Continuous Antisolvent Crystallization of α-Lactose Monohydrate: Impact of Process Parameters, Kinetic Estimation, and Dynamic Analysis

Crystallization Thermodynamics of α-Lactose Monohydrate in Different Solvents

It is common to find that some of the lactose in dairy powders and pharmaceutical tablets is present in the unstable amorphous state. Therefore, their crystallization thermodynamics in different solvents are particularly important. In this paper, the solubility of α-lactose monohydrate (α-LM) in 15 mono-solvents such as ethanol, isopropanol, methanol, 1-propanol, 1-butanol, 2-butanol, isobutanol, 1-pentanol, isoamylol, 1-hexanol, 1-heptanol, 1-octanol, propanoic acid, acetonitrile, and cyclohexanone was evaluated by using the gravimetric method in the temperature ranges from 274.05 K to 323.05 K at constant pressure (1 atm). In the given temperature range, the solubility of α-LM in these solvents increased with the rising of temperature, the highest solubility of α-LM was found in methanol (2.37 × 104), and the lowest was found in 1-hexanol (0.80 × 105). In addition, the increase of α-LM solubility in isopropanol was the largest. The sequence at 298.15 K was: methanol > 1-butanol > isopropanol > ethanol > 1-propanol > 1-heptanol > isobutanol > propionic acid > 1-pentanol > 1-octanol > acetonitrile > isoamylol > 2-butanol > cyclohexanone > 1-hexanol. Solvent effect analysis shows that the properties of α-LM are more important than those of solvents. The Apelblat equation, λh equation, Wilson model, and NRTL model were used to correlate the experimental values. The root-mean-square deviation (RMSD) and relative average deviation (RAD) of all models were less than 2.68 × 10−2 and 1.41 × 10−6, respectively, implying that the fitted values of four thermodynamic models all agreed well with the experimental values. Moreover, the thermodynamic properties of the dissolution process (i.e., dissolution Gibbs free energy (ΔdisG), molar enthalpy (ΔdisH), and molar entropy (ΔdisS)) for α-LM in selected solvents were determined. The results indicate that ΔdisH/(J/mol) (from 0.2551 to 6.0575) and ΔdisS/(J/mol/K) (from 0.0010 to 0.0207) of α-LM in these solvents are all positive, and the values of ΔdisH and ΔdisS. ΔdisG/(J/mol) (from −0.0184 to −0.6380) are all negative. The values were observed to decrease with rising temperatures, implying that α-LM dissolution is an endothermic, entropy-driven, and spontaneous process. The solid−liquid equilibrium data and dissolution thermodynamics of α-LM were obtained, which provide a basis for industrial production.

A Comprehensive Review on Novel Liposomal Methodologies, Commercial Formulations, Clinical Trials and Patents

Liposomes are well-recognized and essential nano-sized drug delivery systems. Liposomes are phospholipid vesicles comprised of cell membrane components and have been employed as artificial cell models to mimic structure and functions of cells and are of immense use in various biological analyses. Liposomes acquire great advantages and provide wide range of applications as useful drug carriers in pre-clinical and clinical trials. This review summarizes exclusively on scalable techniques for liposome preparation and focuses on the strengths and limitations with respect to industrial applicability. Also, this review discusses the updated recent advancements in biomedical applications with a mention of key highlights of commercially available formulations, clinical trials and patents in recent past. Furthermore, this review also provides brief information of the classification, composition and characterization of liposomes.

Solution Cocrystallization: A Scalable Approach for Cocrystal Production

With an increasing interest in cocrystals due to various advantages, demand for large-scale cocrystallization techniques is rising. Solution cocrystallization is a solvent-based approach that utilizes several single-component crystallization concepts as well as equipment for generating cocrystals. Solution-based techniques can produce cocrystals with reasonable control on purity, size distribution, morphology, and polymorphic form. Many of them also offer a scalable solution for the industrial production of cocrystals. However, the complexity of the thermodynamic landscape and the kinetics of cocrystallization offers fresh challenges which are not encountered in single component crystallization. This review focuses on the recent developments in different solution cocrystallization techniques for the production of pharmaceutically relevant cocrystals. The review consists of two sections. The first section describes the various solution cocrystallization methods, highlighting their benefits and limitations. The second section emphasizes the challenges in developing these techniques to an industrial scale and identifies the major thrust areas where further research is required.