Isoniazid injection is available as a 100-mg/mL solution in 10-mL multiple-dose vials.3921 Each mL of solution contains isoniazid 100 mg with chlorobutanol 0.25% as a preservative and sodium hydroxide or hydrochloric acid for pH adjustment.3921 The air in the vials is replaced with nitrogen at the time of manufacture.3921 Other formulations, concentrations, or packages sizes may be available.
pH
6 to 7.3921
Isoniazid injection is administered by intramuscular injection only;3921 however, the drug also has been administered by intravenous injection.3922
Isoniazid is stated to be slowly affected by exposure to air and light.3921 Intact vials should be stored at controlled room temperature and protected from light.3921
Crystallization
Isoniazid may crystallize when exposed to low temperatures and may be resolubilized by warming to room temperature.3921
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