Antibiotic elution from calcium phosphate beads continues for about how many hours after the peak?

• A. 24 hours
• B. 48 hours
• C. 72 hours
• D. 96 hours

Answer: (C)

Antibiotic release from calcium phosphate beads happens in two phases: a rapid initial burst that creates the peak, followed by a taper as the beads resorb. After that peak, the elution continues for about 72 hours, providing locally high antibiotic levels for roughly three days before the concentrations drop off. The beads are resorbable, so they don’t sustain long-term delivery the way nonresorbable materials might; this short tail means that for prolonged local antibiotic exposure you’d rely on systemic therapy or additional delivery strategies, rather than expecting extended release from the beads alone.