Section 529.778 - Doxycycline(a)Specifications. Doxycycline hyclate solution contains 8.5 percent doxycycline activity. A syringe of N-methyl-2-pyrrolidone and poly (DL-lactide) mixed with a syringe of doxycycline produces 0.5 milliliter of solution.(b)Sponsor. See 054771 in § 510.600(c) of this chapter.(c)Conditions of use in dogs -(1)Amount. Apply subgingivally to periodontal pocket(s) of affected teeth.(2)Indications for use. For treatment and control of periodontal disease.(3)Limitations. Federal law restricts this drug to use by or on the order of a licensed veterinarian. 79 FR 10973 , Feb. 27, 2014