Comparative Evaluation of Pellet Cushioning Agents by Various Imaging Techniques and Dissolution Studies

Tableting of coated multiparticulates: Influences of punch face configurations

The influences of the punch face design on multi-unit pellet system (MUPS) tablets were investigated. Drug-loaded pellets coated with sustained release polymer based on ethylcellulose or acrylic were compacted into MUPS tablets. Punch face designs used include standard concave, deep concave, flat-faced bevel edge and flat-faced radius edge. MUPS tablets compacted at 2 or 8 kN were characterized for their tensile strength. The extent of pellet coat damage after tableting was evaluated from drug release profiles. Biconvex tablets were weaker by 0.01-0.15 MPa, depending on the pellet type used, and had 1-17 % higher elastic recovery (p < 0.000) than flat-faced tablets. At higher compaction force, the use of the deep concave punch showed a 13-26 % lower extent of pellet coat damage, indicated by a relatively higher mean dissolution time, compared to other punch face configurations (p < 0.000). This was attributed to increased rearrangement energy of the compacted material due to the high punch concavity, which sequestered compaction stress exerted on pellet coats. Although the deep concave punch reduced the stress, the resultant tablets containing pellets coated with acrylic were weaker (p = 0.01). Overall, the punch face configuration significantly affected the quality of MUPS tablets.

Cushion-coated pellets for tableting without external excipients

Multiple-unit dosage forms prepared by compacting pellets offer important manufacturing and compliance advantages over pellet-filled capsules. However, compaction may negatively affect the release control mechanism of pellets, and subunits may not be readily available after intake. Application of a cushioning layer to the starting units is here proposed as a strategy to obtain tablets with satisfactory mechanical strength, rapid disintegration and maintenance of the expected release profile of individual subunits while avoiding the use of mixtures of pellets and excipients to promote compaction and limit the impact of the forces involved. Cushion-coating with PEG1500, a soft and soluble material, was proved feasible provided that the processing temperature was adequately controlled. Cushioned gastro-resistant pellets were shown to consolidate under relatively low compaction pressures, which preserved their inherent release performance after tablet disintegration. Adhesion problems associated with the use of PEG1500 were overcome by applying an outer Kollicoat® IR film. Through design of experiment (DoE), robustness of the proposed approach was demonstrated, and the formulation as well as tableting conditions were optimized. The tableted cushion-coated pellet systems manufactured would allow a relatively high load of modified-release units to be conveyed, thus setting out a versatile and scalable approach to oral administration of multiple-unit dosage forms.

Microparticles and multi-unit systems for advanced drug delivery

Microparticles have unique benefits in the formulation of multiparticulate and multi-unit type pharmaceutical dosage forms allowing improved drug safety and efficacy with favorable pharmacokinetics and patient centricity. On the other hand, the above advantages are served by high and well reproducible quality attributes of the medicinal product where even flexible design and controlled processability offer success as well as possible longer product life-cycle for the manufacturers. Moreover, the specific demands of patients can be taken into account, including simplified dosing regimens, flexible dosage, drug combinations, palatability, and ease of swallowing. In the more than 70 years since the first modified-release formulation appeared on the market, many new formulations have been marketed and many publications have appeared in the literature. More unique and newer pharmaceutical technologies and excipients have become available for producing tailor-made particles with micrometer dimensions and beyond. All these have contributed to the fact that the sub-units (e.g. minitablets, pellets, microspheres) that make up a multiparticulate system can vary widely in composition and properties. Some units have mucoadhesive properties and others can float to contribute to a suitable release profile that can be designed for the multiparticulate formula as a whole. Nowadays, there are some available formulations on the market, which are able to release the active substance even for several months (3 or 6 months depending on the type of treatment). In this review, the latest developments in technologies that have been used for a long time are presented, as well as innovative solutions such as the applicability of 3D printing to produce subunits of multiparticulate systems. Furthermore, the diversity of multiparticulate systems, different routes of administration are also presented, touching the ones which are capable of carrying the active substance as well as the relevant, commercially available multiparticle-based medical devices. The versatility in size from 1 µm and multiplicity of formulation technologies promise a solid foundation for the future applications of dosage form design and development.

Wurster Technology-Assisted Step-by-Step Engineering of Multi-layered Pellets (Sprinkles): Microscopy, Micro-CT, and e-Tongue-Based Analysis

The advancement in the formulation and characterization techniques have paved the path for development of new as well as modification of existing dosage forms. The present work explores the role of micro-computed tomography (micro-CT) as advanced characterization technique for multi-layered-coated pellets to ascertain the quality of coated pellets. The work further explored in-house e-tongue technique for understanding palatability of formulation in early stages of development thus by reducing clinical taste evaluation time. The developed multi-layered-coated pellets were characterized using microscopy (optical and electron microscopy). The obtained results demonstrated formation of spherical-shaped pellets with uniform coating. The uniform coating was further confirmed by results obtained from scanning electron microscopy (SEM) and cross-sectional SEM analysis, which showed visible difference in pellet surface before and after multi-layered coating. The micro-CT results confirmed the visible demarcation of layers (drug and polymer, i.e., hydroxypropyl methylcellulose (HPMC) and eudragit (EPO)) along with uniform thickness of various layering. The dissolution study of developed pellets suggested the role of layering EPO on drug release from pellets. The e-tongue analysis proved to be an excellent tool for early prediction of taste masking of drug via multi-layered pellets and can serve as potential platform for taste masking with high specificity. The overall results suggest the suitability of developed multi-layered platform as efficient dosage form (sprinkle) in pediatric/geriatric product development.

Review on Starter Pellets: Inert and Functional Cores

A significant proportion of pharmaceuticals are now considered multiparticulate systems. Modified-release drug delivery formulations can be designed with engineering precision, and patient-centric dosing can be accomplished relatively easily using multi-unit systems. In many cases, Multiple-Unit Pellet Systems (MUPS) are formulated on the basis of a neutral excipient core which may carry the layered drug surrounded also by functional coating. In the present summary, commonly used starter pellets are presented. The manuscript describes the main properties of the various nuclei related to their micro- and macrostructure. In the case of layered pellets formed based on different inert pellet cores, the drug release mechanism can be expected in detail. Finally, the authors would like to prove the industrial significance of inert cores by presenting some of the commercially available formulations.

Development and Dissolution Study of a β-Galactosidase Containing Drinking Straw

Today, in addition to many different physicochemical and pharmacological properties of the active ingredients and excipients, the developer of a pharmaceutical formulation must take into account several factors during the formulation process in order for the patient to cooperate to use the formulation accurately. One of the innovative solutions in paediatrics may be the use of medicated drinking straws. For our studies, we successfully prepared lactase-containing, rapid disintegration particles by two techniques commonly used in the pharmaceutical industry. The simulation of the usage of the filled straws was presented from a new perspective for the patient by an in vitro method. The effect of the temperature of the liquid used during the administration of the straw and the effect of the frequency during the application on the dissolution rate were investigated. According to our results, in the case of a straw containing rapidly dissolving particles, the temperature of the used liquid and the mode of administration (frequency) play a significant role in the release rate from the composition.

Development of a Biphasic-Release Multiple-Unit Pellet System with Diclofenac Sodium Using Novel Calcium Phosphate-Based Starter Pellets

Novel calcium phosphate-based starter pellets were used to develop a biphasic-release multiple-unit pellet system (MUPS) with diclofenac sodium as a model drug in the form of hard gelatin capsules. For comparative purposes, corresponding formulations based on the inert cores made of microcrystalline cellulose, sucrose and isomalt were prepared. The developed system consisted of two types of drug-layered pellets attaining different release patterns: delayed-release (enteric-coated) and extended-release. Dissolution characteristics were examined using both compendial and biorelevant methods, which reflected fed and fasting conditions. The results were collated with an equivalent commercial product but prepared with the direct pelletization technique.