Physicochemical characterization of colloidal drug delivery systems such as reverse micelles, vesicles, liquid crystals and nanoparticles for topical administration

Hyaluronic acid (HA) and chitosan (CH) are biopolymers that are widely used in many biomedical applications and for cosmetic purposes. Their chemical properties are fundamental to them working as drug delivery systems and improving their synergistic effects. In this work, two different protocols were used to obtain zwitterionic liposomes coated with either hyaluronic acid or chitosan. Specifically, the methodologies used to perform vesicle preparation were chosen by taking into account the specific chemical properties of these two polysaccharides. In the case of chitosan, liposomes were first synthesized and then coated, whereas the coating of hyaluronic acid was achieved through lipidic film hydration in an HA aqueous solution. The size and the zeta-potential of the polysaccharide-coated liposomes were determined by dynamic light scattering (DLS). This approach allowed coated liposomes to be obtained with hydrodynamic diameters of 264.4 ± 12.5 and 450.3 ± 16.7 nm for HA- and CH-coated liposomes, respectively. The chemical characterization of the coated liposomal systems was obtained by surface infrared (ATR-FTIR) and nuclear magnetic resonance (NMR) spectroscopies. In particular, the presence of polysaccharides was confirmed by the bands assigned to amides and saccharides being in the 1500–1700 cm−1 and 800–1100 cm−1 regions, respectively. This approach allowed confirmation of the efficiency of the coating processes, evidencing the presence of HA or CH at the liposomal surface. These data were also supported by time-of-flight secondary ion mass spectrometry (ToF-SIMS), which provided specific assessments of surface (3–5 nm deep) composition and structure of the polysaccharide-coated liposomes. In this work, the synthesis and the physical chemistry characterization of coated liposomes with HA or CH represent an important step in improving the pharmacological properties of drug delivery systems.

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Development of lipid nanocarriers for tuberculosis treatment: evaluation of suitable excipients and nanocarriers

Current Drug Delivery ◽

10.2174/1567201818666210212092112 ◽

2021 ◽

Vol 18 ◽

Author(s):

Gabriela Hädrich ◽

Cristiana Lima Dora ◽

Gustavo Richter Vaz ◽

Raphael Boschero ◽

Arthur Sperry Appel ◽

...

Keyword(s):

Drug Delivery ◽

Drug Delivery Systems ◽

Physicochemical Characterization ◽

Entrapment Efficiency ◽

Delivery Systems ◽

Water Soluble ◽

Scanning Calorimetry ◽

Lipid Nanocarriers ◽

Low Toxicity

Background: Lipid nanocarriers have been widely tested as drug delivery systems to treat diseases due to their bioavailability, controlled release, and low toxicity. For the pulmonary route, the Food and Drug Administration favors the use of substances generally recognized as safe, as well as biodegradable and biocompatible to minimize the possibility of toxicity. Tuberculosis (TB) remains a public health threat worldwide, mainly due to the long treatment duration and adverse effects. Therefore, new drug delivery systems to treat TB are needed. Objective: Physicochemical characterization of different lipid-based nanocarriers was used to optimize carrier properties. Optimized systems were incubated with Mycobacterium tuberculosis to assess whether lipid-based systems act as an energy source for the bacteria, which could be counterproductive to therapy. Method: Several excipients and surfactants were evaluated to prepare different types of nanocarriers using high-pressure homogenization. Results: A mixture of trimyristin with castor oil was chosen as the lipid matrix after differential scanning calorimetry analysis. A mixture of egg lecithin and PEG-660 stearate was selected as an optimal surfactant system as this mixture formed the most stable formulations. Three types of lipid nanocarriers, solid lipid nanoparticles, nanostructured lipid carriers (NLC), and Nano emulsions, were prepared, with the NLC systems showing the most suitable properties for further evaluation. It may provide the advantages of increasing the entrapment efficiency, drug release, and the ability to be lyophilized, producing powder for pulmonary administration being an alternative to entrap poor water-soluble molecules. Conclusion: Furthermore, the NLC system can be considered for use as a platform for the treatment of TB by the pulmonary route.

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Development of Lipid-Based Drug Delivery Systems for Gene Therapy: Physicochemical Characterization of Charged Lipid Interactions

Biophysical Journal ◽

10.1016/j.bpj.2015.11.1358 ◽

2016 ◽

Vol 110 (3) ◽

pp. 247a

Author(s):

Bashe Y. Bashe ◽

Sherry S.W. Leung ◽

Karelia H. Delgado-Magnero ◽

Mohsen Ramezanpour ◽

Pieter R. Cullis ◽

...

Keyword(s):

Drug Delivery ◽

Gene Therapy ◽

Drug Delivery Systems ◽

Physicochemical Characterization ◽

Delivery Systems ◽

Lipid Interactions

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Biopolymers with Medical Applications Optimized method for obtaining chitosan-based delivery systems

Revista de Chimie ◽

10.37358/rc.18.7.6411 ◽

2018 ◽

Vol 69 (7) ◽

pp. 1756-1759 ◽

Cited By ~ 1

Author(s):

Luminita Confederat ◽

Iuliana Motrescu ◽

Sandra Constantin ◽

Florentina Lupascu ◽

Lenuta Profire

Keyword(s):

Drug Delivery ◽

Drug Delivery Systems ◽

Average Diameter ◽

Delivery Systems ◽

Cross Linking ◽

Low Molecular Weight ◽

Polymeric Systems ◽

Chitosan Microparticles ◽

Degree Of Swelling

The aim of this study was to optimize the method used for obtaining microparticles based on chitosan � a biocompatible, biodegradable, and nontoxic polymer, and to characterize the developed systems. Chitosan microparticles, as drug delivery systems were obtained by inotropic gelation method using pentasodiumtripolyphosphate (TPP) as cross-linking agent. Chitosan with low molecular weight (CSLMW) in concentration which ranged between 0.5 and 5 %, was used while the concentration of cross-linking agent ranged between 1 and 5%. The characterization of the microparticles in terms of shape, uniformity and adhesion was performed in solution and dried state. The size of the microparticles and the degree of swelling were also determined. The structure and the morphology of the developed polymeric systems were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The average diameter of the chitosan microparticles was around 522 �m. The most stable microparticles were obtained using CSLMW 1% and TPP 2% or CSLMW 0.75%and TPP 1%. The micropaticles were spherical, uniform and without flattening. Using CSLMW in concentration of 0.5 % poorly cross-linked and crushed microparticles have been obtained at all TPP concentrations. By optimization of the method, stable chitosan-based micropaticles were obtained which will be used to develop controlled release systems for drug delivery.

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