37259 - Modified Release Pharmaceutical Systems

Learning outcomes

At the end of the course, the student will possess the necessary skills for the formulation and production of modified drug release systems. In particular, the student is able to: - characterize modified drug release systems from a biopharmaceutical point of view; - identify the different mechanisms underlying drug release from unconventional pharmaceutical systems; - know the most recent strategies aimed at improving the bioavailability of drugs; - design nano- and micro-pharmaceutical carriers on the basis of the chemical-physical properties of the drug, of the support materials and of the preparation methodologies.

Course contents

MODIFIED DRUG RELEASE - 5 cfu (Prof. B. Luppi)

Bioavailability and Modified drug release

Immediate release systems and modified release systems: definition, biopharmaceutical, clinical and indutrial aim. The concept of biopharmaceutics. LADME. Bioequivalence. Important factors influencing steady-state plasma concentration of a drug. Repeat action versus sustained action drug therapy.

Polymers in the pharmaceutical field and drug diffusion in polymeric systems

Classification. Crystalline and amorphous polymers. Polymer synthesis: addition polymerization and condensation polymerization. Water-soluble polymers. Water-insoluble polymers. Biocompatible and biodegradable polymers. Examples of pharmaceutical polymers.

Polymeric systems and main mechanism of drug release. Theory of mass transfert. Fick's First and Second Lows. Diffusion coefficient. Partition coefficient. Stagnant diffusion layer. Macroporous systems, microporous systems and unporous systems. Diffusion through hydrate polymers. Solubility and partition coefficient.

Modified drug delivery systems

Controlled release kinetics. A) Diffusion controlled devices. I) Monolithic devices. II) Reservoir devices. B) Chemically controlled devices. C) Solvent controlled devices: I) Osmotically controlled devices. II) Swelling controlled devices. D) Pulsatile systems and intelligent systems.

Enhancement of drug solubility and dissolution rate

Dissolution and Noyes-Whitney Law. Thermodynamic parameters (Gibbs equation and Van't Hoff equation). Solubility enhancement strategies. Micelle formation. Cyclodextrins and phase-solubility diagrams. Salt formation.

MICRO and NANOCARRIERS - 2 cfu (Prof. F. Luppi)

Drug targeting and site-specific delivery

Main mechanisms of spatial controlled drug release: drug targeting and site-specific delivery. Passive targeting. Physical targeting. Active targeting.

Pharmaceutical carries. Micro and nanoparticulate carriers (spheres, capsules, liposomes, niosomes, polymeric micelles, solid lipid nanoparticles), macromolecular carriers and cellular carriers.

MICRO and NANOCARRIERS LABORATORY ACTIVITY 1 cfu (Prof. B. Luppi, shift A and shift B)

The students are divided into two successive shifts (A and B). The practical acivities in the laboratory will be conducted in small groups of students and will concern the preparation and characterization of vesicular systems (liposomes, transferosomes) and polymeric micro and nanoparticles (albumin, polylactic acid, alginate, chitosan, polyvinylpyrrolidone).

Readings/Bibliography

A.T. Florence, D. Attwood, Physicochemical Principles of Pharmacy, Pharmaceutical Press, 2011

P. Colombo et al., Principi e Tecnologie Farmaceutiche, casa Editrice Ambrosiana, Milano, II Ed. 2015

Slides discussed during the course

Teaching methods

Theoretical lectures. Practical Activities. Multiple choise test for discussion during class and lab.

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

Oral examination. For the oral examination, registration by AlmaEsami list is required.

Teaching tools

Video-projector and PC.

Office hours

See the website of Barbara Luppi