Radiolabeled Risperidone microSPECT/CT Imaging for Intranasal Implant Studies Development.

Area of Science:

• Pharmaceutical Sciences
• Biomedical Engineering
• Radiochemistry

Background:

• Intranasal implantable drug delivery systems offer sustained release and improved patient compliance.
• Developing effective intranasal implants requires precise methods to study drug release kinetics.

Purpose of the Study:

• To establish a proof-of-concept methodology for evaluating intranasal implants using radiolabeled risperidone (RISP).
• To provide valuable data for the design and optimization of sustained-release intranasal implants.

Main Methods:

• Radiolabeling of RISP with 125I and incorporation into poly(lactide-co-glycolide) (PLGA) implants.
• Intranasal administration of implants to rats and in vivo non-invasive quantitative microSPECT/CT imaging over 4 weeks.
• Comparison of in vivo release data with in vitro release studies (HPLC and radiolabeled implants).

Main Results:

• Intranasal implants remained in place for up to a month, dissolving slowly and steadily.
• All methods indicated a rapid initial release of the lipophilic drug, reaching a plateau around 5 days.
• In vivo imaging provided high-resolution, quantitative data on radiolabeled drug release.

Conclusions:

• The developed experimental approach is feasible for high-resolution, non-invasive imaging of drug release from intranasal implants.
• This method offers valuable insights for the pharmaceutical development of advanced intranasal drug delivery systems.
• The study highlights the potential of sustained drug delivery via intranasal implants for improved therapeutic outcomes.