Drug-Smectite Clay Amorphous Solid Dispersions Processed by Hot Melt Extrusion.

Improving drug solubility remains a challenge in pharmaceutical development. Established methods often rely on organic polymers for amorphous solid dispersions. However, these approaches may face limitations in stability or scalability. Inorganic matrices offer an alternative but are less explored in this context. Smectite clays have shown potential in drug delivery due to their layered structures. Their ability to adsorb and stabilize amorphous drugs is not well characterized. This gap motivated the investigation of smectite clays as carriers for amorphous solid dispersions. The study aimed to assess whether these materials could enhance drug dissolution and stability.

The study aimed to evaluate smectite clays as a novel carrier for amorphous solid dispersions. Specifically, it focused on indomethacin, a poorly soluble drug. The researchers sought to determine if these clays could maintain the drug in an amorphous state. They also aimed to assess drug distribution and potential interactions with the matrix. The method of hot melt extrusion was chosen for its scalability and efficiency. The goal was to compare the performance of two different smectite types. The researchers wanted to measure dissolution rates in varying pH environments. This work aimed to provide a foundation for using inorganic matrices in drug delivery.

The researchers used hot melt extrusion to combine indomethacin with two smectite clays. Magnesium aluminium and lithium magnesium sodium silicates were selected as matrices. Scanning electron microscopy was applied to analyze the physical structure of the dispersions. Powdered X-ray diffraction and differential scanning calorimetry confirmed the amorphous state of the drug. Energy-dispersive X-ray spectroscopy was used to assess drug distribution within the matrix. Attenuated total reflectance-Fourier transform infrared spectroscopy detected molecular interactions. In vitro dissolution tests were conducted in acidic and neutral pH environments. The study focused on the physical and chemical stability of the drug-clay system.

Both PXRD and DSC analyses confirmed the amorphous form of indomethacin in the dispersions. EDX showed uniform drug distribution across the extruded powder samples. ATR-FTIR suggested hydrogen bonding between the drug and the smectite matrix. Dissolution studies revealed a lag time of approximately 2 hours in acidic media. At pH 7.4, the drug released rapidly, indicating improved solubility. The results suggest that smectite clays can stabilize the amorphous form of the drug. The extrusion process did not cause degradation or phase separation. The findings support the use of inorganic matrices for enhancing drug dissolution.

The study demonstrated that smectite clays can serve as effective carriers for amorphous solid dispersions. The amorphous form of indomethacin was maintained through hot melt extrusion. The drug showed uniform distribution and no chemical degradation in the matrix. Hydrogen bonding between the drug and clay was suggested by ATR-FTIR data. Dissolution profiles indicated a delayed release in acidic conditions. Rapid release at neutral pH suggests improved solubility in physiological environments. The researchers propose that smectite clays offer a viable alternative to organic polymers. These findings may guide future work on inorganic drug delivery systems.