Browsing by Subject "flowability"

Microcrystalline cellulose (MCC) is a purified, partially depolymerized cellulose, which is obtained by treating α-cellulose with mineral acids. Ever since the first microcrystalline cellulose was commercialized, different grades of microcrystalline cellulose have widely been used in the manufacture of solid dosage forms, such as tablets. MCC obtained from different sources will exhibit different physico-chemical properties, including moisture content, degree of polymerization, crystallinity, and particle morphology. In wet granulation, microcrystalline cellulose can be used as a filler, binder, and disintegrant. Recently, Aalto University has introduced a novel microcrystalline cellulose obtained from renewable raw materials by an integrated process, which has a short retention time, low energy and chemical consumption. However, very few studies have evaluated the use of AaltoCellTM as an excipient in solid dosage forms. The objective of this study was to evaluate the filler properties of three grades of AaltoCellTM to prepare paracetamol tablets with 50% (w/w) drug load and compare AaltoCellTM with a commercial microcrystalline cellulose, Vivapur 101. Due to the poor flowability of paracetamol and the experimental microcrystalline celluloses, it is challenging to direct compress tablets from paracetamol and microcrystalline mixtures. Thus, the powder mixtures were granulated by high-shear wet granulation method to improve the flowability. After the granulation, the formulations were characterized for particle size distribution, morphology and powder flow. Carr’s index Hausner ratio and angle of repose were calculated to evaluate the flowability of the formulations. In addition, an image-based analysis of powder flow was performed. A rotary tablet press equipped with single punches of 9 mm diameter was used to compress tablets. To evaluate the quality of tablets, European Pharmacopoeia tests of friability, disintegration, uniformity of mass, uniformity of content and dissolution were conducted. The AaltoCellTM A and Vivapur 101 formulations had the smallest particle size, whereas the AaltoCellTM B had the largest particle size. According to Carr’s index and Hausner ratio, the flowability of AaltoCellTM powders and Vivapur 101 varied from poor to very, very poor. After the granulation, the flowability of AaltoCellTM B and AaltoCellTM C were classified as good, while AaltoCellTM A and Vivapur 101 formulations had fair flowability. However, the results were conflicting with the flowability index values obtained in the image-based analysis. According to the results, the AaltoCellTM tablets complied with all criteria of European Pharmacopoeia and were comparable with Vivapur 101 tablets. The average tablet weight deviated ± 3.2% from the target weight. The variations in weight and drug content were small, as indicated by low RSD values. The disintegration time of the AaltoCellTM tablets was between 1-8.5 minutes. In addition, the AaltoCellTM tablets had fast dissolution with 78-84% of paracetamol released within 1 minute. Overall, AaltoCellTM is a promising excipient for use as a filler in tablets. In further studies, characterizing the powder properties, such as morphology, surface properties and hygroscopicity, would provide a better understanding of the properties of AaltoCellTM.

Flowability of powders is in critical role when manufacturing the most popular dosage forms, tablets and capsules, of pharmaceutical industry. Re-formulation is expensive and time-consuming, so it is important to determine powder flow properties at the initial stage of drug development prior to tabletting and encapsulation processes. There are many different methods, like shear cell, flow through an orifice and bulk and tapped density, to examine powder flowability. Despite the methods, the most reliable means of examining powder flowability is often empirical. In early stages of drug development, it would be good to have faster, more reliable and cheaper methods to examine powder flowability. FT4 Powder Rheometer is a relatively new flowability characterization technique. The aim of this study is to find out whether the library created using the FT4 Powder Rheometer methods makes it possible to characterize the rheological properties of solids in the early stages of drug development. In addition, the aim is to investigate whether FT4 Powder Rheometer methods can predict the success of masses in tableting and encapsulation processes. The information gained from the research can be used in the future, for example, in continuous processes, because flowability plays an important role, especially in the supply of raw materials to the process, which is the most important division of continuous processes. To the library were selected for particle size and shape 15 different types of material. These materials were subjected to five different FT4 Powder Rheometer basic test methods. In addition, the particle size and shape of the materials and the flow through an orifice and the bulk and tapped density were determined to support the results of the powder rheometer. The principal component analysis was used to process the results. As the tablet and capsule masses examined, the masses of a previous study were utilized. Those masses were tableted and encapsulated in that previous study. These tablet and capsule masses contain a variable amount of cohesive drug substance. FT4 Powder Rheometer methods provide more complex information about materials and their behaviour than conventional flowability test methods. From the powder rheometer parameters pressure drop, compressibility and specific energy distinguish the cohesive and the non-cohesive materials, because the cohesive materials with these parameters obtain clearly higher values than non-cohesive materials. Additionally, the cohesion of FT4 Powder Rheometer shear cell test mainly distinguishes highly cohesive materials from other materials. The flow rate index makes it possible to separate the materials to which the change in flow rate particularly affects. Fluidizing materials, due to the air flow, are distinguished by the aeration test. Avicel PH-102 could be used as a rough limit value for well and poorly flowing materials in the created library (excluding the aeration and shear cell test). Stability index -, flow rate index -, specific energy -, pressure drop -, and compressibility-results of the FT4 Powder Rheometer correlated to the proportional proportion of the cohesive drug in the mixture. These parameters could possibly be used to distinguish mixtures containing the cohesive material. Additionally, specific energy, compressibility, pressure drop, basic flowability energy, stability index and flow rate index correlated with the weight variation of the tablets. With these parameters one could possibly assess the tabletability of the mixtures. A much larger library is needed to evaluate and predict the rheological properties of new materials. FT4 Powder Rheometer can possibly be used to predict the tableting success of tablet and capsule masses. This would be interesting to look more extensively, for example as part of a library. Additionally, it would be good to investigate whether the results of powder rheometer correlate to continuous production.