Doxycycline Compounded Oral Suspension, Veterinary contains NLT 90.0% and NMT 110.0% of the labeled amount of doxycycline (C22H24N2O8). Prepare Doxycycline Compounded Oral Suspension, Veterinary 50 mg/mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 795). For this preparation, a Paraben solution needs to be separately prepared.

Prepare a Paraben solution by dissolving the Methylparaben and Propylparaben in a sufficient amount of Purified Water to bring to final volume.

Pour the calculated amount of Doxycyline Hyclate powder into a suitable mortar, and mix with about 12.5 mL of Paraben solution until all the solids are dissolved. Do not use more than 5 mL of Paraben solution for each g of the calculated amount of Doxycyline Hyclate. Add the calculated amount of Calcium Hydroxide to the mortar, and mix with the pestle until the mixture thickens up and has a pasty consistency. [Note—Reaction may take a few minutes to occur. The pasty mixture may look dry and harden up which is an indication that the reaction is complete. ]

In a separate beaker, mix Glycerin and Polysorbate 20 with about 30 mL of the Paraben solution. Add Sodium Metabisulfite to the mixture of Glycerin, Polysorbate 20, and Paraben solution with mixing.

Add approximately two thirds of the separately prepared mixture of Glycerin, Polysorbate 20, Sodium Metabisulfite, and Paraben solution to the mortar in small increments with continuous mixing to make an even mixture free of lumps. Transfer the doxycyline mixture from the mortar to an appropriately sized beaker. Rinse the mortar three times, each time with one third of the remaining Glycerin, Polysorbate 20, Sodium Metabisulfite, and Paraben solution, and combine with the doxycycline mixture in the beaker. Add Steviol Glycosides 95% to the beaker. Disperse Carboxymethylcellulose Sodium through a 40-mesh sieve, and mix into the suspension until homogenous. Add sufficient Paraben solution to bring to final volume. Mix well.