An Ultra-Sensitive and Selective LC-UV Method for the Simultaneous Determination of Pravastatin, Diltiazem, Naproxen Sodium and Meloxicam in API, Pharmaceutical Formulations and Human Serum
Najma Sultana,
Muhammad Saeed Arayne,
Saeeda Nadir Ali
Issue:
Volume 1, Issue 1, April 2013
Pages:
1-8
Abstract: The aim of the present work was to develop a sensitive liquid chromatographic method for the quantitation of pravastatin and diltiazem along with naproxen and meloxicam using ultraviolet detector. The separation of components was achieved on Purospher Star, C18 (5 µm, 25 x 0.46 cm) column using methanol-water (80:20 v/v) as mobile phase and pH adjusted 3.4 with 85% o-phosphoric acid. Related parameters that may influence the enrichment efficiency of speration of drugs such as the kind and volume of elute, sample flow rate, sample pH, and volume of the drug samples were investi-gated. Detection was performed at ambient temperature at 220 nm by pumping the mobile phase at the flow rate 1.0 mL min-1. The experimental results indicated a good linearity (R 2 > 0.9947) over the concentration range of 0.5-20 µg mL-1 for pravastatin, naproxen and meloxicam and 0.75-24 µg mL-1 for diltiazem. The method was compared by programming the detector adjusting the wavelength with time to match the individual analyte's chromophore which enhanced sensitivity with linear range 0.25-8.0, 0.5-16, 0.4-12 and 0.2-4.0 µg mL-1 for pravastatin, diltiazem, naproxen and meloxicam respectively. The LOD values shifted down from 33, 70, 50 and 80 ng mL-1 to 15, 42, 20 and 10 ng mL-1 for pravastatin, diltiazem, na-proxen and meloxicam respectively. Validation of the method showed good precision and accuracy for the proposed method. All the results indicated that this procedure could allow the simultaneous determination of these four compounds in API, pharmaceutical formulations and serum at trace levels. The method can be successfully applied for the determination of these drugs in human serum, clinical laboratories and in pharmaceutical formulations without diode array detector and without interference of excipients or endogenous components of serum.
Abstract: The aim of the present work was to develop a sensitive liquid chromatographic method for the quantitation of pravastatin and diltiazem along with naproxen and meloxicam using ultraviolet detector. The separation of components was achieved on Purospher Star, C18 (5 µm, 25 x 0.46 cm) column using methanol-water (80:20 v/v) as mobile phase and pH adju...
Show More
Preparation of Dielectric Greases from Some Inorganic Thickeners
A.M. Hassan,
A. M. Hassan,
M. A. Youssif,
M.A. Youssif,
A.M. Mazrouaa,
A. M. Mazrouaa,
R. M. Abou Shahba,
R.M.Abou Shahba,
M.A.E. Youssif,
M. A. E. Youssif
Issue:
Volume 1, Issue 1, April 2013
Pages:
9-16
Received:
2 May 2013
Published:
30 May 2013
Abstract: According to this study wax gel grease (S0) is formulated from base lube oil grade 260/290, transformer oil, microcrystalline wax, additives (0.1-2%) of Polyoxyethylene sorbiton-nano-palmitate antioxidant and 2, 2` methylene bis (4-methyl-6-tertiary butyl phenol) anticorrosion, was found that it had not well enough physico-chemical and dielectric properties, so other thicker may be used as (nano talc, nano kaolin, sodium silicate, ultramarine and silica from rice husk) and added to wax gel in certain proportions in an attempt to improve its physico-chemical properties (viscosity, penetration, dropping point and water resistance) and dielectric properties (dielectric constant, dielectric loss and volume resistivity) at frequency ranging 1-1000KHz at 35°C. Grease includes nano talc and silica from rice husk which has the best dielectric properties
Abstract: According to this study wax gel grease (S0) is formulated from base lube oil grade 260/290, transformer oil, microcrystalline wax, additives (0.1-2%) of Polyoxyethylene sorbiton-nano-palmitate antioxidant and 2, 2` methylene bis (4-methyl-6-tertiary butyl phenol) anticorrosion, was found that it had not well enough physico-chemical and dielectric ...
Show More
