Preface

Liposomes have received increased attention in recent years. Nevertheless, liposomes, due to their various forms and applications, require further investigation. These structures can deliver both hydrophilic and hydrophobic drugs. Preparation of liposomes results in different properties for these systems. In addition, there are many factors and difficulties that affect the development of liposome drug delivery structures.

The purpose of this book is to concentrate on recent developments in liposomes. The articles collected in this book are contributions by invited researchers with long-standing experience in different research areas. We hope that the material presented here is understandable to a broad audience, not only scientists but also people with a general background in many different biological sciences. This volume offers up-to-date, expert reviews of the fast-moving field of liposomes and is divided in two major sections encompassing four chapters.

In the first chapter, Dr. Català describes liposomes advances and perspectives. In Chapter 2, lipid hydration and bilayer properties are described by Dr. Disalvo. General perception of liposomes and their formation, manufacturing, and applications are summarized by Dr. Krause Rui in Chapter 3. In Chapter 4, Dr. López-Rendón describes dissipative particle dynamics simulations of self-assemblies of liposomes for drug delivery applications, and finally Dr. Porfire describes the pharmaceutical development of liposomes using the QbD approach.

I would like to express my gratitude to Mr. Luka Cvjetkovic, the publishing process manager, and Intech Open Access publisher for their efforts in the publishing process.

#### **Angel Català**

Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA-CCT La Plata-CONICET), Universidad Nacional de La Plata, La Plata, Argentina

**1**

Section 1

Introduction

Section 1 Introduction

**3**

**Chapter 1**

*Angel Catala*

**1. Introduction**

of liposomes.

places in the human body.

**2. Brief history of liposomes**

the same as phosphatidylcholine alone.

microscopy by negative staining [3].

Point of View

Introductory Chapter: Liposomes -

Liposomes are vesicular arrangements composed of one or more phospholipid

Liposomes can carry both hydrophilic and hydrophobic molecules. The preparation of the liposomes results in different properties for these systems. There are several factors involved in the preparation of liposomes that can modify their structures. Due to its biological compatibility, nonimmunogenicity, greater solubility of chemotherapeutic agents, and its ability to encapsulate a wide variety of drugs, the supply of drugs using liposomes has meant a great advance. The purpose of this book is to focus on recent developments in liposomes. The chapters selected in this book are contributions from invited researchers with long experience in different areas of research. This book offers expert and updated reviews of the field

Liposomes were discovered in 1961 by Alec Bangham, a British scientist who studied blood coagulation. Bangham and RW Horne were testing the new electron microscope of the Agricultural Research Council Institute of Animal Physiology, Babraham, Cambridge, England, when they observed for the first time applying the negative staining technique for the study of the structures of the lipid phase that the dispersions of lecithin contained spherulites composed of concentric sheets [1]. These images served as the first evidence that the cell membrane was a two-layered lipid structure. The width of the lipid layer was estimated at 44 Å. Preparations of phosphatidylcholine-cholesterol of equal molar ratios were described as basically

A year later, in a Cambridge pub, Weissmann in a discussion with Bangham called these structures "liposomes" in honor of the lysosome, a simple organelle whose latency linked to the structure could be interrupted with detergents and streptolysins. [2], and that his laboratory had been studying: liposomes can be easily distinguished from micelles and hexagonal lipid phases by transmission electron

bilayers surrounding an aqueous core. Liposomes were discovered almost six decades ago. Due to its versatility, liposomes are now analyzed for their applicability both in laboratory techniques and in medical studies. Its interest lies in its ability to traverse cell membranes and to transport certain types of molecules to defined

Advances and Perspectives - My

### **Chapter 1**
