Product identification: Sijiqing Injection Veterinary Grade API, manufacturer code SJQ-IV-API-2025-01, is a purified dried extract of Ilex chinensis Sims leaf. It is standardized for use as an active pharmaceutical ingredient in tablets, injectable solutions, capsules, powders, granules, oral premixes, and liquid solutions. The material is not a simple milled botanical powder; release is controlled through a multi-compendial specification for residual moisture, heavy metals, bioburden, and bacterial endotoxin. The principal chromatographic marker is protocatechuic acid, monitored by HPLC-DAD at 280 nm against a certified reference standard. The API is supplied as a brownish-yellow to tan spray-dried or lyophilized powder with a nominal total phenolic acid content of not less than 4.0% (w/w) expressed as chlorogenic acid equivalents. The extraction process concentrates phenolic acids from the leaf using aqueous ethanol and column purification; each batch is traceable to the botanical harvest date and geographical origin, with retained samples maintained at 25 °C and 60% RH for 36 months.

No single harmonised veterinary monograph exists for this botanical API in the Ph. Eur. or USP. Where no species-specific monograph is published, the manufacturer applies compendial general methods from the United States Pharmacopeia and Ph. Eur., while the Chinese Veterinary Pharmacopoeia 2020 provides the botanical identification framework. This API is intended for veterinary medicine only and is not assigned a human-use monograph.

What specification profile governs release of a multi-route veterinary herbal API?

The release specification must control both chemical purity and the process burden transferred into downstream sterile or non-sterile manufacturing. Solid oral dosage forms tolerate higher bioburden than injectable solutions, but the API release limit is set at a single conservative profile to avoid segregated warehouse flows. The injection-grade specification applies when the API is ordered for parenteral manufacturing. Each batch is released with a certificate of analysis containing retention time windows, integration parameters, and residual solvent chromatograms.

The bacterial endotoxin limit of 0.50 EU/mg is applied to injection-grade releases, while non-injection solid oral grades may be released against a general bioburden limit without routine endotoxin testing. The low endotoxin specification reduces terminal filtration burden and permits direct integration into sterile filling lines. The residual ethanol limit is set below the ICH Q3C Class 3 solvent concentration threshold and is verified by headspace gas chromatography on every batch.

When the API is reconstituted for injectable solutions

For injectable solutions, a known mass of API is dissolved or suspended in Water for Injection at 20–30 °C under aseptic conditions. The reconstituted liquid is adjusted to pH 4.5–6.5 with citrate or acetate buffer because protocatechuic acid and chlorogenic acid degrade rapidly at alkaline pH above 8.0. The solution is passed through a 0.22 µm PVDF or polyethersulfone membrane filter. Terminal steam sterilization at 121 °C for 15 min is conditionally acceptable only for formulations whose HPLC assay shows no more than 5.0% marker loss during thermal challenge. Aseptic filtration is preferred because phenolic acid oxidation accelerates above 100 °C at pH greater than 7.0.

Particulate matter is controlled at the solution stage rather than only at API release. After filtration, the solution is filled into Type I glass vials or cyclic olefin polymer vials under Grade A laminar flow. Product-contact surfaces are qualified by endotoxin recovery; rinse samples are tested with Limulus amebocyte lysate. If the API is stored at RH greater than 60%, pre-drying at 45 °C for 4 h is required before use. Rehydration generates a mildly acidic, oxygen-sensitive solution; headspace nitrogen blanketing is specified when the formulation contains trace metal ions or when the filling line allows extended dwell time. Published data for prolonged storage of reconstituted intermediate at concentrations above 50 mg/mL are limited; pilot stability evaluation is required before full production.

Tablet, capsule, powder, and granule processing of SJQ-IV-API-2025-01 begins with pre-blending with 1.0% (w/w) colloidal silicon dioxide and 1.5% (w/w) sodium starch glycolate to control agglomeration and improve powder flow. Direct compression is feasible only when ambient RH is below 60%; above this threshold, dry granulation with a roller compactor is recommended. Tablet hardness is maintained at 60–90 N on a rotary tablet press, and friability is maintained below 1.0% by the addition of 0.5% (w/w) magnesium stearate. Capsule filling uses a dosator-type or tamping pin machine; powder bed density is controlled at 0.45–0.60 g/mL. For powders and granules, the API is dry-blended with dextrose or lactose monohydrate to a target fill weight determined by marker assay. The blend is packaged in aluminium foil sachets when moisture-sensitive formulations are used. Published data for roller-compacted ribbons at API loadings above 40% are limited; pilot-scale evaluation is required before full production.

Premix carriers alter marker recovery through alkaline hydrolysis

Premix and feed applications expose the API to transition-metal ions and alkaline carriers that degrade phenolic acids. When the API is blended with limestone or dicalcium phosphate premixes at pH greater than 8.0, protocatechuic acid recovery in HPLC assay can decline by more than 10% after 48 h at 40 °C and 75% RH. Copper sulfate, ferrous sulfate, and choline chloride in the same premixture exacerbate oxidation; copper levels above 250 mg/kg in the final premix should be segregated by time or spatial separation. A protective coating of the API or the use of acidified carriers with pH 5.5–6.5 is required. Pelleting temperatures above 80 °C for longer than 3 min reduce marker content; extruder barrel temperatures should be kept below 75 °C when die-friction heat is considered. Although published data for this specific botanical extract in a soy hull carrier are limited, the degradation trend is consistent with known phenolic acid–metal chelation behaviour.

Comparator differences against technical-grade Sijiqing powders

The operational difference is primarily release depth. Injection-grade batches are released only after endotoxin recovery, heavy-metal testing, and residual solvent analysis. Technical-grade powders may be non-standardised and unsuitable for parenteral use. The lower endotoxin specification and controlled particle size support direct integration into sterile filling lines, while the lower bioburden reduces terminal filtration load. For tablet and capsule production, the injection-grade endotoxin limit is not strictly required, but the unified specification allows a single supplier qualification to cover both solid and liquid production.

For oral solutions and drench formulations, the API is dissolved in aqueous systems buffered to pH 5.0–6.0. Without buffering, the solution drifts toward pH 6.8–7.2 and accelerates oxidation; sodium metabisulfite at 0.1% (w/v) is used when oxygen-sensitive formulations are packaged in non-barrier containers. Light exposure at 450 nm and below reduces protocatechuic acid content; amber polyethylene terephthalate or Type III glass containers with induction-sealed closures are specified. The solution should be stored at or below 25 °C. Long-term stability data support a 24-month shelf life in unopened containers when stored at 25 °C and 60% RH. If the solution is diluted in hard water with alkalinity above 250 mg/L as CaCO₃, precipitation of metal-phenolic complexes may occur.