Regardless of the production method, the microspheres must meet (the following requirements: close to spherical shape and smooth surface. These conditions are essential for further coating in an optimal manner; particle sizes should not vary greatly.
The optimum particle size of microspheres for use in pharmaceutical needs is between 600 and 1000 µm; microspheres should contain the highest possible amount of active ingredient.
In the last twenty years, microspheres have strengthened their position in the pharmaceutical industry due to many reasons. Pellets have high density and abrasion resistance, are well suited for automatic dosing, and their particle size distribution lies within a wide size range.
From a technological point of view, microspheres make the process of creation and production of solid dosage forms more flexible. They are able to flow freely and compact without any difficulties, which determines the homogeneity and reproducibility of the average mass of tablets and capsules.

Due to the fact that microspheres have a spherical shape and minimal specific surface area, they are ideal for coating. At the same time, a single dosage form can contain microspheres with different drug substances.
This ability allows two or more active ingredients, chemically compatible or incompatible, absorbed in the same or different parts of the gastrointestinal tract to be combined in the same dosage form.
The same dosage form may contain microspheres having different release rates of the drug substance, which allows the release of the active ingredient to be programmed and controlled and the therapeutic action to be delivered with a greater degree of efficacy.
Pelletized drugs can improve the safety and efficacy of the active ingredient. These multi-element dosage forms, usually presented in the form of suspensions, capsules or disintegrating tablets, have several advantages over single element dosage forms.
Pelletized forms are able to distribute freely in the gastrointestinal tract as single particles, which maximizes absorption and reduces peak changes in plasma drug concentration.