Relation between dissolution profiles and toxicity of cisplatin-loaded microspheres

Area of Science:

• Pharmacology
• Drug Delivery Systems
• Materials Science

Background:

• Cisplatin is a widely used chemotherapy drug with significant systemic toxicity.
• Microsphere formulations offer potential for controlled drug release, but their in vivo performance and toxicity prediction remain challenging.

Purpose of the Study:

• To evaluate and compare in vitro and in vivo dissolution profiles of cisplatin-loaded microspheres (CDDP-MS).
• To establish the relationship between in vitro dissolution and systemic toxicity of CDDP-MS.
• To assess the predictability of systemic toxicity using in vitro dissolution data.

Main Methods:

• Three types of CDDP-MS with varied release rates (1, 2, and 5 weeks) were prepared.
• In vitro dissolution studies were conducted in phosphate-buffered saline (pH 7.4).
• In vivo studies involved assessing plasma platinum concentration and maximal tolerable dose (MTD) in mice after intraperitoneal administration.

Main Results:

• In vivo dissolution profiles of CDDP-MS correlated well with in vitro studies, achieving controlled plasma platinum concentrations.
• The MTD of CDDP-MS was significantly higher than that of cisplatin dissolved in saline (CDDP-SOL), increasing with longer release durations.
• A strong linear correlation (R²=0.9935) was found between MTD and the time for 50% drug release (T50) in vitro.

Conclusions:

• In vitro dissolution testing is a reliable method for predicting the in vivo performance and systemic toxicity of CDDP-MS.
• CDDP-MS formulations demonstrate improved safety profiles compared to conventional cisplatin solutions.
• The established correlation provides a valuable tool for optimizing CDDP-MS development and clinical application.