QUANTITATIVE ANALYSIS OF DRUGS A - L

The course aims to provide the student with the theoretical knowledge and practical skills for the quantitative analysis of substances of pharmaceutical interest through volumetric and instrumental techniques.

The course includes class lectures and laboratory practice. At the beginning of the course, for each academic year, laboratory practice schedule is defined and published. The laboratory practice includes:

• Consignment of the work station. Safety in laboratory. Glassware and analytical balance usage.
• Titre determination of a NaOH solution. Use of acid-base indicators.
• Standardization of a HCl solution by means of anhydrous Na₂CO₃ as primary standard.
• Quantitative determination of an unknown Na₂CO₃ sample through an acidimetric titration.
• Quantitative determination of an unknown L-(+) tartaric acid sample through an alkalimetric titration.
• Determination of total hardness in drinking water. Determination of mg/L of Ca⁺⁺ ion and Mg⁺⁺ ion.
• Determination of per cent purity of a caffeine sample by UV spectrometry. Beer-Lambert law use.
• pHmeter calibration and use. Potentiometric detection of the end-point in a neutralization titration. Construction of the titration curve.
• Quantitative determination of an unknown caffeine sample by UV spectrometry. Construction of the calibration line.

Course syllabus (6 CFU)

Module 1 (3 CFU)

Introduction to quantitative analysis. Materials, reagents and instruments used in laboratory. Safety in the laboratory. Validation of an analytical method. Accuracy and precision. Rejection of outliers: 4d method and test of Dixon. Analytic balance, weighing operations and methods.

Volumetric analysis

Preparation of standard solutions; control and determination of solution concentration. Volumetric instruments. Calculations in volumetric analysis.

Acid-base titrations

Acidimetry and alkalimetry. Preparation and standardization of acid and basic solutions. Indicators. Acid-base titrations in non-aqueous solvents: generality, intrinsic acidity e basicity, levelling and differentiating effects, classification of solvents. Equilibrium in non-aqueous solvents, criteria of selection of solvent. Applications, particularly, referred to the monographs reported from Italian Official Pharmacopoeia (FUI) XII ed. and European Pharmacopeia (Eur. Ph.) X ed. and supplements. Determination of: sodium carbonate, sodium bicarbonate, mixture of carbonates and alkaline hydroxide, mixture of carbonates and bicarbonates, ephedrine hemihydrate, aminic nitrogen with the Kjeldahl method, tartaric acid, phosphoric acid, citric acid, naproxen, ibuprofen, nimesulide, omeprazole, benzyl benzoate, acetylsalicylic acid, boric acid, saccharine; nicotinamide, diazepam, aspartame, atropine sulfate, sodium benzoate, sulfafurazole.

Titrations based on precipitation

Argentometry. Preparation and standardization of silver nitrate and of ammonium thiocyanate solutions. Titration methods. Applications, particularly, referred to the monographs reported from FUI XII ed. and Eur. Ph. X ed. and supplements. Determination of: alkaline halides, chlorobutanol.

Chelometric titrations

Titration methods. Preparation and standardization of an EDTA solution. Applications, particularly, referred to the monographs reported from FUI XII ed. and Eur. Ph. X ed. and supplement. Determination of Al, Ca, Mg, Pb, Zn, Hg, Fe salts. Water hardness determination.

Titrations based on ox-red reactions

Permanganometric, cerimetric, iodimetric, iodometric, bromometric titrations.

Applications, particularly, referred to the monographs reported from FUI XII ed. and Eur. Ph. X ed. and supplements. Determination of: Ca salts, iron(II) salts, hydrogen peroxide and expression of concentration of hydrogen peroxide solutions in volumes of oxygen produced; iron(II) sulfate, menadione, paracetamol, nifedipine; sodium sulfite heptahydrate, ascorbic acid, ascorbyl palmitate, captopril; potassium permanganate, chloramine, iron(III) chloride; isoniazid, phenol.

Learning outcomes

The purpose of this module is to familiarize students with the various types of volumetric analysis in the pharmaceutical field and with operational techniques. At the end of this module the student will be able to deal with analytical problems from theoretical and practical point of view and he will then properly approach a quantitative analysis using the most appropriate technique, measure and operation; he will also be able to make some simple, both manuals and instrumental laboratory operations. Moreover, he will able to explain selected monographs of the FUI XII ed. and of the Eur. Ph. X ed.

Module 2 (1,4 CFU)

Analytical instrumental methods

Electrochemical analytical methods. Potentiometric determination of pH. Biamperometric determination of primary aromatic amino-nitrogen: application to sulphamides reported from FUI XII ed. and Eur. Ph. X ed. and supplements.

Optical methods of analysis

Spectrophotometry UV/Vis. General principles. Instrument. Quantitative analysis: working wavelength selection, method for the determination of concentration, construction of a calibration curve. Applications, particularly, referred to the monographs reported from Eur. Ph. X ed. Determination of: chloramphenicol palmitate.

Spectrofluorimetry. General principles. Instrument. Quantitative analysis: methods for the determination of concentration.

LABORATORY PRACTICES (1,6 CFU)

Quantitative analysis of substances reported from FUI XII ed. and from Ph. Eur. X ed. using volumetric and instrumental analysis methods.

1. E. Abignente, D. Melisi, M. G. Rimoli – Principi di analisi quantitativa DEI medicinali - Ed. Loghìa, Napoli.
2. G. C. Porretta - Analisi DI PREPARAZIONI FARMACEUTICHE. Analisi quantitativa. - Ed. CISU, Roma.
3. D. C. Harris - Chimica Analitica Quantitativa - Zanichelli, Bologna.
4. R. Cozzi, P. Protti, T. Ruaro - Analisi chimica: moderni metodi strumentali - Zanichelli, Bologna.
5. Vogel's Texbook of Quantitative Chemical Analysis - Fifth edition - Ed. Longman Scientific & Tecnical.
6. Farmacopea Ufficiale Italiana XII edition.
7. European Pharmacopoeia X edition and supplements.
8. V. Cavrini, V. Andrisano - Principi di analisi farmaceutica. Ed. Esculapio. Bologna
9. A. Carrieri - Manuale di Analisi Quantitativa dei Medicinali. EdiSES. Napoli