Preparation and assessment of chitosan-coated superparamagnetic Fe3O4 nanoparticles for controlled delivery of methotrexate.

In this study, Fe3O4 superparamagnetic nanoparticles were synthesized and stabilized by chitosan. Then the nanoparticles were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy (TEM). Particle size distribution and Zeta potential of the particles also was assessed using Malvern Zetasizer. The paramagnetic behaviors of the uncoated and chitosan coated nanoparticles were measured using vibrating scanning magnetometry Particles morphology and size ranges of uncoated iron oxide nanoparticles were evaluated by TEM, showing uniform and narrow size distribution about 10 nm. After coating nanoparticles with chitosan and loading of methotrexate (MTX), the change in size was assessed using Zetasizer. Considerable increase in size was observed following the coating of the particles with chitosan and loading with MTX (the average size was 152 nm). Paramagnetic properties of the uncoated and chitosan-coated particles were assessed showing significant decrease in paramagnetic behavior after coating with chitosan, but it was enough to respond to the magnetic field. Finally loading efficiency, release rate and cytotoxicity of MTX were assessed indicating slow release behavior with the same levels of cell toxicity in SK-BR-3 cell lines, suggesting this formulation as a good candidate for the controlled delivery of MTX.

Preparation and in vitro evaluation of carrier erythrocytes for RES-targeted delivery of interferon-alpha 2b.

Carrier erythrocytes is one of the most promising systemic drug delivery systems investigated in recent decades. In this study, human erythrocytes have been loaded with interferon-alpha 2b (IFN) with the aim to benefit the reticuloendothelial system (RES) targeting potential of the carrier cells. Hypotonic preswelling method was used for drug loading in erythrocytes and the entire loading procedure was evaluated and validated. The loaded amount, entrapment efficiency and cell recovery of the loading procedure were 2906.33+/-588.35IU/0.1ml, 14.53+/-2.94%, and 83.61+/-0.49%, respectively, all being practically feasible. The carrier erythrocytes were characterized in vitro in terms of their drug release kinetics, hematological indices, particle size distribution, SEM analysis, and osmotic and turbulence fragility. IFN release from carrier cells was a relatively rapid process in comparison to the cell lysis kinetics, which is unusual considering the whole body of data published on this delivery system and other protein drugs, so far. All the tested in vitro characteristics showed significant, sometimes notable changes upon drug loading procedure, both with and without the drug.

Preparation and in vitro characterization of carrier erythrocytes for vaccine delivery.

Erythrocytes as the most readily available and abundant cells within the body, have been studied extensively for their potential application as drug delivery carriers. In this study, human erythrocytes have been loaded by bovine serum albumin (BSA) as a model antigen/protein using hypotonic preswelling method for targeted delivery of this antigen to antigen-presenting cells (APCs). A series of in vitro tests have been carried out to characterize the carrier cells in vitro, including loading parameters, BSA and hemoglobin release kinetics, hematological indices, particle size distribution, SEM analysis, osmotic and turbulence fragility, and osmotic competency. BSA was loaded in erythrocytes with a loaded amount of 1.98+/-0.009mg with antigen release from carrier cells showing a zero-order kinetic consistent to that of the cell lysis. The apparent cell sizes, measured using laser scattering, were not significantly different from normal erythrocytes, but the real sizes, measured using SEM, and surface topologies were quite different between loaded and unloaded cells. The BSA-loaded cells were remarkably more fragile and less deformable compared to the normal cells. Totally, BSA-loaded erythrocytes seem to be a promising delivery system for reticuloendothelial system (RES) targeting of the antigens.

Antihirsutism activity of Fennel (fruits of Foeniculum vulgare) extract. A double-blind placebo controlled study.

Idiopathic hirsutism is defined as the occurrence of excessive male pattern hair growth in women who have a normal ovulatory menstrual cycle and normal levels of serum androgens. It may be a disorder of peripheral androgen metabolism. In this study we evaluated the clinical response of idiopathic hirsutism to topical Fennel extract. Fennel, Foeniculum vulgare, is a plant, which has been used as an estrogenic agent. The ethanolic extract of Fennel was obtained by using a soxhlete apparatus. In a double blind study, 38 patients were treated with creams containing 1%, 2% of Fennel extract and placebo. Hair diameter was measured and rate of growth was considered. The efficacy of treatment with the cream containing 2% Fennel is better than the cream containing 1% Fennel and these two were more potent than placebo. The mean values of hair diameter reduction was 7.8%, 18.3% and -0.5% for patients receiving the creams containing 1%, 2% and 0% (placebo) respectively.

An approach to controlled-release dosage form of propranolol hydrochloride.

It is possible to release a drug with only limited diffusion from a membrane-coated system using osmotic pumping. In this study, a propranolol osmotic pump was produced by coating the core tablets with cellulose acetate. The effects of membrane thickness, pore size, and stirring rate on the release rate of propranolol hydrochloride were studied. It was found that the thickness of cellulose acetate membrane had a profound effect on the release rate of propranolol hydrochloride from the membrane-coated tablets. The results showed that, when the membrane thickness increased, the release rate of propranolol decreased. The drug release follows a zero-order release when the delivery orifice is between 200 and 800 microns, but when the delivery orifice size is increased to 1000 microns, the release kinetic is abnormal. Fluid dynamics have an important effect on the delivery rate of propranolol from this device; the delivery rate increases as a function of the fluid flow. The drug release is higher under a turbulent condition with high rate of stirring.

Effect of polysorbates on atenolol release from film-coated tablets.

The effects of different concentrations of various polysorbates on the release rate of atenolol from film-coated tablets were evaluated. The release profile of atenolol showed that increasing the concentration of polysorbate resulted in an increase in the release rate of atenolol. The type of polysorbate had less effect on the release rate of atenolol. This study revealed that the release kinetic of atenolol from these film-coated tablets was a function of polysorbate concentration. Correlation coefficients of kinetic models could not solely determine the suitability of the models; the sum of the least square of differences also should be calculated when different kinetic models have similar correlation coefficients.