Sterile injectable solutions of Viticis Fructus veterinary API are prepared from the dry hydroalcoholic extract standardized to agnuside and casticin. The extract is jet-milled with nitrogen at −20 °C to a particle size below 40 µm D₉₀ and a specific surface area above 2.0 m²/g before use. Milling heat must be controlled because the extract softens above 45 °C. The milled API is dispersed in Water for Injection heated to 45 °C ± 2 °C under high-shear mixing at 8,000 rpm for 15 min. A co-solvent system is screened across propylene glycol 20%–40% v/v, ethanol 10%–15% v/v, and benzyl alcohol 1.5%–2.0% v/v as preservative. The bulk solution is buffered with 10 mM citrate buffer to pH 4.5 ± 0.2. The solution is clarified through a 0.45 µm PVDF filter and sterilized through a 0.22 µm polyethersulfone filter validated per ASTM F838-20. Filling is performed in an ISO 14644-1:2015 Grade B suite with Grade A laminar airflow. The container is nitrogen-flushed before and after filling to a residual oxygen level below 2.0% headspace. Bioburden before sterile filtration is controlled below 10 CFU/100 mL per Ph. Eur. 2.6.12, and endotoxin load is controlled below 0.5 EU/mL per USP <85>. Sterility is tested by membrane filtration per USP <71> with 14-day incubation.

Terminal sterilization by moist heat at 121 °C for 15 min is permitted only when pilot-scale autoclave validation shows assay loss below 2.0% and total degradation products below 1.0%. If these limits are exceeded, sterile filtration followed by aseptic filling is selected. The aqueous phase is maintained below pH 7.5 because agnuside is an iridoid glycoside with an ester linkage that undergoes rapid hydrolysis under neutral-to-alkaline conditions. The API is not formulated with strong oxidizing agents or with polyvinylpyrrolidone in aqueous injectable liquids because the extract contains phenolic flavonoids that can interact with peroxide residues. Container closure integrity is tested with dye ingress per USP <1207> using methylene blue. Published data for terminal sterilization of Viticis Fructus injection is limited; therefore, each new bulk solution requires a forced degradation study at pH 3.0, pH 5.0, and pH 7.0 over 7 days at 40 °C.

What limits reconstitution time in lyophilized veterinary powders for injection?

Freeze-dried cakes of Viticis Fructus are rehydrated at the point of use for parenteral administration. Cake collapse is the primary defect controlling reconstitution time. Collapse temperature is determined for each extract batch by freeze-dry microscopy because botanical extract glass transition temperatures shift with residual moisture and extract ratio. A conservative cycle uses freezing at −40 °C for 120 min, primary drying at −15 °C and 150 µbar for 36 h, and secondary drying at 20 °C and 50 µbar for 12 h. If product temperature exceeds the collapse boundary, the cake shows visible shrinkage, reconstitution time exceeds 120 s, and residual moisture remains above 1.0% by USP <921> Karl Fischer titration. Fill volume is limited to 40% of vial brim volume to maintain adequate sublimation surface. After lyophilization, particulate matter is measured per USP <788> Method 1 after reconstitution: not more than 6,000 particles ≥10 µm and not more than 600 particles ≥25 µm per container.

Diluent selection is constrained by casticin solubility. Casticin is poorly water soluble, so the diluent may contain propylene glycol 10%–20% v/v and ethanol 10% v/v; published casticin solubility data in this exact vehicle is limited. The reconstitution diluent is equilibrated to 25 °C before addition. Vacuum-assisted wetting is avoided because rapid vacuum drops can fracture brittle cakes. The diluent stream is directed to the cake center rather than the vial wall; a 21 G needle directed at the wall increases subvisible particles. Reconstituted solution is held at 2–8 °C and used within 6 h when no antimicrobial preservative is present. Compatibility with rubber stoppers is tested over 24 h by visual inspection and by assay of casticin; a loss of more than 5.0% indicates adsorption or oxidation.

Oral tablet compression and the casticin/agnuside compactibility boundary

Viticis Fructus veterinary tablets are manufactured by wet granulation because the untreated dry extract has poor compactibility and high hygroscopicity. Incoming extract ratio may vary from 4:1 to 10:1 across suppliers; this shifts the binder requirement by 2–5% w/w, so granulation water volume is adjusted from the API certificate of analysis. A standard batch uses 30.0 wt% API, 45.0 wt% microcrystalline cellulose PH-102, 20.0 wt% lactose monohydrate, 3.0 wt% crospovidone, 1.0 wt% colloidal silicon dioxide, and 1.0 wt% magnesium stearate. Granulation is performed in a high-shear mixer at impeller speed 300 rpm and chopper speed 1,500 rpm for 4 min, using purified water at 25% w/w as binder. The wet mass is screened through 1.5 mm, dried in a fluid bed at inlet air temperature 60 °C until loss on drying is 2.0%–3.5%, and calibrated through 0.8 mm. Particle size distribution is checked by sieve analysis with not more than 20% fines below 75 µm.

Compression is carried out on a rotary tablet press with 16 stations, main compression force 12–20 kN, pre-compression force 5–8 kN, and turret speed 25–45 rpm. Tablet hardness is held at 70–120 N and friability at ≤1.0% per USP <1216>. Disintegration time is ≤30 min in water at 37 °C per USP <701>. Dissolution is run per USP <711> Apparatus II at 50 rpm in 900 mL 0.1 N hydrochloric acid with 0.5% sodium lauryl sulfate at 37 °C ± 0.5 °C; a discriminating specification for casticin is Q ≥75% at 60 min. Lamination is observed above 20 kN main compaction force when casticin-rich extract fraction exceeds 35 wt% of the formulation; this defines the upper boundary of the compaction window. Content uniformity is tested per USP <905> with acceptance value ≤15. If relative humidity exceeds 60%, the API is pre-dried at 60 °C for 4 h before blending; without pre-drying, sticking and picking defects on punch tips increase tablet mass variation above ±5% RSD.

Hard gelatin capsule filling of Viticis Fructus API is restricted to low-humidity suites. The process area is maintained at 20 °C–22 °C and RH 35%–40% because gelatin shells become brittle below RH 35% and soften above RH 45% when filled with a hygroscopic plant extract. The API is mixed with 2.0% w/w colloidal silicon dioxide and 0.5% w/w magnesium stearate prior to filling on a dosing-disc machine. Fill weight is controlled at target ±3% using gravimetric checkweighing every 10 min. Bulk density is measured per USP <616> Method I; the target tapped density is 0.45–0.60 g/mL to keep capsule size constant without excessive compression. Dissolution from capsule formulations uses USP <711> Apparatus I at 100 rpm in 900 mL 0.1 N hydrochloric acid containing 0.5% SLS. Microbial quality is verified per USP <61> with total aerobic microbial count ≤10³ CFU/g and combined yeasts and molds ≤10² CFU/g. Published data for this specific extract in hard gelatin capsules is limited, so capsule shell compatibility is assessed by visual inspection and dissolution profile comparison after 1, 3, and 6 months at 25 °C/60% RH per VICH GL3.

Veterinary oral powders and premixes containing Viticis Fructus are blended into feed at inclusion rates of 0.5–5.0 kg per tonne. The API is first combined with 2.0 wt% fumed silica to improve flow and reduce electrostatic adhesion. A two-step geometric dilution is performed in a ribbon blender with fill level 60% and mixing time 12 min at 20 rpm. Content uniformity is tested using 10 sampling points across the blender discharge; the relative standard deviation of casticin assay must be ≤5.0% for a validated blend. The casticin assay is performed by HPLC with UV detection at 254 nm; system suitability requires resolution between casticin and adjacent peak ≥2.0 and tailing factor ≤2.0. Particle size of the premix is controlled at D_v90 ≤500 µm by milling through a 0.5 mm screen to prevent segregation during pneumatic conveyance. The premix is packaged in multi-wall paper sacks with an inner polyethylene liner and stored below 25 °C and RH 60%. Stability studies follow VICH GL3 long-term conditions at 25 °C/60% RH for 24 months.

Elemental impurity limits for lead, arsenic, and cadmium are set by the receiving feed mill specification at ≤10 mg/kg, ≤2 mg/kg, and ≤1 mg/kg via USP <233> ICP-MS. Microbial enumeration is performed per USP <61> with total aerobic microbial count ≤10⁴ CFU/g and total combined yeasts and molds ≤10² CFU/g. Residual solvent levels are controlled per VICH GL18(R2): methanol ≤200 ppm and ethanol ≤5000 ppm if ethanol was used in extraction. Bin discharge studies are repeated when the extract ratio changes by more than 10% because botanical extract surface properties shift with extract ratio.

Fluid-bed granulation parameters for multi-dose oral granules

Granules for direct administration in horses or cattle are manufactured in a top-spray fluid-bed processor. The API is suspended in a binder solution of 5.0% w/w povidone K30 in purified water at 60 °C. Spray rate is set at 8–12 g/min per kg of substrate, atomization air pressure 1.5–2.0 bar, inlet air temperature 60 °C, product temperature 32 °C–36 °C, and exhaust relative humidity 20%–30%. Spraying continues until granule moisture reaches 12%–15%, after which drying proceeds at 65 °C inlet air until loss on drying is 2.5%–3.0%. The finished granules are sieved through 1.0 mm and 0.3 mm; oversize is milled through 0.5 mm, and fines below 0.3 mm are recycled at no more than 5.0% of the batch to avoid excessive friable material.

A hygroscopicity concern is controlled by packaging in aluminum foil laminate with desiccant. Granule flow is measured by USP <1174> powder flow: Carr index target is 15–20 and Hausner ratio ≤1.25. Palatability is assessed in a standard 24 h refusal test with 5 animals per formulation; a batch is rejected if refusal exceeds 10% of the offered dose. Published data for Viticis Fructus granule stability in equine feed is limited; therefore, a 3-month in-use stability study is performed at 25 °C/60% RH with the container open for 15 min daily. Residual moisture after opening is checked at each weekly time point by USP <921>; an increase to more than 3.5% indicates desiccant replacement or packaging revision.

When Viticis Fructus API is dissolved into drinking-water vehicles and oral drenches

Oral solutions of Viticis Fructus for poultry or swine drinking water require a co-solvent and a preservative system because the API is poorly soluble in water. A concentrated 10.0% w/v solution is prepared with propylene glycol 30% v/v, ethanol 10% v/v, polysorbate 80 2.0% w/v, and deionized water. The pH is adjusted to 4.5–5.5 with citric acid and 50 mM sodium citrate. The solution is clarified through a 1.0 µm depth filter and bottled under nitrogen. Density is measured per USP <841>; viscosity at 20 °C is controlled below 50 mPa·s using a Brookfield viscometer spindle 2 at 60 rpm to ensure accurate proportioning in drinking water dosing pumps.

The dilution ratio in drinking water is 1:1000 to 1:5000 v/v depending on body weight and water consumption rate. Stability in hard water is tested at 500 ppm CaCO₃ and pH 7.0; precipitation occurs if the dilution water pH exceeds 7.5 because casticin and agnuside ionization changes. The drinking water solution is used within 24 h after dilution to avoid microbial growth and oxidation. Preservative efficacy is tested per USP <51> category 2 with not less than 1.0 log reduction at 14 days for bacteria and no increase at 28 days for yeast and molds. Residual solvent levels are controlled per VICH GL18(R2): methanol ≤200 ppm and ethanol ≤5000 ppm in the concentrated solution.