Fumei Powder Veterinary Grade API for Tablets / Injections / Capsules / Powders / Granules / Premix / Solutions is supplied as a white to off-white crystalline powder under manufacturer model FP-VET-200; additional grades include FP-VET-200M for micronized oral suspensions and FP-VET-200I for parenteral processing. Identification is confirmed by infrared absorption spectrophotometry (Ph. Eur. 2.2.24) and retention-time matching in HPLC. The release specification requires assay 98.0–102.0% on the dried basis by HPLC (Ph. Eur. 2.2.29), loss on drying ≤ 0.5% (105 °C, 2 h, Ph. Eur. 2.2.32), sulfated ash ≤ 0.1% (Ph. Eur. 2.4.14), heavy metals ≤ 20 ppm (Ph. Eur. 2.4.8), total related substances ≤ 1.0%, and residual solvents within ICH Q3C limits for Class 2 and Class 3 solvents. Standard-grade powder has a laser-diffraction particle-size distribution of D10 ≥ 5 µm, D50 15–35 µm, and D90 ≤ 75 µm (ISO 13320:2020), with bulk density after sieving of 0.42–0.58 g/mL. The particle-size span, (D90-D10)/D50, is controlled to ≤ 2.5 for standard grade. The material is double-bagged in low-density-polyethylene liners inside aluminium-laminated fibre drums and carries a retest period of 24 months at 15–25 °C and ≤ 35% relative humidity.

What Limits Direct-Compression Suitability in Tablet and Capsule Formulations?

Direct-compression suitability is governed primarily by flowability and particle-size distribution. FP-VET-200 standard grade has a Hausner ratio of 1.25–1.38 and a Carr Index of 18–25 after moisture-controlled sieving through a 500 µm screen; these values support direct compression only at active loads up to 15% w/w in formulations based on microcrystalline cellulose and crospovidone. Above 20% w/w active, production-scale rotary tablet presses with 8 mm biconcave tooling require wet granulation to maintain weight uniformity within USP <905>; die-fill consistency falls when the blend’s flow function coefficient drops below 4.8 in a Schulze ring-shear tester. Capsule filling on dosator-type machines is more tolerant at active loads up to 25% w/w when the powder is preblended with lactose monohydrate and 0.5% magnesium stearate.

Tableting trials on an instrumented rotary press with a maximum compression force of 60 kN indicate that FP-VET-200 at 12.5% w/w with microcrystalline cellulose and 2.0% crospovidone yields tablet hardness of 80–110 N and friability 0.3–0.7% at compression forces of 12–18 kN. At 25% w/w active, the same direct-compression blend produces friability above 1.0% and edge capping; wet granulation in a high-shear mixer at impeller tip speed 5–10 m/s and granule moisture 2.0–3.5% is required to restore tablet integrity. The micronized FP-VET-200M grade with D90 ≤ 25 µm is not recommended for direct compression because low bulk density and high electrostatic charge produce capping at compression pressures above 120 MPa; its intended use is low-dose oral suspension and high-potency capsule filling with extensive preblending.

The three primary pharmaceutical models differ as follows.

Thermal and Hygroscopic Stability Boundaries for Drying, Wet Granulation, and Terminal Sterilization

Moisture control during wet granulation is critical. The release limit of ≤ 0.5% loss on drying applies to unopened containers; after opening at relative humidity above 60%, the powder can gain 0.3–0.6% moisture within 4 h, which reduces flow function coefficient and can shift HPLC assay if sampling is not representative. Aqueous granulation with 5% w/w binder solution is acceptable at product temperatures between 20 °C and 30 °C; fluid-bed drying should maintain inlet air at 60–70 °C and product temperature at 35–40 °C. The micronized FP-VET-200M after jet milling has amorphous content measured by dynamic vapour sorption that should remain below 5%; batch rejection is triggered above this threshold because recrystallization in suspension can alter particle size and content uniformity.

Tray drying above 60 °C for more than 8 h is not recommended because residual water content may fall below 0.2%, increasing electrostatic charging and reducing compactability in subsequent dry granulation. Residual solvent control follows ICH Q3C; the release CoA includes headspace GC limits for Class 2 and Class 3 solvents per Ph. Eur. 2.4.24, with methanol limited to 3000 ppm and dimethyl sulfoxide to 5000 ppm unless otherwise validated. Published data for the specific combination of FP-VET-200 with non-aqueous granulation solvents is limited; process qualification for solvent-based granulation is required at site level. Terminal sterilization by moist heat at 121 °C for 15 min should be validated only for the FP-VET-200I grade in sealed aqueous solution, because the standard oral grade does not carry a bacterial-endotoxin specification and may contain pyrogens above injectable limits.

Injectable-Grade Requirements, Endotoxin Control, and Filterability

For parenteral and ophthalmic formulations, FP-VET-200I is the only designated model. The grade is depyrogenated and tested for bacterial endotoxins at ≤ 0.05 EU/mg using Ph. Eur. 2.6.14 and for sub-visible particulate matter after reconstitution according to Ph. Eur. 2.9.19. It is not supplied as a sterile powder; terminal sterilization or aseptic filtration is performed during pharmaceutical manufacturing. In injection formulation, the powder is dissolved in water for injection at 20–25 °C, the solution pH is adjusted to 4.5–6.0, and the batch is passed through a 0.22 µm polyethersulfone membrane. Filterability trials with 1.2 m² capsule filters and a 10-inch cartridge show that the flow rate should be controlled below 8 L/min to avoid flux-driven membrane fouling when solution concentration exceeds 50 g/L.

Sterile filtration is preceded by a 0.45 µm prefilter and a 0.22 µm final membrane; filter compatibility with solution pH below 4.5 or above 6.0 is confirmed by extractable studies under USP <1663> before production. Hold times in stainless steel tanks should not exceed 8 h at 20–25 °C. The FP-VET-200I particle-size profile has D90 ≤ 45 µm; this distribution is coarser than the micronized oral grade but is selected to reduce electrostatic adhesion during aseptic powder transfer. Endotoxin reduction cannot be achieved by sterile filtration alone; therefore, the standard FP-VET-200 grade must not be substituted into injectable processes.

Oral solutions, premixes, and granular feeds use the standard FP-VET-200 grade; where low-dose homogeneity is required, FP-VET-200M may be dispersed after pre-wetting with 0.5–1.0% polysorbate 80 in water. For solution preparation, the API is added to a pH 4.0–6.5 buffer system at 25 °C; the solution should be protected from direct light and used within 24 h unless a preservative system containing methyl parahydroxybenzoate and propyl parahydroxybenzoate is validated. Premix operations blend the standard grade with lactose monohydrate or maize starch in double-cone blenders; potency uniformity is evaluated by Ph. Eur. 2.9.5 or USP <905>. Blending time in double-cone blenders should not exceed 20 min at 17 rpm to avoid segregation by particle size. Granulation for sachets and feed supplements commonly employs fluid-bed granulators with inlet air at 55–70 °C and a spray rate of 80–120 g/min for 100 kg batch sizes; the resulting granules are dried to a moisture content of 1.5–3.0% and sieved through a 710 µm screen. Capsule filling uses either tamping-pin or dosator machines at 60–85% relative humidity; product contact containers should be low-density polyethylene or glass with desiccant sachets to maintain the moisture limit. The powder is also suitable for dry granulation by roller compaction at roll pressures of 4–8 MPa, with ribbon density maintained at 1.05–1.25 g/mL to avoid loss of tablet hardness.

When Co-Processing with Acidic or Amine-Bearing Excipients Demands Batch Segregation

Compatibility trials are required before blending FP-VET-200 with strongly acidic excipients such as citric acid or with amine-functional polymers used in taste-masked granules. At pH below 3.0, the API shows pH-dependent related-substance formation; at pH above 8.5, amine-bearing excipients can accelerate degradation and produce yellow discoloration within 72 h at 40 °C. Because published data for this specific API in the presence of all amine-bearing excipients is limited, binary compatibility screening should be performed at 40 °C/75% RH for 4 weeks. If citric acid is required for effervescent tablets, the blend should be dried to loss on drying ≤ 0.2% and packaged immediately in aluminium-foil blisters; contact time before packaging should not exceed 4 h. Cleaning validation between Fumei Powder and beta-lactam or sulfonamide veterinary APIs is mandatory under 21 CFR 211.67 equipment-cleaning requirements, given the cross-contamination risk in multiproduct facilities. Dedicated scoops and intermediate bulk containers are used for the FP-VET-200I grade to preserve the depyrogenated state; storage of the opened container at relative humidity above 60% triggers re-testing for loss on drying and microbial limits before further use.

The main differential specification between FP-VET-200 and feed-grade powders is the combination of pharmacopeial impurity control, residual-solvent testing, and particle-size uniformity. Feed-grade powders may carry total ash up to 3.0% and heavy metals up to 50 ppm, while FP-VET-200 limits sulfated ash to ≤ 0.1% and heavy metals to ≤ 20 ppm. Non-pharmaceutical powders are not manufactured under current good manufacturing practice for active substances and do not provide a retest period supported by stability data under ICH Q1A(R2) conditions. Feed-grade materials may lack residual-solvent certification entirely; FP-VET-200 includes the ICH Q3C profile and is suitable for veterinary formulations where solvent exposure must be documented. FP-VET-200 standard-grade is suitable for oral solid and liquid dosage forms but is not intended for parenteral use; FP-VET-200I adds bacterial-endotoxin and sub-visible particulate controls that are absent from feed-grade and industrial raw materials. The micronized FP-VET-200M grade reduces D90 from ≤ 75 µm to ≤ 25 µm, which improves content uniformity in low-dose oral suspensions but increases hygroscopic surface area and requires silica-based flow aids at 0.2–0.5% w/w. Product-specific dissolution in veterinary oral tablets is controlled by the finished-product manufacturer, not by the API release specification; according to Ph. Eur. 5.11, the API supplier provides the physical and chemical attributes relevant to downstream formulation.

The following release and compliance matrix applies to FP-VET-200 unless otherwise indicated.