Tetramisole HCl Pharma Grade API — Application Data by Dosage Form and Route

In immediate-release tablet production, the technical boundary condition is not dissolution but blending uniformity and anti-adhesion on high-speed compression. A 50 mg base-equivalent tablet incorporates 59.0 mg tetramisole hydrochloride per unit, corresponding to 29.5% w/w in a 200 mg core. The remaining mass consists of microcrystalline cellulose 110 mg, pregelatinized starch 20 mg, croscarmellose sodium 6 mg, colloidal silicon dioxide 2 mg, and magnesium stearate 3 mg. Direct compression is feasible only when the API lot is pre-milled to d90 ≤150 µm; if not, the API is passed through a conical mill fitted with a 0.5 mm screen. If ambient humidity exceeds 60% RH, the blend is pre-dried in a fluid-bed dryer at 45°C for 20 minutes. The powder is mixed in a 100 L bin blender at 10 rpm for 12 minutes, then compressed on a 10-station rotary tablet press with B-tooling 8.0 mm flat-faced beveled punches. Target hardness is 60–100 N, friability ≤1.0% per USP <1216>, disintegration ≤15 minutes per USP <701>, and content uniformity per USP <905> with acceptance value ≤15.0. Magnesium stearate is not increased above 1.5% w/w because hydrophobic coating of the soluble particles prolongs disintegration beyond the acceptance window; if sticking persists, 50% of the magnesium stearate is replaced with sodium stearyl fumarate at 0.75% w/w.

Compliance for non-sterile solid oral dosage forms is anchored to ICH Q3D (R2) elemental impurity limits, ICH Q3C (R8) residual solvent classes, and the current Ph. Eur. monograph for levamisole hydrochloride as the enantiopure comparator. Where a tetramisole-specific monograph is not adopted, the API certificate of analysis is assessed against Ph. Eur. 2.2.29 liquid chromatography and Ph. Eur. 2.2.32 loss on drying. Dissolution testing for the finished tablet uses USP <711> Apparatus 2, paddle 50 rpm, 900 mL 0.1 N HCl, with Q 80% at 30 minutes. The terminal dosage form is an uncoated immediate-release 50 mg base-equivalent tablet, packaged in HDPE bottles with a desiccant canister. Residual solvent and microbiological release testing follow Ph. Eur. 5.1.4 categories for oral preparations; a preservative is not added because the dosage form is a non-aqueous solid fill.

What Terminal Fill Parameters Govern Low-Dose Tetramisole HCl Capsule Uniformity?

Capsule filling of tetramisole hydrochloride differs from tablet compression primarily because the API’s low bulk density creates flow discontinuities on dosator-type filling heads if the blend is not densified. A 25 mg base-equivalent capsule contains 29.5 mg tetramisole HCl, which in a 180 mg final fill weight gives 16.4% w/w. The remaining fill consists of lactose monohydrate, pregelatinized starch, crospovidone, and 0.5% w/w magnesium stearate. When supplier certificates do not report tapped density, the preferred densification step is slugging with a 12 mm flat-faced tool at 8–12 kN. The granules are passed through a 0.8 mm screen and filled into size 1 hypromellose capsules on a dosator-type machine at 60 strokes/min. Fill weight is monitored in-line by net weight checkweighing; batch-to-batch moisture variance above 0.5% w/w can shift fill weight by 2–3% on dosator-type machines, so granule moisture is held ≤2.0% w/w.

Uniformity of dosage units is tested per Ph. Eur. 2.9.40 with acceptance value ≤15.0, and dissolution for immediate-release capsules uses USP <711> Apparatus 2, paddle 50 rpm, 900 mL 0.1 N HCl, Q 80% at 30 minutes. Microbiological quality is controlled per Ph. Eur. 5.1.4 for oral preparations; total aerobic microbial count ≤10³ CFU/g, total yeast/mold ≤10² CFU/g, and absence of Escherichia coli. The capsule shell is specified as hypromellose for gelatin-free and halal-certified markets; the API fill is not enteric coated because tetramisole HCl is intended for rapid release in the stomach. The terminal finished product is a 25 mg base-equivalent hard capsule, blister-packed with desiccant where stability zone IVb conditions are expected.

When a Sachet Granule Must Rehydrate to a Homogeneous 50 mg/5 mL Suspension

When a sachet granule is reconstituted by the patient or caregiver, the formulation must rehydrate to a homogeneous suspension without floating or caking of API particles. A 50 mg/5 mL dose after reconstitution is supplied as a 2.0 g sachet granule containing 59.0 mg tetramisole HCl, corresponding to 2.95% w/w. The granule matrix is composed of mannitol, sorbitol, povidone K30, citric acid, and sodium benzoate. Granulation is performed in a top-spray fluid-bed granulator with a 5 L bowl, inlet air temperature 60±5°C, exhaust air 35±3°C, and binder solution spray rate 4 g/min. Povidone K30 binder solution is prepared at 5% w/w solids using high-shear dispersion at 400–600 rpm to avoid fisheyes. The dried granules are sieved through a 0.8 mm screen and packaged into polyester/aluminium/polyethylene sachets. Final moisture is controlled to 1.5–2.5% w/w, as higher moisture causes caking during storage and lower moisture increases electrostatic adhesion to the sachet film.

Uniformity of mass for single-dose preparations is confirmed per Ph. Eur. 2.9.5; loss on drying per Ph. Eur. 2.2.32; and microbial quality per Ph. Eur. 5.1.4. Residual solvents are controlled under ICH Q3C (R8), with particular attention to ethanol if a diluted tincture-based binder is used. Published data for this specific preservative-bearing granule configuration is limited, so the design space requires a three-batch stability study under ICH Q1A (R2) at 25°C/60% RH and 40°C/75% RH before commercial release. The terminal finished product is a single-dose sachet granule for oral solution, reconstituted with 5 mL purified water at the point of administration.

Aseptic Processing Windows for 50 mg/mL Tetramisole HCl Injection

A 50 mg/mL base-equivalent tetramisole hydrochloride injectable solution is compounded under nitrogen-blanketed conditions in a 316L stainless-steel vessel equipped with bottom magnetic impeller at 150–200 rpm. Each millilitre contains 59.0 mg tetramisole HCl, 0.9% w/v sodium chloride, and water for injection q.s., with pH adjusted to 3.0–4.5 using 0.1 N hydrochloric acid or 0.1 N sodium hydroxide. The solution is pre-filtered through a 0.45 µm polypropylene cartridge, then sterile-filtered through a 0.22 µm double-layer PES membrane under 0.5 bar differential pressure. Filling is performed with a peristaltic pump into 5 mL Type I borosilicate glass vials under Grade A laminar airflow within Grade B background. If terminal sterilization is validated by stability data, steam sterilization at 121°C for 15 minutes is used; otherwise aseptic filtration remains mandatory under EU GMP Annex 1 (2022). Dissolved oxygen is kept below 0.5 ppm by nitrogen sparging; the solution must not be held unfilled for more than 2 hours at 20–25°C, as oxidative degradation products rise above the 0.5% total impurity threshold after longer holding.

Compatibility with silicone tubing and gaskets is controlled by limiting contact time to ≤4 hours; extractables from the filling line are verified below 0.1 mg/L by high-performance liquid chromatography. The terminal package is a 5 mL Type I glass vial with a chlorobutyl rubber closure and aluminium flip-off seal. Product quality is released against the matrix below.

A preservative-free single-dose injectable configuration is appropriate only for single-patient administration; multi-dose vials would require a preservative efficacy test per Ph. Eur. 5.1.3 and would introduce an additional compatibility variable for the rubber closure surface.

Where veterinary oral liquid lines require a preservative-free single-drench pack, the racemic salt is dissolved directly into deionized water at 25±5°C before adding propylene glycol 10% v/v and sodium metabisulfite 0.1% w/v. A representative 75 mg/mL base-equivalent oral drench uses 88.5 mg/mL tetramisole HCl, corresponding to 8.85% w/v. Mixing is completed in a 500 L jacketed stainless-steel tank with bottom propeller at 60 rpm; viscosity is measured by Brookfield RV spindle 2 at 25°C and maintained ≤150 mPa·s to ensure consistent filling and pour-out. The liquid is filtered through a 0.45 µm polypropylene cartridge and filled into HDPE jugs at 20–25°C. Foaming is controlled by vacuum deaeration; the packaged solution is not autoclaved because the HDPE container is not rated for terminal steam cycles.

Compliance is assessed under VICH GL18 residual solvents, Ph. Eur. 2.2.29 assay for tetramisole hydrochloride, and microbial limits per Ph. Eur. 5.1.4 for oral liquids. Published data for this specific preservative-free configuration is limited, so shelf-life assignment requires three production-scale validation batches under high-temperature and humidity storage. The terminal finished product is an oral drench for sheep and cattle, supplied in 1 L, 2.5 L, and 5 L HDPE jugs with a polypropylene pour spout.