Multi-particulates or multiple-unit dosage forms are small, discrete, repetitive units of drug particles which may or may not possess a similar drug release pattern. They can be tailored for pulsatile, controlled and/or delayed, targeted drug release depending upon the polymer employed in manufacturing. Blending of multi-particulates can be used to achieve a desired drug release profile. The most common galenical formulations are either pellets or mini-tablets. Multi-particulates reduce the risk of dose dumping, systemic toxicity, local irritation and variation in bioavailability as they are less dependent on gastrointestinal transit time. Due to their reduced size, they are an ideal application form for paediatric and elderly patient medication.
Pellets and micro-tablets are normally further processed by filling them into capsules, sachets or compressing them to MUPS – tablets. Pellets are spherical particles with a diameter of 0.5–2 mm. Our pelletising solutions include extrusion and spheronisation, production by powder and liquid layering, and wet granulation.
Liquid layering of pellets: Nonpareil starter pellets made of sugar or cellulose are sprayed with an aqueous or organic solution or suspension of the active material and dried simultaneously. These kinds of pellets are manufactured on modern bottom spray fluid bed equipment.
Extrusion and spheronisation: This production method is usually used if high amounts of an active ingredient have to be incorporated in the pellet core. Wet powders continuously pass through a low-shear radial extruder; the extrusions are fragmented and formed into pellets in the twin spheroniser. After drying and sieving, pellets are usually coated in the bottom spray fluid bed equipment.
Powder layering of pellets: When the active ingredient is in powder form, pelletisation can be achieved by the intermittent process of adding liquid binder solution and active powder to build up the pellet core. This process is performed in automated drum coaters.
Micro- or mini-tablets are compressed tablets with typical diameters between 1 and 2.5 mm. Micro-tablets can offer versatile applications, including as a paediatric dosage form, for patients with dysphagia, and uses where rapid or flexible dose adjustments are needed. Variations of the tablet formulation and coating systems can achieve specific functionalities such as orally disintegrating tablets (ODTs), extended-release formulations, or gastrointestinal-targeted delivery. Due to their small size, the manufacturing of these multi-particulate formulations requires a high degree of expertise and know-how.