Action and use
Lincosamide antibacterial.
DEFINITION
Lincomycin Premix contains Lincomycin Hydrochloride.
The premix complies with the requirements stated under Premixes and with the following requirements.
Content of lincomycin, C18H34N2O6S
90.0 to 105.0% of the stated amount.
IDENTIFICATION
In the Assay the chromatogram obtained with solution (2) shows a peak with the same retention time as the peak due to the trimethylsilyl derivative of lincomycin in the chromatogram obtained with solution (1).
TESTS
Lincomycin B
Examine solution (3) as described in the Assay but increasing the sensitivity by eight to ten times while recording the peak due to the trimethylsilyl derivative of lincomycin B, which is eluted immediately before the trimethylsilyl derivative of
lincomycin.
LIMITS
The area of the peak due to the trimethylsilyl derivative of lincomycin B, when corrected for the sensitivity factor, is not more than 5% of the area of the peak due to the trimethylsilyl derivative of lincomycin.
ASSAY
Carry out the method for gas chromatography, Appendix III B, using the following solutions.
(1) Add 10 mL of a 0.8% w/w solution of dotriacontane (internal standard) in chloroform to 0.1 g of lincomycin hydrochloride BPCRS, dilute to 100 mL with a 2% w/v solution of imidazole in chloroform, shake to dissolve and filter. Place 4 mL of the filtrate in a 15 mL ground-glass-stoppered centrifuge tube, add 1 mL of a mixture of 99 volumes of N,O-bis(trimethylsilyl)acetamide and 1 volume of trimethylchlorosilane and swirl gently. Loosen the glass stopper and heat at 65° for 30 minutes.
(2) Prepare in the same manner as solution (1) but omitting the internal standard and using a quantity of the premix containing the equivalent of 90 mg of lincomycin in place of the lincomycin hydrochloride BPCRS.
(3) Prepare in the same manner as solution (1) but using a quantity of the premix containing the equivalent of 90 mg of lincomycin in place of the lincomycin hydrochloride BPCRS.
CHROMATOGRAPHIC CONDITIONS
(a) Use a glass column (1.5 m × 3 mm) packed with acid-washed silanised diatomaceous support impregnated with 3% w/w of phenyl methyl silicone fluid (50% phenyl) (OV-17 is suitable) and maintained at 260°.
(b) Use helium as the carrier gas at a flow rate of about 45 mL per minute.
(c) Use an inlet temperature of 260° to 290°.
(d) Use a flame ionisation detector at a temperature of 260° to 290°.
(e) Inject 1 μL of each solution.
DETERMINATION OF CONTENT
Calculate the content of C18H34N2O6S in the premix using the declared content of C18H34N2O6S in lincomycin hydrochloride BPCRS.
LABELLING
The quantity of active ingredient is stated in terms of the equivalent amount of lincomycin.
