Process-scale batches of veterinary injectable solutions containing Ligustici Rhizoma Et Radix extract typically begin with a hydroalcoholic pre-dissolution stage because the ligustilide-rich fraction shows limited cold-water solubility but disperses in ethanol-water mixtures above 30% v/v ethanol at 35–40 °C. Production records from sterile filling lines indicate that terminal steam exposure above 114 °C reduces ligustilide HPLC area percent by more than 8–12% per 15 min cycle, which pushes qualified formulations toward aseptic filtration rather than terminal sterilization. The working concentrate is prepared at 8.0–20.0 mg/mL of native extract, adjusted to pH 6.2 ± 0.2 with citrate buffer, and osmolality is corrected to 280–320 mOsm/kg using sodium chloride. Compliance for this step rests on sterility per Ph. Eur. 2.6.1, bacterial endotoxin per Ph. Eur. 2.6.14, particulate contamination per Ph. Eur. 2.9.19, and filter integrity per ASTM F838-20. The bulk solution is passed through a 0.45 µm polyethersulfone prefilter and then a 0.22 µm PVDF membrane at differential pressure not exceeding 0.5 bar, with a Grade C background and Grade A filling zone in line with EudraLex Volume 4 Annex 1. Nitrogen overlay is applied throughout storage to limit oxidative isomerization of phthalide markers. Batch-to-batch variance in polysaccharide residue can raise solution viscosity from 3.0 mPa·s to 6.5 mPa·s at 25 °C; when viscosity exceeds 6.0 mPa·s, filtration throughput on 0.22 µm capsules drops by 30–40%, requiring an additional prefilter layer. For this reason, the pre-dissolution vessel uses a high-shear mixer at 1,500 rpm for 30 min to reduce gel agglomerates before transfer. Terminal packaging uses amber Type I glass vials in 10 mL, 20 mL, 50 mL, and 100 mL presentations; multi-dose configurations require 0.2% w/v benzyl alcohol where regional registration permits. Published data for this specific injectable formulation configuration is limited, so filter compatibility and marker recovery should be confirmed on each extract lot before line transfer.

How Much Carrier Dilution Is Necessary Before a 10:1 Extract Becomes Uniformly Dispersible in Complete Feed Powders?

Complete feed premix operations receive the extract as a dry powder with particle size D50 45–75 µm and bulk density 0.42–0.58 g/cm³. Segregation in final feed occurs when the extract is added directly below 0.05% w/w to a carrier whose median particle size exceeds 1,200 µm; therefore the first production stage uses a 1:9 pre-blend with precipitated calcium carbonate or pre-gelatinized rice flour. Blending is executed in a horizontal ribbon mixer at 60–70% gross volume, tip speed 100–150 m/min, for 12–15 min dry mixing, with a coefficient of variation target not exceeding 5% across 10 sampling points. The final complete feed inclusion range is 0.02%–0.10% w/w, while concentrated premix batches carry 8%–15% w/w extract. When dust suppression is required, 2% w/w soybean oil is added after dry blending and mixed for an additional 3–5 min. Ferrous sulfate above 1.0 g/kg must not be included in the same pre-blend because ferric-phenolic complexation produces black specks and marker loss. Regulatory anchors for this route include ISO 22000 clause 8.2 for prerequisite programs, ISO 6497:2002 for feed sampling, FDA 21 CFR Part 225 for medicated feed premix CGMP where applicable, and VICH GL18 stability testing. Terminal products include 20 kg woven polypropylene bags and 1 kg moisture-barrier pouches, with overfill adjusted to 1.0–1.5% based on auger filler variability. High-ash extract lots above 5.0% w/w total ash require pre-drying at 55 °C for 2 h when ambient RH exceeds 60%, to prevent bridging in volumetric dosing screws.

Roller Compaction Parameters for High-Hygroscopic Extract Blends in Tablet and Capsule Lines

Companion animal oral solid dosage forms containing Ligustici Rhizoma Et Radix extract are processed by dry granulation because the amorphous extract absorbs more than 8% w/w moisture within 6 h at 65% RH, and wet mass granulation produces end-of-run punch sticking on rotary tablet presses. The dry granulation route first screens the extract with 0.8 mm mesh, then blends 30%–45% w/w extract with 25%–40% microcrystalline cellulose PH102, 5% crospovidone, and 0.5% magnesium stearate in a bin blender at 8–12 rpm for 15 min. Amine-based lubricants are avoided because they accelerate phthalide ring opening; magnesium stearate is limited to 1.0% w/w. The blend is compacted on a roller compactor at specific roll force 8–14 kN/cm, roll speed 3–6 rpm, and mill screen size 0.8–1.2 mm. Roll force below 8 kN/cm yields granule fines above 35% w/w, while force above 14 kN/cm increases work hardening and tablet capping at compression. Tablets are compressed on a 12-station B-tooling press at 10–16 kN, with hardness 60–90 N and friability below 0.5%; capsules are filled with 40%–60% w/w extract blends into size 1 or size 0 capsules under ambient RH below 45%. In-process controls follow 21 CFR 211.110(a) for blend uniformity, Ph. Eur. 2.9.5 uniformity of mass, and Ph. Eur. 2.9.3 content uniformity. Regulatory submission stability batches are placed at 40 °C / 75% RH per VICH GL18, with HPLC marker retention of 90%–105% for ferulic acid and ligustilide used as release criteria. Terminal products are 100 mg and 200 mg film-coated tablets, and 100 mg and 250 mg capsule strengths; enteric coating is not applied because ferulic acid release is already susceptible to alkaline degradation above pH 7.4.

When Drinking Water Line Pressure Is Below 1.5 Bar, Soluble Granule Dispersion Behaves as a Function of Binder Composition

Soluble granules for proportioner dosing in poultry and swine barns require a binder system that dissolves before the extract particles swell; a 7:3 ratio of maltodextrin DE10 to polyvinylpyrrolidone K30 yields a 45 s wetting time in 1.0 L of water at 25 °C, while extract load above 55% w/w extends wetting beyond 180 s and causes incomplete delivery through 1:100 proportioners. The granulation matrix is prepared at 40%–55% w/w extract, with the balance binder and 0.5% colloidal silicon dioxide as flow aid. Final drinking water concentration is 1.0–3.0 g/L of granular product, corresponding to 0.5–1.5 g/L native extract. Production is performed in a fluid bed granulator with top spray configuration at inlet air 60–65 °C, product temperature 34–40 °C, spray rate 12–20 g/min/kg batch mass, and final moisture below 4.0% w/w. Granules are sieved to 0.5–1.5 mm; overs above 1.5 mm are dry-milled and returned, while fines below 0.5 mm are reintroduced into the next granulation batch at no more than 15% w/w. Compliance anchors include EU Regulation 2019/6 Article 97 for veterinary medicinal product quality, VICH GL18 for stability, Ph. Eur. 2.9.34 dissolution testing where a monograph exists, and drinking water matrix verification per EU Directive 2020/2184. Terminal packaging uses 100 g, 500 g, and 1 kg PET/PE sachets for powder sachet dosing, and 1 L or 5 L co-extruded polyethylene containers for oral solutions. The oral solution variant is prepared with 8%–12% v/v ethanol to suppress microbial growth, but precipitation occurs if hard water above 180 mg/L CaCO₃ is mixed with that solution; farms should be informed of hard water dilution limits.

Vacuum coating after extrusion is selected for warmwater aquafeed because differential scanning calorimetry at 10 K/min shows that the phthalide marker fraction of Ligustici Rhizoma Et Radix extract begins thermal degradation below 100 °C; direct extrusion at barrel temperatures above 95 °C lowers ligustilide HPLC area percent by more than 12% relative to unprocessed feed. The extract is therefore pre-dissolved at 1:10 in fish oil heated to 40 °C, then metered into a double-shaft vacuum coater after extruded pellets have cooled to 55–65 °C. Vacuum is pulled to −0.06 MPa to −0.08 MPa for 20–30 min with paddle speed 8–12 rpm; coating oil uptake is 3%–5% w/w, giving an extract deposition of 0.2%–0.5% w/w on finished pellets. The process is anchored to EU Regulation 183/2005/EC Annex II for feed hygiene, ISO 22000 for food safety management, and FAMI-QS where the extract is placed on the market as a specialty feed ingredient. Finished pellets are cooled to below 25 °C and bagged only when water activity is ≤0.65; 25 kg polyethylene-lined woven bags and 5 kg retail bags are filled under modified atmosphere with residual oxygen below 2% v/v to slow oxidative loss of unsaturated markers. Terminal products include 2.0–4.0 mm floating pellets for warmwater finfish, with post-coating durability above 98% measured by Holmen tester NH001.

Terminal Gamma Irradiation Does Not Remove Hard Water Incompatibility in Calf Drench Powders

Oral drench powders for neonatal calves are prepared by micronization of dense extract to D90 below 25 µm to achieve uniform reconstitution in 50 mL water at 20–25 °C. Each single-dose unit contains 0.5 g native extract, 1.0 g lactose monohydrate, and 0.05 g sodium citrate dihydrate; hard water above 180 mg/L CaCO₃ causes ferulic acid aggregates, so water hardness is specified on the foil sachet. The powder is filled into 50 g or 100 g multi-dose sachets, then subjected to terminal gamma irradiation at 5–10 kGy per ISO 11137-1:2006/A1:2013 to reduce bioburden. Microbiological release uses Ph. Eur. 2.6.13 and 2.6.12; homogeneity is verified by ISO 6497:2002 feed sampling procedures where the product is distributed as a complementary feed. Stability follows VICH GL18, with storage at 25 °C / 60% RH for 24 months in high-barrier aluminum-polyethylene sachets containing oxygen scavengers. Production process: micronization, pre-blend with lactose, final blending in a twin-shell V blender at 12 rpm for 20 min, and sachet filling under RH below 35%. Terminal product types include 50 g and 100 g aluminum-foil drench powder sachets, and 5 kg bulk packs for veterinary pharmacy reconstitution.