Menthae Haplocalycis Herba Veterinary Grade API is evaluated in this document strictly as a botanical active substance for six downstream manufacturing routes: oral solid dosage, drinking-water soluble powder, feed mill premix, parenteral aqueous concentrate, oral granule, and botanical capsule. The inclusion ranges and processing limits that follow are expressed on an as-received basis unless otherwise stated and require correction for extract ratio, moisture content, and the marker compound level of the specific vendor batch. Critical quality attributes that cut across all routes are loss-on-drying, total ash, heavy metal residues, pesticide residues, residual solvents, and total volatile oil retention. A vendor certificate that lacks a residual solvent statement per VICH GL18 or a risk-based elemental impurities profile per Ph. Eur. 2.4.8 / USP <232>/<233> should be rejected for veterinary use.

In small-animal oral solid dose manufacturing, Menthae Haplocalycis Herba extract is incorporated into direct-compression and dry-granulation tablet lines for companion animals and zoo species where tablet disintegration in the gastrointestinal tract must be controlled within USP <701> / Ph. Eur. 2.9.1 limits. A 10:1 aqueous-ethanol extract powder is typically dry-blended with microcrystalline cellulose, lactose monohydrate, crospovidone at 2.0–5.0 wt%, and magnesium stearate at 0.5 wt%. The extract addition ratio lies between 5.0 wt% and 15.0 wt% of total core weight; above 15.0 wt%, blend Carr Index exceeds 28 and tablet tensile strength drops below 1.2 MPa at 12 kN compression force on a 16-station rotary press. The API should be pre-dried to ≤5.0% moisture and processed at 25 ± 2°C with ≤35% RH to avoid punch sticking; production-scale trials show that hygroscopic fractions above 6.0% moisture generate subvisual capping within 48 h of blending. Terminal product types include non-chewable tablets, coated caplets, and hard-shell botanical capsules. Chewable veterinary tablets require additional sodium starch glycolate at 2.0–4.0 wt% because the extract may suppress disintegration in low-shear wet granulations.

What Are the Constraints on Aqueous Solubility in Poultry Drinking-Water Soluble Powder?

When the API is formulated as a soluble powder for drinking-water administration in poultry or swine, the manufacturing batch is classified as a veterinary medicinal product under Directive 2001/82/EC or equivalent outside the EU, and stability must be governed by VICH GL3. In the EU, application in food-producing species requires residue data or an explicit maximum residue limit waiver; Menthae haplocalycis is a botanical substance without a harmonized MRL in many jurisdictions, so the formulation must not be used in food-producing animals without a verified withdrawal period or species-specific residue data. In China, comparable products follow CVP 2020 General Chapter 0101 for oral liquids and powders. For a 5:1 aqueous extract with water-soluble carrier, in-use concentration in final drinking water is typically 0.1–0.3 g/L for poultry, corresponding to a target daily exposure of 20–60 mg/kg bodyweight per day. In a 100 g water-soluble powder sachet, the extract load is usually 20.0–50.0 wt%, with anhydrous dextrose or sorbitol q.s. and colloidal silicon dioxide at 0.5–1.0 wt% as anti-caking agent. Manufacturing is executed by pre-blending the extract with carrier in a high-shear mixer at 800–1,200 rpm for 3–5 min, then passing the blend through a 0.8 mm conical mill to break agglomerates and filling into foil-lined polyethylene terephthalate/aluminum/polyethylene sachets with residual oxygen ≤2.0%. Before field use, the powder is reconstituted in 30–35°C water at a 1:10 w/v ratio and diluted to final volume; water pH above 7.5 accelerates hydrolysis of the volatile oil fraction, so buffering to pH 3.5–5.5 is recommended. Avoid chlorinated water above 1.0 ppm free chlorine due to oxidation of terpene alcohols; sodium thiosulfate at 0.1 g/L can be used to neutralize chlorine before mixing. Terminal product types are water-soluble powder for oral solution, oral drench solutions, and drinking-water liquid concentrate.

Volatile Oil Loss in Pelleted Feed Premixes Requires Overage Validation

Menthae Haplocalycis Herba extract is allocated to 1% or 0.5% veterinary premix systems for medicated feed or complementary feed under feed safety assurance flowing from GMP+ BA2, FAMI-QS Code Version 6, and Regulation (EC) No 1831/2003 where applicable as a feed material or additive. In the United States, feed-use botanical ingredients must comply with 21 CFR Part 589 contaminant limits, although no FDA approval should be assumed for this botanical as a feed ingredient. Batch homogeneity is assessed according to ISO 6497:2002 or equivalent, with target coefficient of variation ≤5.0% for the marker compound. A 5:1 extract is typically incorporated into a 1% premix at 0.2–0.8 wt% of the premix, producing complete-feed inclusion of 2.0–8.0 kg/tonne dry matter; for piglet starter feed, the lower third of this range is used to avoid feed intake suppression, while breeder poultry may require the upper end after palatability trials. Ribbon mixer batch capacity is usually 0.5–1.0 tonne, paddle speed 25–35 rpm, mixing time 8–12 min; the extract should be added as a pre-diluted 1:10 mix with ground limestone or wheat middlings to avoid segregation. Post-pelleting retention of the volatile oil marker is process-sensitive: at conditioning temperature 70°C, retention generally exceeds 90%; at 85°C, retention may fall below 70%; and at 90°C, losses above 40% are observed in limited production runs. Published data for this specific configuration is limited; every pellet die size and conditioning time requires a retention validation batch. Terminal products are complete pelleted feed, extruded feed crumbles, mineral-vitamin premix bags, and top-dress complementary feed.

Injectable formulations containing Menthae Haplocalycis Herba extract are constrained by the low aqueous solubility of the volatile oil fraction and by the requirement for bacterial endotoxin control. The route is limited to large-animal veterinary products where a qualified compound botanical injection is already registered; monotherapy injectable formulations are not typical and should not be assumed. Injectable concentrates are prepared as submicron oil-in-water emulsions or cyclodextrin inclusion complexes, not as simple aqueous solutions. Core manufacturing must follow EU GMP Annex 1 for terminally sterilized or aseptic products, Ph. Eur. 2.6.1 sterility, Ph. Eur. 2.6.14 bacterial endotoxin, VICH GL10 for degradation products, and VICH GL18 for residual solvents. If terminal sterilization at 121°C for 15 min is used, volatile oil degradation products must be profiled; aseptic filtration through a 0.22 μm hydrophobic PVDF membrane may be preferred but requires pre-filtration through 0.45 μm and bioburden control. For preserved aqueous parenterals, a typical volatile oil loading is 1.0–3.0 mg/mL with sulfobutylether-β-cyclodextrin at a 1:20 molar ratio; for an emulsion, the oil phase is 0.1–0.5% v/v with egg lecithin 1.2% w/v and polysorbate 80 0.5–2.0% w/v. Total extract weight fraction in the final injectable should not exceed 2.0% w/v because higher loads increase viscosity above 5.0 mPa·s at 25°C and create pre-filter fouling. Aqueous and oil phases are heated to 45 ± 2°C, coarsely mixed by rotor-stator at 15,000–20,000 rpm for 5–10 min, then homogenized at 800–1,000 bar for three passes. Mean droplet size after three passes should be 200–300 nm, confirmed by laser diffraction or dynamic light scattering. Do not combine with amine-based antioxidants because volatile oil oxidation increases; use nitrogen overlay during filling. Terminal products are injectable solutions, oil-in-water emulsions, and lyophilized powders for reconstitution.

When Fluid-Bed Granulation Is Applied to High-Dose Swine Oral Granules

Oral granule products for swine are manufactured under GMP for veterinary medicinal products, with release testing according to CVP 2020 General Chapter 0103 for granules, or Ph. Eur. 2.9.10 dissolution for oral powders and granules where justified. Unless the product is registered as a veterinary medicinal product, feed-use granules fall under feed law; therefore, the regulatory status must be fixed before selecting the granulation binder. The dry granulation feed contains 20.0–50.0 wt% of a 5:1 extract; above 50.0 wt%, the granule structure becomes friable and produces fines above 25% on sieving. Binder systems include polyvinylpyrrolidone K-30 at 3.0–5.0 wt% or low-viscosity hydroxypropyl methylcellulose at 2.0–4.0 wt%. Top-spray fluid-bed granulation is conducted at inlet air temperature 55–65°C, product temperature 35–42°C, air flow 60–100 m³/h for a 5 kg pilot batch, spray rate 8–12 g/min, and atomization pressure 1.5–2.0 bar. After granulation, drying continues to final moisture ≤4.0%; the dried granules are sieved through 1.0 mm and 0.18 mm screens to collect the 0.18–1.0 mm fraction. Production-scale batches show that the volatile oil is partially lost during fluid-bed drying; therefore, a 10% overage of extract is used if the finished marker content must meet label claim at end of shelf-life. Terminal products include oral granules for top-dressing, sachet granules for direct oral administration, and pre-fill syringe paste after reconstitution with vegetable oil.

Powder Blends and Palatability Masking in Equine Botanical Capsules

Equine oral capsule products are treated as botanical new animal drugs or complementary feed ingredients depending on therapeutic claim; current Good Manufacturing Practice per 21 CFR Part 210/211 applies if a drug claim is made in the United States. In the EU, horse products must be evaluated for food-producing status under Regulation (EU) No 37/2010, and a non-food declaration is required for certain botanical ingredients. The capsule fill formulation contains 25.0–40.0 wt% of a 5:1 extract, with dibasic calcium phosphate dihydrate as densifier at 20.0–30.0 wt%, fumed silica at 1.0–2.0 wt%, and a palatability mask such as apple fiber or yeast at 15.0–25.0 wt%. For size 0 hard gelatin capsules, fill weight is 400–500 mg, providing an extract dose of 100–200 mg per capsule. Encapsulation is performed on a tamping pin machine at ≤50% RH; the powder is blended in a V-blender at 15–20 rpm for 15–20 min. Due to static charging, blending vessels are grounded and ionizing bars are used at the discharge port. The blend is filled to a powder density of 0.55–0.65 g/mL; capsule moisture is monitored at ≤8.0% to prevent shell brittleness. Do not use hygroscopic carriers such as sorbitol in high-humidity zones, and avoid gelatin cross-linking aldehyde-containing excipients. Terminal products are hard gelatin capsules, hypromellose capsules, and veterinary botanical two-piece capsules.