Qinghao Changshan Granules Veterinary Grade API is a granulated botanical extract intermediate derived from the aerial parts of Artemisia annua L. and the root or rhizome of Dichroa febrifuga Lour. It is supplied as a non-sterile granular solid, typically brown to green-brown, and is intended solely for further pharmaceutical processing into veterinary tablets, injections, capsules, powders, granules, premixes, and solutions. The product is not a final dosage form and cannot be administered directly without route-specific formulation, in-process control, and release testing. Because no universal compendial model code exists for this multi-source extract, the commercial model identifier is assigned by the manufacturer and commonly encodes the extraction ratio, particle-size cut, and assay target. Procurement records should therefore link the model code to the supplier Certificate of Analysis and the current veterinary drug GMP statement rather than relying on the product name alone.

Standardisation is normally based on high-performance liquid chromatography markers, commonly artemisinin from Artemisia annua and febrifugine or isofebrifugine from Dichroa febrifuga. The granule retains residual plant-matrix components including polyphenols, polysaccharide fragments, mineral ash, and minor alkaloids. This matrix is both a technical difference from purified artemisinin API and a source of batch-to-batch variation. Consequently, the acceptable assay range, moisture limit, particle-size profile, heavy-metal limits, and microbial enumeration are supplier-specific. A single universal specification cannot be imposed across all veterinary formulation routes because oral solids, oral liquids, and parenterals require different control strategies.

How does the granule's extraction and drying history affect its performance as an API for tablets, capsules, and premixes?

The extraction and drying process determines bulk density, residual moisture, particle morphology, and the size distribution of finished granules. Spray-dried or fluid-bed granulated extracts tend to produce free-flowing porous agglomerates, while high-shear granulated material may be denser and less dusty. For solid-dosage processing, the granule should be characterised before blending because fine fractions below 75 µm can segregate during low-shear mixing, whereas oversized particles above 500 µm may require dry size reduction before capsule filling. The exact cut is application-specific and should be stated on the supplier CoA; published data for the specific botanical combination are limited.

The API is released under a specification that should be aligned to the intended route of administration. For oral solid applications, the critical material attributes include marker assay, loss on drying, bulk and tapped density, particle-size distribution, and microbial enumeration. For liquid applications, cold-water dispersibility, pH of a 1% w/v dispersion, and subvisible particle burden after reconstitution are relevant. For any route, residual solvents and heavy metals are controlled because the extract may concentrate soil-derived contaminants. The following table lists the attributes that a veterinary manufacturer should request from the supplier.

The table is a screening matrix rather than an approved specification. For a given dosage form, the acceptance limits are set by the formulation batch size, target marker dose, and manufacturing process capability. Any limit that is not listed on the supplier CoA should be addressed by vendor qualification and incoming inspection.

For tablet formulations, the main process risk is elastic recovery of the extract particle under compression. Direct compression of a dry herbal extract granule is generally limited by poor flow, high hygroscopicity, and low compressibility; wet granulation is therefore used more often. In a typical rotary tablet process, microcrystalline cellulose at 10% w/w to 30% w/w, polyvinylpyrrolidone K30 at 2% w/w to 5% w/w as a binder solution, and croscarmellose sodium at 1% w/w to 3% w/w as a disintegrant provide a starting formulation, but the optimum is confirmed by tablet hardness, friability, and disintegration testing. Extract loading above 60% w/w can increase sticking and lamination on the press; precompression force, turret speed, and punch-tip dwell time should be adjusted on the production machine rather than extrapolated from laboratory compaction simulators. Tablet breaking force can be checked according to USP <1217>, friability according to USP <1216>, and disintegration according to USP <701>.

Granulation endpoint can be monitored by power consumption of the high-shear mixer or by product temperature in fluid-bed drying. Drying above 60°C is often avoided for artemisinin-containing extracts because thermal degradation may occur, but the actual degradation threshold should be determined by forced-degradation studies. The dry granule should be sieved to remove lumps, and the oversized fraction may be milled and recycled; recycling should be controlled because fines generated during milling can increase dust and reduce flow.

Capsule filling and sachet powders are more sensitive to flow and bulk density than tablets. The granule may exhibit acceptable flow after conditioning with 0.5% w/w to 1.0% w/w colloidal silicon dioxide or equivalent glidant, but the addition level should be minimised because low-density fines can create dust and reduce content uniformity. An auger dosator capsule filler may require different granule flow than a vibratory feed plate; fill weight variability is measured by weight uniformity tests in the finished-product pharmacopoeia. Open handling at relative humidity above 60% RH can cause moisture uptake and caking within minutes for hygroscopic extract granules, so controlled-humidity rooms and desiccated storage are advised. The granule should be tested for water activity and loss on drying after any exposure; a water activity below 0.60 is a common microbiological control reference for non-sterile botanical powders, with microbial limits set by USP <2021> or equivalent.

Differences from raw herb powders, purified artemisinin, and semisolid extract pastes.

The veterinary-grade granule is not interchangeable with raw Qinghao and Changshan powders. Raw powders retain intact plant cell walls, fibres, and variable moisture; they may pass a coarse sieve but do not have a defined marker assay across the blend. The granulated extract has been concentrated and sized, which reduces fibrous load and allows a narrower particle-size distribution, but it also concentrates soluble matrix constituents that can affect dissolution and excipient compatibility. It differs from purified artemisinin API because it contains co-extracted polyphenols, alkaloids, ash, and marker compounds from Changshan; a milligram-for-milligram replacement based on artemisinin content is invalid without reformulation. Compared with semisolid extract pastes, the granular form is easier to store and meter, but it may be more hygroscopic after grinding and can cake if moisture control is inadequate. The distinction matters in regulatory filings because a change from purified API to whole-extract granules alters the impurity profile and the stability-indicating assay.

Two granule products carrying the same Chinese common names may differ in extraction solvent, evaporation temperature, carrier addition, and marker specification. Ethanol-water extracts may contain different residual solvent profiles than water-only decoctions; vacuum-dried material may differ from spray-dried material in particle morphology and oxidative degradation. The supplier approved specification should be compared line-by-line before replacing one source with another, and the formulation should be revalidated because blend behaviour, colour, and dissolution may shift even if marker assay remains within the same range.

When the intended route is parenteral, the granule is a preprocessing intermediate, not a sterile injectable API. The starting material must be dissolved or dispersed in water-for-injection, pH-adjusted, clarified, depyrogenated, and sterile-filtered. Herbal extracts can contribute subvisible particles, endotoxin, and colour that are not present in a purified single-molecule starting material; therefore the filtration train should include a coarse prefilter followed by membrane filtration. A final sterilising-grade filter at 0.22 µm is not a substitute for upstream clarification, because high extract colloids can foul the membrane and reduce throughput. The solution must meet the applicable veterinary pharmacopoeial requirements for sterility, bacterial endotoxin, and particulate matter; particulate load can be assessed according to USP <788>, sterility according to USP <71>, and endotoxin according to USP <85>. Published stability data for this specific combination in injectable form are limited, so formulation developers should generate batch-specific pH, oxygen, light, and temperature stability data rather than adopting parameters from a single-artemisinin injection.

Sterile filtration validation for herbal solutions should include filter compatibility in addition to bacterial retention. Extract constituents may adsorb onto filter membranes, reducing marker recovery in the first few litres of filtrate; flushing and recirculation may be necessary. The solution should be protected from oxidation by nitrogen overlay and stored in low-oxygen-permeability containers. Light protection is relevant because artemisinin and related endoperoxides can undergo photodegradation; amber glass or opaque primary packaging is used unless photostability data support otherwise.

Artemisinin has low aqueous solubility; aqueous solutions may require organic cosolvents, cyclodextrins, or pH control, but each change must be justified for the target animal species. Febrifugine-related alkaloids may be pH-sensitive and can precipitate or degrade in alkaline media. For oral solutions and drench preparations, the same principles apply but the acceptance criteria for visible particulates and endotoxin are less restrictive than for parenterals; still, clarity, taste masking, and microbial preservation should be evaluated because botanical extracts support microbial growth if water activity and preservative load are not controlled.

When hard water or mineral premixes are combined with the granule, pH and divalent-ion compatibility screening is required.

In premix and drinking-water applications, the granule is distributed into a feed carrier or water supply before administration. Blend uniformity in feed premix should be validated by sampling and measuring marker assay at multiple points; a coefficient of variation of ≤5% is a common industrial acceptance point but may be tightened for low-dose feed additives. Hard water containing calcium and magnesium ions can react with polyphenols and form turbidity or precipitates, so a laboratory solubility screen should be run before field use. The alkaloid fraction of Dichroa febrifuga can ionise as pH changes; local pH above 9 in mineral premixes or after addition to alkaline feed may accelerate degradation or precipitation unless compatibility data demonstrate otherwise. Oxidative degradation of artemisinin can be accelerated by trace metals, so antioxidant addition and opaque, moisture-barrier packaging are evaluated for long-term stability. The granule should not be combined with strongly alkaline drug premixes or oxidising disinfectants without data.

For dry premixes, segregation is a processing bottleneck when the granule size differs substantially from the feed carrier. Matching the granule particle-size band to the carrier, or using a post-blend milling step, reduces marker assay drift. A ribbon blender or paddle mixer with baffles is generally suitable for feed premises, but the mixer load, fill level, and discharge sequence must be validated. In drinking-water systems, stock solutions should be prepared as a predilution and then dosed by proportioning pump; direct dumping of granules into water tanks can cause settling and dose variation.

The product name itself contains the dosage forms for which the granule is intended as an API, but it does not indicate that the granule is directly injectable or directly tablet-ready. A typical model code may appear as a manufacturer-specific alphanumeric string, for example combining an internal code, extraction ratio, and mesh cut. Such codes are not standardised by pharmacopoeias; they should be traced to a certified product data sheet. When comparing two sources, compare the actual CoA, residual solvent profile, and impurity profile, not just the product name.

Quality agreements for this product should specify the analytical marker, assay tolerance, moisture limit, particle-size distribution, residual solvent class, heavy-metal limits, and microbial enumeration. Because the granule is a non-sterile botanical intermediate, incoming inspection under the dosage-form manufacturer supplier qualification programme is required, and each finished veterinary product line should be validated independently. Use in food-producing species is subject to the residue and withdrawal requirements of the competent regulatory authority; the API itself does not carry a universal withdrawal period.