Strategies to Obtain Encapsulation and Controlled Release of Small Hydrophilic Molecules

Abstract

The therapeutic effect of small hydrophilic molecules is limited by the rapid clearance from the systemic circulation or a local site of administration. The unsuitable pharmacokinetics and biodistribution can be improved by encapsulating them in drug delivery systems. However, the high-water solubility, very hydrophilic nature, and low molecular weight make it difficult to encapsulate small hydrophilic molecules in many drug delivery systems. In this mini-review, we highlight three strategies to efficiently encapsulate small hydrophilic molecules and achieve controlled release: physical encapsulation in micro/nanocapsules, physical adsorption via electronic interactions, and covalent conjugation. The principles, advantages, and disadvantages of each strategy are discussed. This review paper could be a guide for scientists, engineers, and medical doctors who want to improve the therapeutic efficacy of small hydrophilic drugs.

Self-assemblies of pluronic micelles in partitioning of anticancer drugs and effectiveness of this system towards target protein

“…The pharmacokinetics of hydrophilic molecules can be enhanced by incorporating them in nanocarriers which allow prolonged release and targeted delivery. 18,19 The current study focuses on the quantitative understanding of partition characteristics of anti-cancer drugs in pluronic F127 (PEO 100 -PPO 65 -PEO 100 ) and F68 (PEO 76 -PPO 29 -PEO 76 ) micelles and their interaction with protein upon release from micelles. Pluronic F127 and F68 are commonly used pluronic polymers for drug delivery applications.…”

Applications of capillary action in drug delivery

“…Hydrophobic interaction is an attractive technique for encapsulating hydrophobic drugs because of the high drug encapsulation efficiency exceeding 90% (Ong et al, 2016). However, due to the weak interaction between hydrophilic molecules and hydrophobic carriers, the encapsulation efficiency of hydrophilic and/or amphiphilic small molecules is unsatisfactory (Li et al, 2020). In addition, this method involves using organic solvents in the manufacturing process, leading to solvent residue problems in the formulation (Sah and Sah, 2015;Shim and Sah, 2020).…”

“…Cavity loading refers to the encapsulation of drugs in hollow carriers (Li et al, 2020;Shomorony et al, 2019;Wang et al, 2019). The hollow carrier has internal voids to provide a space for accommodating the drug and has a shell as a barrier to prevent the encapsulated drug from suddenly leaking out of the particles.…”

“…Drug delivery is approached by loading the drug in a carrier or medical device and releasing it in a controlled manner to the target area of the body. After decades of development since the 1950s, three major strategies were explored to obtain drug encapsulation and controlled release: non-covalent interaction, cavity loading, and covalent conjugation (Li et al, 2020;Lu et al, 2016;Wang et al, 2019;Zhao et al, 2013). Based on these strategies, numerous drug delivery devices, particles, and implants were reported, many of which were used clinically for disease treatment (Bulbake et al, 2017;Shomorony et al, 2019;Sorenson and Chesnut, 2019;van Eerden et al, 2020).…”

Efficient Hydrophilic Small Molecule Delivery To Retinal Cell Lines Using Solid Lipid Nanoparticle Containing Gel Core

“…Multiple DDS have been previously considered, such as liposomes [15] and polymeric particles [16]. However, these systems are characterized by low encapsulation efficiency, undesired leakage, or initial burst release [17]. For instance, when the water-in oil-in water (W 1 /O/W 2 ) emulsion method is used to prepare lipid based particles such as liposomes, a small hydrophilic molecule can suffer low encapsulation efficiency due to leakage during preparation [18].…”