Polymer-mediated disruption of drug crystallinity

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Ibuprofen (IB) is a BCS Class II drug with poor solubility due to its crystalline nature.
• Improving the dissolution rate of poorly soluble drugs is crucial for enhanced bioavailability.

Purpose of the Study:

• To investigate the disruption of ibuprofen's crystalline structure by cross-linked polyvinylpyrrolidone (PVP-CL) using low-energy mixing.
• To explore the molecular interactions and their impact on ibuprofen's crystallinity and dissolution properties.

Main Methods:

• Differential Scanning Calorimetry (DSC) to assess changes in melting enthalpy.
• X-ray Powder Diffractometry (PXRD) to confirm structural changes.
• Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectroscopy to investigate molecular interactions.

Main Results:

• Simple mixing significantly reduced ibuprofen's melting enthalpy by approximately 30%, indicating loss of crystallinity.
• PXRD confirmed the structural changes through peak broadening and intensity reduction.
• Spectroscopic analysis suggested hydrogen bonding and electrostatic/hydrophobic interactions between ibuprofen and PVP-CL.

Conclusions:

• Low-energy mixing effectively disrupts ibuprofen's crystalline structure when combined with PVP-CL.
• The observed molecular interactions contribute to the loss of crystallinity.
• This disruption holds potential for improving ibuprofen's dissolution rate and bioavailability.