Cephradin-plaga microspheres for sustained delivery to cattle

Area of Science:

• Pharmaceutical Sciences
• Veterinary Medicine
• Materials Science

Background:

• Controlled drug delivery systems are crucial for therapeutic efficacy and patient compliance.
• Sustained-release formulations present unique challenges, especially for veterinary applications requiring specific release profiles.
• Poly(alpha-hydroxy acid)s are FDA-approved biodegradable polymers suitable for drug matrices.

Purpose of the Study:

• To develop and optimize poly(lactic-co-glycolic acid) (PLGA) microspheres for sustained delivery of cephradin to cattle.
• To achieve a targeted release rate of 4-5 mg/kg/day over 3-4 days via intramuscular injection.
• To investigate factors influencing encapsulation yield and drug release characteristics.

Main Methods:

• Solvent evaporation technique using poly(vinyl alcohol) (PVA) as an emulsion stabilizer.
• Optimization of experimental conditions, including aqueous phase volume, addition of organic solvents/non-solvents, and sodium chloride concentration.
• Modification of temperature and pressure to enhance drug entrapment.
• In vivo studies in dogs to assess pharmacokinetic profiles.

Main Results:

• Microspheres containing up to 30% cephradin were successfully prepared by adding sodium chloride to the aqueous phase.
• Drug entrapment was increased to 40% by decreasing temperature and pressure.
• Preliminary canine studies showed 20% cephradin microspheres extended drug presence in blood circulation up to 48 hours.
• Higher drug loading resulted in increased blood concentrations but reduced sustained release duration.

Conclusions:

• Optimized PLGA microspheres can effectively encapsulate and provide sustained release of cephradin for veterinary applications.
• The developed microsphere formulation shows promise for extended antibiotic delivery in cattle.
• Further optimization is needed to balance drug load, release duration, and injection volume constraints for cattle.