Performance Upgrade: A New-Generation Powder Formulation Process Reshaping Product Competitiveness

1.  Introduction
Medicating through drinking water is widely used on pig farms due to its advantages: simple operation, rapid administration, minimal stress response, quick onset of action, reduced labor input, and suitability for mass dosing. However, limitations arising from the physicochemical properties of veterinary drugs—such as low solubility, poor stability of aqueous solutions after dissolution (discoloration, crystallization, precipitation), and blockage of dosing systems—remain major technical bottlenecks. Therefore, adopting innovative formulation technologies to enhance solubility and aqueous stability has become a key direction for improving veterinary drug dosage form technology.

2.  Technology Upgrade
(Taking Oxytetracycline Hydrochloride Soluble Powder as an Example)
Tetracycline antibiotics contain multiple hydroxyl, enol-hydroxyl, and carbonyl groups, making them prone to chelation with metal ions and formation of insoluble complexes. Oxytetracycline hydrochloride darkens upon exposure to light, remains stable in acidic aqueous solutions, but degrades easily under alkaline conditions due to ring-opening reactions, reducing potency and causing loss of efficacy.

Upgrade Highlight 1: Metal Ion Masking Technology
By adding competitive chelation promoters to mask abundant metal ions present in tap water, the formulation prevents chelation reactions with tetracyclines that would otherwise form insoluble complexes, thereby resolving precipitation issues.

 
Upgrade Highlight 2: Reaction Inhibitors
Through pH adjustment and incorporation of reaction inhibitors, the product maintains solution stability across diverse water qualities, ensuring consistent efficacy.

3. Achievements of the Technology Upgrade

Achievement 1: Formulation Stability
Under high-temperature conditions, the formulation remains stable without discoloration or caking. After dissolution at the recommended dosage, no precipitation occurs within 8 hours; content and pH remain stable.

Achievement 2: Excellent Solubility — Up to 80× the Clinical Dose
•    Label drinking-water dosage: 0.5 g/L
•    Veterinary Pharmacopoeia standard: 1 g/L
•    Internal product quality standard: 10 g/L
After five rounds of process iteration, the maximum solubility reached ≥82 g/L.

Achievement 3: High Stability After Secondary Dilution
In clinical practice, medicators require a concentrated stock solution, which is then diluted through the water. Simulating field use, stock solution at 82 g/L was diluted by 10× (8.2 g/L), 20× (4.1 g/L), 50× (1.64 g/L), and 100× (0.82 g/L). Drug content remained stable for 24 hours, with reductions <10%.

Achievement 4: Feed Does Not Interfere — Stable for Both Drinking and Feed Mixing
Calcium salts, iron salts, and other multivalent ions in feed can affect tetracycline stability. Simulated drinking-water administration showed that the product remained clear and stable for 6 hours when mixed with electrolyte- and vitamin-containing feed additives and regular feed. Simulated administration via wet-feed mixing demonstrated stable drug content within 4 hours.

Achievement 5: True Gastric–Intestinal Stability
In simulated gastric and intestinal fluids containing food components, pepsin, and trypsin, the product showed no degradation and maintained stable drug content—ensuring stability in the digestive tract and preserving bioavailability.

4. Conclusion
Through iterative process upgrades, powder formulations represented by oxytetracycline hydrochloride soluble powder now feature:
    High water solubility
    High stability in drinking water
    High stability when mixed with feed
    High gastric stability
    High intestinal stability
    High bioavailability
These advancements significantly enhance product performance and competitiveness.

（By Fangtong Overseas Affairs Dept. 19. November, 2025）