Yupingfeng Oral Solution Veterinary Grade API is supplied as a concentrated aqueous-ethanolic extract prepared from Astragalus membranaceus, Atractylodes macrocephala, and Saposhnikovia divaricata at a typical crude drug input ratio of 3:1:1. The intermediate is vacuum-concentrated at ≤65°C, filtered through 1.0 µm stainless steel depth media, and standardized to 35–45 g/100 g dry matter before release. pH is controlled to 4.5–6.0 by the receiving formulation unit. Residual ethanol in water-diluted stock preparations is maintained below <0.5% v/v, but batch-specific verification against VICH GL18 and the relevant veterinary pharmacopoeia monograph is required. The scenarios below cover downstream processing into drinking-water solutions, medicated premixes, granules, water-soluble powders, tablets, capsules, and injections. Each scenario identifies the unit operation, critical process window, terminal performance attribute, and applicable standard designation.

If the concentrate is injected into a 1:128 proportioner drinking-water manifold

Stock solution preparation begins with reverse-osmosis water meeting hardness ≤150 mg/L as CaCO₃ and total dissolved solids <500 mg/L to prevent precipitation of Saposhnikovia chromone fractions. A calibrated Dosatron D25RE2 or similar positive-displacement proportioner set at 1:128 to 1:256 is connected after the particulate filter and before the final drinking line. UVC irradiation above 40 mJ/cm² accelerates polyphenol oxidation; the injection point is therefore located downstream of any UV disinfection module. The concentrate is pre-diluted in a vented stainless steel mixing tank at 20–25°C, agitated at 150 rpm for 15 min, and passed through a 200 mesh basket strainer before entering the proportioner. Medicated water stability on farm is limited to 8 h at ambient temperature and 24 h at 2–8°C. Beyond these windows, microbial load in poultry drinker lines frequently exceeds 10⁴ CFU/mL, and polysaccharide hydrolysis can shift pH by more than 0.5 units. Terminal product is a clear-to-opalescent oral solution for swine respiratory stress programs. Acidification below pH 4.0 is avoided because chromone glycosides undergo acid-catalyzed cleavage. Chlorinated water above 1 ppm free chlorine requires sodium thiosulfate addition at a 2:1 molar ratio to chlorine. Compliance with EU 2019/6 Article 115 and water-quality guidance per USP <1231> is required.

Premix distribution after 3-ton horizontal ribbon mixing

For feed mill integration, the liquid extract is spray-absorbed onto hydrated calcium silicate or precipitated silica at 1.8–2.2 kg extract/kg carrier using a low-shear paddle agitator. The adsorbed premix intermediate is dried at 40–45°C in a vacuum tray dryer until water activity reaches aw ≤0.45, then milled through a 1.0 mm conidur screen. The final premix is incorporated into a 3-ton horizontal ribbon mixer at 60–70% working volume and mixed for 8 min after all ingredients are loaded. Mixer uniformity is verified by tracer-based assay of sodium chloride, with acceptance at RSD ≤5% under EU 2019/4 homogeneity expectations. Terminal pelleted feed must be conditioned at 70–75°C for no more than 30 s; higher conditioning temperatures depress Astragalus polysaccharide recovery below 90% in post-pellet ELISA. Carryover into unmedicated batches is controlled by flushing with 25 kg ground maize and measuring marker residue below 0.1% of the active premix addition rate. Ingredient order matters: the extract-loaded silica is added after the mineral premix but before soybean oil to avoid hydrophobic coating of carrier pores. Compliance with REACH and EU 2019/4 medicated feed rules applies to the finished premix.

Fluid-bed top-spray granulation of Yupingfeng extract on a Glatt GPCG 30 or equivalent unit requires binder solution viscosity to remain below 150 mPa·s at 25°C; higher viscosity causes nozzle coalescence and heel buildup on the Wurster partition. The extract is first combined with maltodextrin DE 10–12 and colloidal silicon dioxide at 1:0.8:0.03 mass ratio. A binder solution of 5% w/w polyvinylpyrrolidone K30 in water is sprayed at 0.8–1.2 g/min per kg bed weight using a 0.8 mm two-fluid nozzle at 1.8 bar atomizing air. Inlet air temperature is held at 55–60°C, product temperature at 32–36°C, and dew point at 8–10°C to maintain a stable moisture endpoint of 2.5–3.5% w/w. Drying continues until outlet air relative humidity falls below 20%. Friability of finished granules measured by USP <1216> after 10 min in a Roche friabilator is typically <1.5%. Terminal product is a bulk granule for oral drench or sachet filling for weaned piglets. When relative humidity exceeds 65% in the granulation suite, lactose monohydrate must be pre-dried at 60°C for 4 h because moisture-driven bridging blocks the bottom screen. Povidone with peroxide impurity above 400 ppm accelerates chromone oxidation and discolours granules from tan to dark brown within 72 h at 40°C.

Water-soluble powder production from Yupingfeng oral solution requires a two-stage spray-drying step. The liquid extract is first mixed with 2.0 parts of maltodextrin DE 15–18 and 0.05 parts of gum arabic per part dry matter; feed solids content is adjusted to 20–25% w/w. Spray drying on a Niro MOBILE MINOR vibrating atomizer at inlet temperature 180–200°C, outlet temperature 85–90°C, and atomizer speed 20,000 rpm produces a free-flowing powder with median particle size 35–55 µm and moisture <4% w/w. The powder is dry-blended with dextrose monohydrate and 0.3% w/w hydrophobic fumed silica in a 200 L V-blender for 15 min; sachet filling is conducted below 30% RH. Dissolution of a 10 g dose in 1 L tap water at 25°C must be complete within 3 min without foaming; insoluble residue on a 200 mesh screen is limited to <0.2%. Terminal product is a water-soluble powder for pig and poultry oral administration. Storage at 40°C/75% RH for 6 months is used to confirm sachet moisture vapor transmission rate below 0.5 g/m²/day; above this value, caking and brown discoloration are observed. Particle size distribution is confirmed by ISO 13320:2020, and water content is determined by USP <921>.

Does water activity below 0.35 permit direct compression of Yupingfeng extract?

Direct compression is feasible only after spray-drying the liquid extract with a 1:1.5 ratio of maltodextrin and fumed silica to produce a powder with bulk density 0.45–0.55 g/mL, angle of repose <35°, and water activity <0.35. Tableting on a 16-station rotary press at 30 rpm with 8 mm flat-faced tooling requires precompression force 8–10 kN and main compression force 16–20 kN. Tablet hardness is maintained at 60–80 N, with friability <0.8% per USP <1216>. Disintegration time in 900 mL water at 37°C is <15 min when croscarmellose sodium is used at 4% w/w. Magnesium stearate lubrication is limited to 0.5% w/w and blended for 3 min because hydrophobic films delay dissolution by more than 20%. Terminal product is an immediate-release tablet for calves and foals. When press room humidity exceeds 55% RH, tablet weight variation exceeds 2% RSD due to powder adhesion to the feed frame; in that case, external lubrication or 0.3% w/w sodium stearyl fumarate is used. Uniformity of mass is verified by European Pharmacopoeia 2.9.5, and content uniformity is confirmed by USP <905>.

Hard gelatin capsule filling of the spray-dried extract on a Zanasi 40E intermittent-dosing machine requires plug density between 0.55 and 0.65 g/cm³ at filling speed 12,000 capsules/h. The powder blend contains 1.0% w/w colloidal silicon dioxide and 0.5% w/w magnesium stearate, but lubrication time is capped at 2 min to avoid delayed dissolution. Empty capsule shell moisture is held at 13–16%; below 13%, shells crack during separation on the machine hopper. Filled capsule weight is set at 250 mg or 500 mg net fill, with weight variation <2% RSD for 100 capsules per USP <905>. Disintegration in 900 mL simulated gastric fluid without pepsin at 37°C is <10 min. Terminal product is an oral capsule for companion animals under respiratory stress. Direct filling of the liquid extract into hard capsules is possible only in band-sealed or enteric-coated capsules, but published data for this specific configuration is limited; long-term stability beyond 3 months at 25°C/60% RH must be generated per ICH Q1A(R2). Pure hypromellose capsules with residual moisture below 4% are avoided, because the hydroethanolic extract plasticizes the cap body and causes telescoping.

Parenteral aqueous extraction demands endotoxin and particulate reduction to 0.25 EU/mL and 600 particles per container

Injectable dosage forms are prepared only from injection-grade extract that has been further clarified through 0.22 µm PVDF membrane filtration and diafiltered against water for injection to remove ethanol below 0.01% v/v. The extract must pass USP <85> bacterial endotoxin testing at <0.25 EU/mL, USP <788> particulate matter limits for small-volume injections, and sterility testing per USP <71>. Aseptic filling on a six-head peristaltic filling line in a Grade A/ISO 5 zone with Grade B surrounding is required. Nitrogen overlay is used during filling because dissolved oxygen above 0.5 mg/L promotes Saposhnikovia chromone oxidation. Terminal heat sterilization at 121°C for 15 min is generally avoided; size-exclusion chromatograms show polysaccharide chain scission reduces peak molecular weight by more than 20%, and the clinical relevance of this reduction in target species is not fully established. Terminal product is a single-dose 10 mL or 20 mL intramuscular injection for swine and cattle. Aqueous solubility of Atractylodes sesquiterpene fractions is poor below pH 5.5; the injection is buffered with citrate at pH 6.5–7.0. Divalent cations above 1 mmol/L are avoided because astragalus polysaccharide forms precipitable aggregates. Published data for this specific configuration is limited to pilot-scale lots; production-scale compatibility with silicone tubing and gamma-sterilized stoppers must be evaluated under ISO 10993-5 and ICH Q8 design-of-experiment protocols.