In Vitro Evaluation of Native Taro Boloso-I Starch as a Disintegrant in Tablet Formulations

Introduction. In drug delivery, solid dosage forms, of which tablet is the commonest, are still the leading preferences. An area of research focus in tablet drug delivery is the search for tablet excipients. This study was aimed at evaluating and optimizing native Taro Boloso-I starch as a tablet disintegrant. Methods. The response surface method with central composite design (CCD-RSM) was used for the analysis and optimization of the concentration of native Taro Boloso-I starch and compression force. Wet granulation method was used for the preparation of paracetamol tablets. The response variables considered were tablet crushing strength, friability, and disintegration time. Results and Discussion. Both the native Taro Boloso-I starch concentration and compression force had increasing effect on the tablet breaking force. The friability of the tablets was shown to decrease with increasing levels of the disintegrant concentration. On the other hand, compression force had a decreasing effect on friability in the investigated range. The disintegration time of the tablets was found to decrease with the concentration of the starch. The paracetamol tablets prepared with the optimized levels of native Taro Boloso-I starch and compression force showed tablet breaking force of 116.24 N, friability of 0.153%, disintegration time of 1.36 min, disintegration efficiency ratio of 562.3 N/(%Min), and comparative disintegration efficiency ratio of 13.6 with respect to commercial potato starch. Conclusions. The tablets exhibited improved crushing strength, friability, in vitro disintegration time, and disintegration efficiency ratio which suggest the novel applicability of the native Taro Boloso-I starch as an efficient pharmaceutical tablet disintegrant.

Development of a Calcium Aluminate Cement from steelmaking slag by altering its mineralogical compositions

Strict environmental norms and raising concern to recycle solid wastes generated during ironmaking and steelmaking processes has been the key driving force in developing various technologies. The present study describes a calcium-aluminate clinker prepared from steel ladle slag by modifying its mineral compositions. The slag paste prepared by mixing with water exhibited flash setting behaviour due to the presence of C12A7 and C3A phases. In contrast, the slag clinker, developed by sintering a mixture of pre-determined quantity of slag and Al2O3 at 1400°C for 2h and 4h, contained CA, CA2, Gehlenite and ‘Q’ phases. Hydration of slag clinker contained stable C3AH6, AH3 and stratlingite with preferential growth of calcium-aluminate hydrate prisms along c-axis that provided a well-defined raceme like morphology with interlinked structure. It improved the setting time and crushing strength of the clinkers after 6h and 24h curing at room temperature. Additionally, presence of ‘Q’ phase with lamellar prismatic crystals also helped in enhancing the strength. The developed clinker also exhibited superior crushing strength as compared to commercially available calcium aluminate cement of medium purity. The slag, used as a source of CaO could replace CaCO3 completely and thus contributed to reduction in CO2 emission during clinker making process.

Prediction of quality attributes (mechanical strength, disintegration behavior and drug release) of tablets on the basis of characteristics of granules prepared by high shear wet granulation

High shear wet granulation is commonly applied technique for commercial manufacturing of tablets. Granulation process for tablets manufacturing is generally optimized by hit and trial which involves preparation of granules under different processing parameters, compression of granules and evaluation of the resultant tablets; and adjustment is made in granulation process on the basis of characteristics of tablets. Objective of the study was to optimize the process of high shear wet granulation and prediction of characteristics of tablets on the basis of properties of granules. Atenolol granules were prepared by high shear wet granulation method, using aqueous solution of polyvinyl pyrrolidone (PVP k-30) as binder. Concentration of binder solution and granulation time were taken as process variables, both studied at three levels. Different combinations of process variables were determined by Design Expert software. Granules were evaluated for different parameters on the basis of SeDeM-ODT (Sediment Delivery Model-Oro Dispersible Tablets) expert system. Granules from all the trials were compressed using round (10.5 mm) flat faced punches at compression weight of 250 mg/tablet. Tablets were evaluated of different quality control parameters as per USP. Results showed that both the process variables had positive effect on mechanical strength of tablets and negative effect on disintegration and dissolution rate. Granule prepared with highest level of binder concentration (15%) and highest granulation time (60 sec) resulted in tablets with highest crushing strength (11.8 kg), specific crushing strength (0.328 kg/mm2), tensile strength (0.208 kg/mm2), lowest value of friability (0.19%) and highest disintegration time (10.9 min), as predicted from granules characteristics on the basis of SeDeM-ODT expert system. Drug release from Trial-13 (processed under highest level of both process parameters) was also lower than rest of the trials. It is concluded from the study that quality characteristics of tablets can be predicted from granules characteristics using SeDeM-ODT expert system. Furthermore, SeDeM-ODT expert system can also be used for optimization of the process of high shear wet granulation.

A crack theory-based bonded particle model for rock particles considering size effect on crushing strength

Particle breakage shows significant effect on the macroscopic behavior of rock materials, and the discrete element method is a powerful tool to investigate the relationship between micro fracture and macro deformation and strength. In this study, the concept of crack is introduced into the bonded particle model (BPM) to simulate the breakage behaviour of rockfill materials, with randomly placed weak bonds representing cracks. Different from traditional BPM, the number, position and strength of the weak bonds are directly related to the number, position and length of cracks. With a reasonable length distribution of cracks, the proposed model can successfully reflect both the crushing strength variation and size effects. A set of crack parameters including the crack density, minimum crack length, maximum crack length and fractal dimension, are suggested. The crushing characteristics of realistic rockfill particles with two typical shapes are simulated quantitatively and verified with test data. It is found that the proposed model with suggested crack parameters can give reasonable prediction on the Weibull's modulus and size effect of rockfill particles.

Utilization of Pectin from Okra as Binding Agent in Immediate Release Tablets

Polymeric materials from plants continue to be of interest to pharmaceutical scientists as potential binders in immediate release tablets due to availability, sustainability, and constant supply to feed local pharmaceutical industries. Paracetamol tablet formulations were utilized in investigating the potential binding characteristics of pectin harnessed from various okra genotypes (PC1-PC5) in Ghana. The pectin yields from the different genotypes ranged from 6.12 to 18.84%w/w. The pH of extracted pectin ranged from 6.39 to 6.92, and it had good swelling indices and a low moisture content. Pectin extracted from all genotypes were evaluated as binders (10, 15, and 20%w/v) and compared to tragacanth BP. All formulated tablets (F1-F18) passed the weight uniformity, drug content, hardness, and friability tests. Based on their crushing strength, tablets prepared with pectin from the various genotypes were relatively harder ( P ≤ 0.05 ) than tablets prepared with tragacanth BP. Tablets prepared with pectins as binders at 10%w/v and 15%w/v passed the disintegration and dissolution tests with the exception of PC4 at 15%w/v. Incorporation of pectin from all genotypes (excluding PC5) as a binder at concentrations above 15%w/v (F13, F16, F14, and F15) produced tablets which failed the disintegration test and showed poor dissolution profiles. Thus, pectin from these genotypes can be industrially commodified as binders in immediate release tablets using varying concentrations.

Fabrication of Ni-NiO Foams by Powder Metallurgy Technique and Study of Bulk Crushing Strength

Despite the importance of Nickel Oxide (NiO) in diverse functional applications, very little information is available on the mechanical properties of bulk or porous NiO or, mostly unnoticed. In this study, porous Ni-NiO foam was synthesized using space holding-powder metallurgy and sintering methods to produce opened-cell structure with macrogravel and Neolamarckia cadamba (Cadamba flower) like surface morphology. Four different types of porous Ni-NiO with different pore diameter of 35.65 ± 12.77, 36.10 ± 8.85, 68.20 ±7.36 and 62.45 ± 17.48 µm were fabricated for evaluating the effect of porosity on the mechanical properties of bulk porous Ni-NiO foam. The mechanical properties such as bulk crushing force of as synthesized Ni-NiO foam with various porosities such as 20.55, 27.35, 27.85 and 28.82 % exhibited the average crushing load of 115.40, 39.95, 138.10 and 151.20 N, respectively. This study suggests that crushing load of Ni-NiO foam is not only depending on the porosity but also on the sintering temperature and crystallite sizes of NiO. HIGHLIGHTS Ni-NiO foam is synthesized using space holding-powder metallurgy and sintering methods Different pore diameter is fabricated for evaluating the effect of porosity on the mechanical properties of bulk porous Ni-NiO foam Crushing strength of Ni-NiO foam is not only depending on the porosity but also on the sintering temperature and crystallite sizes of NiO GRAPHICAL ABSTRACT

Evaluation of the Disintegrant Properties of Silicified Oryza sativa Starch Co-Processed with Dioscorea dumentorum Starch in Directly Compressed Paracetamol Tablet Formulations

Starch is a readily available excipient which finds application in the pharmaceutical industry as binders, diluents and disintegrants. The use of starch is however limited by its poor flow characteristics. Co-processing exploits the desirable attributes of excipients, while masking the undesirable properties. Co-processed starch, thus presents great potential for use in formulation of directly compressed tablets which require materials with strong inherent cohesive and free flowing properties. In this study, Dioscorea dumentorum (Family: Dioscoreaceae) Starch (DdS) is co-processed with silicified rice starch (SRS) obtained from Oryza sativa; Family: Poaceae was incorporated as a disintegrant in directly compressed paracetamol tablet formulations in comparison with silicified rice starch and Avicel® as the official standard. Rice and DdS were extracted following standard procedures. The rice starch was silicified using colloidal silicon dioxide and co-processed with DdS in the ratio SRS:DdS (1:2). The DdS, SRS and SRS:DdS (1:2) were characterized using FTIR, particle size, angle of repose, bulk and tapped densities, Hausner ratio and Carr’s index. Paracetamol powder was directly compressed into tablets incorporating the co-processed excipient (SRS:DdS; 1:2) as disintegrants alongside Avicel®, SRS and DdS at varying concentrations (10% w/w, 15% w/w, 20% w/w, 25% w/w). The properties of the tablets were evaluated using friability, crushing strength and disintegration as the assessment parameters. Measurements were made in triplicates and the results were statistically analyzed. The yield of the starches was 41% w/w and 39% w/w for rice starch and DdS respectively. Silicifying the rice starch markedly improved the flow of the starch with a change of Carr’s index and Hausner ratio from 16.7 and 1.32 to 2.33 and 1.02 respectively. Tablets containing Avicel® had better crushing strength and friability values than those containing SRS: 2DdS at all disintegrant concentrations. The disintegration times for Avicel® and SRS: DdS compared favourably at all concentrations of disintegrant and at 15% w/w disintegrant, SRS: DdS showed better disintegrant properties than Avicel®.

Experiment on Size Effect and Fractal Characteristics of Waste Brick and Concrete Recycled Aggregate

Herein, the size effect of single-particle crushing of recycled brick and concrete recycled macadam under static load and the fractal characteristics of aggregate under impact load are investigated. The mechanical change law of recycled macadam after compaction crushing under static load is analyzed through single-particle load crushing and impact crushing tests with different particle groups. Furthermore, the fractal dimension D is introduced to study the effects of impact energy, particle size, and different materials on the fractal characteristics of the recycled macadam. Consequently, the material, shape, and particle size of a single-particle significantly affect the crushing strength under static loading, and there is an apparent size effect on the crushing strength. Moreover, the proportion of unbroken particles in the overall mass sieve increased with decreasing particle group order under impact loading. The proportion of unbroken particles in the 4.75–9.5-mm group constituted more than 60% of the total, indicating that its anticrushing ability was significant. In addition, the model relationship between fractal dimension D, nonuniformity coefficient, and curvature coefficient is established. When 1.887 ≤ D ≤ 2.631, the gradation of recycled macadam is superior.