Changes in Volume and Compression Energy upon Compression of Calcium Silicate Tablets

The compression mechanism of calcium silicate (Florite®RE, FLR)was evaluated by determining the physicochemical properties such as compression energy, volume reduction percentage during the compression process, and elastic recovery of FLR tablets. The results obtained were compared with those of microcrystalline cellulose (MCC), anhydrous dibasic calcium phosphate (ADCP), cornstarch (CS), and lactose (LAC). FLR is found to have higher plasticity in the compression process and lower elastic recovery in a wide range of tablet hardnesses compared with the other 4 excipients. The results also indicate that a large part of compression energy was consumed for plastic deformation and fragmentation of particles. These characteristics are attributable to FLR's porous structure and are responsible for FLR tablets' high hardness, an important propen'y in tablet formulation. As a consequence, it was suggested that FLR would be a useful excipient for the formation of tablets in the pharmaceutical industry.     

The compression of spheres coated with an aqueous ethylcellulose dispersion

Tablets were compressed from commercial samples of Sugar Spheres NF, Sucrose NF, Corn Starch NF, as well as ground spheres and a physical mixture of ground sucrose plus cornstarch. Additional tablets were compressed from spheres that had been coated with a water-soluble cellulosic polymer solution followed by an aqueous ethylcellulose dispersion. Tableting parameters measured “in-die” included work of compression, peak offset time, tablet density, and Young's modulus. Following ejection, tensile strength was determined under diametrical loading. Dissolution of a marker contained in the water-soluble layer was determined for both compressed and uncompressed spheres. Porosities at peak pressure and peak offset times or tensile strength as functions of peak pressure did not differ between tablets compressed from pristine spheres or from ground spheres. Tablets compressed from spheres had higher values for porosity, tensile strength, and peak offset time than those compressed from sucrose or the sucrose:starch mixture. Values for work of compression were higher for tablets compressed from pristine spheres or from starch. This was attributed to the work required for particle deformation and for breaking of the spheres. The greatest elastic recovery during decompression was observed for tablets compressed from pristine spheres or starch. More brittle behavior was observed for tablets compressed from sucrose or the sucrose:starch mixture. Tablets compressed from ground spheres were more brittle than those compressed from the pristine spheres, indicating an effect due to grinding. Most mechanical properties of tablets compressed from the coated spheres were comparable to those of tablets compressed from uncoated spheres. An exception was diametric strain for tablets compressed from spheres coated with the aqueous ethylcellulose dispersion. These values increased since the plasticized ethylcellulose allowed greater distortion of the tablet before failure occurred. The dye marker was released more rapidly from tablets compressed from spheres coated with the aqueous ethylcellulose dispersion than from comparable uncompressed spheres. At both the 5% and 10% coating levels, spheres coated with the aqueous ethylcellulose dispersion fused into nondisintegrating matrices during compression. Little difference in release rates was seen between the two tablets.     

The Compression of Spheres Coated with an Aqueous Ethylcellulose Dispersion

Tablets were compressed from commercial samples of Sugar Spheres NF, Sucrose NF, Corn Starch NF, as well as ground spheres and a physical mixture of ground sucrose plus cornstarch. Additional tablets were compressed from spheres that had been coated with a water-soluble cellulosic polymer solution followed by an aqueous ethylcellulose dispersion. Tableting parameters measured “in-die” included work of compression, peak offset time, tablet density, and Young's modulus. Following ejection, tensile strength was determined under diametrical loading. Dissolution of a marker contained in the water-soluble layer was determined for both compressed and uncompressed spheres. Porosities at peak pressure and peak offset times or tensile strength as functions of peak pressure did not differ between tablets compressed from pristine spheres or from ground spheres. Tablets compressed from spheres had higher values for porosity, tensile strength, and peak offset time than those compressed from sucrose or the sucrose:starch mixture. Values for work of compression were higher for tablets compressed from pristine spheres or from starch. This was attributed to the work required for particle deformation and for breaking of the spheres. The greatest elastic recovery during decompression was observed for tablets compressed from pristine spheres or starch. More brittle behavior was observed for tablets compressed from sucrose or the sucrose:starch mixture. Tablets compressed from ground spheres were more brittle than those compressed from the pristine spheres, indicating an effect due to grinding. Most mechanical properties of tablets compressed from the coated spheres were comparable to those of tablets compressed from uncoated spheres. An exception was diametric strain for tablets compressed from spheres coated with the aqueous ethylcellulose dispersion. These values increased since the plasticized ethylcellulose allowed greater distortion of the tablet before failure occurred. The dye marker was released more rapidly from tablets compressed from spheres coated with the aqueous ethylcellulose dispersion than from comparable uncompressed spheres. At both the 5% and 10% coating levels, spheres coated with the aqueous ethylcellulose dispersion fused into nondisintegrating matrices during compression. Little difference in release rates was seen between the two tablets.     

Carboxymethylstarches in Wet Granulation

Abstract

Commercialized carboxymethystarches (CMS) are both carboxyme-thylated and cross linked potato starch.

The influence of carboxymethylation and cross linkage on the disintegrating properties of starch are studied.

Tablets are made with acetaminophen as drug, Emcompress as diluant, Magnesium stearat as lubricant, and potato starch or its derivatives as disintegrants.

Tablets are prepared by direct compression or by wet granulation with the disintegrant intervening only in internal phasis.

Five disintegrants were studied, with two different concentrations:

native potato starch

potato starch simply cross linked

potato starch simply carboxymethylated

two potato starches both cross linked and carboxymethylated at two different degrees

Compressibility of powders blending and grain for compression are discussed.

The hardness, the tablet disintegration and the rate of drug dissolution are studied.

The results showed that the simply carboxymethylated starch has a totally different behaviour after direct compression or wet granulation. The poor results after wet granulation could be imputed to the bursting of starch granules during grain drying. Since it has lost its granular structure, the carboxymethylated starch will only allow a poor disintegration and a slow dissolution of the drug.

A very similar behaviour of native and simply cross linked starch: the results of which are bad for tablets either prepared by wet granulation or direct compression.

A very similar behaviour of the starches both carboxymethylated and cross linked, allowing a very good disponibility, either with tablets prepared by direct compression or wet granulation. These experiments prove :

the need for an sufficient cross linkage for CMS in a wet granulation process     

Development of Diclofenac Sodium Controlled Release Solid Dispersion Tablet Using Optimization Strategy

Directly compressed diclofenac sodium (DS) controlled release tablets were prepared from spray-dried DS controlled release solid dispersion of optimum dissolution projile. Optimization strategy using a central composite design and multiple regression was used to study the influences of four parameters: compression force, the amounts of spray-dried rice starch (Era-TabR), croscarmellose sodium (Ac-Di-Sol^R), and magnesium stearate, on tablet physical properties and dissolution. The optimum conditions of those parameters were searched and an optimum DS controlled release tablet formulation was formulated. The dissolution profile of the optimized DS controlled release tablet was similar to that of the DS controlled release solid dispersion. The mechanism of drug release from the optimized DS tablet was found to be diffusion controlled.     

The 3D model: explaining densification and deformation mechanisms by using 3D parameter plots

The aim of the study was to analyze very differently deforming materials using 3D parameter plots and consequently to gain deeper insights into the densification and deformation process described with the 3D model in order to define an ideal tableting excipient. The excipients used were dicalcium phosphate dihydrate (DCPD), sodium chloride (NaCl), microcrystalline cellulose (MCC), xylitol, mannitol, alpha-lactose monohydrate, maltose, hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose (NaCMC), cellulose acetate (CAC), maize starch, potato starch, pregelatinized starch, and maltodextrine. All of the materials were tableted to graded maximum relative densities (rhorel, max) using an eccentric tableting machine. The data which resulted, namely force, displacement, and time, were analyzed by the application of 3D modeling. Different particle size fractions of DCPD, CAC, and MCC were analyzed in addition. Brittle deforming materials such as DCPD exhibited a completely different 3D parameter plot, with low time plasticity, d, and low pressure plasticity, e, and a strong decrease in omega values when densification increased, in contrast to the plastically deforming MCC, which had much higher d, e, and omega values. e and omega values changed only slightly when densification increased for MCC. NaCl showed less of a decrease in omega values than DCPD did, and the d and e values were between those of MCC and DCPD. The sugar alcohols, xylitol and mannitol, behaved in a similar fashion to sodium chloride. This is also valid for the crystalline sugars, alpha-lactose monohydrate, and maltose. However, the sugars are more brittle than the sugar alcohols. The cellulose derivatives, HPMC, NaCMC, and CAC, are as plastic as MCC, however, their elasticity depends on substitution indicated by lower (more elastic) or higher (less elastic) omega values. The native starches, maize starch and potato starch, are very elastic, and pregelatinized starch and maltodextrine are less elastic and exhibited higher omega values. Deformation behavior as shown in 3D parameter plots depends on particle size for polymers such as CAC and MCC; however, it does not depend on particle size for brittle materials such as DCPD. An ideally deforming tableting excipient should exhibit high e, d, and omega values with a constant ratio of e and omega at increasing densification.     

Carboxymethylstarches in Wet Granulation

Commercialized carboxymethystarches (CMS) are both carboxyme-thylated and cross linked potato starch.

The influence of carboxymethylation and cross linkage on the disintegrating properties of starch are studied.

Tablets are made with acetaminophen as drug, Emcompress as diluant, Magnesium stearat as lubricant, and potato starch or its derivatives as disintegrants.

Tablets are prepared by direct compression or by wet granulation with the disintegrant intervening only in internal phasis.

Five disintegrants were studied, with two different concentrations:

native potato starch

potato starch simply cross linked

potato starch simply carboxymethylated

two potato starches both cross linked and carboxymethylated at two different degrees

Compressibility of powders blending and grain for compression are discussed.

The hardness, the tablet disintegration and the rate of drug dissolution are studied.

The results showed that the simply carboxymethylated starch has a totally different behaviour after direct compression or wet granulation. The poor results after wet granulation could be imputed to the bursting of starch granules during grain drying. Since it has lost its granular structure, the carboxymethylated starch will only allow a poor disintegration and a slow dissolution of the drug.

A very similar behaviour of native and simply cross linked starch: the results of which are bad for tablets either prepared by wet granulation or direct compression.

A very similar behaviour of the starches both carboxymethylated and cross linked, allowing a very good disponibility, either with tablets prepared by direct compression or wet granulation. These experiments prove :

the need for an sufficient cross linkage for CMS in a wet granulation process     

Compressional Behaviour of an Agglomerated Cellulose Powder

The ability of an agglomerated cellulose powder to total and plastic deformation was evaluated and compared with those of Avicel PH 101, Emcocel and an experimental depolymerized cellulose powder. The elastic recovery of compressed cellulose tablets was also measured. The effects of deformation of the material during the tableting process and recovery of tablet after maximum compression on the mechanical strength of tablets were also discussed.

The apparent net work done into tablets during compression as well as the yield pressures to total and plastic deformation, determined from the Heckel treatment, showed no great differences between the agglomerated cellulose powder and the other cellulose powders. Thus all the cellulose materials studied had rather similar ability to total, i.e. elastic and plastic, deformation and to permanent, i.e. pure plastic, deformation. The obvious fragmentation of the agglomerated cellulose powder already at low compressional pressure, however, seemed to be advantageous for the formation of strong compacts.

Both rapid and total elastic recovery of compressed cellulose tablets showed clear differences between the cellulose materials and these differences correlated with the previously measured strength of cellulose tablets. The agglomerated cellulose powder had the smallest tendency to both kind of elastic recoveries of tablets. Obviously, due to the large interparticle contact areas, the ability of this material to establish more bonds between adjacent particles during compression was greater than those of other celluloses. The elastic recovery was greatest for depolymerized cellulose tablets indicating the poorest binding ability of the particles of this material.     

Evaluation of tablet formation of different lactoses by 3D modeling and fractal analysis

The aim of this study was to use 3D modeling to differentiate not only among the four different types of lactose alpha-lactose monohydrate, spray-dried lactose, agglomerated lactose and lactose anhydrous but also between products from different manufacturers. Further "box-counting" fractal analysis of SEM images was done to gain additional information on tableting characteristics and tablet properties which can be found in the fractal structure. Twelve different materials from different manufacturers were analyzed for their powder-technological and physicochemical properties. They were tableted on an eccentric tableting machine at graded maximum relative densities and the recorded data, namely force, time, and displacement were analyzed by the 3D modeling technique. Tablet properties such as, elastic recovery, crushing force and morphology were analyzed. The results show that 3D modeling can precisely distinguish deformation behavior for different types of lactose and also for the same type of material produced with a slightly different technique. Furthermore, the results showed that the amorphous content of the lactose determined the compactibility of the material, which is due to a reversible exceeding of the glass transition temperature of the material. The three fractal dimensions DBW (box surface dimension), DWBW (pore/void box mass dimension), and DBBW (box solid mass dimension) are capable of describing morphological differences in lactose materials. Multivariate regression analysis showed that the fractal surface structure of the lactose-based materials is strongly correlated to tableting characteristics and tablet properties. Especially with regards to 3D modeling, it was found that the fractal indices can describe the parameters time plasticity d, pressure plasticity e, and fast elastic decompression, which is the inverse of omega. In addition, the 3D parameters are able to describe the powder and tablet fractal indices. In conclusion, the 3D modeling is not only able to characterize the compression process but it can also provide information on the final tablet morphology.     

A study of the compaction process and the properties of tablets made of a new co-processed starch excipient

This article deals with the study of the energetic relationships during compaction and the properties of tablets produced from a co-processed excipient based on starch and called StarCap 1500?. This article compares it with the substance Starch1500?. The study also includes the mixtures of StarCap 1500? and the granulated directly compressible lactose Pharmatose DCL?15. The tablet properties tested included tensile strength and disintegration time, examined in dependence on compression force, and also a 0.4% addition of magnesium stearate. The results show a better compressibility of StarCap 1500 in comparison with Starch 1500 and a lower elastic component of energy. The tablets were stronger and disintegrated more rapidly, but the substance possessed a higher sensitivity to an addition of a lubricant than Starch 1500. Increasing portions of StarCap 1500 in the mixtures with Pharmatose DCL 15 increased the tensile strength of tablets, disintegration period as well as the sensitivity to an addition of a lubricant. From the energetic viewpoint, energy for friction was decreasing, while the energy accumulated by the tablet during compaction and the elastic component of energy were increased.     

Evaluation of Era-Tab as a Direct Compression Excipient

The physical and compressional properties of a modified rice starch, Era-Tab, were evaluated and compared with those of 4 commercially available direct compression excipients, namely, microcrystalline cellulose (Avicel PH-101), partially pregelatinized starch, spray-dried lactose (Super-Tab Lactose), and granular dicalcium phosphate dihydrate (Emcompress). It was found that Era-Tab possessed high flowability and adequate compressibility. The compacted material made with Era-Tab has a higher crushing strength and a lower friability than 3 other direct compression excipients, except microcrystalline cellulose. Tablets containing terfenadine of the same degree of hardness (10 kg) were also prepared using different direct compression excipients. The disintegration time of the tablets made with Era-Tab was approximately 2.5 min. The maximum of the accumulated percentage of terfenadine released from the tablet reached 90%, and 63.2% of it was released within 20 min. Both the powder characteristics and tablet properties show that the modified rice starch, Era-Tab, is a useful product as a direct compression tablet excipient.     

Tablet Properties and Dissolution Characteristics of Compressed Cellulose Acetate Butyrate Microcapsules Containing Succinyl Sulfathiazole

Cellulose acetate butyrate microcapsules of succinyl sulfathiazole were prepared by a modified emulsion-solvent evaporation method and formulated for compression with microcrystalline cellulose and carboxymethyl starch. Tablet hardness decreased and friability increased as microcapsule content increased. Formulations containing up to 50% microcapsules produced satisfactory tablets, but at 70% microcapsules, the tablets were unacceptably fragile. Variation of microcapsule size fraction from 75 μm up to 428 μm had only a small effect on tablet properties when formulated at the 40% level. Tablet hardness increased with increasing compression pressure from 1.9 kg at 17.6 MPa to 14.9 kg at 210.7 MPa. Dissolution properties of the microcapsules were essentially unchanged at compression pressures up to 351 MPa with T_50% values ranging from 121 to 132 minutes. Uncompressed microcapsules had a T_50% value of 130 minutes.     

Effect of Re-Conpression on the Properties of Tablets Prepared by Dry Granulation

The effect of re-compression on the tableting properties of some direct compression excipients (directly compressible starch, dicalcium phosphate dihydrate and microcrystalline cellulose) and their formulations was examined. Re-compression generally reduced the tablet strength and this reduction was more significant when the initial compaction was carried out at a higher pressure. The reason for the reduction of tensile strength upon re-working is attributed to work hardening and the production of robust granules, which have increased resistance to deformation compared to unworked granules.

This paper is based on a presentation made to the 31st National meeting of the Academy of Pharmaceutical Sciences, American Pharmaceutical Association, held at Orlando, Florida, U.S.A. on November 15-19th, 1981.     

Evaluation of Tablet Formation of Different Lactoses by 3D Modeling and Fractal Analysis

ABSTRACT

The aim of this study was to use 3D modeling to differentiate not only among the four different types of lactose α-lactose monohydrate, spray-dried lactose, agglomerated lactose and lactose anhydrous but also between products from different manufacturers. Further “box-counting” fractal analysis of SEM images was done to gain additional information on tableting characteristics and tablet properties which can be found in the fractal structure. Twelve different materials from different manufacturers were analyzed for their powder-technological and physicochemical properties. They were tableted on an eccentric tableting machine at graded maximum relative densities and the recorded data, namely force, time, and displacement were analyzed by the 3D modeling technique. Tablet properties such as, elastic recovery, crushing force and morphology were analyzed. The results show that 3D modeling can precisely distinguish deformation behavior for different types of lactose and also for the same type of material produced with a slightly different technique. Furthermore, the results showed that the amorphous content of the lactose determined the compactibility of the material, which is due to a reversible exceeding of the glass transition temperature of the material. The three fractal dimensions D_BW (box surface dimension), D_WBW (pore/void box mass dimension), and D_BBW (box solid mass dimension) are capable of describing morphological differences in lactose materials. Multivariate regression analysis showed that the fractal surface structure of the lactose-based materials is strongly correlated to tableting characteristics and tablet properties. Especially with regards to 3D modeling, it was found that the fractal indices can describe the parameters time plasticity d, pressure plasticity e, and fast elastic decompression, which is the inverse of ω. In addition, the 3D parameters are able to describe the powder and tablet fractal indices. In conclusion, the 3D modeling is not only able to characterize the compression process but it can also provide information on the final tablet morphology.     

玉米淀粉醋酸酯的制备及成膜性能

以冰醋酸和醋酸酐为改性剂,浓硫酸作催化剂,合成了玉米淀粉醋酸酯,用傅立叶红外(FT-IR)、扫描电镜(SEM)、差示扫描量热法(DSC)、X射线衍射(XRD)分别对淀粉醋酸酯的结构、形貌、玻璃化转变温度和结晶度等进行测试和表征,分析了不同酯化度对淀粉的微观结构和热性能的影响。结果表明,淀粉经酯化后,结晶度降低,热性能提高,制备的酯化淀粉/聚乙烯醇的复合膜具有较好的力学性能和疏水性。     

A study of the compaction process and the properties of tablets made of a new co-processed starch excipient

This article deals with the study of the energetic relationships during compaction and the properties of tablets produced from a co-processed excipient based on starch and called StarCap1500^®. This article compares it with the substance Starch1500^®. The study also includes the mixtures of StarCap 1500^® and the granulated directly compressible lactose Pharmatose DCL^®15. The tablet properties tested included tensile strength and disintegration time, examined in dependence on compression force, and also a 0.4% addition of magnesium stearate. The results show a better compressibility of StarCap 1500 in comparison with Starch 1500 and a lower elastic component of energy. The tablets were stronger and disintegrated more rapidly, but the substance possessed a higher sensitivity to an addition of a lubricant than Starch 1500. Increasing portions of StarCap 1500 in the mixtures with Pharmatose DCL 15 increased the tensile strength of tablets, disintegration period as well as the sensitivity to an addition of a lubricant. From the energetic viewpoint, energy for friction was decreasing, while the energy accumulated by the tablet during compaction and the elastic component of energy were increased.     

Evaluation of critical binder properties affecting the compactibility of binary mixtures

The aim of this study was to identify essential physical and mechanical properties of various binders and to investigate their influence on the tensile strength and porosity of tablets made from binary mixtures with sodium bicarbonate. The binders were characterized according to axial and radial tensile strength after compression into tablets, yield pressure and minimum porosity during compression, and elastic recovery after compression. The addition of a binder generally resulted in an increase in the tensile strength and a decrease in the porosity of the sodium bicarbonate tablets. The location of the binder in the voids between the sodium bicarbonate particles thus decreasing the porosity of the tablet seemed to be an important consideration. Consequently, the addition of binders with a low yield pressure value and a relatively small elastic recovery value (e.g., polyethylene glycol 3000 and polyvinylpyrrolidone) resulted in tablets of low porosity and high tensile strength, especially in the axial direction. The tensile strength of the pure binder also seemed to be important, especially for binders with a lower degree of deformability (e.g., microcrystalline cellulose and pregelatinised starch). The results also indicated the value of using both axial and radial tensile strength measurements in assessing the effect of a dry binder and showed that the importance of different binder properties varied according to the direction of the tablet strength measurements. The results demonstrated that the applied characteristics of the binders used in this study may serve as a useful tool in evaluating the effectiveness of binders.     

Mechanical properties of cellular solids produced from hollow stainless steel spheres

Mechanical properties of cellular hollow sphere structures are studied in this work. The material was fabricated by coating the metallic powder slurry on expanded polystyrol (EPS) spheres, drying, forming under compression, debinding, and final sintering of the spheres to each other. Longitudinal elastic wave velocities were measured using ultrasound phase spectroscopy while compression tests were carried out up to a homologous temperature of 0.6. Dependence of the relative Young’s modulus on the relative density is similar to conventional open-cell foams. Compression stress–strain plots show the three stages of elastic deformation, plateau, and densification. With increasing temperature the overall level of the compressive stress–strain plots shifts to lower stresses. The hollow sphere solids show slightly better high temperature strength in comparison to the base metal. However, due to the considerable scatter in the experimental data points, this improvement seems to be insignificant. Structural observations on samples deformed to within the plateau region clearly show the heterogeneous progress of deformation.     

高温处理后闭孔泡沫铝压缩性能及变形机理

目的 探究温度和孔隙率对闭孔泡沫铝材料压缩力学性能和变形机理的影响。方法 将孔隙率为84.3%～87.3%的泡沫铝试件在温度25～700 ℃内进行加热处理,对处理后的试样开展准静态压缩实验。结果 在准静态压缩条件下,闭孔泡沫铝材料在不同温度加热处理后的压缩应力–应变曲线均经历了3个阶段:弹性阶段、塑性平台阶段和密实阶段。孔隙率从87.3%减小到84.3%时,其弹性模量增大了44.4 MPa,屈服强度增大了0.39 MPa,平台应力增大了0.94 MPa。孔隙率为84.3%的泡沫铝,在25 ℃时,其弹性模量为141.4 MPa、屈服强度为4.25 MPa、平台应力为4.75 MPa;当加热温度为500 ℃时,弹性模量减小到了128.0 MPa、屈服强度减小到了4.22 MPa、平台应力减小到了4.51 MPa。结论 泡沫铝的弹性模量、抗压屈服强度和平台应力均随孔隙率的增加而减小;加热温度低于500 ℃以下时,泡沫铝材料力学性能变化很小,但屈服强度和弹性模量均小幅度降低;在压缩载荷下,泡沫铝的变形破坏模式呈现出先从试件铝基体较薄弱部分产生孔壁塑性变形、孔洞坍塌,并逐渐出现断裂压缩带,直至泡沫铝孔洞完全坍塌密实。     

Evaluation of Critical Binder Properties Affecting the Compactibility of Binary Mixtures

The aim of this study was to identify essential physical and mechanical properties of various binders and to investigate their influence on the tensile strength and porosity of tablets made from binary mixtures with sodium bicarbonate. The binders were characterized according to axial and radial tensile strength after compression into tablets, yield pressure and minimum porosity during compression, and elastic recovery after compression. The addition of a binder generally resulted in an increase in the tensile strength and a decrease in the porosity of the sodium bicarbonate tablets. The location of the binder in the voids between the sodium bicarbonate particles thus decreasing the porosity of the tablet seemed to be an important consideration. Consequently, the addition of binders with a low yield pressure value and a relatively small elastic recovery value (e.g., polyethylene glycol 3000 and polyvinylpyrrolidone) resulted in tablets of low porosity and high tensile strength, especially in the axial direction. The tensile strength of the pure binder also seemed to be important, especially for binders with a lower degree of deformability (e.g., microcrystalline cellulose and pregelatinised starch). The results also indicated the value of using both axial and radial tensile strength measurements in assessing the effect of a dry binder and showed that the importance of different binder properties varied according to the direction of the tablet strength measurements. The results demonstrated that the applied characteristics of the binders used in this study may serve as a useful tool in evaluating the effectiveness of binders.