Action and use
Penicillin antibacterial.
Definition
Co-fluampicil Capsules contain Flucloxacillin Sodium and Ampicillin Trihydrate, in the proportions, by weight, 1 part flucloxacillin to 1 part ampicillin.
The capsules comply with the requirements stated under Capsules and with the following requirements.
Content of ampicillin, C16H19N3O4S
92.5 to 107.5% of the stated amount.
Content of flucloxacillin, C19H17ClFN3O5S
92.5 to 107.5% of the stated amount.
Identification
A. Carry out the method for
thin-layer chromatography,
Appendix III A, using a silanised silica gel precoated plate (Merck silanised silica gel 60 F
254s (RP-18) plates are suitable) and a mixture 10 volumes of
acetone and 90 volumes of a 15.4% w/v solution of
ammonium acetate adjusted to pH 5.0 with
glacial acetic acid as the mobile phase. Apply separately to the plate 1 µL of each of the following solutions. For solution (1) shake a quantity of the contents of the capsules containing the equivalent of 0.125 g of each of ampicillin and flucloxacillin with 50 mL of
phosphate buffer pH 7.0 and filter through glass-fibre paper (Whatman GF/C is suitable). Solution (2) contains 0.28% w/v of
ampicillin trihydrate BPCRS in
phosphate buffer pH 7.0. Solution (3) contains 0.26% w/v of
flucloxacillin sodium BPCRS in
phosphate buffer pH 7.0. Solution (4) contains 0.28% w/v of each of
amoxicillin trihydrate BPCRS and
ampicillin trihydrate BPCRS in
phosphate buffer pH 7.0. After removal of the plate, allow it to dry in air, expose to iodine vapour until the spots appear and examine in daylight. In the chromatogram obtained with solution (1) the spot with the lower Rf value corresponds to the principal spot in the chromatogram obtained with solution (3) and the spot with the higher Rf value corresponds to the principal spot in the chromatogram obtained with solution (2). The test is not valid unless the chromatogram obtained with solution (4) shows two clearly separated principal spots.
B. Carry out the method for
thin-layer chromatography,
Appendix III A, using a silanised silica gel precoated plate (Merck silanised silica gel 60 F
254s (RP-18) plates are suitable) and a mixture of 30 volumes of
acetone and 70 volumes of a 15.4% w/v solution of
ammonium acetate adjusted to pH 5.0 with
glacial acetic acid as the mobile phase. Apply separately to the plate 1 µL of each of the following solutions. For solutions (1) to (3) use the solutions described under test A. Solution (4) contains 0.26% w/v of each of
cloxacillin sodium BPCRS,
dicloxacillin sodium BPCRS and
flucloxacillin sodium BPCRS in
phosphate buffer pH 7.0. After removal of the plate, allow it to dry in air, expose to iodine vapour until the spots appear and examine in daylight. In the chromatogram obtained with solution (1) the spot with the lower Rf value corresponds to the principal spot in the chromatogram obtained with solution (3) and the spot with the higher Rf value corresponds to the principal spot in the chromatogram obtained with solution (2). The test is not valid unless the chromatogram obtained with solution (4) shows three clearly separated principal spots.
C. In the Assay, the retention times of the two principal peaks in the chromatogram obtained with solution (1) correspond to those of the principal peaks in the chromatograms obtained with solutions (2) and (3).
Assay
Carry out the method for liquid chromatography, Appendix III D, using the following freshly prepared solutions. For solution (1) add a quantity of the mixed contents of 20 capsules containing the equivalent of 0.25 g of each of ampicillin and flucloxacillin to 350 mL of water, mix with the aid of ultrasound for 15 minutes, cool and dilute to 500 mL with water, filter through glass-fibre paper (Whatman GF/C is suitable) and use the filtrate. Solution (2) contains 0.05% w/v of anhydrous ampicillin BPCRS. Solution (3) contains 0.056% w/v of flucloxacillin sodium BPCRS.
The chromatographic procedure may be carried out using (a) a stainless steel column (25 cm × 4.6 mm) packed with octadecylsilyl silica gel for chromatography (5 µm) (Spherisorb ODS 1 is suitable), (b) as the mobile phase with a flow rate of 1.5 mL per minute a mixture of 50 volumes of methanol and 50 volumes of a buffer solution containing 0.01m diammonium hydrogen orthophosphate and 0.005m tetrabutylammonium hydroxide, the pH of the solution being adjusted to 7.0 with orthophosphoric acid and (c) a detection wavelength of 262 nm.
Calculate the content of C16H19N3O4S and of C19H17ClFN3O5S using the declared content of C16H19N3O4S in anhydrous ampicillin BPCRS and the declared content of C19H16ClFN3NaO5S in flucloxacillin sodium BPCRS. Each mg of C19H16ClFN3NaO5S is equivalent to 0.9538 mg of C19H17ClFN3O5S.
Labelling
The quantity of Ampicillin Trihydrate is stated in terms of the equivalent amount of ampicillin and the quantity of Flucloxacillin Sodium is stated in terms of the equivalent amount of flucloxacillin.
The label states that the preparation contains a penicillin.