584 research outputs found
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Development and Validation of Micro Emulsion High Performance Liquid Chromatography(MELC) Method for the Determination of Nifedipine in Pharmaceutical Preparation
YesMicroemulsion is a stable, isotropic clear solution consisting of oil based substance, water surfactant and cosurfactant.
There are two types of microemulsion which are used as a mobile phase; water in oil (w/o) and oil in water
(o/w).Microemulsion has a strong ability to solubilize both hydrophobic and hydrophilic analytes, therefore reducing
the pre-treatment of the sample which is needed for the complex sample. Recent reports found that separating the
analytes by using microemulsion high performance liquid chromatography can be achieved with superior speed and
efficiency compared to conventional HPLC modes. In this work, Oil in water (o/w) microemulsion has been used
for the determination of nifedipine in pharmaceutical preparation. The effect of each parameter on the separation
process was examined. The samples were injected into C18, analytical columns maintained at 30°C with a flow rate 1
ml/min. The mobile phase was 87.1% aqueous orthophosphate buffer 15 mM (adjusted to pH 3 with orthophosphoric
acid), 0.8% of octane as oil, 4.5 SDS, and 7.6% 1-butanol, all w/w. The nifedipine and internal standard peaks were
detected by UV detection at λ max 237 nm
The calibration curve was linear (r2=0.9995) over nifedipine concentrations ranging from 1 to 60 μg/ml (n=6). The
method has good sensitivity with limit of detection (LOD) of 0.33 μg/ml and limit of quantitation (LOQ) of 1.005 μg/
ml. Also it has an excellent accuracy ranging from 99.11 to 101.64%. The intra-day and inter-day precisions (RSD
%) were <0.45% and <0.9%, respectively
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In vitro aerodynamic characterization of the dose emitted during nebulization of tobramycin high strength solution by novel and jet nebulizer delivery systems
YesBackground: Chronic infections with Pseudomonas aeruginosa are a leading cause of morbidity in patients
with cystic fibrosis (CF). The aim of tobramycin inhalation therapy in CF patients with chronic pulmonary
infection is to deliver high amounts of drug directly to the site of infection. TOBI® is a tobramycin
nebulizer solution (300 mg/5 ml) approved by FDA for maintenance therapy for patient with CF. The 20%
tobramycin sulfate solution was reported as the optimal and maximal concentration.
Methods: Nebulization of high strength tobramycin solution (20% tobramycin sulfate) (HSTS) has been
assessed in this study by using different selected high performance nebulizer delivery systems: two
different designs of jet nebulizers, and three new nebulizers based on vibrating mesh technology. The
aerosol particle size distribution and output characteristics were measured for in vitro performance
assessment of the nebulizer systems. The methodology was adapted from the current European standard,
EN 13544-1:2001E.
Results: The particle size distribution characteristic measurements showed that all tested nebulizers may
be suitable for inhalation of HSTS. The mean (SD) of highest percentage of fine particles (<5 mm) was
77.64 (2.3) % for Sidestream®, at flow rate 16 L/min. The highest respirable inhaled mass was for Pari LC
Plus® combined with PariBoyN® compressor, with mean (SD) 90.85 (8.6) mg. The mean (SD) of highest
drug wastage percentage was 63.9 (3.9) % for Sidestream® jet nebulizer combined with compressed air
cylinder at flow rate 16 L/min, while the lowest was 2.3 (0.26) % for NE-U22 Omron® (high frequency).
Conclusions: The HSTS can be nebulized by all tested nebulisers but the high frequency NE-U22 Omron®
and Aeroneb Go® are more efficient. When the HSTS compared to TOBI®, the respirable inhaled dose was
increased to more than 73%
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