Development of PDMS Films Containing Thiamine Bromide and Sodium Iodide: Part 1-Matrix Characterisation and In Vitro...

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Polymer Chemistry

Background:

• Polysiloxane (PDMS) films are explored as matrices for drug delivery.
• Thiamine bromide (ThBr) and sodium iodide (NaI) are water-soluble compounds with potential therapeutic applications.
• Understanding the incorporation and release of these salts within PDMS is crucial for drug formulation.

Purpose of the Study:

• To investigate the preformulation characteristics of polysiloxane films as carrier matrices for thiamine bromide (ThBr) and sodium iodide (NaI).
• To determine how ThBr and NaI are incorporated, distributed, and form solid-state structures within crosslinked PDMS films.
• To evaluate the initial release behavior of ThBr and NaI from these matrices in a saline environment.

Main Methods:

• Preparation of crosslinked PDMS films using varying viscosities of PDMS-OH, TEOS, and Sn(Oct)2 catalyst.
• Characterization of film composition and structure using Raman spectroscopy, confocal Raman depth profiling, and X-ray diffraction.
• In vitro release studies in physiological saline and measurement of film swelling.

Main Results:

• PDMS films successfully incorporated both individual ThBr/NaI crystallites and mixed crystalline domains.
• A higher fraction of mixed domains was observed in films made with lower-viscosity PDMS-OH.
• Release of ThBr and NaI into saline was low (9% and 20% respectively after 72h) with minimal film swelling (1-1.5%).

Conclusions:

• The hydrophobic and weakly swelling nature of PDMS matrices restricts water penetration and limits drug diffusion.
• These preformulation data establish baseline structural and release properties for ThBr and NaI in PDMS films.
• Further research is needed for application-oriented optimization, including transdermal patch development.