Surfactant Effects on Lipid-Based Vesicles Properties

Abstract

Understanding the effect of surfactant properties is critical when designing vesicular delivery systems. This review evaluates previous studies to explain the influence of surfactant properties on the behavior of lipid vesicular systems, specifically their size, charge, stability, entrapment efficiency, pharmacokinetics, and pharmacodynamics. Generally, the size of vesicles decreases by increasing the surfactant concentration, carbon chain length, the hydrophilicity of the surfactant head group, and the hydrophilic-lipophilic balance. Increasing surfactant concentration can also lead to an increase in charge, which in turn reduces vesicle aggregation and enhances the stability of the system. The vesicles' entrapment efficiency not only depends on the surfactant properties but also on the encapsulated drug. For example, the encapsulation of a lipophilic drug could be enhanced by using a surfactant with a low hydrophilic-lipophilic balance value. Moreover, the membrane permeability of vesicles depends on the surfactant's carbon chain length and transition temperature. In addition, surfactants have a clear influence on pharmacokinetics and pharmacodynamics such as sustaining drug release, enhancing the circulation time of vesicles, improving targeting and cellular uptake.

Programmed Recognition between Complementary Dinucleolipids To Control the Self‐Assembly of Lipidic Amphiphiles

“…For compound 1 A , DLS results depended on concentration: it was impossible to obtain good correlograms below the cac, whereas particles with variable, concentration‐dependent sizes in a range from 97.4±42.5 nm (at 500 μ m ) to 244.7±147.3 nm (at 120 μ m ) and good polydispersity values (PDI ≈0.17 and 0.27, respectively) were observed over that threshold (Figure A). This inverse relationship between size and polydispersity values with concentration is common for vesicles from both ionic and neutral surfactants and, together with the found size range and microscopy observations described below, suggests the possible vesicular nature of the 1 A assemblies. Compound 1 T , in contrast, showed narrow signals in the same size range (Figure B); that is, from 86.0±35.2 nm (at 500 μ m ) to 148.8±63.9 nm (at 10 μ m ), with low polydispersity values (PDI ≈0.16 and 0.18, respectively) for the whole range of concentrations at which this dinucleolipid self‐assembles (from 10 μ m 1 T ).…”

Formulation and optimisation of novel transfersomes for sustained release of local anaesthetic

“…Therefore, natural and synthetic phospholipids (EPC and DMPC) were investigated in this study. Additionally, it was reported that the surfactant type and concentration can also affect transfersome size and %EE . For this reason, three surfactants (EA) were used in this DOE in three different percentages (Table ).…”

“…Additionally, it was reported that the surfactant type and concentration can also affect transfersome size and % EE. [18] For this reason, three surfactants (EA) were used in this DOE in three different percentages ( Table 2). Lidocaine-loaded transfersomes were prepared according to the designed experiments (Table 3).…”

“…Novel transfersomes loaded with LA such as lidocaine and intended to be a sustained‐release delivery system could be a better approach to improve patient compliance and achieve the required level of anaesthesia. However, the properties of drug loaded transfersomes usually vary with several parameters such as the nature of lipid and EA component, the concentration of each component, and the preparation process parameters . Although previous studies have attempted to find the optimum composition of transfersomes with some desired properties, a new optimisation study was required since both the drug and sustained‐release transfersomes have not been reported in the literature to date.…”

“…However, the properties of drug loaded transfersomes usually vary with several parameters such as the nature of lipid and EA component, the concentration of each component, and the preparation process parameters. [18] Although previous studies have attempted to find the optimum composition of transfersomes with some desired properties, [19,20] a new optimisation study was required since both the drug and sustained-release transfersomes have not been reported in the literature to date. Optimisation of properties such as size and entrapment efficiency (%EE) was essential in order to obtain transfersomes that could produce the required level of anaesthesia without any systemic side effects.…”