A new method of producing monoclinic paracetamol suitable for direct compression

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Solid-State Chemistry

Background:

• Direct compression is a preferred method for tablet manufacturing due to its simplicity and cost-effectiveness.
• Achieving suitable physical properties for direct compression, such as flowability and compressibility, is crucial for pharmaceutical formulations.
• Polymorphism in active pharmaceutical ingredients (APIs) can significantly impact their physical and chemical properties, including dissolution and bioavailability.

Purpose of the Study:

• To develop an efficient technique for producing monoclinic paracetamol with properties amenable to direct compression without the need for excipients.
• To characterize the physical and mechanical properties of the prepared monoclinic paracetamol.
• To evaluate the performance of tablets manufactured from the developed paracetamol form.

Main Methods:

• Preparation of spongy monoclinic paracetamol via quench-cooling of paracetamol solutions followed by freeze-drying.
• Utilizing X-ray powder diffraction to identify optimal conditions for obtaining pure monoclinic paracetamol particles.
• Characterization using electron microscopy and measurement of compression properties.

Main Results:

• A novel preparation technique yielded fine, spongy monoclinic paracetamol particles (agglomerates 30-200 μm, flat particles 1-10 μm).
• The resulting paracetamol powder was suitable for direct compression without excipients, demonstrating good storage stability and mechanical robustness.
• Tablets pressed from the spongy paracetamol showed improved water solubility compared to commercial formulations containing excipients.

Conclusions:

• The developed method successfully produced spongy monoclinic paracetamol with enhanced properties for direct compression.
• While potentially not cost-effective for inexpensive paracetamol, the freeze-drying technique offers a versatile approach for preparing improved solid forms of other molecular compounds.
• This method holds promise for developing novel pharmaceutical formulations with superior performance characteristics.