A novel technique to quantify film--tablet interfacial thickness.

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Surface Analysis

Background:

• Quantifying the interface between tablet cores and polymer coatings is essential for understanding drug release and stability.
• Traditional methods for analyzing film-tablet interfaces are often destructive or lack depth resolution.

Purpose of the Study:

• To develop and validate a novel X-ray Photoelectron Spectroscopic (XPS) technique for precise quantification of film-tablet interfacial thickness.
• To establish a method for analyzing the interface without sputtering through the entire coating.

Main Methods:

• Utilized X-ray Photoelectron Spectroscopy (XPS) combined with intermittent ion sputtering for depth profiling.
• Defined the film-tablet interface by simultaneous detection of phosphorous (tablet) and chlorine (coating).
• Employed a sample preparation strategy analyzing from the tablet side to enhance efficiency.

Main Results:

• Developed a depth-profiling XPS method to quantify film-tablet interfacial thickness.
• Estimated the film-tablet interfacial thickness to be approximately 34 microns.
• Demonstrated that the interface thickness can be determined by the intersection point of elemental intensity profiles.

Conclusions:

• The developed XPS technique provides a viable method for quantifying film-tablet interfacial thickness.
• The estimated interfacial thickness of 34 microns offers a critical parameter for further investigation into adhesive properties.
• Further research is recommended to correlate quantified interfacial thickness with the adhesive properties of coated pharmaceutical solids.