Tazobactam Veterinary Grade API for Tablets / Injections / Capsules / Powders / Granules / Premix / Solutions is supplied as tazobactam sodium, with the free acid CAS 89786-04-9 and the sodium salt CAS 89785-84-2. The product models are differentiated by physical form: non-sterile micronized, sterile micronized, and sterile crystalline. The sodium salt has the molecular formula C10H11N4NaO5S and a relative molecular mass of 322.27 g/mol. The API is a beta-lactamase inhibitor of the penicillanic acid sulfone class; it is not a standalone antibacterial agent and is used in combination with beta-lactam antibiotics in veterinary formulations. Commercial lots are controlled by intended route of administration. Non-sterile oral grades are controlled for identity, assay, water content, residual solvents, particle size, and microbial enumeration; sterile injectable grades add bacterial endotoxins, sterility, and particulate matter controls. Typical release criteria include an HPLC assay of 98.0–102.0% on the anhydrous, solvent-free basis, water content not more than 2.0% by Karl Fischer titration per USP <921>, and residual solvents aligned with USP <467>. Injectable-grade material is typically controlled to bacterial endotoxins not more than 0.050 EU/mg per USP <85>, sterility per USP <71>, and particulate matter per USP <788>. These values are representative manufacturer release parameters; the registered veterinary product specification is the controlling document. Published data for this specific veterinary-grade configuration is limited.

Compendial Release Limits and Route-Dependent Test Matrix

In compendial testing, the API is identified by infrared absorption spectrophotometry matching the reference standard, and assay is performed by HPLC using a reversed-phase C18 column as described in USP <621>. System suitability criteria commonly require tailing factor not more than 2.0 and relative standard deviation not more than 1.0% for replicate standard injections. The residual solvent profile is generated by headspace gas chromatography under USP <467> Option 1. Water content is determined by Karl Fischer coulometric or volumetric titration under USP <921> Method Ia. The route of administration changes the microbial quality threshold. Non-sterile oral grades are tested for total aerobic microbial count and total combined yeasts and molds count under USP <61>, with objectionable organisms assessed under USP <62>. Sterile injectable grades are released only after membrane filtration and aseptic filling; the finished container is tested for sterility under USP <71> and for subvisible particulate matter under USP <788>. Elemental impurities are controlled by ICP-MS and are specified according to USP <232> and USP <233>. The route-dependent matrix is summarized below.

Micronized tazobactam sodium with a laser-diffraction D90 of 15–50 µm and a bulk density of 0.25–0.45 g/mL is typically selected for tablets, capsules, powders, granules, and premixes. These micromeritic targets are vendor-established rather than compendial, but they directly influence content uniformity. In low-dose dry blends where the API represents 0.5–5.0% w/w of the finished mixture, segregation and electrostatic adhesion are the principal failure modes. Ribbon blenders with working volumes of 200–1,000 L and fill levels of 40–70% are used on production lines. Blend uniformity samples are withdrawn with a sampling thief from defined upper, middle, and lower strata and analyzed by HPLC; a validated protocol commonly requires 90.0–110.0% of target with a relative standard deviation not more than 5.0%. If the carrier is a high-moisture feed matrix above 60% relative humidity, pre-drying of the carrier to water activity below 0.60 is required; otherwise caking at the API-carrier interface reduces homogeneity and accelerates hydrolysis of the beta-lactam ring. For tablet and capsule lines, wet granulation with a fluid-bed dryer is preferred over direct compression when the formulation contains cohesive fillers. Powder flow is assessed by Hausner ratio and Carr compressibility index; values exceeding 1.25 and 25%, respectively, indicate the need for a glidant or a granulation step. Published data for this specific veterinary-grade configuration is limited, and these operational boundaries should be confirmed on the actual manufacturing line.

Tablets containing tazobactam sodium are compressed on rotary tablet presses equipped with force monitoring. Content uniformity is evaluated per USP <905> and dissolution per USP <711> using the registered volume and rotation speed at 37 ± 0.5 °C. Capsule filling is performed on automatic tamping-pin or dosator machines; fill weight is monitored gravimetrically to a relative standard deviation not more than 2.0%. Granules are dried in a fluid-bed dryer to a target loss on drying of 1.0–2.0% before lubrication; residual moisture above this range reduces chemical stability, while over-drying can increase electrostatic charging and segregation. Powders and oral granules are packed in unit-dose sachets or bottles with desiccant. The headspace oxygen in sealed sachets should be below 5.0% where stability data show an oxidative degradation contribution. For medicated premixes, the carrier is usually calcium carbonate, lactose monohydrate, or maltodextrin; the finished premix is sampled at defined intervals during packing to detect segregation. If carryover of tazobactam into the next non-medicated batch exceeds 10 ppm, the cleaning procedure is considered inadequate for shared manufacturing lines. These values are process-specific and are not compendial; the registered veterinary product file governs all acceptance limits.

When Sterile Injectable Grade Is Required, What Processing Conditions Preserve Potency?

Sterile injectable-grade tazobactam sodium is selected when the final product is a solution for intravenous, intramammary, subcutaneous, or intra-articular administration in species where beta-lactamase-producing pathogens are documented. Terminal sterilization is often not applicable because beta-lactam ring opening is temperature-sensitive; aseptic filling through a 0.22 µm membrane filter is the standard manufacturing route. The solution is compounded in stainless-steel vessels maintained at 15–25 °C. The pH is measured per USP <791> and held within the registered range; excursions outside the registered range increase hydrolytic degradation and can reduce assay below specification. Inline filter integrity is confirmed by bubble point or diffusion testing, and post-fill sterility is verified per USP <71>. The API used in this route must meet bacterial endotoxin limits per USP <85> and particulate matter per USP <788>. Residual moisture in the sterile powder is controlled by Karl Fischer titration per USP <921>; a target of not more than 1.0% is common because lower water activity reduces hydrolytic degradation during storage. For lyophilized combinations, the dried cake is reconstituted at the point of use; reconstitution times above 120 seconds may indicate collapsed cake structure or poor crystalline morphology and should be investigated before release.

For reconstitutable oral solutions and injectable diluents, the API is dissolved in water for injection or a buffered vehicle under nitrogen blanketing where dissolved oxygen exceeds 1.0 ppm. Filling lines are configured with peristaltic or rotary piston pumps; fill volume is verified gravimetrically to a tolerance of ±1.0% of target. Solutions are clarified through a 0.45 µm or 0.22 µm filter depending on the sterile status of the product. Non-sterile oral solutions are tested under USP <61> and USP <62>; sterile solutions are tested under USP <71>. The API concentration is confirmed by HPLC after compounding because beta-lactam activity can decline during aqueous hold times. A hold-time study conducted at the production temperature range establishes the maximum permissible aqueous hold time as the point at which assay reaches the registered lower release limit. pH is measured per USP <791> and adjusted with dilute hydrochloric acid or sodium hydroxide; the beta-lactam ring hydrolyzes more rapidly below pH 4.0 and above pH 8.0, so the registered pH range is maintained. Metal-ion contamination from ferric or cupric ions should be avoided; stainless-steel or glass-lined vessels are standard.

If Clavulanate Potassium Is Replaced by Tazobactam Sodium in a Fixed-Dose Combination

The substitution is not direct. Tazobactam sodium and clavulanate potassium belong to different chemical classes: tazobactam is a penicillanic acid sulfone with a relative molecular mass of 322.27 g/mol, whereas clavulanate potassium is a clavam with a relative molecular mass of 237.25 g/mol. The mass difference of 85.02 g/mol changes the active moiety calculation in fixed-dose combination products if the ratio is weight-based. Clavulanate potassium is hygroscopic and is typically stabilized by a desiccant and low-humidity processing; tazobactam sodium is less moisture-sensitive but still undergoes beta-lactam ring hydrolysis under acidic or basic conditions. Sulbactam sodium, another penicillanic acid sulfone, has a relative molecular mass of 255.22 g/mol and generally requires higher molar ratios than tazobactam for equivalent inhibition of certain class A beta-lactamases. The microbiological spectrum of tazobactam includes inhibition of selected Ambler class A beta-lactamases such as TEM, SHV, and some CTX-M enzymes; it does not inhibit metallo-beta-lactamases or carbapenemases. Replacement therefore requires recalculating the beta-lactam-to-inhibitor ratio on a molar basis, revalidating blend uniformity at the new API particle-size distribution, and repeating stability studies under ICH climatic zone conditions. A change in inhibitor cannot rely solely on the registered weight-based ratio of the original product.

In all dosage forms, protection from moisture, excessive heat, and incompatible excipients is required. Bulk packaging should use a heat-sealed polyethylene-aluminum foil laminate with moisture vapor transmission rate below 0.1 g/m²/24 h at 38 °C and 90% relative humidity per ASTM F1249-20. The API should not be dry-blended with strongly acidic excipients, strong oxidizing agents, or amine-based additives that can raise microenvironmental pH and open the beta-lactam ring. For feed premixes, the addition sequence should place the API between two portions of carrier to reduce dust generation and electrostatic segregation. Dust extraction systems should be assessed for operator exposure limits under NIOSH or equivalent occupational hygiene guidance. Each production line requires a dedicated process validation protocol because published data for this specific veterinary-grade configuration is limited.