text: Aquasomes can be characterized by a variety of techniques that analyze the properties of their three functional units: the ceramic core, carbohydrate coating, and bioactive drug. Characterization of aquasomes after synthesis is done to gain a better understanding of each of the facets that provide or contribute to their functionality. Analyzing characteristics of aquasomes such as size distribution, the carbohydrate coat-to-core ratio, and electrical potential between the nanoparticles can be important in understanding an aquasome’s function.
  Solution precipitation as a core synthesis technique produces homogenous-sized nanoparticles, which can be advantageous in controlling specific physical properties such as surface tension and packing density of the atoms in a crystalline lattice structure. The most common methods of characterizing nanoparticle size distribution and morphology of the core in aquasomes include scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In a study by Kommimeni et al. in 2012, researchers employed TEM to verify that the ceramic particles were spherical and also in the acceptable nano-range for aquasomes. The carbohydrate coating size can also be characterized using SEM and TEM, but a Fourier Transform Infrared Spectroscopy (FTIR) is commonly utilized to check for the presence of the coat. In a study by Kommimeni et al. in 2020, FTIR was used to confirm the presence of the coating by analyzing the IR spectra bands that correspond to the functional groups of either the core or the sugar coat. 
  The bioactive drug loaded onto the aquasome can be characterized in a variety of ways depending on the molecular classification of the drug. In Kossovsky et al. in 1996, which studied the effect of insulin as the bioactive drug of interest, immunogold labeling was employed. Through this technique, the different binding efficiencies of carbohydrate coatings for insulin were able to be observed. 
  To characterize the loading of the bioactive drug, it is common to employ mathematical equations that use theoretical estimations for drug concentrations entrapped in the aquasome. One such parameter is entrapment efficiency, which is the amount of drug added that was adsorbed onto aquasomes. Another parameter of interest is drug loading, which is the percentage of the aquasome’s weight that is composed of the drug. In a study done by Kutlehria et al. in 2018, the following equations were used to quantify the entrapment efficiency and drug loading::
  Finally, measuring the mechanism of action of the formulated aquasomes is important for understanding their potential therapeutic effect. Several studies have carried out in vitro drug release studies that place the aquasomes in a dissolution media and measure the subsequent release of drug into the solution. By obtaining these values, a release profile of the aquasome can be postulated and further optimizations can be determined for aquasomes to meet specific therapeutic indices or pharmacological outcomes.