Section 522.90c - Ampicillin sodium(a)Specifications. Each milliliter of aqueous solution constituted from ampicillin sodium powder contains 300 milligrams (mg) ampicillin equivalents.(b) See Nos. 042791 and 054771 in § 510.600(c) of this chapter.(c)Conditions of use in horses - (1)Amount : 3 mg per pound of body weight twice daily by intravenous or intramuscular injection.(2)Indications for use. For the treatment of respiratory tract infections (pneumonia and strangles) due to Staphylococcus spp., Streptococcus spp. (including S. equi), Escherichia coli, and Proteus mirabilis, and skin and soft tissue infections (abscesses and wounds) due to Staphylococcus spp., Streptococcus spp., E. coli, and P. mirabilis, when caused by susceptible organisms.(3)Limitations. Do not use in horses intended for human consumption. Federal law restricts this drug to use by or on the order of a licensed veterinarian. 72 FR 45158 , Aug. 13, 2007, as amended at 79 FR 16184 , Mar. 25, 2014; 86 FR 57997 , Oct. 20, 2021