สารบัญ

Category Antibacterial.

          Cloxacillin Sodium for Oral Solution is a dry mixture of Cloxacillin Sodium and one or more suitable buffers, colours, flavours, and preservatives. It contains the equivalent of not less than 90.0 per cent and not more than 120.0 per cent of the labelled amount of C₁₉H₁₈ClN₃O₅S when constituted as directed.

Strength available 125 mg (base) per 5 ml.

Dose Adults and children weighing more than 20 kg: 250 to 500 mg every 6 hours taken on empty stomach.
          Children up to 20 kg of body weight: 6.25 to 12.5 mg per kg of body weight every 6 hours taken on empty stomach.

Contra-indication; Warning; Precaution See under Penicillin V Potassium, p. 140.

Additional information It is a preferred drug for the treatment of mild to moderate Staphylococcal infections of the skin and soft tissue, respiratory and genitourinary tracts, and joints.
          See also under Penicillin V Potassium, p. 140.

Packaging and storage Cloxacillin Sodium for Oral Solution shall be kept in tightly closed containers and stored at a temperature not exceeding 30º. After constitution, it should be used within the period and stored as stated on the label.

Labelling The label on the container states the quantity equivalent to the amount of cloxacillin.

Identification Carry out the test as described in the “Thin-layer Chromatography” (Appendix 3.1), using a silanized silica gel GF254 as the coating substance and a mixture of 70 volumes of 0.05 M potassium hydrogenphthalate, 30 volumes of acetone and 1 volume of formic acid that has been adjusted first to pH 6.0 with 5 M sodium hydroxide and then to pH 9.0 with 0.1 M sodium hydroxide as the mobile phase. Apply separately to the plate, 1 μl of each of the following solutions. For solution (A), dilute a quantity of the oral solution, equivalent to 50 mg of cloxacillin, to 20 ml with phosphate buffer pH 7.0 and for solution (B), dissolve 25 mg of Cloxacillin Sodium RS in 5 ml of water. After removal of the plate, allow it to dry in air and spray with a mixture of 100 volumes of starch mucilage, 6 volumes of glacial acetic acid and 2 volumes of a 1 per cent w/v solution of iodine in a 4 per cent w/v solution of potassium iodide. The principal spot in the chromatogram obtained from solution (A) corresponds to that obtained from solution (B).

pH 4.0 to 7.5, in the solution constituted as directed in the labelling (Appendix 4.11).

Water Not more than 1.0 per cent w/w (Karl Fischer Method, Appendix 4.12).

Deliverable volume Complies with the requirements described under “Deliverable Volume” (Appendix 4.21).

Assay Carry out the determination as described in the “High-pressure Liquid Chromatography” (Appendix 3.5).
          Mobile phase, Standard preparation, and Chromatographic system Proceed as directed in the Assay under Cloxacillin Sodium Capsules, p. 88.
          Assay preparation Transfer an accurately measured volume of Cloxacillin Sodium for Oral Solution, constituted as directed in the labelling, equivalent to about 50 mg of cloxacillin, to a 50-ml volumetric flask, dilute with Mobile phase to volume, and mix. Filter a portion of this solution through a suitable filter of 0.5 μm or finer porosity, and use the filtrate as the Assay preparation.
          Procedure Proceed as directed under Procedure in the Assay under Cloxacillin Sodium Capsules, p. 88.
          Calculation Calculate the quantity of C₁₉H₁₈ClN₃O₅S, in each ml of the Constituted Oral Solution taken, using the declared content of C₁₉H₁₈ClN₃O₅S in Cloxacillin Sodium RS.

Other requirements Complies with the requirements described under “Oral Liquids” (Appendix 1.16).