Effect of Zeta Potential on the Properties of Nano-Drug Delivery Systems - A Review (Part 2)

The zeta potential (ZP) of colloidal systems and nano-medicines, as well as their particle size exert a major effect on the various properties of nano-drug delivery systems. Not only the stability of dosage forms and their release rate are affected but also their circulation in the blood stream and absorptioninto body membranes are dramatically altered by ZP. In this paper the effect of ZP on the various properties of nano-medicines are reviewed. Furthermore, the ability of employing zeta potential to target drug delivery systems to, and drug release at specific sites of the body are discussed.Keywords: Nano-medicines, Zeta potential, Drug targeting, Site-specific release, Dosage form stabilit

Effect of Zeta Potential on the Properties of Nano-Drug Delivery Systems - A Review (Part 1)

Zeta potential is a scientific term for electrokinetic potential in colloidal systems which has a major effect on the various properties of nano-drug delivery systems. Presently, colloidal nano-carriers are growing at a remarkable rate owing to their strong potential for overcoming old challenges such as poor drug solubility and bioavailability. Furthermore, they show an unlimited capacity in the field of drug targeting. The properties of nano-medicines such as release from dosage forms at specific sites as well as drug circulation and absorption into body membranes are dramatically affected by some physical and chemical characteristics of nano-drugs. Particle size and charge are two major factors which could play key roles in this regard. In this paper, the effect of zeta potential on different properties of nano-drug delivery systems is reviewed.Keywords: Nano-drug delivery, Zeta potential, Drug targeting, Particle size, Particle charg

The effect of chitosan molecular weight on the properties of alginate/ chitosan microparticles containing prednisolone

Purpose: The aim of the present study was to investigate the effect of chitosan molecular weight on size, size distribution, release rate, mucoadhesive properties and electrostatic bonding of alginate/chitosan microparticles containing prednisolone Methods: Three mucoadhesive alginate/chitosan microparticle formulations, f1, f2 and f3, were prepared using low, medium and high chitosan molecular weight (MW) chitosan, respectively, by directly spraying alginate solution into a solution of chitosan and calcium chloride at optimum conditions. Prednisolone was incorporated in the alginate solution prior to spraying. The microparticles were then evaluated for prednisolone content, size, release rate, and mucoadhesive properties using appropriate methods. The formation of electrostatic and hydrogen bonds between chitosan and alginate was assessed by differential scanning calorimetetry (DSC) and Fourier transform infrared (FTIR). Results: The results indicate that high MW chitosan microparticles were significantly (

Preparation of Gold Nanoparticles for Biomedical Applications Using Chemometric Technique

Purpose: To study the effect of process conditions on the size of gold nanoparticles (AuNPs) prepared by chemometric technique.Methods: AuNPs were prepared by adding 5 ml of 5 mM of gold (III) chloride hydrate HAuCl4 (2 mg/mL) to 85 ml of filtered deionized water, then refluxed in a 250 mL flask over a hot plate and heated to boiling point. Five milliliters of sodium citrate solution of varying concentrations were quickly added to the boiling solution and stirred for 30 min until the color turned to wine red. Chemometric approach, based on multivariant analysis, was applied to the optimization of iron oxide nanoparticle size in respect of three parameters, viz, concentration of sodium citrate solution, stirrer speed and ionic strength of the medium. The experiments were performed according to Box-Behnken experimental design.Results: The regression model obtained was characterized by both descriptive and predictive ability. The method was optimized with respect to average diameter as a response. The average diameter of the nanoparticles produced under different conditions were between 17.7 up to 168.8 nm. The criteria for the evaluation of the descriptive capability of a polynomial were R2 = 0.974, standard error = 13.994 and F-ratio = 18.4.Conclusion: It can be concluded that the Box-Behnken experimental design provides a suitable approach for optimizing and testing the robustness of gold nanoparticle preparation method.Keywords: Box-Behnken design, Optimization, Nanoparticles, Gold, Biomedical, Chemometric

Controlled Release Formulation of Indomethacin Prepared With Bee Glue Extracts

Purpose: To prepare and evaluate new sustained release formulations of indomethacin based on extracts of propolis (bee glue).Methods: Standardization of propolis (bee glue) extracts was performed by high performance liquid chromatography (HPLC) and determination of the values of fat and fixed oils. Several indomethacin capsule formulations (F1 - F18) containing varying amounts of chloroform (0.75 - 75 mg) and ethanol extracts (30 - 75 mg) of propolis were prepared. The dissolution rate of the formulations was evaluated by USP dissolution (rotating basket) method I and the release data subjected to various kinetic models. Probable interaction between the drug and propolis extracts was studied by differential scanning calorimetry (DSC).Results: The results show that, although the release rate of formulations F1 - F7 did not show any significant difference (p < 0.05) compared to F18 as blank, the other formulations did. DSC results indicate that incorporation of propolis extract in the formulations lowered indomethacin melting point by between 5 and 30 ºC, indicating interaction between the drug and the waxy extract. Kinetic analysis of the in vitro release data of the formulations showed that the best-fit drug release model varied with the drug:propolis extract ratio of the formulations.Conclusion: Formulation F13 (with equal proportion of drug and bee glue extract) came out best from the dissolution test for indomethacin extended-release capsules as it exhibited zero order kinetics. This fpormulation is therefore suitable for further development as a matrix formulation for controlled release.Keywords: Propolis (bee glue), Indomethacin, Controlled release, Zero order kinetics, Waxy material

Preparation, Characterization and Antibacterial Properties of Silver-Chitosan Nanocomposites Using Different Molecular Weight Grades of Chitosan

Purpose: To study the effect of chitosan molecular weight on the physicochemical and antibacterial properties of silver-chitosan nanoparticles.Methods: A series of silver-chitosan nanoparticles of different sizes were produced using various molecular weight (MW) grades of chitosan by an aqueous chemical reduction method. The nanoparticles were characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), scanningelectron microscopy (SEM), differential scanning calorimetry (DSC), dynamic light scattering (DLS) and laser Doppler electrophoresis (LDE). The antibacterial properties of the nanoparticles were also evaluated by agar diffusion method.Results: The size of the silver-chitosan nanoparticles, ranging from 21.9 to 175.3 nm, was influenced by chitosan MW as well as by other process conditions. Although, the nanoparticles were not stable in liquid form, they however showed good stability in the solid state due to their low zeta potential. SEM images indicate that the nanoparticles were spherical. The antibacterial activity of the nanoparticles against Staphylococcus aureus increased with decrease in particle size owing to increase in surfacearea. The smallest particle size (21.9 nm) was obtained by using high chitosan MW at 4 °C and a stirring speed of 800 rpm.Conclusion: Chitosan is an effective agent for the preparation of silver nanoparticles. The size of the nanoparticles can be modulated by varying both chitosan MW and process conditions such as temperature and stirring speed

Green Synthesis of Silver Nanoparticles Induced by the Fungus Penicillium citrinum

Purpose: To evaluate a green process for the extracellular production of silver (Ag) nanoparticles synthesized and stabilized using Penicillium citrinum isolated from soil.Methods: The pure colonies of Penicillium citrinum were cultured in Czapek dox broth. The supernatant of the broth was examined for the ability to produce silver nanoparticles. The reactions were performed in a dark compartment at 28 oC. After 24 h, the synthesized silver nanoparticles were filtered through a membrane filter (0.45 ƒÊ) and characterized by UV-visible spectroscopy, fluorescence spectroscopy, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR) for particle size, shape and the presence of different functional groups in the nanoparticles.Results: The silver nanoparticles formed were fairly uniform in size with a spherical shape and a Zaverage diameter of 109 nm. FTIR spectra revealed the presence of amide linkage groups which were also found in the fungal extract itself.Conclusion: The current approach suggests that rapid synthesis of nanoparticles of silver nitrate would be suitable for developing a biological process for mass scale production of formulations.Keywords: Green synthesis, Penicillium citrinum, silver nanoparticles