eChapter Name: Pharmacokinetics and Pharmacodynamic Studies of Liposomal Formulation
9789372190540
eBook Name: LIPOSOMAL DRUG DELIVERY: A NOVEL APPROACH FOR THERAPEUTICS
Introduction
Liposomal formulations have emerged as a revolutionary platform in drug delivery systems, significantly enhancing the therapeutic efficacy and safety profile of numerous pharmaceutical agents (Crommelin et al., 2015). Liposomes are spherical vesicles composed of lipid bilayers, providing a versatile and biocompatible method for encapsulating both hydrophilic and hydrophobic drugs (Nsairat et al., 2022) (Liu et al., 2022). This encapsulation protects drugs from degradation, reduces systemic toxicity, and enhances their bioavailability (Gubernator, 2011). Beyond their protective capabilities, liposomes serve as an effective platform capable of delivering a diverse array of therapeutic agents, including conventional drugs, proteins, genes, and oligonucleotides (Gupta et al., 2023) (Salave et al., 2022 a) (Juliano et al., 2009). Their attractive biological properties, such as biocompatibility, enhanced solubility of hydrophobic compounds, stability of large molecules, and improved efficacy, position them as ideal candidates for advanced drug delivery systems. These properties enable precise targeting and controlled release strategies, thereby optimizing therapeutic outcomes across various medical applications (Polaka et al., 2021). The pharmacokinetic (PK) and pharmacodynamic (PD) properties of liposomal formulations are crucial determinants of their clinical success. Pharmacokinetics involves the study of the absorption, distribution, metabolism, and excretion (ADME) of drugs, while pharmacodynamics focuses on the biochemical and physiological effects of drugs and their mechanisms of action (Li et al., 2019) (Negus et al., 2018). Understanding these parameters in the context of liposomal delivery is essential to optimize therapeutic outcomes and minimize adverse effects.
Liposomal encapsulation can significantly alter the PK profile of a drug. By modifying drug release kinetics, liposomes can extend the half-life of encapsulated agents, ensuring sustained therapeutic effects and reducing dosing frequency (Rana et al., 2022). Moreover, the ability of liposomes to target specific tissues or cells through passive and active targeting mechanisms enhances drug distribution to the site of action, increasing efficacy and minimizing off-target effects (Salave et al., 2021)(Salave et al., 2022 b). For instance, the liposome surface can be covalently decorated with targeting ligands, enhancing binding and internalization by cancer cells that express receptors for these ligands (Riaz et al., 2018). These ligands can include immunoglobulins or their subunits, such as immunoglobulin fragment antigen binding (Fab’) and single-chain variable fragments (scFv), or nutrient molecules with affinity for cell surface receptors, such as transferrin and folate (Sapra et al., 2003) (Kang et al., 2011) (Cheng et al., 2010). Liposomes’ unique structural properties facilitate the incorporation of targeting ligands, pHsensitive components, and other modifications to refine the drug’s therapeutic profile (Salave et al., 2022 c)(Salave et al., 2023)(Zangabad et al., 2018). They can also be engineered to release encapsulated drugs at specific sites by sensitizing the bilayer membrane to stimuli such as light exposure, oxidation, enzymatic degradation, heat, or radiation (Lee et al., 2017) (Antoniou et al., 2021). The
