University of Limerick
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Crystal growth kinetics of paracetamol with different morphology: synthesis of carbon-nanodots using hydrothermal carbonisation

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posted on 2022-10-12, 11:28 authored by Ashu Panwar
A crystal is defined as a solid material that is inclusive of the molecules, atoms, and ions that are arranged in an orderly fashion and a repetitive pattern in a spatial arrangement. Crystal growth is a major step in the process of crystallization. The process of crystal growth and kinetics is a dynamic process that is impacted by several factors. Crystals of a compound are a form of solid state that is one the purest form of the solid. The crystals are produced through the process of crystallization that is inclusive of two primary processes. The first process is nucleation, and the second process is crystal growth. In low supersaturation or desupersaturation, crystals are grown and accelerated with nucleation. This results in larger crystal size and distribution. A supersaturated solution is present in thermodynamic equilibrium with the solid phase at a specified temperature. The state of supersaturation is critical for the operation of the crystallization experiment. The crystallization process in the pharmaceutical sciences also helps in improved downstream processes that include filtration, milling and drying. These applications demand a crystallization of even more complicated molecules that can be used as drugs and duplication at a large scale. This paper discusses the process of crystallization of paracetamol in the solvent, isopropanol. The developed crystals have been studied in this thesis by application of the process supersaturation. The developed crystals have also been analyzed by using the PAT tools. The bioavailability of the compounds is essentially dependent on three factors that include solubility, permeability, and dosage. Based on the solubility of the compounds, the physiological pH value and permeability parameters of drugs are classified into several categories. These properties are altered and are impacted by the process of crystallization and crystal growth in the chemical setting. Paracetamol has three polymorphs with the form I being most stable and form II being the least stable. The process of crystal growth and crystallization focuses on the inclusion of the development of the most stable crystal polymorph to be used as a drug and to be mass-produced and applied in the pharmaceutical industry. The crystal data of the molecule reveals that the crystal growth of the molecule is subject to change with alterations in temperature. The bond length and bond angles for the crystal polymorphs of the paracetamol remain unchanged. The optimized geometry for a free molecule crystal is planar, where the phenyl rings and the acetamide lie in different planes. Bulk crystallization of paracetamol has been done as per the controlled conditions in clinical conditions for saturation experiments. The induction and the nucleation time in the process are determined by the changes in the concentration of the solute in the process of crystal growth. The products of the process are microcrystals and are characterized for the strain, shape, and defect in the crystals using diffraction and microscopic studies. Through this thesis, the researchers aim to establish a method of crystal formation for paracetamol through the process of supersaturation and using isopropanol as a solvent with growth trajectory by second-order growth kinetics. This will help in the development of paracetamol crystals that are highly pure and can be used for replication in the medical industry for drug production and development.



  • Master (Research)

First supervisor

Walker, Gavin M.

Second supervisor

Kumar, Vasanth K.





Department or School

  • Chemical Sciences

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