A Comprehensive Physicochemical, In Vitro and Molecular Characterization of Letrozole Incorporated Chitosan-Lipid Nanocomplex.

PURPOSE: The aim of this study is to show a new mesomicroscopic insight into Letrozole (LTZ) loaded nanocomplexes and their ex vivo characteristics as a drug delivery system. METHODS: The LTZ loaded hybrid chitosan-based carrier was fabricated using a modified ionic crosslinking technique and characterized in more detail. To understand the mechanism of LTZ action encapsulated in the hybrid polymer-lipid carrier, all-atom molecular dynamics simulations were also used. RESULTS: The physicochemical properties of the carrier demonstrated the uniform morphology, but different drug loading ratios. In vitro cytotoxic activity of the optimized carrier demonstrated IC50 of 67.85 ± 0.55 nM against breast cancer cell line. The ex vivo study showed the positive effect of nanocomplex on LTZ permeability 7-10 fold greater than the free drug. The molecular dynamic study also confirmed the prsence of hydrophobic peak of lipids at a distance of 5 Å from the center of mass of LTZ which proved drug entrapment in the core of nanocomplex. CONCLUSIONS: The hybrid nanoparticle increased the cytotoxicity and tissue permeability of LTZ for oral delivery. This study also confirmed the atomic mesostructures and interaction of LTZ in the core of hybrid polymer-lipid nanoparticles.

Amphotericin-B and vancomycin-loaded chitosan nanofiber for antifungal and antibacterial application

In the present study, a mucoadhesive non-woven fiber mat (d= 116 nm) was fabricated by the electrospinning method using chitosan (80% Wt), polyethylene oxide (10% Wt), cysteine (4% Wt) and drugs (6% Wt), respectively. In addition, a comparative study was conducted to define effect of drugs and mucoadhesive agent on the nanofiber formation. FTIR, SEM, DSC and DMA were used to investigate the chemical and physical properties of the nanofibers. In vitro release of the drugs was assessed over a 48-hour period by the total immersion method. Release data were fitted to kinetic models, including the zero-order, first-order, Higuchi matrix, and Hixson-Crowell. Zone inhibition investigations were used to describe the inhibition content of vancomycin and amphotericin B loaded in the mats. The SEM images displayed a slight decrease in the fiber diameter with adding drugs and mucoadhesive agents. FTIR spectra confirmed that any undesirable reaction between VAN-AMB and CS-PEO was not observed. DSC test recognized the uniform distribution of drugs in the polymeric bead of the fiber without any crystal form. The elasticity modulus of the nanofiber was in an acceptable range for oral mucosa (approximately 5 Mpa). The results indicated that biodegradable mucoadhesive nanofibrous membranes released high concentrations of VAN in the first 24 hours, but the AMB release was affected in more controlled phenomena

Biomacromolecular Based Fibers in Nanomedicine: A Combination of Drug Delivery and Tissue Engineering.

BACKGROUND: Biopolymers based materials (polysaccharides, lipids, proteins, and nucleic acids) are one of the basic resources in bio-engineering sciences because of desirable features. Moreover, nanobiotechnology innovates nanomaterial and associated technique in nano medicine (drug delivery and tissue engineering). METHODS: In the nano-medicine, fibers are introduced as a successful biomimetic extracellular matrix scaffolds and drug carrier systems. Electrospinning as a simple and cost-effective technique is used to design nanofibers. Natural polymers including chitosan, alginic acid, hyaluronic acid, collagen, gelatin, and albumin are excellent candidates for electrospinning. However, these types of biopolymers typically have difficulty in electrospinning. RESULTS: Therefore, for spinning of these polymers, the condition of the procedure including solvent, copolymer addition, cross-linker addition, and optimization of spinning should be done. CONCLUSION: The present study gathered information about fiber-based nanodevices from biopolymers in a drug transportation or tissue engineering.

Pharmacokinetic study of furosemide incorporated PLGA microspheres after oral administration to rat.

OBJECTIVES: The purpose of the current study was to assess the feasibility of microspheres from biocompatible polymer for oral bioavailability (BA) enhancement of potent sulfonamide- type loop diuretic- Furosemide - which used in the treatment of congestive heart failure, caused edema, cirrhosis, renal disease and as an adjunct in acute pulmonary edema. The comparatively poor and inconstant BA of furosemide, which occurs site-specifically in the stomach and upper small intestine, has been ascribed to the poor dissolution of furosemide. MATERIALS AND METHODS: In attempt to enhance the drug BA, poly (dl-lactic-co-glycolic acid) (PLGA) microspheres of furosemide were obtained using solvent-evaporation method and the carrier characteristics were investigated subsequently. RESULTS: The in vivo performance of optimum formulation was assessed by pharmacokinetic evaluation of drug after orally administration of free and loaded in microspheres to rats (4 mg/Kg). For this reason, the concentration of drug in plasma was measured by a new developed and sensitive method of HPLC. Acceptable drug loading and encapsulation efficiency of microspheres were obtained to be 70.43 and 85.21 %, respectively. Microspheres provided improved pharmacokinetic parameters (Cmax = 147.94 ng/ml, Tmax = 1.92 hr) in rats as compared with pure drug (Cmax = 75.69 ng/ml, Tmax = 1.5 hr). The obtained AUC of drug in microsphere was 10 fold higher than of the free drug. CONCLUSION: The results showed that the prepared microspheres successfully improved BA of the poorly water-soluble drug effectively.

New surface-modified solid lipid nanoparticles using N-glutaryl phosphatidylethanolamine as the outer shell.

BACKGROUND: Solid lipid nanoparticles (SLNs) are colloidal carrier systems which provide controlled-release profiles for many substances. In this study, we prepared aqueous dispersions of lipid nanoparticles using a modified, pH-sensitive derivative of phosphatidylethanolamine. METHODS: SLNs were prepared using polysorbate 80 as the surfactant and tripalmitin glyceride and N-glutaryl phosphatidylethanolamine as the lipid components. Particle size, polydispersity index, and zeta potential were examined by photon correlation spectroscopy. Morphological evaluation was performed using scanning electron microscopy, atomic force microscopy, and differential scanning calorimetry. RESULTS: Photon correlation spectroscopy revealed a particle hydrodynamic diameter of 165.8 nm and zeta potential of -41.6.0 mV for the drug-loaded nanoparticles. Atomic force microscopy investigation showed the nanoparticles to be 50-600 nm in length and 66.5 nm in height. Differential scanning calorimetry indicated that the majority of SLNs possessed less ordered arrangements of crystals compared with corresponding bulk lipids, which is favorable for improving drug-loading capacity. Drug-loading capacity and drug entrapment efficiency values for the SLNs were 25.32% and 94.32%, respectively. CONCLUSION: The SLNs prepared in this study were able to control the release of triamcinolone acetonide under acidic conditions.