Malian Cangzhu Powder Veterinary Grade API for Tablets / Injections / Capsules / Powders / Granules / Premix / Solutions is a controlled botanical raw material derived from the dried rhizome of Atractylodes lancea (Thunb.) DC. or Atractylodes chinensis (DC.) Koidz. The product is supplied as a pale yellow to grey-brown powder that has been dried, comminuted, and air-classified for veterinary pharmaceutical manufacturing. No pharmacopoeial model number is assigned to this material; the supplier identifies it by a batch traceability code, with MCZ-VG-P commonly used on certificates of analysis. The powder is not a sterilized final dosage form and is not intended for direct injection. It is an active pharmaceutical ingredient for further processing into tablets, hard capsules, oral powders, granules, medicated premixes, oral solutions, and injectable intermediates following extraction, clarification, and sterile filtration where required.

The powder is differentiated from commodity feed-grade Rhizoma Atractylodis by four control areas: chromatographic marker assay, mycotoxin screening, microbial enumeration, and particle-size distribution. These controls appear in the release documentation as test methods with acceptance ranges rather than botanical identity alone. The marker compound atractylodin is used because it is a volatile polyacetylene that correlates with the rhizome essential oil fraction; its concentration in commercial material can vary with harvest region, drying temperature, and storage time. Published data for the specific Malian grade is limited, but supplier certificates typically state an atractylodin assay window of 0.30%–0.80% (w/w) on the dried basis. The assay is performed by HPLC using a reversed-phase C18 column, an acetonitrile–water mobile phase, and UV detection at 203 nm.

What Release Criteria Separate Veterinary API Grade from Feed-Grade Rhizoma Atractylodis Powder?

Release testing for the veterinary grade typically includes identity, purity, microbial burden, and selected elemental impurities. Identity is confirmed by macroscopic and microscopic examination against the ChP 2020 Atractylodis Rhizoma monograph, and by thin-layer chromatography on silica gel GF254 using atractylodin reference solution. Loss on drying is controlled at ≤12.0% after 2 h at 105°C. Total ash is controlled at ≤7.0%; acid-insoluble ash at ≤2.0%. Elemental impurities are determined by microwave-assisted digestion and ICP-MS, with typical acceptance of ≤20 mg/kg lead, ≤2 mg/kg cadmium, ≤2 mg/kg arsenic, and ≤0.1 mg/kg mercury. Aflatoxin B1 is controlled at ≤5 µg/kg by immunoaffinity clean-up with HPLC-fluorescence detection. Microbial enumeration follows ChP 2020 methods 1105/1106 or USP 2021/2022: total aerobic microbial count ≤10³ CFU/g, combined molds and yeasts ≤10² CFU/g, Escherichia coli absent in 1 g, and Salmonella absent in 10 g.

The HPLC method for atractylodin must be capable of resolving the marker from co-extracted sesquiterpene lactones. Typical system suitability includes resolution between atractylodin and the nearest peak of not less than 1.5, tailing factor not greater than 2.0, and relative standard deviation of the reference solution injection not more than 2.0%. Because the marker is light-sensitive, reference and sample solutions are prepared in amber volumetric flasks and injected within 12 h if stored at room temperature. If aflatoxin B1 testing is omitted by a feed-grade supplier, the powder may appear identical on visual inspection but carry storage-derived mycotoxin risk; this is one reason the veterinary API grade requires lot-specific mycotoxin release rather than assuming clean status from botanical origin.

Particle-size control is specified according to the intended dosage form. For oral powders and premixes, the material is generally milled to pass an 80-mesh (180 µm) sieve with ≥95% pass rate. For capsules and dry granulations, a finer fraction with D90 ≤ 150 µm is used to reduce segregation. The powder is hygroscopic and its volatile oil fraction is sensitive to high temperature; milling operations should be cooled or interrupted if product temperature exceeds 40°C. Sodium starch glycolate and other superdisintegrants are used in tablets at 2%–4% w/w, but their wicking action can be retarded if the botanical powder carries more than 6% moisture.

When Aqueous Premixes and Oral Solutions Are Prepared from This Powder

Aqueous processing of the powder requires wetting before dispersion because the cuticle-derived hydrophobic surfaces and essential oil-bearing cells slow water penetration. In a high-shear disperser, tip speed of 5–10 m/s is sufficient to wet the powder within 10–20 min at 25–30°C. Above 40°C, the loss of atractylodin becomes measurable in agitated aqueous suspension after 2 h; therefore, hot extraction should be limited to hydroalcoholic systems in closed vessels. Oral solutions are generally prepared from a hydroalcoholic extract of 50%–70% v/v ethanol, concentrated under vacuum at ≤60°C, and filtered through 0.45 µm polyethersulfone membranes. The filtrate may be adjusted to pH 4.5–6.5 with citrate or phosphate buffer before final dilution. For oral suspensions, suspending agents such as carboxymethylcellulose sodium at 0.5%–1.5% w/v can be used. Published data for the Malian powder in these exact aqueous process configurations is limited; the above ranges represent general processing parameters for Atractylodis Rhizoma extracts.

Storage conditions are a critical control because the powder is hygroscopic and contains volatile constituents. It should be kept in sealed, opaque containers at ≤25°C and ≤60% relative humidity. Open-drum storage under humid conditions is a known failure mode, and published data for this specific grade is limited; any moisture gain above the release limit requires re-drying and re-assay because volatile marker loss is not reversible. When caking occurs, sieving through an 80-mesh screen may restore processability, but the re-dried material must be re-assayed against the dried-basis specification.

Tablet, Capsule, and Injection Route Processing Boundaries

For tablet manufacture, direct compression is generally unsuitable for this unprocessed botanical powder because the fibrous particles and irregular surface area reduce flow and increase variation in die fill. Wet granulation with 2%–5% w/w povidone K30 or 5%–10% w/w starch paste improves compression and produces granules with final moisture 3%–5% before compression. Hard capsule filling is performed with the sized powder after addition of 0.5%–1.0% w/w magnesium stearate; lubricant levels above 1.0% w/w may delay dissolution of the water-soluble fraction and should be avoided without dissolution testing. Injectable intermediates require exhaustive extraction, not direct use of the powder. A typical extraction route is reflux in 60%–70% v/v ethanol at 70°C for 2 h, concentration under vacuum, centrifugation at 10,000 × g for 15 min, and sequential filtration through 0.45 µm and 0.22 µm membranes. Terminal steam sterilization at 121°C for 15 min may be used only if the extract has been validated for thermal stability; otherwise aseptic filtration is necessary. The powder’s residual essential oil components can reduce membrane throughput, so pre-filtration with cellulose depth filters is usually required before membrane filtration.

In a wet granulation line, over-wetting the Malian powder with aqueous binder above 15% w/w liquid addition can produce hard lumps that resist dry milling; if the granulator impeller speed is too high, the essential oil cells rupture and release a sticky oleoresin that deposits on the granulator bowl. Cooling the granulator jacket to 15–20°C and reducing binder addition to 8%–12% w/w is used to control this failure mode. Drying in a fluid-bed drier with inlet air above 60°C produces surface crusting and volatile marker loss, while drying below 40°C can extend drying time beyond 90 min and increase residual moisture variability. Final granule moisture before compression is typically specified at 3%–5%; values above 5% increase sticking to tablet punches during long runs.

Compared with Atractylodes macrocephala Koidz. (Baizhu) powder, the Malian Cangzhu material is not interchangeable because the marker chemistry differs. Cangzhu is typically standardized to atractylodin, which elutes as a hydrophobic polyacetylene and is detected at 203 nm by HPLC, whereas Baizhu is often associated with atractylenolide markers detected at 220 nm. The two rhizomes can appear similar after comminution; therefore, the release specification includes both macroscopic/microscopic identity and chromatographic identity. This prevents cross-substitution in veterinary formulations that target gastrointestinal function, where the clinical response depends on the essential oil fraction rather than polysaccharide content alone. Compared with standardized Atractylodes extracts on maltodextrin carriers, the Malian veterinary API powder retains the native cellulose and hemicellulose matrix, which slows dissolution but provides a distinguishable raw-material fingerprint. In tablets, this native matrix may function as a natural filler but can interfere with disintegration; superdisintegrant levels below 2% sometimes fail to achieve disintegration within 30 min in purified water at 37°C using USP 701 apparatus, so higher levels or pregraining are needed.

For oral powders, the API is often preblended with a carrier such as lactose monohydrate or dextrose at 1:5–1:20 before final blending to prevent segregation. An electrostatic charge can develop during low-humidity processing below 30% RH, causing powder adhesion to stainless steel contact surfaces; humidity-controlled blending rooms at 40%–50% RH are recommended. For oral suspensions, particle size must be below 180 µm to minimize grittiness; if a large fraction above 250 µm remains, the product may fail palatability testing. The powder’s natural bitter taste requires palatability masking with sweeteners or flavors, but high levels of citric acid below pH 3.0 may accelerate hydrolysis of ester-type constituents. Therefore, pH of the suspension is usually maintained between 4.0 and 5.5 unless stability data show no marker loss.

In premix production, the powder is typically incorporated at 2–10 kg/t of final medicated feed, but the actual inclusion rate is determined by the veterinary product registration. Homogeneity should be verified by sampling at 10 points or according to ISO 6497:2002. Blend coefficient of variation below 5% is a common acceptance limit, but this depends on mixer geometry and carrier characteristics. In fluidized-bed granulation, inlet air temperature is maintained at ≤60°C because atractylodin loss accelerates above this threshold; outlet air temperature and product moisture are monitored to maintain granule friability. If the powder is blended with hygroscopic carriers such as dextrose monohydrate, the finished premix should be packaged in moisture-barrier pouches and stored at ≤25°C to avoid caking. For oral powders, unit dose sachets of 1–5 g may be filled using auger fillers; the powder’s compressibility and electrostatic charge should be evaluated during line qualification. Published data for this exact Malian product in high-speed sachet lines is limited; therefore, process capability trials are required before commercial batch release.