This paper investigates the Angle of Repose (AoR) of powder materials with respect to their morphological and rheological properties. Glass beads, sand, flour and semolina of different particle sizes were used as the experimental materials. The investigated material was analysed with respect to particle shape and size. The rheological properties of the material were obtained by a shear cell test. The AoR was analysed in terms of cohesion, bulk density, particle size and circularity. More cohesive materials such as the flour samples exhibited the largest AoR > 40°, indicating their poor flowability. Glass bead samples with a high circularity value had significantly lower AoR than the flour. The Angle of Internal Friction values were not dependent on those of the AoR. Using a dimensional analysis, a mathematical model was developed to determine the AoR values based on the material properties. By the application of this model, highly accurate calculation of the value of AoR is made possible.

Co-processed dry binders for ODTs are important multifunctional excipients for tablet manufacturing by direct compression. Testing their binary mixtures with lubricants is an important aspect of their use in combination with drugs. The aim of this study was to evaluate the rheological and compression properties of lubricated mixtures of co-processed dry binders Parteck® ODT, Prosolv® ODT G2 and Ludiflash®, and subsequently also the compactability and disintegration time of the tablets made thereof. The lubricants employed were magnesium stearate and sodium stearyl fumarate in the concentrations of 0.5% and 1%. The best flowability was shown by Prosolv® ODT G2 combined with magnesium stearate in the concentration of 0.5%. Lubricated mixtures with Prosolv® ODT G2 showed a lower angle of internal friction as well as lower pre-compression energy values. The values of plastic deformation energy were the highest in the case of Prosolv® ODT G2, which was also reflected in the highest tablet strength. On the contrary, the ejection force values were the lowest for this co-processed dry binder. Magnesium stearate reduced the ejection force more effectively than sodium stearyl fumarate. Prosolv® ODT G2 tablets exhibited the highest tensile strength and shortest disintegration time.

The aim of this paper was to describe the influence of high-shear wet granulation process parameters on tablet tensile strength and compaction behavior of a powder mixture and granules containing hydralazine. The hydralazine powder mixture and eight types of granules were compacted into tablets and evaluated using the Heckel, Kawakita and Adams analyses. The granules were created using two types of granulation liquid (distilled water and aqueous solution of polyvinylpyrrolidone), at different impeller speeds (500 and 700 rpm) and with different wet massing times (without wet massing and for 2 min). Granulation resulted in improved compressibility, reduced dustiness and narrower particle-size distribution. A significant influence of wet massing time on parameters from the Kawakita and Adams analysis was found. Wet massing time had an equally significant effect on tablet tensile strength, regardless of the granulation liquid used. Granules formed with the same wet massing time showed the same trends in tabletability graphs. Tablets created using a single-tablet press (batch compaction) and an eccentric tablet press showed opposite values of tensile strength. Tablets from granules with a higher bulk density showed lower strength during batch compaction and, conversely, higher strength during eccentric tableting.

This work deals with the creation of a mathematical model which will predict with sufficient accuracy the size of granules in the high-shear granulation process. The aim of the paper was to create a model created with dimensionless criteria to give the size of granules as a function of selected process parameters, equipment, and experimental material. Microcrystalline cellulose granules were manufactured in an experimental granulator of our own construction using a high amount of granulation liquid (absolute humidity >40%). The work also focuses on the study of granule size distribution and the yield of the process in achieving the target granule fraction (0.4–3 mm). Particle size and particle size measurement were performed using 3 D dynamic image analysis (PartAn 3 D, Microtrac). The granules were analyzed with respect to their shape and width of distribution. Using the created model, it is possible with high probability, 89.4%, to predict on our device the median value of the granule size of microcrystalline cellulose, with ±0.1 mm precision.

(1) Background: The study aimed to compare the impact of various natural polymers–sodium alginate, acacia gum, carrageenan, guar gum, xanthan gum, and tragacanth on the formulation and the physical properties of mucoadhesive vaginal tablets containing metronidazole (167 mg/g). (2) Methods: The quality of the tablets prepared by direct compression was evaluated by pharmacopoeia tests (uniformity of mass, resistance to crushing, friability). Mucoadhesion of the tablets was characterized by swelling capacity and mucoadhesive strength, i.e., the force required to detach the tablet from the rabbit mucosa. In vitro drug release was performed by a modified dissolution method in paddle apparatus containing the simulated vaginal fluid (pH 4.5). Scanning electron microscopy observed morphological changes on the swollen tablets’ surface. (3) Results: Pharmacopoeia tests have shown that all prepared tablets met the requirements on quality. The highest mucoadhesive strength was noted in tablets containing guar and xanthan gum. The highest swelling capacity was possessed by tablets containing carrageenan. (4) Conclusions: Summarizing all tests’ results, sodium alginate can be considered the most suitable natural polymer in tablet formulation. The combination of polymers providing higher mucoadhesiveness and at the same time a prolonged release, e.g., xanthan or guar, together with sodium alginate, could also be of interest.

This study aimed to prepare and evaluate pellets containing acyclovir as a model drug. Pellets were prepared by the extrusion–spheronization process. Aqueous solutions of natural marine polymers (sodium alginate, chitosan) were compared to semi-synthetic hydroxypropyl methylcellulose (HPMC) in the role of binders. The study focused on the characterization of the pellet properties that are crucial for the formulation of the final dosage form, such as in multi-unit pellet system (MUPS) tablets or hard gelatin capsules filled with the pellets. Finally, the mentioned dosage forms were tested for drug dissolution. The morphology of pellets observed by scanning electron microscopy correlated with the shape evaluation performed by dynamic image analysis. Sodium alginate pellets exhibited the lowest value of sphericity (0.93), and many elongated rods and dumbbells were observed in this batch. Chitosan pellets had the highest value of sphericity (0.97) and were also less rough on the surface. The pellets maintained a constant surface geometry during the dissolution studies; they only reduced in size. The most significant reduction in size and weight was assessed after 2 h of dissolution testing. This fact was in line with the drug release from pellets in capsules or MUPS tablets, which was massive during the first hour, in both cases. The dissolution profiles of all of the batches were comparable.