qualitative reactivity of the functional groups and the main reactions of the drugs registered in the European Pharmacopoeia selected as part of the course (up to a maximum of 8 points out of 30); c) to integrate qualitative information on the reactivity, the spectral and chromatographic properties of an unknown drug with the final aim of its identification (up to a maximum of 8 points out of 30); d) to properly communicate concepts related to the use of spectroscopic and chromatographic pharmaceutical analysis with particular reference to the related instrumentation (up to a maximum 6 points out of 30). The evaluation of the laboratory notebook (up to 30 points out of 30), compiled during the course, will also contribute to the definition of the final grade .
