Segregation of formulated powders in direct compression process and evaluations by small bench-scale testers.

Powder segregation can cause severe issues in processes of pharmaceutical drugs for control of content uniformity if the powder is likely to be free or easy flowing. Assessing segregation intensity of formulated powders in a process is challenging at the formulation stage because of the limited availability of samples. An advanced segregation evaluation using small bench-scale testers can be useful for formulation decisions and suggestions of operation conditions in the process, which has not been practically investigated before. In this study, eight formulations (two co-processed excipients blended with one active pharmaceutical ingredient at different ratios) were used for the segregation study on two types of bench-scale testers (air-induced and surface rolling segregation tester), and a pilot simulation process rig as a comparative study. The results show that segregation measured on the bench-scale testers can give a good indication of the segregation intensity of a blend if the segregation intensity is not more than 20%. The comparison also shows that both the bench-scale testers have a good correlation to the process rig, respectively, which means either segregation tester can be used independently for the evaluation. A linear regression model was explored for prediction of segregation in the process.

Two-Step Glass Molding Process for Forming Glass Edges with Obtuse Angles for Mobile Displays.

The domain of edge displays with 2.5D or 3D curved designs has been expanded to improve user convenience. The currently available 3D cover glass offers a limited curvature radius of at least 5 mm and a curvature less than 88°, due to limitations in the undercuts and formability of parts. The development of a full 3D cover, applicable to next-generation displays, requires cover glass molding technology with a curvature exceeding 90°. Here, a mold design and molding process, which addresses the current limitations by dividing the existing glass molding press (GMP) process into two stages, is proposed. The bending geometry of the glass prepared on the basis of the proposed mold design plan during single-step compression forming and two-step compression forming was predicted using commercial analysis software. A molding product with a curvature radius of 2.5 mm and an angle of curvature of 138.9° was produced when process conditions with bending by up to 180° with no damage were applied during actual forming experiments. Further research on annealing and cooling processes of GMP is expected to enable the design and process implementation to manufacture curved glass with a single curvature of at least 90° and multiple curvatures.

The use of novel tools for the assessment of powders and granules flow properties and for the analysis of minitablets compression process.

Objective: The purpose of this study was to apply the rheological measurements to assess the flow properties of powders and granules and to compare the results with the standard pharmacopeial tests. Quality by design approach was utilized to better understand the compression of the solids into minitablets.Significance: Insights are provided regarding the methodology of rheological properties of powders and granules using powder flow analyzer (PFA). The 'six sigma' approach was presented as a tool for assessment of the minitablets manufacturing process.Methods: Pharmacopeial methods and rheological tests using PFA were performed to assess the flow properties of designed powder and fractionated granule mixtures - placebo and with benzodiazepines. Compression of 2.5 and 3 mm minitablets was carried out and the compression force registered during the process and weight uniformity were statistically analyzed by calculating the capability indices.Results: The flow rate measurement and cohesion test (PFA test) resulted in the best differentiation between mixtures. Higher values of capability indices were obtained for processes in which granule mixtures with better flow properties were compressed and 3 mm minitablets were produced and the usefulness of QbD tools in assessment of minitablets compression process was confirmed.Conclusion: Performed study showed that the flow properties are the critical quality attributes determining the performance of minitablets compression. The cohesion test is the most discriminative to distinguish the analyzed mixtures. Capability indices can be used to assess the manufacturing process as a useful tool in pharmaceutical development of minitablets.

Grayscale mask-assisted photochemical crosslinking for a dense collagen construct with stiffness gradient.

Despite the potential of a collagen construct with a stiffness gradient for investigating cell-extracellular matrix (ECM) stiffness interaction or recapitulating an in vivo tissue interface, it has been developed in a limited way due to the low and poorly controllable mechanical properties of the collagen. This study proposes a novel fabrication process to achieve a compressed collagen construct with a stiffness gradient, named COSDIENT, at a level of ~ 1 MPa while maintaining in vivo ECM-like dense collagen fibrillar structures. The COSDIENT was fabricated by collagen compression followed by grayscale mask-assisted UV-riboflavin crosslinking. The collagen compression process enabled the remarkable increase in the stiffness of the collagen gel from ~ 1-10 kPa to ~ 1 MPa by physical compaction. The subsequent UV-riboflavin crosslinking with a continuous-tone grayscale mask could simply generate a gradual change of UV irradiation followed by modulating riboflavin-mediated crosslinking, thereby resulting in a continuous stiffness gradient with a range of 1.16-4.38 MPa in the single compressed collagen construct. The suggested grayscale mask-assisted photochemical crosslinking had no effect on the physical and optical properties of the original compressed collagen construct, while inducing gradual changes of chemical bonds among collagen fibrils. A skin wound healing assay with epidermal keratinocytes was finally applied as an application example of the COSDIENT to examine the effect of stiffness on the skin keratinocyte behavior.

Compressed collagen intermixed with cornea-derived decellularized extracellular matrix providing mechanical and biochemical niches for corneal stroma analogue.

Compressed collagen is a promising scaffold for corneal stroma analogue due to its facile incorporation of keratocytes while mimicking the mechanical niche of a native cornea with dense collagen fibrillar structures. However, it does not offer the sufficient biochemical niche crucial for in vivo-like quiescent keratocyte phenotype. In this study, we engineered a scaffold for a corneal stroma analogue that mimics both the mechanical and biochemical niches of the corneal stroma by introducing cornea-derived decellularized extracellular matrix (Co-dECM) to the collagen compression process. The compressed collagen intermixed with Co-dECM (COLEM; Co-dECM content, <50 wt%) maintained a uniform structure and showed an elastic modulus and tensile strength on the order of 100 kPa, which is comparable with that of conventional compressed collagen. The COLEM with the 50 wt% Co-dECM content was found to possess 2-fold higher amount of the glycosaminoglycans as compared to the compressed collagen. The biochemical components of Co-dECM in the COLEM were verified to significantly promote the expression of quiescent keratocyte-specific genes, i.e., KERA and ALDH3A1, while improving the optical transmittance of the COLEM by reducing the diameter of collagen fibrils. The ability of the COLEM to construct multicellular in vitro corneal tissue was demonstrated by an additional corneal epithelial cell culture. The results support the hypothesis that COLEM has strong potential use in the development of corneal equivalent for in vitro models and tissue transplantation.

Efecto de la fuerza de compresión sobre los atributos críticos de calidad en tabletas de liberación inmediata de furosemida / Effect of compression force on critical quality attributes of immediate release tablets of furosemide

RESUMEN La furosemida es un fármaco poco soluble en agua (0,01825 mg/mL). Debido a su baja solubilidad y baja permeabilidad, se ubica en la clase IV del Sistema de Clasificación Biofarmacéutica (BCS, por sus siglas en inglés). Se absorbe rápida pero incompletamente en el tracto gastrointestinal (GI). Actualmente, este fármaco se comercializa en tabletas, las que para su obtención deben ser sometidas a un proceso de compresión. La fuerza aplicada en dicha compresión puede influenciar algunas de las características de calidad del producto; por ello, la presente investigación estudia el efecto de la fuerza de compresión sobre los atributos críticos de calidad en el proceso de fabricación (dureza, friabilidad y desintegración) y en el producto terminado (uniformidad de dosificación y disolución) de comprimidos de furosemida. El efecto sobre la disolución se determinó por los factores de diferencia (f 1) y de similitud (f 2) de los perfiles de disolución y los parámetros de eficiencia de la disolución (ED) y tiempo medio de disolución (TMD), los cuales se calcularon con el software académico kinetDS®. Los resultados obtenidos permitieron definir el rango de la fuerza de compresión para el cual se obtuvo una ED superior al 85% y un TMD inferior a 7,5 min.

SUMMARY Furosemide is poorly water soluble drug (0.01825 mg/mL). Due to its low solubility and low permeability, it is labeled in class IV of the Biopharmaceutical Classification System (BCS). It is rapidly but incompletely absorbed from the gastrointestinal (GI) tract. Currently, this drug is marketed as tablets, which should be subjected to a compression process. The force applied in this compression can influence some of the quality characteristics of the product. Therefore, this investigation was carried out to determine the effect of compression force on the critical quality attributes of the product in process (hardness, friability and disintegration) and of the finished product (uniformity of dosage and dissolution). The effect on the dissolution was determined by the difference factor (f 1) and similarity factor f 2 ) of the dissolution profiles, the dissolution efficiency (ED) and mean dissolution time (TMD) parameters, which were calculated by kinetDS® academic software. The results obtained allowed to define the range of compression force for which the ED was higher than 85% and the TMD lower than 7.5 min.

Modeling of feed-forward control using the partial least squares regression method in the tablet compression process.

In the pharmaceutical industry, the implementation of continuous manufacturing has been widely promoted in lieu of the traditional batch manufacturing approach. More specially, in recent years, the innovative concept of feed-forward control has been introduced in relation to process analytical technology. In the present study, we successfully developed a feed-forward control model for the tablet compression process by integrating data obtained from near-infrared (NIR) spectra and the physical properties of granules. In the pharmaceutical industry, batch manufacturing routinely allows for the preparation of granules with the desired properties through the manual control of process parameters. On the other hand, continuous manufacturing demands the automatic determination of these process parameters. Here, we proposed the development of a control model using the partial least squares regression (PLSR) method. The most significant feature of this method is the use of dataset integrating both the NIR spectra and the physical properties of the granules. Using our model, we determined that the properties of products, such as tablet weight and thickness, need to be included as independent variables in the PLSR analysis in order to predict unknown process parameters.

Preparation optimization of palonosetron hydrochloride oral disintegrating tablets by orthogonal test / 重庆医学

Objective To prepare optimization of palonosetron hydrochloride oral disintegrating tablets by orthogonal test. Methods Palonosetron hydrochloride oral disintegrating tablets were prepared with direct compression process.The content of pal-onosetron hydrochloride was determined by HPLC.The formulation was optimized with disintegration time as evaluation indices. Results The optimal formulation(60 mg/tablet)was as follows:L-HPC 12%,mannitol∶SMCC= 2∶1,magnesium stearate 2%, stevia glycosides 3%.The oral disintegrating tablets showed dine appearance and tested better;the disintegration time was 12 sec-onds;the tablets featured a hardness of 3 kg;4 min dissolution rate was 99%.Conclusion The preparation method is simple and reasonable,and the tablets can disintegrate rapidly.

Mechanical performance of targeted drug eluting stent during compression process / 医用生物力学

Objective To investigate mechanical performances of two different drug eluting stents (DES) during compression process, so as to provide a scientific guideline for design of DES. Methods Using Solidworks, two kinds of stent models, namely the common DES without slots in outside surface (Stent I) and the targeted DES with slots in outside surface (Stent II) were established, respectively. The important mechanical properties of the two stents during compression process, such as rebound ratio of radial contraction, rebound ratio of axial contraction, the inhomogeneity of compression and the distribution of residual stress, were analyzed by ABAQUS. Results With the same outer radius, the difference values of rebound ratio of radial contraction, rebound ratio of axial contraction and inhomogeneity of compressing for the two stents were 0.07%-0.12%, 0.016%-0.033% and 0.013 %-0.048%, respectively; there was a bigger low-stress area on the support of Stent II. Conclusions Compared with the traditional DES, the targeted DES could maintain the same mechanical performances while reducing drug-loading capacity, which shows a good prospect in clinical application of the treatment for cardiovascular stenosis diseases.