by
krickos » Thu Sep 17, 2009 7:19 am
Hi
Your company libery or QA/regulatory department should have a subscription (book or/and via internet).
Below you have the Ph Eur LC method, unsure if the gradient table will come out readeble:
Related substances. Liquid chromatography (2.2.29).
Solvent mixture: mobile phase B, mobile phase A (20:80 V/V).
Buffer solution pH 2.8. Dissolve 3.25 g of sodium octanesulphonate R in 1000 ml of water R by stirring for 30 min and adjust to pH 2.8 with dilute phosphoric acid R.
Test solution. Dissolve 50.0 mg of the substance to be examined in the solvent mixture and dilute to 50.0 ml with the solvent mixture.
Reference solution (a). Dilute 5.0 ml of the test solution to 100.0 ml with the solvent mixture. Dilute 2.0 ml of this solution to 100.0 ml with the solvent mixture.
Reference solution (b). Dissolve the contents of a vial of phenylephrine hydrochloride for peak identification CRS (containing impurities C and E) in 2.0 ml of the solvent mixture.
Column:
— size: l = 0.055 m, Ø = 4.0 mm;
— stationary phase: end-capped octadecylsilyl silica gel for chromatography R (3 µm);
— temperature: 45 °C.
Mobile phase:
— mobile phase A: acetonitrile R1, buffer solution pH 2.8 (10:90 V/V);
— mobile phase B: buffer solution pH 2.8, acetonitrile R1 (10:90 V/V);
Time(min) Mobile phase A (per cent V/V) Mobile phase B (per cent V/V)
0 - 3 93 7
3 - 13 93 → 70 7 → 30
13 - 14 70 → 93 30 → 7
Flow rate: 1.5 ml/min.
Detection: spectrophotometer at 215 nm.
Injection: 10 µl.
Relative retention with reference to phenylephrine (retention time = about 2.8 min): impurity C = about 1.3; impurity E = about 3.6.
System suitability:
— symmetry factor: maximum 1.9 for the principal peak in the chromatogram obtained with the test solution;
— peak-to-valley ratio: minimum 5, where Hp = height above the baseline of the peak due to impurity C and Hv = height above the baseline of the lowest point of the curve separating this peak from the peak due to phenylephrine in the chromatogram obtained with reference solution (b).
Limits:
— correction factors: for the calculation of content, multiply the peak areas of the following impurities by the corresponding correction factor: impurity C = 0.5; impurity E = 0.5;
— impurities C, E: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.1 per cent);
— unspecified impurities: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.10 per cent);
— total: not more than twice the area of the principal peak in the chromatogram obtained with reference solution (a) (0.2 per cent);
— disregard limit: 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.05 per cent).
