Swine water-soluble powder manufacture for oral administration through proportioner pumps begins with a tightly controlled pre-blend of clavulanate potassium and anhydrous glucose or lactose monohydrate. Master formulae typically express the active ratio as 4:1 amoxicillin trihydrate to clavulanic acid, with clavulanate potassium corrected by a factor of 1.19 for salt weight and incorporated at 2.5–5.0% w/w in the finished dry blend. A double-cone tumble blender operating at 12–15 rpm and 60% vessel fill is preferred over high-shear mixers because frictional heat and adsorbed moisture induce hydrolytic ring-opening of the oxapenam nucleus. Blending is executed at 20–25 °C and ≤ 35% RH; continuous logging of room dew point and product moisture by Karl Fischer titration according to Ph. Eur. 2.5.12 documents batch-to-batch consistency. After pre-blending, the mass is screened through a 500 µm stainless-steel sieve and geometrically diluted into amoxicillin trihydrate, followed by addition of anhydrous citric acid to buffer final solution pH below 6.5. Regulatory compliance for batch release requires assay by Ph. Eur. 2.2.29 high-performance liquid chromatography, identification of degradation products, and residual solvent control according to VICH GL18(R2); the finished veterinary medicinal product must be licensed under Regulation (EU) 2019/6. The terminal product forms are foil-laminated sachets of 50 g, 100 g, 1 kg, or high-density polyethylene pails with induction-sealed lids, each containing a desiccant sachet. Powder intended for direct dosing via water medicators is preferred over pelleted feed premixes because clavulanate potassium is not exposed to steam conditioning at feed mill temperatures.

What Limits Clavulanate Potassium Stability in Poultry Drinking-Water Premixes?

Poultry drinking-water medication introduces variables absent from swine proportioner systems: header tank residence times, pH drift due to organic acids in water lines, and residual free chlorine from municipal supplies. The dry premix is formulated at a 4:1 amoxicillin-to-clavulanic acid ratio with clavulanate potassium at 2.0–4.5% w/w; a 100 g sachet is diluted into 500–1000 L of drinking water to achieve 100–200 mg/L amoxicillin activity. Formulation development data generated on production-scale sachet lines show that dissolution is governed by the particle size distribution of the carrier, not by active concentration: a pre-blend milled to a D90 below 250 µm dissolves within 3 minutes in water at 20 °C, whereas unmilled dextrose monohydrate extends wetting time beyond 8 minutes. The powder is filled in an ISO 14644-1 Class 8 cleanroom with relative humidity ≤ 30% RH and sealed in nitrogen-flushed polyester-aluminium-polyethylene laminate sachets. Because clavulanate potassium hydrolyses faster in alkaline water, formulated product includes anhydrous citric acid to depress reconstituted pH to 5.0–6.0; however, published data for degradation in hard water above 200 ppm CaCO₃ remain limited. Compliance is documented against Regulation (EU) 2019/6 and VICH GL3(R) stability testing, with finished-product assay by Ph. Eur. 2.2.29 and uniformity of mass by Ph. Eur. 2.9.40. The terminal product forms are laminated sachets and polypropylene jars for poultry house metering cabinets. Chlorinated drinking water above 1 ppm total residual oxidant is a recognised operational limitation, although published degradation kinetics for this specific configuration are limited.

Where companion animal dose flexibility requires scored tablets at 40 mg/10 mg, 200 mg/50 mg, and 400 mg/100 mg amoxicillin/clavulanic acid, roll-compaction dry granulation is selected to avoid aqueous binder contact. The tablet core formulation incorporates clavulanate potassium in a 4:1 or 7:1 active ratio, with the potassium salt adjusted by factor 1.19; clavulanate potassium typically occupies 10–15% w/w of the core. Roller compaction is performed on a chilsonator with integrated oscillating sieve, using low compaction force and cooled rolls to keep granule temperature below 30 °C; wet granulation, in contrast, produces a granule moisture above 2% and increases clavulanate degradation during storage. Tablets are compressed on a high-speed rotary press with pre-compression to reduce capping, and dissolution is verified according to USP 711 using pH 6.8 phosphate buffer; content uniformity must meet USP 905 or Ph. Eur. 2.9.40. Film coating is limited to a high-solids aqueous dispersion applied with low dew-point inlet air; organic solvent-based coatings are used where local VOC permits allow. Terminal finished product types are blister-packed scored tablets and, for capsules, size 1 or 2 hard gelatin capsules filled with dry granulate. The operational boundary is defined by the moisture permeability of the blister lidding: PVC/PVDC/Alu is required when storage is specified at 25 °C/60% RH; PVC-only lidding has been associated with clavulanate potassium discoloration and loss of assay before the end of shelf life.

When Intramammary Syringes Are Filled Without Terminal Sterilisation

Lactating cow mastitis therapy using an intramammary suspension places the API in an oil-based vehicle inside a pre-filled syringe, a configuration that excludes terminal steam sterilisation because clavulanate potassium degrades rapidly above 60 °C and in the presence of free water. The formulation is a non-aqueous suspension of micronised amoxicillin trihydrate and clavulanate potassium in fractionated coconut oil or medium-chain triglycerides, set at a 4:1 active ratio; a common presentation delivers 200 mg amoxicillin and 50 mg clavulanic acid per 5 mL syringe. The downstream process includes preparation of the oil vehicle by sterilising filtration through 0.2 µm membrane, dry-heat sterilisation of syringe components at 180 °C, and aseptic dispersion of pre-sterilised actives using a colloid mill. Particle size is controlled to D90 ≤ 100 µm to ensure uniform expulsion from the intramammary tip and to reduce sedimentation during shelf storage; sedimentation rate is assessed by visual resuspendability after inversion. Filling is performed under EU GMP Annex 1 Grade A laminar flow in an ISO 14644-1 Class 5 cleanroom, with sterility tested according to Ph. Eur. 2.6.1 and bacterial endotoxins according to Ph. Eur. 2.6.14. VICH GL3(R) stability protocols require long-term storage at 25 °C/60% RH and intermediate 30 °C/65% RH to monitor clavulanate potassium content; any colour shift from white to pale yellow indicates hydrolytic degradation and triggers batch rejection. Terminal finished product types are single-use intramammary syringes packed in polyethylene trays, with the product restricted to lactating cattle under veterinary prescription.

Coping with β-Lactamase Pressure in Injectable Suspension Manufacture for Swine and Cattle

Injectable ready-to-use suspensions for intramuscular administration in cattle and swine are manufactured as sterile non-aqueous suspensions in which clavulanate potassium is dispersed with amoxicillin trihydrate at a 4:1 ratio; published product literature for the standard concentration describes 140 mg/mL amoxicillin and 35 mg/mL clavulanic acid. The manufacturing line uses a high-shear rotor-stator mixer at 800–1200 rpm under nitrogen blanketing to achieve deagglomeration without introducing atmospheric moisture; the suspension is then passed through a colloid mill to reduce D90 to ≤ 30 µm for syringeability through 18-gauge needles. Temperature during milling is maintained below 25 °C with a jacketed vessel, and the dispersion is held under vacuum to remove entrapped gas before aseptic filling into Type I glass vials of 100 mL and 250 mL. Sterility is confirmed by Ph. Eur. 2.6.1, endotoxin by Ph. Eur. 2.6.14, and particulate contamination by Ph. Eur. 2.9.19. Because terminal sterilisation is not feasible, the entire aseptic process must comply with EU GMP Annex 1 and ISO 14644-1 Class 5 conditions. VICH GL3(R) stress testing shows that moisture ingress through bromobutyl rubber stoppers above 0.5% affects clavulanate potassium assay; stopper moisture is therefore controlled by desiccant packaging. The terminal finished product types are sterile injectable suspensions in single-dose or multi-dose vials with labelling that states resuspension instructions and in-use storage at 2–8 °C for 28 days. Published data for specific in-use stability after first puncture vary by rubber closure, so manufacturer-specific validation is required.

Oral Reconstitution Powder for Feline and Canine Dosing Pumps

Dry powder for oral suspension after reconstitution with potable water is manufactured for companion animal use when liquid suspensions cannot be shipped due to clavulanate potassium instability in aqueous media. The powder blend is filled into 60 mL or 100 mL amber glass bottles at a 4:1 amoxicillin-to-clavulanic acid ratio; the clavulanate potassium component is adjusted by 1.19 and represents 8–12% w/w of the dry fill. The downstream process consists of dry granulation of a lactose-monohydrate-based carrier, moisture-controlled blending at ≤ 30% RH, and filling by auger or vacuum-assisted powder filler into bottles containing silica gel canisters. Bottles are induction-sealed with pulp-backed aluminium foil and packed in foil pouches. The terminal product is reconstituted by the end user to a suspension containing 40 mg/mL amoxicillin and 10 mg/mL clavulanic acid, administered through calibrated oral dosing pumps. The reconstituted suspension is limited to 7 days of in-use shelf life at 2–8 °C, after which clavulanic acid concentration falls below the compendial acceptance limit; this limitation is stated on the label and is derived from VICH GL3(R) in-use stability protocols. Compliance verification includes Ph. Eur. 2.9.40 for uniformity of mass of the dry powder and Ph. Eur. 2.2.29 for assay. The terminal finished product types are amber glass bottles with child-resistant closures and oral dosing pumps, distributed as veterinary prescription products under Regulation (EU) 2019/6.