Tablet disintegration is an important pre-requisite for drug dissolution and absorption. The disintegration test is typically conducted at 37 °C, but the intragastric temperature may vary due to meals or fever. This study investigated the effects of temperature and compaction pressure on tablet disintegratability to gain deeper insights into superdisintegrant sensitivity and function. Tablets with either sodium starch glycolate or crospovidone as disintegrant were prepared at various compaction pressures and subjected to the disintegration test using different medium temperatures. Preheating of tablets was also employed to establish instant temperature equilibrium between the tablet and the disintegration medium. Liquid penetration and disintegration were faster as the medium temperature increased or compaction pressure decreased. Swelling or strain recovery disintegrants exhibited similar sensitivity to variations in the medium temperature. Preheating of the tablets resulted in slower disintegration, but this effect was reversible upon cooling, hence the slower disintegration was unlikely to be attributed to changes in the disintegrant physical state. The temperature difference between the tablet and the disintegration medium likely affected the rate of fluid flow into tablets and influenced disintegration. Understanding disintegrant temperature sensitivity would help to avoid unacceptable fluctuations in disintegration due to temperature variations. The temperature difference effect could also be harnessed to boost disintegrant performance.
Multi-unit pellet system (MUPS) tablets were fabricated by compacting drug-loaded pellets of either crospovidone or microcrystalline cellulose core. These pellets were produced by extrusion-spheronization and coated with ethylcellulose (EC) for a sustained drug release function. Coat damage due to the MUPS tableting process could undermine the sustained release function of the EC-coated pellets. Deformability of the pellet core is a factor that can impact the extent of pellet coat damage. Thus, this study was designed to evaluate the relative performance of drug-loaded pellets prepared with either microcrystalline cellulose (MCC) or crospovidone (XPVP) as a spheronization aid and were comparatively evaluated for their ability to withstand EC pellet coat damage when compacted. These pellets were tableted at various compaction pressures and pellet volume fractions. The extent of pellet coat damage was assessed by the change in drug release after compaction. The findings from this study demonstrated that pellets spheronized with XPVP had slightly less favorable physical properties and experienced comparatively more pellet coat damage than the pellets with MCC. However, MUPS tablets of reasonable quality could successfully be produced from pellets with XPVP, albeit their performance did not match that of vastly mechanically stronger pellets with MCC at higher compaction pressure.
Background/Objectives: Hydroxypropyl methylcellulose (HPMC) is one of the most commonly used hydrophilic polymers in formulations of matrix tablets for controlled release applications. However, HPMC attracts moisture and poses issues with drug stability in formulations containing moisture-sensitive drugs. Methods: Herein, the moisture sorption behavior of excipients and drug stability using aspirin as the model drug in matrix tablets were evaluated, using HPMC and the newly developed mannitol-coated HPMC, under accelerated stability conditions (40 °C, 75% relative humidity) with open and closed dishes. Results: Tablets prepared with mannitol-coated HPMC showed a slower drug degradation rate compared to tablets prepared with directly compressible HPMC. Initial moisture content and hygroscopicity were stronger predictors of drug stability compared to water activity when comparing samples without similar moisture content. In the early stage (day 0 to 30), the aspirin degradation rate was similar in both open and closed conditions, as moisture content is the main degradation contributor. In the later stage (day 30 to 90), aspirin degradation was faster under closed conditions than under open conditions, likely due to autocatalytic effects caused by the volatile acidic by-product entrapped in the closed environment. Conclusions: The findings from this study reinforced the importance of judicious excipient selection based on the understanding of excipient–moisture interactions to maximize the chemical stability of moisture-sensitive drugs. Mannitol-coated HPMC is a promising addition to the formulator’s toolbox for the formulation of controlled release dosage forms by direct compression.
Despite being a technology of several decades, high pressure homogenization (HPH) remains widely used in food and pharmaceutical industries, often as an essential unit operation in liquid product processing. Continual advances in the technology are made on multiple fronts, on equipment innovations by the manufacturers, new applications by users, and advances in process understanding by multidisciplinary scientists alongside subject matter experts amongst industry practitioners. While HPH is comparatively simple conceptually, the homogenization process involves complex engineering physics which is influenced by the varied processing conditions and highly diverse inputs with each use-case requiring its own treatment. The successful application of a HPH process indubitably requires practitioners to draw upon insights from multiple domains and the optimization for each case. Thus, this timely review aims to outline the more recent trends and advancements in HPH process understanding and novel applications involving HPH from both academic and industrial perspectives.
Background/Objectives: Compaction of sustained release coated pellets into tablets is associated with damage to the functional coat and loss in sustained release. The influences of precompression, trilayering, and tableting rate on the compaction of sustained release coated pellets into tablets are not well defined and were herein investigated to enhance the current limited understanding of these factors. Methods: Pellets coated with acrylic polymer (AC) or ethylcellulose (EC) were combined with filler material and compacted into multi-unit pellet system (MUPS) tablets prepared using different levels of precompression, as a trilayered MUPS tablet and at different tableting rates. The physical properties of the resulting MUPS tablets were evaluated. Trilayering was achieved by adding cushioning layers at the top and bottom of the MUPS tablet to avoid direct contact of pellets with punch surfaces. Results: With precompression, slightly stronger MUPS tablets were made compared to the tablets without precompression for EC pellets but not AC pellets. However, precompression led to a slight reduction in pellet coat damage for AC pellets but not EC pellets. Trilayering led to significant reductions in pellet coat damage and significant increases in tablet tensile strength. When EC pellets were lubricated with sodium stearyl fumarate, pellet coat damage was significantly lower. Increasing the tableting rate from 20 to 100 rpm did not result in increased pellet coat damage but in significantly weaker tablets due to the shorter dwell time. Conclusions: This study provides key insights on how compaction parameters and techniques could be altered to produce better MUPS tablets.