Liposome Development Service

Liposomes, as an effective drug delivery system, have a good application prospect and can be used in many fields such as tumor, infection, nerve, anesthesia, ophthalmology and diagnosis. BOC Sciences is committed to providing a full range of liposome development services for the biomedical field, from development to preclinical studies, to help customers accelerate product development.

Definition and structure of liposome

Liposomes are drug vesicles formed by lipid self-assembly with bilayer (monolayer) and/or concentric multiple bilayer (multilayer) closed central water cavity, prepared from lecithin and ceramide. Liposome technology can wrap drugs with high toxicity and side effects, poor stability in the blood and fast degradation in liposome, and carry drugs concentrated in the lesion site to achieve targeted drug delivery, thereby improving efficacy, reducing toxicity and enhancing stability. Liposome technology is a very active drug delivery technology in the global pharmaceutical field in recent years. Liposomes are suitable for injection, oral administration, eye administration, pulmonary inhalation and transdermal administration. At present, most liposomes are administered by injection.

Structure diagram of liposome.

According to the structure, liposomes can be divided into single-compartment liposomes, multicompartment liposomes and polycystic liposomes. According to charge, liposomes can be divided into neutral liposomes, negatively charged liposomes and positively charged liposomes. According to performance, liposomes can be divided into general liposomes and special liposomes.

Characteristics and uses of different types of liposomes

Function of liposome

Liposome injection can load insoluble drugs into lipid nanostructures in the form of encapsulation, increase drug solubility and improve drug stability, and the lipid structure can be degraded in vivo, with high safety.

Liposomes can achieve targeted drug delivery and reduce toxic side effects. The inhibition ability of body organs to different particle sizes is different, and the passive targeting effect of drugs can be achieved through the particle size control of liposome injection. At the same time, the lipid surface can modify the ligand of related receptors, guide the drug-containing lipid nanoparticles to actively target specific sites, selectively concentrate the drug concentration in the target tissues, target organs, target cells or cell-like structures, increase the concentration of the drug in the focal area, and carry out targeted therapy. While improving the bioavailability of the drug, the drug may reduce the damage to other organs and tissues.

Liposomes can change the release characteristics of the drug, so that the drug can be released continuously, thereby reducing the frequency of administration and improving patient compliance.

Liposome development services at BOC Sciences

Liposomal formulation

Liposomes are mainly composed of active substances and lipids, but may contain functional lipids modified with, for example, polyethylene glycol (PEG) and/or ligands (targeting parts). In addition, liposome preparations contain excipients, such as pH regulators and stabilizers, such as those found in general injections. Formulations that include lipid compositions can greatly influence the quality, pharmacokinetic and pharmacodynamic properties, and safety of liposome drug products. In the liposome development stage, it is necessary to determine the composition of the liposome, the active substance and the number of each lipid, the molar ratio of lipids (including functional lipids) to the active substance or the percentage by weight, etc.

In recent years, liposome technology has developed rapidly, and new liposome technologies such as lipid nanoparticle (LNP), immune liposome, long circulating liposome, magnetic liposome, membrane fusion liposome and flexible liposome have appeared. We are able to design individual liposome formulations according to customer requirements. Our services cover the design and optimization of liposomes, including the selection of lipid materials, characterization of the physicochemical properties of liposomes, and evaluation of drug carrier efficiency. Customers can choose to integrate small molecule drugs, biological macromolecules (such as nucleic acids, proteins) and multifunctional multi-component drugs into a single liposomal system. The types of liposomes we can provide are:

Manufacturing process

Advanced manufacturing techniques and equipment, such as microfluidic, ultrasonic and high pressure homogenization, are used for large-scale preparation of liposomes. Our production process strictly follows the quality management system to ensure the consistency and high standard of quality of liposome products.

Liposome quality study

Quality studies of liposomes include determination of drug content and detection of lipid-related degradation products, particle size and distribution, structure and morphology, Zeta potential, encapsulation rate, thermodynamic properties of lipid membranes, encapsulation volume, state of encapsulated drugs, in vitro drug release and drug leakage, pH value, drug-to-lipid ratio of liposome drugs, viscosity, stereosis, pyrogen and bacteria of liposome drug suspension endotoxin, etc.

Particle size, structure and morphology

The size and distribution of liposomes affect the ability of liposomes to encapsulate drugs, the stability of liposome particles, drug release behavior and pharmacokinetics in vivo, which are usually detected by dynamic light scattering (DLS). The structure and morphology of the liposomes are characterized by microscopic techniques such as atomic force microscopy (AFM), environmental scanning electron microscopy (ESEM), transmission electron microscopy (TEM), and confocal laser scanning microscopy (CLSM).

Zeta potential

The surface charge of liposomes influences the aggregation, clearance, tissue distribution, and cell interaction of liposomes. The Zeta potential is generally used to measure the strength of the repulsive electrostatic interaction between naturally charged colloidal particles to evaluate the surface charge of liposomes. A particle with an absolute Zeta potential greater than 30 mV is generally considered stable.

Encapsulation rate and drug load

The encapsulation rate refers to the percentage of the drug contained in the liposome (including the aqueous phase and the lipid bilayer) to the total drug in the preparation, while the drug carrying capacity is the percentage of the drug contained in the liposome to the total drug in the liposome (including the drug and the membrane material). The encapsulation rate affects the safety and stability of the drug, while the drug loading quantity affects the clinical application dose of the drug.

Stability test

Lipids with unsaturated acyl chains undergo oxidative degradation, which then causes a change in phase transition temperature, thus affecting the stability of the liposome. Both saturated and unsaturated lipids undergo hydrolysis to form hemolytic lipids and free fatty acids. The degradation of lipids can cause the liposome drug product to lose its original function or lead to the disintegration of the lipid bilayer structure. Therefore, it is necessary to determine the stability of each lipid component in liposome drug products. Due to long-term storage, PEG and other molecules used to modify liposomes may undergo conformational changes, resulting in less efficient modification. Therefore, it is necessary to explore the influence of the water phase type or storage conditions outside the liposome on the quality properties of the liposome.

Preclinical study

Why choose BOC Sciences?

• Multiple liposome preparation techniques: solvent injection method, film hydration method, reverse evaporation method, double emulsion method, microfluidic method
• End-to-end services
• Deep expertise and practical experience in the field of liposome development
• Advanced equipment and facilities: Pharmaceutics laboratory, clinical pharmacokinetics laboratory and bioanalytical laboratory
• Customized liposome development solution
• Regulatory compliance
• Strict quality control

FAQ

1. What types of molecules can liposomes deliver?

Liposomes are capable of carrying hydrophilic and hydrophobic compounds, including DNA, RNA, certain drugs, and nutrients. These molecules can be encapsulated when liposomes are formed.

2. What are the applications of liposomes in drug delivery?

Liposomes can encapsulate drugs internally, and extend their retention time in the blood by reducing drug metabolism and excretion, thus achieving sustained release and targeted delivery of drugs. They are widely used in the delivery of anti-cancer drugs and the enhancement of antibacterial efficacy.

3. What are the preparation methods of liposomes?

The common preparation methods of liposomes include organic solvent film casting, reverse phase evaporation, mixed micelle solution and mechanical method. These methods can control the size distribution and the number of layers of the liposomes.