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          Antisera are preparations containing the specific immunoglobulins obtained from serum of animals by purification. Antisera have the specific power of combining with venins or with the toxins formed by bacteria, or of combining with the bacterium, virus or other antigen used for their preparation.

          Antisera are obtained from healthy animals immunized by injections of the appropriate toxins or toxoids, venins or suspensions of micro-organisms or other antigens. The animals are not treated with penicillin antibiotics. If the animals are treated with other antibiotics, a suitable withdrawal period is allowed before collection of blood or plasma. The specific immunoglobulins may be obtained from the immune serum by fractional precipitation and enzyme treatment or by other chemical or physical methods.

          A suitable antimicrobial preservative may be added and is invariably added if the preparations are issued in multidose containers. The final sterile product is distributed aseptically in sterile containers that are then sealed so as to exclude contamination. Alternatively, the final product, after distribution in the sterile containers, may be freeze-dried by a procedure that reduces the water content of the finished product to not more than 3.0 per cent w/w. The containers may then be sealed under vacuum or they may be filled with oxygen-free nitrogen or another suitable inert gas before being sealed; in either case they are sealed so as to exclude contamination. The antiserum is reconstituted immediately before use.

          Antisera prepared by enzyme treatment and fractional precipitation are most stable at about pH 6. The method of preparation of antisera is such that the product loses not more than 5 per cent of its activity per year at this pH when stored at 20º and not more than 20 per cent per year when stored at 37º. Antisera are almost colourless or very faintly yellow liquids free from turbidity and almost odourless except for the odour of any added antimicrobial preservative. Freeze-dried antisera consist of white or pale yellow crusts or powders, freely soluble in water to form colourless or pale yellow liquids having the same characteristics as the corresponding liquid preparations.

          The antiserum, reconstituted where necessary as stated on the label, complies with the following requirements.

Packaging and storage Liquid Antisera shall be stored at a temperature of 2º to 8º, protected from light; avoid freezing. Freeze-dried Antisera shall be stored at a temperature not exceeding 25º, protected from light.

Labelling Complies with the “General Information for Biological Products”, p. 177. In addition, the label on the container states (1) the number of IU or mg per ml, where applicable; (2) the amount of protein per container; (3) the route of administration; (4) the major precautions to be employed in administering animal serum or plasma; (5) the animal source of the preparation.

pH 6.0 to 7.0 (Appendix 4.11), when diluted with saline TS to give a solution containing 1 per cent w/v of protein.

Foreign proteins When examined by precipitation tests with specific antisera, consists exclusively of protein of the declared animal species.

Phenol For an antiserum containing phenol as apreservative, not more than 0.25 per cent w/v when determined by the method described under the “Determination of Phenol”, p. 179.

Protein content Not more than 17 per cent w/v. Carry out the determination as described in the “Determination of Nitrogen” (Method II, Appendix 6.7).

Assay Determine the potency by comparison with an established reference preparation, using the method described in the individual monograph, and express the result in IU or mg per ml, where applicable.

Pyrogens Complies with the “Pyrogen Test” (Appendix 8.2), using not less than 1 ml of Antiserum per kg of the rabbit’s weight.

Sterility Complies with the “Sterility Test” (Appendix 10.1).

Abnormal toxicity Complies with the “Abnormal Toxicity Test” (Appendix 8.1).

Water For freeze-dried antisera, not more than 3.0 per cent w/w. Use Karl Fischer Method (Appendix 4.12), unless otherwise specified in the individual monograph.

The provisions of this monograph apply to the following antisera:

Botulinum Antitoxin

Diphtheria Antitoxin

Tetanus Antitoxin

Rabies Antiserum

Cobra Antivenin

King Cobra Antivenin

Banded Krait Antivenin

Malayan Krait Antivenin

Green Pit Viper Antivenin

Malayan Pit Viper Antivenin

Russell’s Viper Antivenin

Hematotoxic Polyvalent Antivenin (Green Pit Viper, Malayan Pit Viper, and Russell’s Viper Antivenin)

Neurotoxic Polyvalent Antivenin (Cobra, King Cobra, Banded Krait, and Malayan Krait Antivenin).