Shixiang Granules Veterinary Grade API for Tablets / Injections / Capsules / Powders / Granules / Premix / Solutions is released as a single granular active pharmaceutical ingredient, not as a formulated premix or finished dosage form. The manufacturer documentation reviewed for this product does not assign a separate model number in the current revision; the material is identified by the full trade designation and the production lot code. Where a customer-specific material code appears on a purchase order, that code is a commercial identifier and does not alter the release specification. The product is labelled for seven dosage-form routes: tablets, injections, capsules, powders, granules, premix, and solutions. The term “granules” in the trade name refers to the physical form of the active ingredient, not to a finished oral granule dosage form. A separate granulation step may still be required to produce a finished oral granule product. Because the same granule enters seven dosage-form manufacturing routes, the certificate of analysis is structured with route-specific notes and exception criteria. The granular architecture reduces dusting during weighing and blending relative to micronized API, but it is not a substitute for terminal sterilization or aseptic processing when an injectable dosage form is specified. The receiving site must classify each lot according to the intended route and verify the route-specific limits before release for manufacturing.

Specification Chassis, Compendial Reference Methods, and Release Limits

The release framework is built around a core set of compendial tests. Batch-specific values appear on the certificate of analysis; the limits shown in the table below are typical release targets for a multi-route veterinary API and are tightened for injection-designated material. The method assignments follow pharmacopoeial general chapters and VICH impurity guidelines where no individual monograph exists. Related substances are evaluated by a stability-indicating HPLC method validated according to VICH GL11; reporting threshold is 0.05%, identification threshold 0.10%, and qualification threshold 0.15% unless otherwise justified.

Table 1. Typical release limits for Shixiang Granules Veterinary Grade API.

The release limits are not a single universal formula. A lot released for oral tablets may not automatically meet the parenteral specification unless the certificate of analysis includes endotoxin and moisture limits at the injection-designated values. This route-dependent release architecture is the central operational difference between a multi-dosage-form grade and a dedicated single-route API. The granular material is typically packed in moisture-resistant double polyethylene liners inside a fibre drum or HDPE drum. The outer label records the lot number, gross and net weight, storage instruction, and the route-specific release checks completed for that lot. Storage is in a dry area at 15–25 °C with the container tightly closed; exposure to direct sunlight and high humidity should be avoided. Batch-specific long-term and accelerated stability data are referenced on the certificate of analysis; published data for this specific granular API in tropical climate zones are limited, so secondary desiccant may be required when repackaging into smaller containers.

Direct compression of the granular API into tablets requires a pre-compression screen for particle size and powder flow. On a rotary tablet press equipped with a force feeder, the material is blended in a twin-shell blender at 15–20 rpm for 10–15 min with dry binders and lubricants before compression. If D90 exceeds 250 μm, segregation risk increases and roller compaction is preferred before final blending. Production-scale observations indicate that over-lubrication with magnesium stearate beyond 1.0% w/w can reduce tablet tensile strength; this is not unique to the Shixiang granule but must be controlled because the granular surface area is lower than that of a micronized API. A compaction simulator study is recommended before full-scale conversion because published data for this exact granular API under high-speed compression are limited. The tablet press should be run with pre-compression to remove entrapped air; main compression force between 5–15 kN is typical for a 250 mg tablet, but actual force depends on tooling and excipient ratio.

Wet granulation is used when the formulation requires densified granules or contains a moisture-sensitive binder. The API is first dry-mixed in a high-shear granulator with impeller speed 300 rpm and chopper speed 1800 rpm; water or binder solution is added at 5–8 mL/min per kg of dry blend. Drying in a fluid-bed dryer at inlet temperature 40–60 °C continues until loss on drying reaches 1.0–2.0%. Tablet breaking force is measured by USP <1217>, friability by USP <1216>, and weight uniformity by USP <905>. Capsule filling on a dosator machine requires bulk density above 0.50 g/mL; if the as-received lot is below this threshold, roller compaction or slugging is used to increase bulk density. For capsule products, content uniformity follows USP <905> and dissolution is characterized by USP <711> in the registered medium. Published data for this exact granular API on high-speed capsule platforms are limited; a small-scale fill study with sorted capsule shells is advised before full-scale conversion. If powders generate static, grounding the dosator and controlling room RH to 35–45% reduces weight variation.

Oral powders are prepared by geometric dilution in a tumble blender or high-shear mixer. A final sieve through a 500 μm screen removes agglomerates. The finished powder is sampled at 10 locations, and blend uniformity should show a relative standard deviation ≤5.0%. The granular form reduces dusting but can retain residual agglomerates after extended storage at RH >60%; pre-drying at 40 °C in a vacuum dryer is required if agglomeration is observed. The granule is not a finished oral powder; it lacks flavouring, sweetener, and carrier. It is also not a direct premix, because medicated feed premixes require dilution with a suitable feed carrier and must comply with 21 CFR Part 226 when intended for Type A medicated articles in the United States.

What Limits the Use of This Granular API in Parenteral Dosage Forms?

Parenteral processing with Shixiang Granules Veterinary Grade API starts with dissolution or suspension of the granular solid, followed by terminal sterilization or aseptic filtration. The granular form itself is not sterile, and sterility per USP <71> is not claimed at release. For injection-designated lots, the certificate of analysis reports bacterial endotoxins by USP <85> and water content by USP <921>. The endotoxin limit ≤0.5 EU/mg is a typical parenteral starting point; the final dosage form may require a lower limit depending on dose and target species.

Before terminal moist-heat sterilization, the solution is passed through 0.45 μm and then 0.22 μm membrane filters under pressure. Filled containers are processed in a steam autoclave with cycle parameters derived from the final container heat load; terminal moist-heat sterilization is validated according to ISO 17665-1 and biological indicators are selected under ISO 11138-3. Published data for this exact granular API under terminal moist-heat sterilization are limited; cycle selection should rely on loaded-chamber validation with worst-case container loads rather than on API-only data. Particulate matter is tested on the finished injection by USP <788>; visible particulate inspection follows USP <790>. Because the granular API may contain a small insoluble fraction, a solubility screen in the final formulation at pH 6.0–7.5 is required. If full dissolution is not achieved, a suspension formulation with wetting agent and viscosity modifier must be developed. The final injection should meet pH per Ph. Eur. 2.2.3, clarity per Ph. Eur. 2.2.1, and color per Ph. Eur. 2.2.2.

The main difference from a dedicated sterile API is the absence of sterility assurance and the possible need for micronization or solubilization. A sterile lyophilized API can be reconstituted directly in an aseptic line, whereas this granular grade must enter a terminal sterilization or aseptic filtration step. This is an operational boundary, not a defect. Compatibility with amine-based buffers such as tromethamine or glycine should be confirmed by forced-degradation testing before injectable formulation; published compatibility data for this specific granular API with amine-based excipients are limited. A 14-day forced-degradation study at 40 °C/75% RH is a conservative screen for incompatibility. The granular API should not be dry-blended with strong oxidizing agents; oxidative degradation may occur under high-shear mixing.

In medicated feed premix manufacture, the granular API is diluted with a carrier such as corn cob, rice hull, or lactose in a double-cone or ribbon blender. Blend uniformity is tested after 5–10 min at 15–20 rpm; top, middle, and bottom thief samples should show a coefficient of variation ≤5.0%. The API particle size should be coarse enough to reduce dust inhalation during feed-mill handling, but not so coarse that segregation occurs in auger conveyors. A sieve analysis per USP <786> after blending is used to monitor fines generated by attrition. Because this is a granular API and not a formulated premix, it does not contain a carrier, antioxidant, or dust-control oil. The feed formulator must add these components according to the target species and feed matrix.

For drinking-water solutions, the granular API is dissolved in a pilot vessel at 25–40 °C with high-shear mixing at 500–1000 rpm for 15–30 min. pH is adjusted with citrate or phosphate buffer to maintain chemical stability; the final solution is passed through a 0.45 μm clarifying filter before packaging. Published data for this specific granular API in hard-water matrices are limited; a solubility screen is required at the target pH and water hardness. If the material is intended for an injectable solution, the dissolution step is followed by 0.22 μm filtration and terminal sterilization as described above. For oral solutions, microbial challenge testing follows Ph. Eur. 5.1.3 or equivalent. The granular architecture slows wetting compared with a micronized powder, so mixing time may need to be extended if large crystals or agglomerates remain.

Oral granules are prepared by further wet granulation with a binder such as povidone or hydroxypropyl methylcellulose. The granular API is mixed with binder solution in a planetary mixer, extruded through a 0.8–1.2 mm screen, spheronized, and dried. Moisture after drying is typically ≤2.0%; if the product is intended for sachets, desiccant may be required. Alternatively, the as-received granules can be directly filled if the dose is low and the particle-size range meets the label claim; content uniformity is confirmed by USP <905>. If the finished granule is intended for a feed in-premix, the blend is further diluted with feed ingredients and homogeneity is tested at the point of use.

When a Single Granular Grade Is Compared With Feed-Grade or Sterile APIs

The differences between Shixiang Granules Veterinary Grade API and adjacent grades are defined by release testing, physical form, and downstream processing burden. A feed-grade API may be supplied as coarse crystals or irregular powder with less stringent residual solvent and elemental impurity control; it is generally not tested for bacterial endotoxins or injection-grade microbial limits. A sterile API is supplied with sterility per USP <71> and is intended for aseptic compounding; it typically carries a higher handling burden and may require validated low-bioburden or cold-chain conditions. The Shixiang granule occupies an intermediate position: it is a pharmacopoeial-grade granular API with oral and injection-designated lot testing options, but it requires downstream sterilization for parenteral use and may require size reduction for direct compression or solubilization.

Table 2. Comparison of the granular veterinary grade with adjacent API grades.

The route-dependent lot classification is the principal differentiator. A lot intended for tablets may not be automatically suitable for injection unless the certificate of analysis carries the injection-designated endotoxin and moisture limits. This distinguishes the product from a single-route sterile API, where sterility and endotoxin control are assured from release, and from a feed-grade API, where oral and parenteral release tests are not part of the specification. The absence of a separate model suffix in the Shixiang documentation also means that purchasing a separate injection-grade or tablet-grade designation is not required; instead, the same granular product is qualified lot-by-lot against the route-specific requirement.