37 research outputs found
Preparation and characterization of Eudragit L 100-55/chitosan enteric nanoparticles containing omeprazole using general factorial design: in vitro/in vivo study
No full textBackground and purpose: Omeprazole (OMP) is broadly used for the treatment of gastroesophageal reflux and other acid-related diseases. The current study aimed to prepare enteric-coated nanoparticles containing OMP to achieve a stable powder formulation easily prescribed in children.
Experimental approach: The nanoparticles were formed by complex coacervation method using chitosan (CTS) and Eudragit L100/55 (EU) and the impact of various formulation variables (the concentrations of EU solution and its volume ratio to CTS solution) were assessed using 32 fractional design. The mean particle size (PS), zeta potential (ZP), encapsulation efficiency (EE), and drug loading (DL) were determined. Finally, the pharmacological effects of the optimized OMP enteric nanoparticles were evaluated by an in vivo antiulcer study using Sprague-Dawley rats.
Findings/Results: The highest desirability value was for formulation F5 (containing EU concentration 4 mg/mL and EU/CTS volume ratio 2:1). PS, ZP, EE, and DL of the optimized OMP-loaded nanoparticles were confirmed 810 ± 14 nm, -38.2 ± 1.8 mV, 83.1± 4.2%, and 13.1± 1.5%, respectively. in vitro release studies showed the pH sensitivity of nanoparticles and OMP release was pH-dependent. in vivo pharmacological assessment revealed that the optimized formulation was able to protect rat stomach against ulcer formation induced by indomethacin compared to the group that received normal saline which demonstrated severe peptic ulcer and hemorrhagic spots.
Conclusion and implication: Our results indicated that the enteric EU/CTS nanoparticles were successfully prepared via a complex coacervation method and their efficacy could be comparable with commercial OMP pellets
A simple and sensitive high-performance liquid chromatography method for determination of ciprofloxacin in bioavailability studies of conventional and gastroretentive prolonged-release formulations
No full textBackground: A very simple, sensitive, and accurate high-performance liquid chromatography (HPLC) method with ultraviolet detector was developed and applied to determine ciprofloxacin in human plasma following administration of a gastroretentive formulation developed in our laboratory.
Materials and Methods: HPLC analysis was performed on a C18μ-Bondapack column (250 mm × 3.9 mm) using acetonitrile: potassium dihydrogen phosphate solution 0.1 M (20:80, v/v, pH 3) at a flow rate of 1.5 ml/min and eluate was monitored at 276 nm. After addition of phenacetin as internal standard, plasma samples were treated with 0.1 M phosphate buffer (pH: 7) and followed by extraction with dichloromethane. The method was validated for linearity, precision, accuracy, limit of quantitation (LOQ), robustness, stability, and applied in bioavailability studies of our developed gastroretentive formulation in healthy volunteers.
Results: The calibration curves were linear over the concentration range 0.025–4 μg/ml with the detection limit of 15 ng/ml. Accuracy % were within 93–115 and the coefficient of variance % ranged from 0.20 to 12.8. The very low LOQ (25 ng/ml) allowed avoiding fluorometric detection which is more expensive and is not available in all laboratories. Ciprofloxacin was stable in samples with no evidence of degradation during 3 freeze-thaw cycles and 3 months storage at –70°C.
Conclusion: This validated HPLC method was successfully used for the determination of ciprofloxacin in human plasma following oral administration of controlled release formulation, conventional immediate-release tablets and when administered concomitantly with divalent and trivalent cations such as aluminum-, magnesium-, or calcium-containing products under which the bioavailability of ciprofloxacin is significantly reduced
Preparation and characterization of an injectable thermosensitive hydrogel for simultaneous delivery of paclitaxel and doxorubicin
No full textIn the current study, we aimed to develop a novel injectable thermosensitive hydrogel for simultaneous intratumoral administration of paclitaxel (PTX) and doxorubicin hydrochloride (DOX). At first, mixed micelles composed of Pluronic F127 and alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) was loaded with PTX and their physicochemical properties including particle size, zeta potential, drug loading content, entrapment efficiency, and the drug release were investigated in details. In the second step, the optimized PTX-loaded micelles prepared in the first step were incorporated into the thermosensitive Pluronic F127/hyaluronic acid (PF127/HA) hydrogel containing fixed amount of DOX. Gel formation temperature, rheological properties, injectability, degradation rates of the hydrogel, and the release rate of PTX and DOX from the hydrogel were examined. The mean particle sizes and zeta potentials of the PTX-loaded micelles were 157.5 +/- 20.1 nm and -9.6 +/- 1.1 mV, respectively. The entrapment efficiency of the formulation was about 51. The hydrogel containing PTX-loaded micelles and DOX existed as a solution with low viscosity at 4 degrees C converted to a semisolid upon increasing the temperature to 35 degrees C. DOX was completely released from the hydrogel within 12 h, while 40-80 of PTX could be released from the different formulations during 3 days. This novel thermosensitive hydrogel prepared in the current study could be efficiently used for co-delivery of PTX and DOX in solid tumor types
Comparison the effects of chitosan and hyaluronic acid-based thermally sensitive hydrogels containing rosuvastatin on human osteoblast-like MG-63 cells
Get PDFBackground and purpose: Bone regeneration can be accelerated by localized delivery of statins. Here, we aimed to evaluate the effect of two thermosensitive hydrogels containing rosuvastatin (RSV) on proliferation and differentiation of human osteoblast-like MG-63 cells.
Experimental approach: Firstly, chitosan (CTS)/glycerophosphate (GP)/gelatin (G) thermosensitive hydrogel was prepared and characterized based on rheological properties, in vitro erosion, and release pattern of RSV and then the optimized mixture was loaded with nanoparticles containing RSV(NRSV). Secondly, the effect of NRSV-embedded in CTS/GP/G on cell viability, alkaline phosphate activity, and cell calcification was evaluated using MG-63 cells and compared with RSV-embedded into hyaluronic acid (HA)/Pluronic® F127 (PF127) hydrogel.
Findings / Results: CTS/GP mixtures with 1 and 1.5 % gelatin existing in solution with low viscosity at 4 °C were solidified at 32-34 °C while the mixture containing 2% gelatin was jellified at room temperature. The gelation times of CTS/GP/G with 1 and 1.5% gelatin were 72 and 44 s, respectively. The hydrogel containing 3% w/v NRSV was also converted to a semisolid upon increasing the temperature to 33-36 °C. Due to the higher gel strength of CTS/GP/G compared to HA/PF127 hydrogel, the release rate of RSV from the NRSV-embedded CTS/GP/G hydrogel was significantly slower than that of HA/PF127 system. As revealed by alkaline phosphatase and mineralization assays, NRSV-embedded in CTS/GP/G hydrogel had the most promotive effect on differentiation of osteoblasts among other mixtures.
Conclusion and implication: NRSV-embedded in CTS/GP/G hydrogel could be efficiently used in the future for bone defects such as osteoporosis and bone fractures
Mechanical testing for cartilages
No full textCartilage tissues have unique physical properties that should be characterized, mainly to produce neocartilages in tissue engineering. Mechanical tests play a significant role in functional cartilage tissue engineering to define the mechanical characteristics of tissue-engineered constructs with a view to comparing them with their native tissue. This study aims to briefly describe connections between the contents of cartilages (hyaline cartilage, fibrocartilage, and elastic cartilage) and their mechanical functions, as well as elaborate on the most common relevant mechanical tests, specifically compression and tensile. In addition, materials, methods, and specific modulus for each test are explained in detail, and practical examples are mentioned. As these classifications and measurements show, each type of cartilage construct needs to be examined by specific mechanical tests associated with its physiological conditions.</p
A novel mixed polymeric micelle for co-delivery of paclitaxel and retinoic acid and overcoming multidrug resistance: synthesis, characterization, cytotoxicity, and pharmacokinetic evaluation
No full textThe effect of graphitic target density on carbon nanotube synthesis by pulsed laser ablation method
No full textPreparation and in vitro characterization of histidine trimethyl chitosan conjugated nanocomplex incorporated into injectable thermosensitive hydrogels for localized gene delivery
No full textIncorporation of rosuvastatin-loaded chitosan/chondroitin sulfate nanoparticles into a thermosensitive hydrogel for bone tissue engineering: preparation, characterization, and cellular behavior
No full textDevelopment and optimization of transferrin-conjugated nanostructured lipid carriers for brain delivery of paclitaxel using Box-Behnken design
No full textThe treatment of brain cancer remains one of the most difficult challenges in oncology. The purpose of this study was to develop transferrin-conjugated nanostructured lipid carriers (Tf-NLCs) for brain delivery of paclitaxel (PTX). PTX-loaded NLCs (PTX-NLCs) were prepared using solvent evaporation method and the impact of various formulation variables were assessed using Box-Behnken design. Optimized PTX-NLC was coupled with transferrin as targeting ligand and in vitro cytotoxicity of it was investigated against U-87 brain cancer cell line. As a result, 14.1mg of cholesterol, 18.5mg of triolein, and 0.5 poloxamer were used to prepare the optimal formulation. Mean particle size (PS), zeta potential (ZP), entrapment efficiency (EE), drug loading (DL), mean release time (MRT) of adopted formulation were confirmed to be 205.4 +/- 11 nm, 25.7 +/- 6.22mV, 91.8 +/- 0.5, 5.38 +/- 0.03 and 29.3 h, respectively. Following conjugation of optimized PTX-NLCs with transferrin, coupling efficiency was 21.3mg transferrin per mmol of stearylamine; PS and MRT were increased while ZP, EE and DL decreased non-significantly. Tf-PTX-NLCs showed higher cytotoxic activity compared to non-targeted NLCs and free drug. These results indicated that the Tf-PTX-NLCs could potentially be exploited as a delivery system in brain cancer cells
