The DM423 live spore concentrate is presented as a lyophilized or spray-dried powder with a nominal viable count of 1.0×10^9 CFU/g to 1.0×10^10 CFU/g. Release testing follows ISO 4833-1:2013 for mesophilic spore-forming plate count and Ph. Eur. 2.6.12 / USP <61> for non-sterile microbial enumeration. The API remains viable in dry form only when water activity is maintained below 0.45; exposure to ambient moisture above 60% RH without desiccant protection leads to progressive loss of count that becomes measurable after 48 h. Downstream formulation therefore shares a common constraint: all blending, granulation, compression, and filling operations must be carried out at 20–30°C and 20–35% RH unless otherwise stated, and no terminal steam sterilization is applied to any finished product containing live spores.

Swine Post-Weaning Enteric Dysbiosis Control via Dry Powder and Premix Blending

In swine production, the spore concentrate is incorporated into non-sterile feed premixes and oral powders for managing post-weaning diarrhea episodes associated with gut microbiota disruption. Compliance in this segment is anchored to EU Regulation (EC) No 183/2005 for feed hygiene, ISO 4833-1:2013 for enumeration, and VICH GL18 for stability testing; destination-market feed additive registries may impose additional strain-specific registration requirements. The addition ratio for a spore concentrate at 1.0×10^10 CFU/g is 100–200 g per metric ton of complete feed, yielding 1.0×10^7 to 2.0×10^8 CFU/kg finished feed. In oral top-dress powders, the same API is diluted with lactose monohydrate and silicon dioxide at 1:9 and dosed at 2–5 g per piglet per day for 3–7 days. The downstream production process uses a low-shear ribbon blender at 65% nominal working volume; the API is first dry-extended with carrier at 1:10 to reduce electrostatic segregation, then mixed for 8–12 min at 20–25°C. Pelleting at 75–80°C for 30 s is tolerated by the spore form with an expected loss of 0.3–0.5 log, but post-pelleting liquid spray application is preferred when label claims require exact CFU recovery. Batch-to-batch viable count variance of the API is controlled by release testing and adjusted by assay-based calculation of the carrier dilution factor; the blend is not released until triplicate enumeration across sampling thief locations shows relative standard deviation RSD ≤5.0%. Terminal finished product types are feed premix, oral powder, and dry granules packaged in foil-lined multiwall paper bags with desiccant sachets.

Poultry drinking water delivery requires a water-soluble powder in which the lyophilized spore ingredient is combined with a buffering carrier and a dispersing agent. The formulation is designed for short-duration administration in broiler or pullet flocks, typically 3–5 days, rather than continuous feed inclusion. The addition ratio is 0.5–1.0 g/L of drinking water using a powder standardized to 1.0×10^9 CFU/g; this delivers approximately 1.0×10^8 CFU per bird per day under standard water intake assumptions. Compliance testing for microbiological quality follows Ph. Eur. 2.6.12 / USP <61>, and water-soluble powder stability evaluation follows VICH GL18 with storage at 25°C/60% RH. During production, the powder is blended in a double-cone blender at 50% fill volume for 20 min; the carrier system consists of anhydrous glucose monohydrate 70–80%, anhydrous citric acid 3–5%, and sodium citrate dihydrate 3–5% to maintain a solution pH of 6.2–6.8 after reconstitution. Dissolution time is controlled to ≤60 s in water at 20°C using a 500 μm sieve fraction. Free chlorine in the drinking water above 1.0 ppm is considered incompatible because prolonged contact reduces viable count; acidified water below pH 4.0 should be avoided for the same reason. Terminal finished product types are water-soluble powder, oral solution concentrate, and acidified drinking water premix for automatic medicators.

Can Low-Compression Tableting Maintain Spore Viability in Companion Animal Dosage Forms?

For client-owned dogs and cats, tableting live spore biomass presents a process conflict between dose uniformity and viable count preservation. Direct compression at high force destroys a fraction of the spore population; wet granulation is not viable because the water activity threshold for germination is approached when granulation moisture exceeds 6.0%. The formulation therefore uses roller-compacted dry granulation with microcrystalline cellulose 45%, lactose monohydrate 20%, crospovidone 4%, and magnesium stearate 0.5%; the DM423 spore concentrate at 5.0×10^9 CFU/g is added at 30% of tablet mass. Each 500 mg tablet is targeted to contain 1.0×10^9 CFU, with a finished-tablet water activity of ≤0.35. Compression is performed on a rotary tablet press equipped with flat-faced beveled tooling; compression force is limited to 6–10 kN, and tablet hardness is maintained at 40–70 N to avoid excessive shear-induced loss of viable count. Content uniformity testing follows USP <905> or Ph. Eur. 2.9.40; disintegration is evaluated by USP <701> with a limit of ≤15 min. Film coating, when applied, must be carried out in a pan coater with inlet air below 35°C to avoid spore inactivation; aqueous coating systems are used only when the tablet core water activity remains below 0.30 throughout the coating cycle. Terminal finished product types are uncoated tablets, film-coated tablets, and chewable tablets.

When a companion animal formulation must avoid compression force entirely, the spore concentrate is filled into two-piece hard gelatin or hypromellose capsules as a dry blend. The capsule route is preferred for cats and small dogs because it allows larger payload variability and avoids the friability loss observed with low-hardness tablets. The addition ratio is 40% spore concentrate at 1.0×10^10 CFU/g in a 250 mg size-3 capsule, targeting 1.0×10^9 CFU per capsule. The filler base includes pregelatinized starch 55%, colloidal silicon dioxide 1.5%, and magnesium stearate 0.5%. Production is carried out on a dosator capsule-filling machine at 20–25°C and ≤30% RH; the powder blend is passed through a 600 μm screen before loading into the hopper. In-process controls include fill weight every 15 min and moisture content by Karl Fischer titration with a limit of ≤5.0%. Microbiological enumeration of the finished capsules is performed according to Ph. Eur. 2.6.12 / USP <61>, and the absence of specified pathogens is assessed by Ph. Eur. 2.6.13 / USP <62>. Terminal finished product types are hard gelatin capsules, hypromellose capsules, and moisture-protective blister-packed oral capsules for canine and feline gastrointestinal support.

Ruminant Oral Drench Solutions and the pH-Buffering Requirement

Neonatal calves and lambs receiving DM423 by oral drench require a suspension vehicle whose ionic strength and pH do not trigger premature germination before administration. The API is suspended at 0.2 g/mL in a vehicle composed of 0.9% sodium chloride, 10% glycerol, and 0.5% carboxymethylcellulose sodium; the suspension is buffered to pH 6.5–7.0 with 10 mM phosphate buffer. The target count is 2.0×10^8 CFU/mL, and the dose is 5–10 mL per neonatal animal once daily for 3 days. The production process uses a low-shear propeller mixer at 150–200 rpm and 20–25°C; the spore concentrate is first wetted with glycerol for 10 min to reduce hydrophobicity, then added to the buffered saline vehicle under continuous mixing. The suspension is filled into amber HDPE bottles with child-resistant closures and stored at 2–8°C; a stability study per VICH GL18 supports a shelf life of 12 months when unopened. Microbiological quality of the non-sterile liquid is assessed by Ph. Eur. 2.6.12 and Ph. Eur. 2.6.13. Terminal finished product types are oral drench suspension, suckling bottle suspension, and disposable prefilled oral syringe.

Aseptically processed lyophilized vials represent a separate downstream route in those limited jurisdictions or experimental protocols where parenteral administration of a live spore preparation is explicitly authorized; no routine injectable indication is recognized in the major veterinary pharmacopoeias, and published data for this specific configuration is limited. The fill solution is prepared by dispersing the API at 1.0×10^10 CFU/g in a vehicle containing 4% mannitol and 1% sucrose at pH 7.0, filled at 0.5 mL per glass vial under ISO 14644-1 grade A laminar airflow. Lyophilization is controlled with primary drying at -35°C for 24 h and secondary drying at 20°C for 6 h; the resulting cake is reconstituted to 1 mL immediately before use to give a nominal 1.0×10^7 CFU/vial. Because live spores cannot be terminally steam-sterilized, sterility is achieved by aseptic filtration of excipients and aseptic processing of the spore concentrate; final sterility testing follows Ph. Eur. 2.6.1 and bacterial endotoxin testing follows Ph. Eur. 2.6.14. The spore pellets are collected and washed in sterile 0.9% saline before formulation to remove germination inhibitors. Terminal finished product types are lyophilized cake in glass vials for injection, reconstituted injectable suspension, and diluent co-packaged vials for veterinary hospital use.