Unlocking the Potential of Liposome Drug Delivery

Introduction to Liposome

Owing to their flexible physicochemical and biophysical characteristics, which allow easy manipulation to address various delivery requirements, liposome drug delivery has evolved into an attractive delivery system. Liposome was initially identified and described as swollen phospholipid systems, called Banghasomes, by British hematologist Alec D. Bangham, in 1961 at the Babraham Institute, University of Cambridge. Later, the structural description of liposomes was revealed as small systems constituting one or more closed phospholipid bilayers. The liposomal vesicles are considered as either nanoparticles or microparticles due to their wide range of particle sizes, from 20 nm to several µm, and their ability to encapsulate substances of different polarity and type. Owing to the increasing demand for liposome drug delivery systems, the liposome manufacturing market is estimated to grow at CAGR of 9.7% during the forecast period. 

Formation of Liposomes

The liposomal vesicle is derived from hydration of phospholipids, which are amphiphilic molecules having a hydrophilic head group and two hydrophobic acyl-tails. The phospholipid molecules self-assemble into a bilayered structure in an aqueous environment, where the polar groups of phospholipid align within the bilayer to create a water-attracting surface, while their lipophilic chains face each other to provide a water-free zone. The phospholipid bilayers continuously surround the dispersing aqueous media and create a vesicular system in response to mechanical shaking or heating. The hydrophobic portion contains two fatty acid chains with 10-24 carbon atoms, while the hydrophilic part primarily consists of phosphoric acid linked to a water-soluble molecule. Furthermore, a wide variety of drugs and macromolecules, including DNA, proteins, and imaging agents, can be encapsulated in liposomal vesicles due to their unique ability to entrap both lipophilic and hydrophilic substances.

Diagram for Structure of Liposome - Roots Analysis

Liposome Drug Delivery Platforms

As compared to coventional drug delivery systems, liposomes possess better properties, including sustained or controlled release, lower toxic side effects, site-targeting, protection of drugs from degradation and clearance and superior therapeutic effects. Primarily, there are four types of liposome drug delivery platforms, which include:

  • Conventional Liposomes: These liposomes consist of a lipid bilayer composed of cationic, anionic, or neutral phospholipids and cholesterol, surrounding an aqueous core. The lipid bilayers and the aqueous space can incorporate the hydrophobic or hydrophilic compounds.
  • PEGylated Liposomes: These liposomes consist of modified behavior and characteristics a that are incorporated by the addition of a hydrophilic polymer coating, such as polyethylene glycol (PEG), to the liposome surface in order to provide steric stabilization.
  • Ligand-targeted Liposomes: These liposomes can be employed for site- specific targeting by attaching ligands (including antibodies, peptides, and carbohydrates) to their surface or to the terminal end of the attached PEG chains.
  • Theranostic Liposomes: This represents a single system consisting of a nanoparticle, a targeting element, an imaging and a therapeutic component.
Smart diagram for Liposomal Drug Delivery Systems - Roots Analysis

Therapeutic Applications of Liposome Drug Delivery

In comparison to existing formulations, liposomes offer greater therapeutic efficacy and safety. The various therapeutic applications of liposome drug delivery have been highlighted in the figure.

What are the different applications of Liposomes Drug Delivery systems - Roots Analysis

Methods for Liposome Manufacturing

Liposome manufacturing using various methods involves combining lipids with aqueous media, and in some way modifying the liposomes characteristics, such as size, lamellarity and encapsulation efficiency. Further, the most fundamental stages involved in liposome formulation include dissolution of lipids in organic solvents, drying of the resultant solution, hydration of dried lipid (using various aqueous media), isolation of liposomal vesicles and performing quality control assays. The figure presents various methods used for liposome preparation.

What are the different Liposome Preparation Methods - Roots Analysis

Liposome Analysis and Characterization Methods

Following production, liposome formulations are subjected to evaluation process in which the physicochemical characteristics of liposomes that influence their biological performance and shelf stability, are assessed. The figure highlights several parameters considered during liposome characterization.

liposome drug delivery - Analysis and Characterization - Roots Analysis

Pharmaceutical and Industrial Applications of Liposomes

Liposomes are frequently used for the delivery of drugs, genes, vaccines, and diagnostic products. Other applications of liposomes include the encapsulation of food and cosmetic materials, along with routine chemical analysis. Currently, there are several liposomal formulations clinically approved for the treatment of various diseases, including cancer, fungal and viral infections, and many are currently in advanced stages of clinical studies. The figure highlights various applications of liposomes in pharmaceutical and other industrial segments.

Pharmaceutical and Industrial Applications for liposome drug delivery systems as per Roots Analysis

Challenges in Liposome Development and Manufacturing

Although recent studies have shown encouraging advances in liposome drug delivery systems, there are several challenges that severely hinder development and manufacturing of liposomes. The most common drawback of liposomes is associated with their poor stability under shelf and in vivo conditions. This is mainly caused by the possibility of lipid oxidation and hydrolysis, leakage and loss of hydrophilic cargos, along with particles fission and fusion. Currently, some of these issues can be circumvented by experimenting with formulation adjuvants, such as antioxidants, or post-preparation processing, such as freeze-thawing and freeze-drying. Another major challenge is the manufacturing of liposomes on large-scale since it is a multi-step and multi-test process and therefore, the innovation in this domain is essential.

Future Perspectives

Owing to various advantages offered by liposome drug delivery systems, advanced liposome technologies are being developed to fully substructure the therapeutic applications of liposomes and extensive research is being conducted to develop methods for liposomal formulation with high level of purity and sensitivity. Despite several advancements, there are various challenges in development of liposomes, for which stakeholders are leveraging the expertise of various contract service providers offering development and manufacturing services. These service providers are actively upgrading their capabilities and infrastructure to accommodate the demand for these vesicles. Driven by the growing research efforts, development of advanced methods for preparation and characterization of liposomes, and efforts of various stakeholders, liposome drug delivery systems is likely to witness noteworthy growth in the foreseen future.

For further information on this market, access the SAMPLE PAGES on our latest Liposome Manufacturing Market report.