Comprehensive solubility analysis of Clarithromycin drug in SC-CO2: Experimental data and evaluation of multiple theoretical and semi-empirical models

Abstract

Clarithromycin, an antibiotic drug, was studied for its solubility in a supercritical carbon dioxide (SC-CO2) green solvent at various temperatures (308 K, 318 K, 328 K, and 338 K) and pressures (100 bar, 120 bar, 150 bar, 180 bar, 210 bar, 240 bar, and 270 bar). This investigation provides previously unreported solubility data for this drug in SC-CO₂. The measured solubility of Clarithromycin ranged from 0.025 ˂ y (solubility) × 104 ˂ 4.09 and 0.012 ˂ S (equilibrium solubility, kg.m-3) ˂ 5.72. Two methods were employed to model solubility of Clarithromycin: 1) a well-known cubic Peng-Robinson (PR) equation of state (EoS), using van der Waals type-II mixing rule. The performance of this EoS was satisfactory, with an AARD value of 8.87, 2) 22 semi-empirical equations were also utilized, i.e. Chrastil, Bartle et al., Garlapati and Madras (model I & II), Andonova and Garlapati, Kumar and Johnston, del Valle and Aguilera, Sung and Shim, Ch and Madras, Adachi and Lu, Alwi and Garlapati, Bian et al., Si-Moussa et al., Mendez-Santiago and Teja, Nejad et al., Sodeifian et al., model I & II, Keshmiri et al., Jouyban et al. Hozhabr et al., Khansary et al., and Gordillo et al., with 3-6 adjustable coefficients and in three y=f(T,P,ρ), y=f(T,P) and y=f(T,ρ) categories. In category y=f(T,P,ρ), MST model with AARD value of 8.41% and in category y=f(T,ρ), Si-Moussa et al. model with AARD value of 8.01% showed better performance. Enthalpies for binary combination of Clarithromycin and SC-CO2 have been determined.