Tabletting Articles

The purpose of this research was to evaluate the influence of dry granulation parameters on granule and tablet properties of spray-dried extract (SDE) from Maytenus ilicifolia, which is widely used in Brazil in the treatment of gastric disorders. The compressional behavior of the SDE and granules of the SDE was characterized by Heckel plots. The tablet properties of powders, granules, and formulations containing a high extract dose were compared. The SDE was blended with 2% magnesium stearate and 1% colloidal silicon dioxide and compacted to produce granules after slugging or roll compaction. The influences of the granulation process and the roll compaction force on the technological properties of the granules were studied. The flowability and density of spray-dried particles were improved after granulation. Tablets produced by direct compression of granules showed lower crushing strength than the ones obtained from nongranulated material.

The purpose of this work was to investigate the effect of different polysulfonate resins and direct compression fillers on physical properties of multiple-unit sustained-release dextromethorphan (DMP) tablets. DMP resinates were formed by a complexation of DMP and strong cation exchange resins, Dowex 50 W and Amberlite IRP69. The tablets consisted of the DMP resinates and direct compression fillers, such as microcrystalline cellulose (MCC), dicalcium phosphate dihydrate (DCP), and spray-dried rice starch (SDRS). Physical properties of tablets, such as hardness, disintegration time, and in vitro release, were investigated. A good performance of the tablets was obtained when MCC or SDRS was used. The use of rod-like and plate-like particles of Amberlite IRP69 caused a statistical decrease in tablet hardness, whereas good tablet hardness was obtained when spherical particle of Dowex 50 W was used.

Sticking occurs when granules attach themselves to the faces of tablet press punches. Picking is a more specific term that describes product sticking o­nly within the letters, logos, or designs o­n the punch faces. This article explains the causes of sticking and picking and describes the steps you can take to resolve both problems.


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Ossi Korhonen, Seppo Pohja, Soili Peltonen, Eero Suihko, Mika Vidgren, Petteri Paronen, Jarkko KetolainenAAPS PharmSciTech. 2002; 3(4): article 34.

The aim of this study is to apply 3-D modeling to data obtained from different tableting machines and for different compression wheels o­n a linear rotary tableting machine replicator. A new analysis technique to interpret these data by 3-D parameter plots is presented. Tablets were produced o­n an instrumented eccentric tableting machine and o­n a linear rotary tableting machine replicator. The materials used were dicalcium phosphate dihydrate (DCPD), spray-dried lactose, microcrystalline cellulose (MCC), hydroxypropyl methylcellulose (HPMC), and theophylline monohydrate. Tableting was performed to different maximum relative densities (ρ rel, max). Force, time, and displacement were recorded during compaction. The 3-D data plots were prepared using pressure, normalized time, and porosity according to Heckel. A twisted plane was fitted to these data according to the 3-D modeling technique. The resulting parameters were analyzed in a 3-D parameter plot.

The objective of this study is to test the hypothesis that time plasticity (parameter d from 3-D modeling) is influenced by tableting speed. Tablets were produced at different maximum relative densities (ρrel, max) o­n an instrumented eccentric tableting machine and o­n a linear rotary tableting machine replicator. Some 3-D data plots were prepared using pressure, normalized time, and porosity according to Heckel. After fitting of a twisted plane, the resulting parameters were analyzed in a 3-D parameter plot. The materials used were dicalcium phosphate dihydrate (DCPD), spray-dried lactose, microcrystalline cellulose (MCC), hydroxypropyl methylcellulose (HPMC), κ-carrageenan (CAR), and theophylline monohydrate (TheoM). The results show that tableting speed especially influences the parameter d (time plasticity) of the 3-D model for plastically and viscoelastically deforming materials such as MCC, HPMC, CAR, and TheoM.

Prions cause neurodegenerative diseases, such as scrapie in sheep, bovine spongiformencephalopathy (BSE) in cattle, Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler-Scheinker syndrome (GSS), fatal familial insomnia (FFI), kuru, and a new variant of CJD in humans. These diseases are associated with conversion of the normal cellular form of the prion protein (PrPC) to a pathogenic scrapie form (PrPSc), which is apparently the infectious agent in transmitted forms of the disease. The sequences of PrPSc and the noninfectious precursor PrPC are identical. Although both isoforms are chemically identical, they possess very different physicochemical properties. PrPC is substantially helical, but PrPSc has ~40% -sheet.

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The purpose of this study was to determine the factors that influence fill weight and weight variability of capsules produced o­n the In-Cap and to assess any differences in terms of capsule defects between gelatin and HPMC (Quali-V) shells. The In-Cap is an automatic tamping type capsule-filling machine and the low output of ~3000 capsules/hour makes it ideal for early formulation development and phase I/IIa clinical supplies manufacture. Four commonly used excipients (Avicel PH101, Avicel PH302, A-Tab, and Prosolv HD90) and a poorly flowing drug blend were encapsulated at various pin settings and powder bed heights. The average fill weight and coefficient of weight variation were determined. The percentage of defective capsules formed during encapsulation was calculated. Results of the study showed that pin setting was critical for controlling the fill weight and the weight variation.

The effects of moisture o­n the flow properties, tensile strength, Heckel plot (particle rearrangement, yield pressure), energies involved in compaction (gross, plastic, and elastic energies), and elastic recovery are reviewed. The identification and quantification of the numerous parameters that affect the compaction process are vital for product uniformity. For example, moisture adsorption plays an important role in physical and chemical stability, in the properties of solid dosage forms and excipients, and in polymers for sustained-release formulations. The vapor pressure of water in the atmosphere is quantified by the percent relative humidity (% RH). The moisture content at which a solid material produces a water vapor pressure equal to that of the surrounding environment is defined as the equilibrium moisture content (EMC). The solid’s resultant weight gain at a specified temperature and % RH is expressed as a percentage of its initial dry weight.

Hydroxypropylcellulose (HPC) is a water-soluble cellulose ether, avaiolable in a range of molecular weights and particle sizes


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