57359 - Analysis of Medicines I

Learning outcomes

At the end of the course, which also includes laboratory activity, the student will have knowledge of the methods of quantitative analysis both volumetric and instrumental, as reported in the monographs of the European Pharmacopoeia (Ph. Eur) and Italian Official Pharmacopoeia (FUI), and related to the determination of the purity of raw materials as well as to that of the content of active ingredients in pharmaceuticals. In particular, the student is able to apply the knowledge to real problems such as quantitative analysis and quality control of pharmaceuticals and other health products.

Course contents

INTRODUCTION: Program and aims of the course. Introduction to quantitative pharmaceutical analysis. Quality control of active ingredients of pharmaceutical interest. European Pharmacopoeia (Ph. Eur) and Italian Official Pharmacopoeia (FUI)

SAMPLE PREPARATION: Solubilization of active ingredients of pharmaceutical interest. Extractive techniques. Liquid-solid extraction, liquid-liquid extraction (partition coefficient, effect of pH and electrolytes).

VOLUMETRIC ANALYSIS: general information on Equivalence and titration reactions. Practical aspects in volumetric analysis: instrumentation and laboratory glassware. Acid - base titrations: titration curves of acids and bases. Determination of the end point of the titration: acid-base indicators. Practical aspects: primary standards and applications. Acid - base titration in aqueous-organic solvents. Acid – base titrations in non-aqueous medium: autoprotolysis and acid - base solvents; dielectric constant. Equilibria in glacial acetic acid and titration of weak bases with examples by the pharmacopoeias; titration of weak acids in non-aqueous medium with examples by the pharmacopoeias. Precipitation titrations: Titration curves. Argentometric methods (Mohr, Fajans, Volhard methods). Applications. Complex-formation titrations: EDTA titrations. Influence of pH on EDTA ionization and complexation constants. Indicators for EDTA titrations; applications (direct titrations; back-titrations; substitution titrations). Redox titrations: Overview of oxidizing and reducing agents. Scale of redox potentials and Nernst equation. Redox titration curves and applications.

ELECTROCHEMICAL METHODS OF ANALYSIS: Potentiometry. General principles, electrodes and definition of standard reduction potentials. Electrochemical cells as analytical probes. Most common electrodes: reference electrodes and measurement electrodes. Glass electrode for pH measuring and other selective electrodes. Potentiometric titrations and examples of applications of the pharmacopoeias. Amperometric titrations: Definitions. Amperometric titrations with two measurement electrodes (for diazotization titrations and Karl – Fisher titrations).

QUANTITATIVE ANALYSIS BY UV-vis SPECTROPHOTOMETRY: Theoretical principles of UV-vis absorption. Beer-Lambert law. Methods of chromogenic derivatization. Applications to the analysis of drugs and examples by the pharmacopoeias.

LABORATORY ACTIVITY
- Behavior in lab and risks arising from handling chemicals.
- Acid-base titrations: standardization of sodium hydroxide and hydrochloric acid and purity determination of various compounds according to the pharmacopoeias.
- Acid-base titrations in non-aqueous media of weak acids, weak bases and salts (hydrochlorides) according to the pharmacopoeias.
- Potentiometric acid-base titration (phosphoric acid).
- Precipitation titrations (argentometric methods).
- Redox titrations using permanganate, iodine/iodide etc.
- Complex-formation titrations with EDTA (calcium, magnesium, alluminium etc.) in pharmaceuticals.
- Amperometric titration of sulfonamides.
- Karl-Fisher titration.
- UV-vis spectrophotometry in quantitative analysis: determination of active ingredients (vit B12, procaine, iron etc..) in pharmaceuticals.

Readings/Bibliography

1) V. CAVRINI, V. ANDRISANO, Principî di analisi farmaceutica, Ed. Esculapio, Bologna, quarta edizione 2017.

2) A. CARRIERI, Manuale di analisi quantitativa dei medicinali, EdiSES 2019.

3) Slides from lessons.

4) European Pharmacopoeia 11th Ed

Teaching methods

The theoretical lessons are intended to provide the basic knowledge of quantitative pharmaceutical analysis by titrimetry and instrumental methods. In the laboratory activity the students will apply analytical procedures for the quantitation of raw materials and active ingredients in pharmaceuticals.

As concerns the teaching methods of this course unit, all students (including all the international incoming exchange students, i.e. ERASMUS) must attend Module 1, 2 online [https://www.unibo.it/it/servizi-e-opportunita/salute-e-assistenza/salute-e-sicurezza/sicurezza-e-salute-nei-luoghi-di-studio-e-tirocinio], while Module 3 on health and safety is to be attended in class. Information about Module 3 attendance schedule is available on the website of your degree programme ("studiare"--"formazione obbligatoria su sicurezza e salute").

Assessment methods

The learning assessment should evaluate the achievement of the objects of teaching, specifically:

- Knowledge of the chemical and physico-chemical methods of quantitative analysis, as well as the acquisition of the practical ability necessary for the correct solution of various analytical problems;
- The ability to apply the achieved theoretical and practical knowledge, at the determination of the purity of active ingredients and quality control of commercial formulations;
- The ability to critically discuss and apply the analytical methods reported in the Italian Official Pharmacopoeia and European Pharmacopoeia for quantitation of drugs and purity determination.
The assessment is evaluated by means of laboratory practice test, to be carried out at the end of the lab activity, and final oral examination. The lab practice test has to be passed before oral examination.

Teaching tools

The theoretical lessons will be held by using slides.

The lab activity will be carried out in laboratories equipped with specific reagents and analytical instrumentation suitable for the drug quality control

Office hours

See the website of Michela Rosini