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Two methods are described for determination of Doxophylline in a solid dosage form. The first method was based on ultraviolet (UV)-spectrophotometric determination of the drug.

It involves absorbance measurement at 274 nm (λ max of Doxophylline) in 0.1 N hydrochloric acid. The calibration curve was linear, with the correlation coefficient between 0.99 and 1.0 over a concentration range of 0.20–30 mg/ml for the drug. The second method was based on high-performance liquid chromatography (HPLC) separation of the drug in reverse-phase mode using the Hypersil ODS C 18 column (250 × 4.6 mm, 5 mm). The mobile phase constituted of buffer acetonitrile (80:20) and pH adjusted to 3.0, with dilute orthophosphoric acid delivered at a flow rate 1.0 ml/min. Detection was performed at 210 nm.

Separation was completed within 7 min. The calibration curve was linear, with the correlation coefficient between 0.99 and 1.0 over a concentration range of 0.165–30 mg/ml for the drug. The relative standard deviation was found to be. Structure of Doxophylline It is a new antibronchospastic drug recently introduced in therapy, with pharmacological properties like theophylline, a potent adenosine receptor antagonist. Doxophylline does not affect gastric acid secretion, either in vivo or in vitro, unlike theophylline.

The lack of side-effects with doxophylline indicates that the drug can be used safely and effectively in the treatment of chronic obstructive pulmonary disease (COPD).[] Doxophylline inhibits phosphodiesterase (PDE IV) activities with the consequent increase of cyclic AMP, which determines relaxation of the smooth musculature. Doxophylline appears to have decreased affinities toward adenosine A1 and A2 receptors, which may account for the better safety profile of the drug. For UV-spectrophotometric and HPLC methods Twenty tablets were weighed and crushed into fine powder. An accurately weighed quantity of powder equivalent to about 125 mg of Doxophylline was transferred into a 250 ml volumetric flask. Add 100 ml of diluent and sonicate it for 30 min with continuous shaking. Make the volume up to the mark with 0.1 N HCl.

This solution was filtered through a 0.45 μm HVLP nylon filter. Make an appropriate dilution to get the final concentration of Doxophylline 20 μg/ml. Appropriated aliquots were subjected to the above methods and the amount of Doxophylline was determined. Assay of the tablet formulation Twenty tablets were weighed and crushed into fine powder. An accurately weighed quantity of powder equivalent to about 125 mg of Doxophylline was transferred into a 250 ml volumetric flask. Add 100 ml of diluent and sonicate it for 30 min with continuous shaking.

Make the volume up to the mark with 0.1 N HCl. Dragon Quest 4 Iso Jogging more. This solution is then filtered through a 0.45-μm HVLP (High Vinyl Liquid Polymer) nylon filter. Make appropriate dilution to get the final concentration of Doxophylline 20 μg/ml.

Appropriated aliquots were subjected to the above methods and the amount of Doxophylline was determined. Assay of the tablet formulation Twenty tablets were weighed and crushed into fine powder. An accurately weighed quantity of powder equivalent to about 125 mg of Doxophylline was transferred into a 250-ml volumetric flask. Add 100 ml of diluent and sonicate it for 30 min with continuous shaking.

Make the volume up to the mark with 0.1 N HCl. This solution was filtered through a 0.45-μm HVLP nylon filter. Make appropriate dilution to get the final concentration of Doxophylline 20 μg-ml.