{'fraction_non_alphanumeric': 0.017585931254996003, 'fraction_numerical': 0.0031974420463629096, 'mean_word_length': 4.961904761904762, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Batch Crystallization of Uric Acid: Modeling, Simulation, and the Impact of 3,7 – dimethylxanthine

Crystallization of uric acid (UA) in the urine marks the beginning of UA urolithiasis. As previously reported, 3,7‐dimethylxanthine (DMX) has the capacity to impede the crystallization of UA. The main objective of the present study is to explore the impact of urinary pH and the addition of DMX as an inhibitor on the crystallization of UA. The presence of DMX results in a significant delay in the induction of UA crystallization. Also, a significant change in crystal habit and decrease in the crystal size is observed in the presence of DMX in synthetic urine. The UV spectrum of mother liquor and the FTIR spectra and PXRD patterns of UA crystals show that DMX does not get incorporated into the crystal lattice and impedes the process of crystallization being in the liquid phase. A mathematical model is also formulated by coupling the population balance equation with the mass balance. The kinetic parameters of growth and nucleation are estimated by fitting the model predictions with experimental values. A decrease in the mean value of nucleation and growth coefficient upon DMX addition also highlights the inhibition of UA crystallization.