Picrasma Quassioides Injection Veterinary Grade API is a standardised botanical extract intermediate derived from the dried stem wood or bark of Picrasma quassioides (D. Don) Benn. The injectable-grade designation identifies the material as suitable for further manufacture into veterinary parenteral dosage forms, provided the finished-product manufacturer applies terminal sterilisation or aseptic filtration and confirms sterility and pyrogen compliance. The injectable-grade powder is assigned model code PQI-VG-01; oral and feed-grade material may be supplied under separate codes with less stringent endotoxin control. The API is an amorphous, hygroscopic powder with a target laser-diffraction particle size of D90 ≤ 75 µm for solid oral processing, whereas injectable reconstitution quality is defined by particulate burden after dissolution and passage through a 0.22 µm membrane. The extract is standardised to quassinoid markers by chromatographic fingerprint rather than to a single isolated molecule. The material is intended exclusively for licensed veterinary drug manufacturing and is not for direct administration to animals.

What Distinguishes an Injection-Grade Quassioides API from a Conventional Botanical Powder or Single-Marker Fraction?

Conventional powdered Picrasma quassioides herb contains lignocellulosic particles, chlorophyll, resins, and a variable microbial burden. The injection-grade API is produced by heated aqueous-ethanol extraction, high-speed centrifugal separation, depth filtration, and low-temperature concentration or drying. This sequence removes a substantial fraction of insoluble fibre and high-molecular-weight polysaccharide material that otherwise blinds sterilising-grade membranes. The API is standardised to total quassinoids and to marker ratios by high-performance liquid chromatography with UV detection; individual quassinoid markers such as quassin and neoquassin are quantified against certified reference materials. In contrast, a crude botanical powder is usually identified by macroscopic and microscopic characters without marker quantification. Compared with a single-marker fraction, PQI-VG-01 retains co-occurring constituents that may influence reconstitution behaviour and pH-dependent solubility. This compositional difference requires the finished-product manufacturer to control both total marker content and marker ratio, rather than a single HPLC purity value.

Table 1. Comparative release and process attributes.

Filtration Load and Endotoxin Control in Injectable Dosage Development

For parenteral veterinary products, the release of PQI-VG-01 is controlled for bacterial endotoxin by the chromogenic LAL method of Ph. Eur. 2.6.14. Endotoxin limits for the finished injection are not fixed at the API stage; they are calculated according to Ph. Eur. 5.1.10 from the maximum intended dose and species-specific endotoxin threshold. For a 10 kg animal receiving 1 mg/kg, the finished product limit is derived from the parenteral endotoxin threshold divided by the dose; the API is supplied with batch endotoxin data to support that calculation. Because the limit is dose-dependent, an injection-grade botanical API cannot be assigned a single universal endotoxin specification without knowing the intended dosing schedule.

The main filtration bottleneck in injectable processing is gel-layer blinding of 0.45 µm and 0.22 µm polyethersulfone cartridges by residual pectin-like polysaccharides and protein-polyphenol complexes. Preclarification by disk-stack centrifugation at 8,000–10,000 × g and charged depth filtration reduces the feed burden sufficiently to keep the differential pressure across a 10-inch cartridge below the 1.5 bar threshold at which constant-pressure flux decline becomes non-linear. Without preclarification, production-scale filter runs may show 40–60% flux loss within 20 minutes under constant pressure. Terminal steam sterilisation at 121 °C for 15 minutes may degrade heat-sensitive quassinoid markers; therefore aseptic filtration through 0.22 µm membrane is the preferred route unless finished product stability data demonstrate no marker loss under steam load.

Reconstitution pH is a formulation variable because quassinoid solubility is pH-dependent. Saturation shake-flask testing at 25 °C and pH 4.0–7.4 is used to select the buffer system. Precipitation may occur above pH 7.0 or in the presence of divalent cations from hard water; water for injection with a chelating agent may be required. Particulate matter in the reconstituted solution is controlled by light-obscuration particle count according to Ph. Eur. 2.9.19. Solutions for injection should meet the relevant test limits for particles ≥ 10 µm and ≥ 25 µm after filtration. The formulation is protected from light and oxidative conditions because photolytic and oxidative degradation can alter the quassinoid fingerprint without immediate visible colour change.

When Tablets, Capsules, and Granules Demand Controlled Particle Size and Moisture

For solid oral dosage forms, PQI-VG-01 is treated as a hygroscopic, low-density botanical powder. The target particle size of D90 ≤ 75 µm is verified by laser diffraction per ISO 13320. Direct compression is limited to low drug loadings because the amorphous extract particles are cohesive and irregular; above approximately 5 wt%, flowability fails and the blend tends to stick to hopper walls. Wet granulation in a high-shear granulator at impeller speed 150–250 rpm and fluid-bed drying at inlet air temperature 50–60 °C are used to produce granules with residual moisture below 5.0% by Karl Fischer titration, Ph. Eur. 2.5.12. If dry granulation is selected, roller compaction with 1.0–2.0 mm roll gap and 0.8–1.2 mm screen improves granule density and reduces dust.

Blend uniformity is assessed on production-scale bin blenders using stratified sampling at 10–12 positions and content assay according to Ph. Eur. 2.9.40. Demixing risk increases when the particle-size ratio between API and filler exceeds 10:1; geometric dilution with a glidant or filler is therefore used before main blending. Capsule filling on tamping-pin machines requires a final blend Carr index below 25. Dosator-type machines may densify the powder and cause sticking if the process room exceeds 50% RH; processing conditions of 40–50% RH and 20–25 °C are recommended. Tablet compression is typically controlled to hardness 60–100 N and friability below 1.0% according to Ph. Eur. 2.9.7. Disintegration is assessed by Ph. Eur. 2.9.1. Dissolution testing may require a surfactant-containing medium, such as 0.1 N HCl with 0.5% sodium lauryl sulfate, using paddle agitation at 50–75 rpm per Ph. Eur. 2.9.3.

Stability of PQI-VG-01 is assessed at 25 °C/60% RH and 40 °C/75% RH in intended packaging. Marker degradation is monitored by HPLC, and hygroscopicity is monitored by dynamic vapour sorption. If the product is stored above 25 °C, agglomeration and colour change may occur before marker loss. Shelf life is assigned from real-time stability data, not from accelerated data alone.

Premix, Powder, and Solution Incorporation in Veterinary Feed and Drinking Water

For feed premix and dry powder applications, PQI-VG-01 is dispersed onto a carrier such as calcium carbonate or lactose monohydrate in a ribbon blender. Mixing time is established by cross-sectional sampling for quassinoid assay; the coefficient of variation for active ingredient homogeneity is typically required to be ≤ 5% during mixing validation. Because the powder is sticky at elevated humidity, the premix is packed immediately into moisture-barrier sacks. Granules are prepared by fluid-bed spraying of the extract solution onto a carrier, producing a dust-reduced intermediate with residual moisture below 5.0%. For oral solution or drinking-water administration, the API is dissolved in purified water with pH adjustment to 5.5–6.5. Compatibility with antioxidants such as sodium metabisulphite is confirmed by forced degradation at 40 °C/75% RH for 4 weeks. Precipitation may occur in hard water containing calcium or magnesium; EDTA at 0.01–0.05% is evaluated as a chelator.

In comparison with synthetic veterinary APIs, the multi-component fingerprint requires both marker content and marker ratio to be controlled. This creates batch-to-batch variance that is managed by normalising total solids to the quassinoid HPLC area. Published data for this specific configuration in target species is limited, so therapeutic equivalence is evaluated on a product-specific basis. The API is not a direct substitute for a fermented or synthetic antiprotozoal drug unless the finished product authorisation supports such substitution.

Analytical release of PQI-VG-01 combines identity, purity, and process consistency. A reversed-phase HPLC method using a 250 × 4.6 mm, 5 µm C18 column and a gradient of acetonitrile and 0.1% phosphoric acid is used to quantify total quassinoids and marker ratio. Detection at 254 nm is suitable for the quassinoid chromophore. The method is validated for specificity, linearity, accuracy, and precision according to ICH Q2(R1). Batch-specific total quassinoid content is reported as the sum of major peaks in the chromatographic window relative to the certified reference standard. The fingerprint acceptance range is derived from historical production batches; published data for this specific configuration is limited, so the range is not transferable to other botanical extracts without revalidation.

Elemental impurities are controlled under ICH Q3D with routine screening for lead, cadmium, arsenic, and mercury. Residual ethanol from extraction is controlled under VICH GL18 and is typically below the Class 3 limit; the actual batch value is verified by headspace GC. Non-sterile oral-grade material is released with microbial limits aligned to Ph. Eur. 2.6.12 and 2.6.13. Injection-grade material is released with a tighter internal bioburden specification to support downstream aseptic filtration. Sterility testing is performed on the finished sterile dosage form, not on the API. Bulk packaging is double food-grade LDPE liners inside aluminium-laminated kraft drums. Storage is at 2–8 °C or below 25 °C in a dry environment, depending on batch stability assignment. Opened material is re-sealed with desiccant and used promptly.