硫酸软骨素英国药典.doc

硫酸软骨素英国药典
Test solution (a)
Weigh g (m1) of the substance to be examined, dissolve in water R
and dilute to ml with the same solvent.

Test solution (b)
Dilute ml of test solution (a) to ml with water R.

Reference solution (a)
Weigh g (m0) of chondroitin sulphate sodium CRS, previous
dried as described in the test for loss on drying, dissolve in water R and dilute to ml
the same solvent.

Reference solution (b)
Dilute ml of reference solution (a) to ml with water R.

Titrant solution (a)
Weigh g of cetylpyridinium chloride monohydrate R and dilute to
1000 ml with water R.

Titrant solution (b)
Weigh g of cetylpyridinium chloride monohydrate R and dilute to
1000 ml with water R.

Perform either visual or photometric titration as follows:

Visual titration
Titrate ml of reference solution (a) and ml of test solution (a) wit
titrant solution (a). The solution es turbid. At the end point, the liquid appears clear,
with an almost-white precipitate in suspension. The precipitate is more apparent if ml of a
1 per cent solution of methylene blue R is added before starting the titration. The precipitated
particles are more apparent against the blue background.

Photometric titration
Titrate ml of reference solution (b) and ml of test solution (b)
with titrant sol