Action and use
Non-selective phosphodiesterase inhibitor (xanthine); treatment of reversible airways obstruction.
DEFINITION
Etamiphylline Tablets contain Etamiphylline Camsilate. They are coated.
The tablets comply with the requirements stated under Tablets and with the following requirements.
Content of etamiphylline camsilate, C13H21N5O2,C10H16O4S
95.0 to 105.0% of the stated amount.
IDENTIFICATION
Prepare a quantity of the residue as described in the Assay. The residue complies with the following tests.
A. The infrared absorption spectrum, Appendix II A, is concordant with the reference spectrum of etamiphylline (RSV 19).
B. Yields the reactions characteristic of xanthines, Appendix VI.
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
(1) Shake a quantity of the powdered tablets containing 0.2 g of Etamiphylline Camsilate with 5 mL of methanol and centrifuge.
(2) Dilute 1 volume of solution (1) to 500 volumes with methanol.
CHROMATOGRAPHIC CONDITIONS
(a) Use as the coating silica gel HF254.
(b) Use the mobile phase as described below.
(c) Apply 10 μL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm).
MOBILE PHASE
1 volume of 13.5M ammonia, 20 volumes of ethanol (96%) and 80 volumes of chloroform.
LIMITS
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.2%).
ASSAY
Weigh and powder 20 tablets. Dissolve a quantity of the powder containing 0.5 g of Etamiphylline Camsilate in 30 mL of water, make alkaline with 5M ammonia and extract with three 25-mL quantities of chloroform, washing each chloroform extract with the same 5-smL quantity of water. Evaporate the combined chloroform extracts to dryness, dissolve the residue in 25 mL of water and titrate with 0.05M sulfuric acid VS using bromocresol green solution as indicator. Each mL of 0.05M sulfuric acid VS is equivalent to 51.16 mg of C13H21N5O2,C10H16O4S.
