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Lipid-Based Nanoparticles: SLN, NLC, and MAD
Published in Madhu Gupta, Durgesh Nandini Chauhan, Vikas Sharma, Nagendra Singh Chauhan, Novel Drug Delivery Systems for Phytoconstituents, 2020
Rita Cortesi, Paolo Mariani, Markus Drechsler, Elisabetta Esposito
The lamellar phase L is characterized by the presence of lamellae leading to a phase described as a well-ordered monodimensional (1-D) lipid and water foils in planar succession. Particularly, the hydrophilic groups lie on the surface of the sheet and the hydrophobic chains are folded inside the lipid layer.
Liposomes
Published in Danilo D. Lasic, LIPOSOMES in GENE DELIVERY, 2019
In general, however, aqueous systems of amphiphiles exhibit a very rich phase behavior and some of the structures formed are shown in Figure 6-2. While in drug delivery basically only the dispersed self-closed lamellar phase — the liposome — is important, in gene transfer several other structures and phases, including the open lipid bilayer fragment, the inverse hexagonal phase, and the micelle, may be also important.
Liquid Crystals as Drug Delivery Systems for Skin Applications
Published in Andreia Ascenso, Sandra Simões, Helena Ribeiro, Carrier-Mediated Dermal Delivery, 2017
To form a liquid crystal, amphiphilic molecules arrange themselves to minimize the free energy of the system when in contact with water, exposing the hydrophilic regions to the aqueous environment and packing the hydrophobic domains to minimize interfacial forces [3]. A lamellar phase is usually obtained at low water contents and consists of planar bilayers separated by layers of water [4,9]. These bilayers present no curvature (zero curvature), although nonlamellar phases are characterized by a nonzero curvature of the lipid bilayer. A lipid bilayer tends to curl to relieve stress within the layers, and this tendency depends on the composition and interactions between the lipids and water [6,21]. The presence of unsaturations in the molecule is also reported to favor the formation of nonlamellar phases by increasing the tendency of a bilayer to curve.
Transport of hydrocortisone in targeted layers of the skin by multi-lamellar liposomes
Published in Journal of Liposome Research, 2023
Antoine Bernasqué, Muriel Cario, Stéphanie Krisa, Sophie Lecomte, Chrystel Faure
Multi-lamellar liposomes, composed of P100, Tween®80 and water, were prepared according to a previously described protocol (Beaumont et al.2021). A lamellar phase obtained from lipids, Tween®80 and water in specific proportions was sheared to obtain MLLs in close contact. Tween®80 increases bilayer fluidity, i.e. MLLs elasticity, and the amount of water fixes liposomes size (Touti et al.2020). First, P100, Tween®80 and, if necessary HyC, were independently weighted and co-solubilized in ethanol. The organic solvent was evaporated under nitrogen flux followed by the addition of water and a freeze-drying process. The dry mixture was then accurately weighed and placed in a 2 ml vial. Half of the final amount of milli-Q water was added, and a first shearing/centrifugation cycle was applied. Four consecutive cycles of shearing/centrifugation were carried out after the addition of the remaining water. In all cases, shearing lasted 2 min and centrifugation was performed at 12 000 RCF for 5 min. The resulting paste was stored for 24h at 4 °C. Three final cycles were performed, giving rise to a vicious cream-like phase, the so-called “paste”, composed of MLLs in close contact that was directly spread on the surface of Strat-M® or human excised skins.
Smart phase transformation system based on lyotropic liquid crystalline@hard capsules for sustained release of hydrophilic and hydrophobic drugs
Published in Drug Delivery, 2020
Xuejuan Zhang, Yujun Xiao, Zhengwei Huang, Jintian Chen, Yingtong Cui, Boyi Niu, Ying Huang, Xin Pan, Chuanbin Wu
It is interesting that it has a good chance for the synergistic release behaviors occurring in a LLC system loaded with both hydrophilic and hydrophobic drugs. According to the results above, hydrophilic drug may present an initial burst release, while for the hydrophobic drug may exhibit a rather slow release. For a LLC system loaded with both hydrophilic and hydrophobic drugs, the appearance of hydrophilic drug may facilitate the release of the hydrophobic drug by promoting the water uptake and further retarding the phase transition from lamellar phase/cubic phase into hexagonal phase. On the contrary, the appearance of hydrophobic drug may retard the release of the hydrophilic drug by decreasing the water uptake and further promoting the phase transition from lamellar phase/cubic phase into hexagonal phase. To be specific, the synergistic release behaviors rely on the balance between the opposite impaction from the two drugs. The balance could be influenced by many factors, such as the drug loading, the logP value of drug and so on. In our previous study, a LLC system loaded with silver nanoparticles and chlorhexidine acetate was established by us. No synergistic release behaviors were observed due to the same hydrophilic property and the huge different in size of two drugs (Zheng et al., 2018). Further study on the LLC system loaded with both the hydrophilic and hydrophobic drugs is meaningful and to be conducted in the near further.
Some observations on the liquid crystalline and gel behaviors of aqueous dispersions of a prodrug
Published in Drug Development and Industrial Pharmacy, 2019
Li Tao, Jinjiang Li, Swathi Pinamanenni, Krishnaswamy Raghavan
This paper focus on formation of lamellar phases by a developmental compound, BMS-830216 [24]. Structurally, BMS-830216 is an amphiphilic compound with a CAC of 0.2 mM. In pH 4 acetate buffer, BMS-830216 forms organized structures, leading to formation of a lamellar phase, in which amount of the lamellar phase increases with concentration, and gel phase (>20 mg/mL). Mechanistically, it appears that BMS-830216 molecules first self-organize (>0.2 mM) and then form a lamellar phase at a concentration >2 mg/mL in solution followed by formation of gels (>20 mg/mL). This gel is highly elastic (high G’). As confirmed by SAXS measurement, the lamellar phase formed by this prodrug seems to have two d-spacing values (5 and 10 nm). Presently it is hypothesized that the gel phase is composed of the lamellar phase as shown in Figure 8. However, the nature of these liquid crystalline phases needs to be further investigated. Practically, understanding of the gel nature of these liquid crystalline phases can facilitate the product development of this prodrug.