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Nanotechnological-Based Drug Delivery System for Magical Molecule Curcumin: Delivery, Possibilities and Challenges
Published in Madhu Gupta, Durgesh Nandini Chauhan, Vikas Sharma, Nagendra Singh Chauhan, Novel Drug Delivery Systems for Phytoconstituents, 2020
Madhu Gupta, Vikas Sharma, Durgesh Nandini Chauhan, Nagendra Singh Chauhan, Kamal Shah, Ramesh K. Goyal
Nanostructured lipid carriers (NLCs), the second generation of lipid particulate system, were architected to overcome the drawbacks associated with SLNs such as limited drug loading, risk of gelation, and drug leakage during storage due to lipid polymorphism. NLCs are prepared by combining the solid lipids with the liquid lipids (Gupta et al., 2012). A blend of a solid and liquid lipid leads to formation of a more irregularly disordered crystalline structure having numerous imperfections. This provides more space for drug accommodation. Moreover, by adjusting the amount of liquid lipids added to the formulation, the drug release can be easily modified.
Solid Lipid Nanoparticles for Anti-Tumor Drug Delivery
Published in Mansoor M. Amiji, Nanotechnology for Cancer Therapy, 2006
Ho Lun Wong, Yongqiang Li, Reina Bendayan, Mike Andrew Rauth, Xiao Yu Wu
The occurrence of lipid polymorphism is a phenomenon fairly unique to SLN as compared to other lipid formulations. Lipid polymorphism is referred to the multiple crystalline forms of solid lipids. One of these polymorphic forms, usually the one that forms perfect crystalline lattice, is more thermodynamically stable. For example, triglyceride has three forms, i.e., α-form, β-form, and β′-form. Among them, only the β-form is stable.36 The relatively less stable or meta-stable forms would eventually transform to the stable polymorphic form, leading to a number of challenges in the development of SLN formulations. Drug molecules are primarily loaded into SLN in the defects of the lattices of solid lipids. When the lipid molecules are converted from the metastable forms into the stable form, they become more orderly packed, and some of the defects in the lattices disappear. As a result, drug expulsion from the lipid core to the particle surface may occur, contributing to high initial burst release and drug leakage during storage.
Polymorphic Phase Behaviour of Membrane Lipids
Published in Sek Wen Hui, Freeze-Fracture Studies of Membranes, 1989
Lipid polymorphism is one area of membrane research which depends most on freeze-fracture electron microscopy.1-10 It would not be wrong to say that many lipid structures would not have been known today if the technique of freeze-fracture electron microscopy was not available. While techniques like X-ray diffraction11 and nuclear magnetic resonance (NMR)12 have been extremely useful in determining lipid phase behavior, they are not very useful in examining the lipid system at microscopic resolution. Situations where the majority of lipids are in one phase and a small proportion of the lipids is in a different phase, in a separated domain, are especially well suited for freeze-fracture electron microscopy. Some intermediate phases in lamellar to hexagonal transition, like lipidic particles,2,3,5 are not detectable by X-ray diffraction, and NMR data can at best be ambiguous. Many such phases have been detected by the use of freeze-fracture electron microscopy. In this chapter, I will discuss the various lipid phases as revealed by freeze-fracture electron microscopy.
Nanostructured lipid carriers for intraocular brimonidine localisation: development, in-vitro and in-vivo evaluation
Published in Journal of Microencapsulation, 2018
Noha S. El-Salamouni, Ragwa M. Farid, Amal H. El-Kamel, Safaa S. El-Gamal
The preparation method of NLCs affects the lipid polymorphism, which differs after solidification in the nanoparticles, compared to bulk lipid (Gonzalez-Mira et al., 2011). GMS was analysed using DSC, recording one heating run and revealing a peak maximum at 64.761 °C. When analysing NLCs dispersion, GMS was previously melted during preparation, thus, DSC involves a second heating run, showing a peak maximum at 60.052 °C. This change in peak maximum may be due to the effect of heating process on the polymorphism of the bulk lipid. There is a pronounced decrease in enthalpy from the bulk lipid to the nanoparticles. Low energy is required to melt less ordered crystals or amorphous substances, compared to crystalline substances which need high energy to overcome the lattice forces (Lin et al., 2007). Thus, low melting enthalpy values suggest less ordered crystal lattice. Lipids in nanoparticles are in less ordered arrangement compared to bulk lipids and the oil incorporation in NLCs causes a less ordered lipid matrix compared to SLNs with a completely amorphous inner core allowing better drug incorporation, as confirmed with the DSC analysis. Comparing the CI results of both formulations confirmed the higher crystallinity of SLNs (19.65%), compared to NLCs (17.12%) which might be due to crystal disturbance in the lipid matrix. A linear correlation was previously reported between the oil content in nanoparticles and the m.p. reduction in NLCs (Gonzalez-Mira et al., 2011). Oils incorporation cause broad melting endotherms due to delayed crystallisation of lipid matrix upon cooling (Gonzalez-Mira et al., 2011).
Innovative nanocompounds for cutaneous administration of classical antifungal drugs: a systematic review
Published in Journal of Dermatological Treatment, 2019
Rafael Silva Santos, Kahynna Cavalcante Loureiro, Polyana Santos Rezende, Luciana Nalone Andrade, Raquel de Melo Barbosa, Antonello Santini, Ana Cláudia Santos, Classius Ferreira da Silva, Eliana Barbosa Souto, Damião Pergentino de Sousa, Ricardo Guimarães Amaral, Patrícia Severino
The SLN are efficient carriers capable of increasing the bioavailability of lipophilic drugs (79–82), with limited to absent cytotoxicity (83). The advantages attributed to SLN for drug delivery and drug targeting include their long-term physicochemical stability, large-scale production facilities, and possibility for sterilized production (84,85). SLN can be administered by several routes, including parenteral, oral, ophthalmic, and topical. However, the success of SLN as drug delivery system is highly dependent on the loaded drug solubility in the lipid matrix, the method used for SLN production, and on the solid lipid polymorphic state. Changes in the lipid polymorphism may undergo crystal lattice reorganization and decrease of drug encapsulation efficiency (86).
Rationale utilization of phospholipid excipients: a distinctive tool for progressing state of the art in research of emerging drug carriers
Published in Journal of Liposome Research, 2023
Koilpillai Jebastin, Damodharan Narayanasamy
Phospholipids can form a variety of complex structures assemblies in water due to their molecular shapes and properties, including micelles, liposomes, and a hexagonal phase. Structure in water demonstrates their polymorphism characteristics (Miere et al. 2021). Understanding lipid polymorphism is critical for developing a stable lipid-based drug product. Temperature, hydrocarbon unsaturation, ionic strength, pH, the presence of divalent cations, such as sodium, potassium, and calcium, and the existence of inverted cone molecules are all factors to consider when it comes to phospholipid polymorphism (Table 1) (Düzgüneş et al. 1981).