Cavities spatial distribution confined by microcrystalline cellulose particles determines tablet disintegration patterns

Advances in Structure Pharmaceutics from Discovery to Evaluation and Design

Drug delivery systems (DDSs) play an important role in delivering active pharmaceutical ingredients (APIs) to targeted sites with a predesigned release pattern. The chemical and biological properties of APIs and excipients have been extensively studied for their contribution to DDS quality and effectiveness; however, the structural characteristics of DDSs have not been adequately explored. Structure pharmaceutics involves the study of the structure of DDSs, especially the three-dimensional (3D) structures, and its interaction with the physiological and pathological structure of organisms, possibly influencing their release kinetics and targeting abilities. A systematic overview of the structures of a variety of dosage forms, such as tablets, granules, pellets, microspheres, powders, and nanoparticles, is presented. Moreover, the influence of structures on the release and targeting capability of DDSs has also been discussed, especially the in vitro and in vivo release correlation and the structure-based organ- and tumor-targeting capabilities of particles with different structures. Additionally, an in-depth discussion is provided regarding the application of structural strategies in the DDSs design and evaluation. Furthermore, some of the most frequently used characterization techniques in structure pharmaceutics are briefly described along with their potential future applications.

pH/enzyme dual sensitive Gegenqinlian pellets coated with Bletilla striata polysaccharide membranes for the treatment of ulcerative colitis

Gegen Qinlian Decoction, derived from Zhang Zhongjing's Treatise on Typhoid Fever, has been widely used in the treatment of various common diseases, frequently-occurring diseases and difficult and complicated diseases, such as ulcerative colitis. In this study, Bletilla striata polysaccharide (BSP) was innovatively used as a film coating material to prepare Gegen Qinlian pellets with dual sensitivity of pH enzyme for the treatment of ulcerative colitis. BSP has the ability to repair the inflamed colon mucosa and can produce synergistic effects, while avoiding the adverse therapeutic effects caused by the early release of drugs from a single pH-sensitive pellets in the small intestine. The prepared pellets have a uniform particle size, good roundness, a particle size range from 0.8 mm to 1.0 mm, and a particle yield is 85.6 %. The results of in vitro release showed that ES-BSP pellets hardly released drugs in the pH range of 1.2-6.8. However, in the colon mimic fluid containing specific enzymes, the drug release was significantly accelerated, demonstrating the sensitivity of the pellets to pH enzymes. In vivo and ex vivo fluorescence imaging of small animals showed that Gegen Qinlian pellets with dual sensitivity of pH enzyme remained longer in the colon compared with pH-sensitive pellets. In vivo pharmacodynamics study showed that the Gegen Qinlian pellets with dual sensitivity of pH enzyme had a better therapeutic effect in the rat model of the ulcerative colon than the commercially available Gegenqinlian pellets in the control group.

Characterization of Pharmaceutical Tablets by X-ray Tomography

Solid dosage forms such as tablets are extensively used in drug administration for their simplicity and large-scale manufacturing capabilities. High-resolution X-ray tomography is one of the most valuable non-destructive techniques to investigate the internal structure of the tablets for drug product development as well as for a cost effective production process. In this work, we review the recent developments in high-resolution X-ray microtomography and its application towards different tablet characterizations. The increased availability of powerful laboratory instrumentation, as well as the advent of high brilliance and coherent 3rd generation synchrotron light sources, combined with advanced data processing techniques, are driving the application of X-ray microtomography forward as an indispensable tool in the pharmaceutical industry.

Evaluating the Effect of Microcrystalline Cellulose Variations on Tablet Quality of Natural Plant Product Using a Design of Experiment Approach

Microcrystalline cellulose (MCC) of different grades from different manufacturers differ in particulate and powder properties significantly. The choice of MCC is important to the development of a tablet formulation with satisfactory quality. In this study, the effects of five different MCCs (KG 802, Pharmacel 102, MC 302, M 200, and PH 112) that had different compactibility and tablet disintegration on the tablet quality of two different natural plant products (NPPs) were evaluated systematically, including Crataegi Folium ethanol extract (CF-E) and Sarcandrae Herba water extract (SH-W). The result of D-optimal mixture designs demonstrated that KG 802 showed the best ability to improve compression properties and tensile strength, followed by Pharmacel 102, MC 302, and M 200. PH 112 did the weakest. However, MCCs of different grades had no different influence on the disintegration of NPP tablets. Similar results were found in the experiments of the two different NPP powders, suggesting the generalization of the finding. Moreover, KG 802-containing CF-E formulations showed the largest optimum region size, that is, the lowest production risk. The design space sizes of SH-W were hardly sensitive to the change of MCCs, due to the better tabletability. In conclusion, the properties of MCCs could transfer to the high NPP loading (70%) formulations, leading to the variations on the compression properties and tablet quality. The poorer the tabletability of NPP, the more obvious the variation. The result is promising for the use of MCC and the manufacturing of high drug-loading NPP tablets by direct compression.

An update on microcrystalline cellulose in direct compression: Functionality, critical material attributes, and co-processed excipients

Microcrystalline cellulose (MCC) is one of the most popular cellulose derivatives in the pharmaceutical industry. Thanks to its outstanding tabletability, MCC is generally included in direct compression (DC) tablet formulations containing poor-tabletability active pharmaceutical ingredients. Nowadays, numerous grades of MCC from various brands are accessible for pharmaceutical manufacturers, leading to variability in MCC properties. Hence, it seems to be worthy and urgent to evaluate the influences of MCC variability on tablet quality and to identify critical material attributes (CMAs) based on the idea of Quality by Control. Besides, MCC-based co-processed excipients can effectively combine the functions of the filler, binder, disintegrant, lubricant, glidant, or flavor, and thus have drawn extensive interest. In this review, we focused specifically on the recent advances and development of MCC on DC tableting, including the functions in tablet formulations, potential CMAs, and MCC-based co-possessed excipients, therefore providing a reference for further studies.