The use of natural product-papaya pulp powder as a disintegrant in tablet formulation and their invitro evaluation

Objective:An attempt was made to study the use of papaya pulp powder as a disintegrant in tablet formulations. The objective of the present work is to identify a natural binding and disintegrating agent for formulating tablets and to study the effect of disintegrating agents and binding agents on the dissolution of the formulation containing paracetamol.Methods:Papaya pulp powder is obtained from unripe papaya fruit.The fruit was screened for its physical and chemical characteristics and used in tablet formulations.In order to find out the percentage that could be used to formulate a product containing good disintegrating and dissolution characteristics, several formulations(Paracetamol) with different concentrations of 8%,10%,12%,15%,20%,25%& 30%were prepared.As a comparison,an already established disintegrant,sodium starchgylcolate was selected and several formulations containing similar concentrations,were also prepared.The invitro evaluation of the formulations were undertaken,and the results compared.In the present study preformulation studies on the purity, development of calibration curve of the drug and the compatibility between the drug and excepients were carried out.The fruits were cut into small pieces,grated,dried and powdered,passed through different sieves and made into fine powder.Fine powder of papaya was mixed with required amount of drug and sodium starchgylcolate individually in different concentrations along with other additives & binding agents.The dried granules were compressed into tablets and all the formulated dosage forms of paracetamol tablets were subjected to quality control tests like hardness disintegration and dissolution.Results:From the results it was observed that formulations S1 and P7 containing 8%of sodium starchgylcolate and 30%of papaya pulp powder showed good disintegration and dissolution characteristics.Conclusion:Since the tablet formulation P7 containing 30%of papaya pulp powder shows good disintegration and dissolution characteristics and also falls with in the limits of other tablet evaluation parameter,it justifies the possible use of papaya pulp powder as a disintegrant in tablet formulation.The percentage of papaya pulp powder to be used could depend on the nature of the formulation and other excepients used along with it.

Microwave Assisted Synthesis and Evaluation of Cross-Linked Carboxymethylated Sago Starch as Superdisintegrant

The aim of this study was to modify the sago starch and evaluate its efficacy as tablet disintegrant. Cross-linked car-boxymethylated sago starch (CMSS) was synthesized using native sago starch (SS) and monochloroacetic acid (MCA) with sodium hydroxide in microwave radiation environment. FT-IR analysis of the sample confirmed the carboxy-methylation by showing absorption peak at 1607.2 cm-1. CMSS with degree of substitution (DS) of 0.31 was formed and, it was further evaluated as disintegrant in Ondasetron based tablets. The results revealed that CMSS could be used as disintegrant in tablet formulation in concentration dependant manner.

Acetylation of Starch Extracted from Rejected Fruits of <i>Musa ×paradisiaca L.</i>to Obtain a Pharmaceutical Disintegrant

There are many natural sources to obtain pharmaceutical grade starch, one of which is banana (Musa × paradisiaca L.);nevertheless, the use of native starch has certain disadvantages compared to modified starches, whose disintegrating properties are better. In this study, starch extracted from rejected fruits of Musa × paradisiaca L., was modified by acetylation, under the following optimized experimental conditions: 130 mL acetic anhydride, 3 mL sodium hydroxide 50% p/v for each 15 grams of native starch, at 123℃ during 3 hours. The reaction resulted in a modified green banana starch with twice as much swelling capacity compared to unmodified (native) starch;acetylation was verified by infrared spectroscopy and degree of substitution of acetyl groups by back titration. The dissolution profiles of Ibuprofen tablets made with banana modified starch and commercial disintegrant, have no differences according with their similarity factor, f2. It is concluded that it is feasible to use green banana starch modified through acetylation as a pharmaceutical disintegrant.

Influencer identification of dynamical networks based on an information entropy dimension reduction method

Identifying critical nodes or sets in large-scale networks is a fundamental scientific problem and one of the key research directions in the fields of data mining and network science when implementing network attacks, defense, repair and control.Traditional methods usually begin from the centrality, node location or the impact on the largest connected component after node destruction, mainly based on the network structure.However, these algorithms do not consider network state changes.We applied a model that combines a random connectivity matrix and minimal low-dimensional structures to represent network connectivity.By using mean field theory and information entropy to calculate node activity,we calculated the overlap between the random parts and fixed low-dimensional parts to quantify the influence of node impact on network state changes and ranked them by importance.We applied this algorithm and the proposed importance algorithm to the overall analysis and stratified analysis of the C.elegans neural network.We observed a change in the critical entropy of the network state and by utilizing the proposed method we can calculate the nodes that indirectly affect muscle cells through neural layers.

Impact of wetting-drying cycles and acidic conditions on the soil aggregate stability of yellow‒brown soil

Soil aggregate is the basic structural unit of soil,which is the foundation for supporting ecosystem functions,while its composition and stability is significantly affected by the external environment.This study was conducted to explore the effect of external environment(wetting-drying cycles and acidic conditions)on the soil aggregate distribution and stability and identify the key soil physicochemical factors that affect the soil aggregate stability.The yellow‒brown soil from the Three Gorges Reservoir area(TGRA)was used,and 8 wetting-drying conditions(0,1,2,3,4,5,10 and 15 cycles)were simulated under 4 acidic conditions(pH=3,4,5 and 7).The particle size distribution and soil aggregate stability were determined by wet sieving method,the contribution of environmental factors(acid condition,wetting-drying cycle and their combined action)to the soil aggregate stability was clarified and the key soil physicochemical factors that affect the soil aggregate stability under wetting-drying cycles and acidic conditions were determined by using the Pearson’s correlation analysis,Partial least squares path modeling(PLS‒PM)and multiple linear regression analysis.The results indicate that wetting-drying cycles and acidic conditions have significant effects on the stability of soil aggregates,the soil aggregate stability gradually decreases with increasing number of wetting-drying cycles and it obviously decreases with the increase of acidity.Moreover,the combination of wetting-drying cycles and acidic conditions aggravate the reduction in the soil aggregate stability.The wetting-drying cycles,acidic conditions and their combined effect imposes significant impact on the soil aggregate stability,and the wetting-drying cycles exert the greatest influence.The soil aggregate stability is significantly correlated with the pH,Ca^(2+),Mg^(2+),maximum disintegration index(MDI)and soil bulk density(SBD).The PLS‒PM and multiple linear regression analysis further reveal that the soil aggregate stability is primarily influenced by SBD,Ca^(2+),and MDI.These results offer a scientific basis for understanding the soil aggregate breakdown mechanism and are helpful for clarifying the coupled effect of wetting-drying cycles and acid rain on terrestrial ecosystems in the TGRA.

Classification and rating of disintegrated dolomite strata for slope stability analysis

Although disintegrated dolomite,widely distributed across the globe,has conventionally been a focus of research in underground engineering,the issue of slope stability issues in disintegrated dolomite strata is gaining increasing prominence.This is primarily due to their unique properties,including low strength and loose structure.Current methods for evaluating slope stability,such as basic quality(BQ)and slope stability probability classification(SSPC),do not adequately account for the poor integrity and structural fragmentation characteristic of disintegrated dolomite.To address this challenge,an analysis of the applicability of the limit equilibrium method(LEM),BQ,and SSPC methods was conducted on eight disintegrated dolomite slopes located in Baoshan,Southwest China.However,conflicting results were obtained.Therefore,this paper introduces a novel method,SMRDDS,to provide rapid and accurate assessment of disintegrated dolomite slope stability.This method incorporates parameters such as disintegrated grade,joint state,groundwater conditions,and excavation methods.The findings reveal that six slopes exhibit stability,while two are considered partially unstable.Notably,the proposed method demonstrates a closer match with the actual conditions and is more time-efficient compared with the BQ and SSPC methods.However,due to the limited research on disintegrated dolomite slopes,the results of the SMRDDS method tend to be conservative as a safety precaution.In conclusion,the SMRDDS method can quickly evaluate the current situation of disintegrated dolomite slopes in the field.This contributes significantly to disaster risk reduction for disintegrated dolomite slopes.

Mechanism of disintegrant action of polacrilin potassium: Swelling or wicking?

The effect of particle size,pH of medium,and presence of lubricant on the swelling behaviour,water uptake properties and disintegrant performance of polacrilin potassium was examined.Particle size did not affect the bulk swelling of disintegrant particles when measured as settling volume,but increased the water uptake and decreased the disintegration time of tablets containing this disintegrant.An increase in the pH of the medium from acidic to neutral increased the bulk swelling of the particles,whereas it decreased water uptake and disintegrant performance.Addition of lubricant had no effect on settling volume,but decreased the water uptake rate and the disintegrant performance significantly.It is concluded that wicking,i.e.capillary action,rather than swelling,is the major factor that contributes to the disintegration behaviour of polacrilin potassium.

Complex systems and network science:a survey

Complex systems widely exist in nature and human society.There are complex interactions between system elements in a complex system,and systems show complex features at the macro level,such as emergence,self-organization,uncertainty,and dynamics.These complex features make it difficult to understand the internal operation mechanism of complex systems.Networked modeling of complex systems is a favorable means of understanding complex systems.It not only represents complex interactions but also reflects essential attributes of complex systems.This paper summarizes the research progress of complex systems modeling and analysis from the perspective of network science,including networked modeling,vital node analysis,network invulnerability analysis,network disintegration analysis,resilience analysis,complex network link prediction,and the attacker-defender game in complex networks.In addition,this paper presents some points of view on the trend and focus of future research on network analysis of complex systems.

SNCDM: Spinal Tumor Detection from MRI Images Using Optimized Super-Pixel Segmentation

Conferring to the American Association of Neurological Surgeons(AANS)survey,85%to 99%of people are affected by spinal cord tumors.The symptoms are varied depending on the tumor’s location and size.Up-to-the-min-ute,back pain is one of the essential symptoms,but it does not have a specific symptom to recognize at the earlier stage.Numerous significant research studies have been conducted to improve spine tumor recognition accuracy.Nevertheless,the traditional systems are consuming high time to extract the specific region and features.Improper identification of the tumor region affects the predictive tumor rate and causes the maximum error-classification problem.Consequently,in this work,Super-pixel analytics Numerical Characteristics Disintegration Model(SNCDM)is used to segment the tumor affected region.Estimating the super-pix-els of the affected region by this method reduces the variance between the iden-tified pixels.Further,the super-pixels are selected according to the optimized convolution network that effectively extracts the vertebral super-pixels features.Derived super-pixels improve the network learning and training process,which minimizes the maximum error classification problem also the efficiency of the system was evaluated using experimental results and analysis.

Mechanical stirring for highly efficient gas injection refining

In gas injection refining processes,wide dispersion of small bubbles in the bath is indispensable for high refining efficiency.Eccentric mechanical stirring with unidirectional impeller rotation was tested using a water model for pursuing better bubble disintegration and dispersion.Effects of various factors on bubble disintegration and dispersion were investigated.These factors were stirring mode,eccentricity and rotation speed,nozzle structure,nozzle immersion depth,and gas flow rate.Gas injection from a nozzle at the end of the impeller shaft and from an immersed lance was studied.Under eccentric stirring,a vortex was formed away from the shaft.Small bubbles were produced in the strong turbulence or high shear stress field near the rotating impeller and moved in the direction to the vortex keeping up with the macroscopic flow induced by the mechanical stirring.Thus small bubbles could disperse widely in the bath under eccentric stirring with unidirectional rotation.

High Resolution Determination of Ondansetron in Human Plasma by HPLC and Pharmacokinetics of Orally Disintegrating Tablets

Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved liquid-liquid extraction, separation on a CN column and ultraviolet detection at 310 ran with granisetron as an internal standard. Pharmacokinetics and bioequivalence of ondansetron in orally disintegrating tablets by direct compression and conventional 8 mg tablets were evaluated and compared in 20 healthy human male volunteers after a single oral dose in a randomized cross-over study. Results The limit of quantification was 0.25 ng· mL^-1. The recovery was about 85 % or over for ondan setron and about 90% for internal standard. Linearity was good within the concentration range of 0.5 - 50 ng·mL^-1 with r^2 ranging from 0.997 1 to 0.999 9. Intra- and inter-assay coefficients of variation ranged from 1.78% to 2.38% and 3.88% -5.19%, respectively. Accuracies for spiked concentrations of 2.0, 10.0, and 30.0 ng·mL^-1 were 104.7% ±4.4%, 102.2% ± 1.1%, and99.51% ±2.34%, respectively. Pharmacokinetic parameters of AUCo-t, AUCo-∞ , Cmax, Tmax, and T1/2 were 230.2 ± 78.0 ng·h·L^-1 , 265.2± 101.5 ng·h·mL^-1, 35.67 ± 8.94 ng·mL^-l, 1.51 ±0.79 h, and 5.00± 1.41 h for orally disintegrating tablets, respectively. The analysis of variance did not show any significant difference between orally disintegrating tablets and conventional tablets, and 90% confidence intervals fell within the acceptable range for bioequivalence. Conclusion High resolution HPLC method has been set up and applied in pharmacokinetic evaluation of ondansetron in orally disintegrating tablets.

银黄酮片的处方优化

目的 :筛选银黄酮片的最佳处方。方法 :考察糊精、羧甲基淀粉钠、微晶纤维素和低取代羟丙基纤维素对银黄酮片的质量影响。结果 :筛选的最佳处方为5 %低取代羟丙基纤维素。按照最佳处方制备的银黄酮片崩解度大为提高。结论 :本法处方合理 ,工艺简单 ,所制备的银黄酮片适合临床应用。

Formulation Study for Rotundine Rapidly Disintegrating Tablet

Aim The aim of the present study was to prepare tablets which can rapidlydisintegrate in saliva, containing active ingredient in high dose (37.5% W/W). Methods Rapidlydisintegrating tablets containing rotundine were prepared by direct compression, wet granulation andmoulding, respectively . Different disintegrants and excipients were decided by single factor test.The typical disintegration time measurement and a new method of wetting time measuring wereintroduced for assessing rapidly disintegrating tablets. Results The tablets (80 mg) prepared bydirect compression have the crushing strength of 4.0 kg ?mm^(-2) and rapidly disintegratewithin 15 s in the saliva of healthy volunteers; the tablets prepared by wet granulation also havesufficient strength, a little longer but acceptable disintegration time (within 25 s in saliva) ;and the tablets obtained by moulding show disintegration within 40 s in saliva but low strength (2kg·mm^(-2)) . Disintegration time profiles of tablets are similar to those of wetting time, and thedisintegration and wetting times in vitro are similar to the disintegration time in vivo, thelatter having higher correlation with that in oral cavity. Conclusion The rapidly disintegratingtablets can be prepared by using these three techniques and excipients. Both in vitro disintegrationtime and wetting time are necessary indexes for judgment of in vitro disintegration profile.

ZONAL DISINTEGRATION MECHANISM OF DEEP CRACK-WEAKENED ROCK MASSES UNDER DYNAMIC UNLOADING

Size and quantity of fractured zone and non-fractured zone are controlled by cracks contained in deep rock masses. Zonal disintegration mechanism is strongly dependent on the interaction among cracks. The strong interaction among cracks is investigated using stress superposition principle and the Chebyshev polynomials expansion of the pseudo-traction. It is found from numerical results that crack nucleation, growth and coalescence lead to failure of deep crack- weakened rock masses. The stress redistribution around the surrounding rock mass induced by unloading excavation is studied. The effect of the excavation time on nucleation, growth, interaction and coalescence of cracks was analyzed. Moreover, the influence of the excavation time on the size and quantity of fractured zone and non-fractured zone was given. When the excavation time is short, zonal disintegration phenomenon may occur in deep rock masses. It is shown from numerical results that the size and quantity of fractured zone increase with decreasing excavation time, and the size and quantity of fractured zone increase with the increasing value of in-situ geostress.

Influences of different modifiers on the disintegration of improved granite residual soil under wet and dry cycles

The disintegration of granite residual soil is especially affected by variations in physical and chemical properties. Serious geologic hazards or engineering problems are closely related to the disintegration of granite residual soil in certain areas. Research on the mechanical properties and controlling mechanisms of disintegration has become a hot issue in practical engineering. In this paper, the disintegration characteristics of improved granite residual soil are studied by using a wet and dry cycle disintegration instrument, and the improvement mechanism is analyzed. The results show that the disintegration amounts and disintegration ratios of soil samples treated with different curing agents are obviously different. The disintegration process of improved granite residual soil can be roughly divided into 5 stages:the forcible water intrusion stage, microcrack and fissure development stage, curing and strengthening stage, stable stage, and sudden disintegration stage. The disintegration of granite residual soil is caused by the weakening of the cementation between soil particles under the action of water. When the disintegration force is greater than the anti-disintegration force of soil, the soil will disintegrate. Cement and lime mainly rely on ion exchange agglomeration, the inclusion effect of curing agents on soil particles, the hard coagulation reaction and carbonation to strengthen granite residual soil. Kaolinite mainly depends on the reversibility of its own cementation to improve and strengthen granite residual soil. The reversibility of kaolinite cementation is verified by investigating pure kaolinite with a tensile, soaking, drying and tensile test cycle. Research on the disintegration characteristics and disintegration mechanism of improved granite residual soil is of certain reference value for soil modification.

Zonal disintegration phenomenon in enclosing rock mass surrounding deep tunnels—mechanism and discussion of characteristic parameters

The mechanism of the zonal disintegration phenomenon(ZDP) was realized based on the analysis of the stressedstrained state of the rock mass in the vicinity of the maximum stress zone, which resides in the creep instability failure of rock mass due to the development of a plastic zone and transfer of the maximum stress zone within the rock mass.Some characteristic parameters of the ZDP are discussed theoretically.In first instance, the analytical critical depth condition for the occurrence of ZDP was obtained, which depends on the characteristics and stress concentration coefficient of the rock mass.Secondly, based on creep theory, the expression of the outer radius of the undisturbed zones in the deep rock mass was obtained with the use of an improved Burgers rheological model, which indicated that the radius depends on the characteristics of the rock mass and the depth of excavation and increases quasi-linearly with the rise of creep compliance of the rock mass.Finally, the formula for the distance of the most remote fissured zone away from the working periphery was derived, which increases logarithmically with the increase in the ratio of the in-situ stress and ultimate strength of rock mass.The distances between fissured zones are discussed in qualitative terms.

Quantitative analysis of rockburst for surrounding rocks and zonal disintegration mechanism in deep tunnels

Rock masses without pre-existing macrocracks can usually be considered as granular materials with only microcracks.During the excavation of the tunnels,microcracks may nucleate,grow and propagate through the rock matrix;secondary microcracks may appear,and discontinuous and incompatible deformation of rock masses may occur.The classical continuum elastoplastic theory is not suitable for analyzing discontinuous and incompatible deformation of rock masses.Based on non-Euclidean model of the discontinuous and incompatible deformation of rock masses,the distribution of stresses in the surrounding rock masses in deep tunnels is fluctuant or wave-like.The stress concentration at the tips of microcracks located in vicinity of stress wave crest is comparatively large,which may lead to the unstable growth and coalescence of secondary microcracks,and consequently the occurrence of fractured zones.On the other hand,the stress concentration at the tips of microcracks located around stress wave trough is relatively small,which may lead to the arrest of microcracks,and thus the non-fractured zones.The alternate appearance of stress wave crest and trough thus may induce the alternate occurrence of fractured and non-fractured zones in deep rock masses.For brittle rocks,the dissipated energy of microcrack growth is small,but the elastic strain energy stored in rock masses may be larger than the dissipated energy growths of pre-existing microcracks and secondary microcracks.The sudden release of the residual elastic strain energy may lead to rockburst.Based on this understanding,the criteria of rockburst are established.Furthermore,the relationship between rockbursts and zonal disintegration in the surrounding rock masses around deep tunnels is studied.The influences of the in-situ stresses and the physico-mechanical parameters on the distribution of rockburst zones and the ejection velocity of rock fragments are investigated in detail.

Application of thermally stimulated acoustic emission method to assess the thermal resistance and related properties of coals

Traditional methods of coal thermal resistance characterization are informative but considerably timeconsuming and require utilization of a complex and expensive equipment. This limits the effectiveness of their application. In this paper, authors experimentally investigated potential application of thermally stimulated acoustic emission method for developing of relatively simple and rapid coals thermal resistance assessment method. Features of thermally stimulated acoustic emission of anthracite, lignites and bituminous coal samples subject to cyclic thermal loading have been experimentally investigated.For the first time, it has been shown that there exists a relationship of such patterns with structural parameters and properties of the coal samples, as well as their thermal resistance. The results indicate the possibility of applying the method of thermally stimulated acoustic emission to control processes of cryogenic disintegration and thermal resistance of fossil coals. The description of the equipment and methodological support needed for the implementation of this method have been provided.

Zonal disintegration phenomenon in enclosing rock mass surrounding deep tunnels——Elasto-plastic analysis of stress field of enclosing rock mass

The zonal disintegration phenomenon （ZDP） is a typical phenomenon in deep block rock masses. In order to investigate the mechanism of ZDP, an improved non-linear Hock-Brown strength criterion and a bi-linear constitutive model of rock mass were used to analyze the elasto-plastic stress field of the enclosing rock mass around a deep round tunnel. The radius of the plastic region and stress of the enclosing rock mass were obtained by introducing dimensionless parameters of radial distance. The results show that tunneling in deep rock mass causes a maximum stress zone to appear in the vicinity of the boundary of the elastic and the plastic zone in the surrounding rock mass. Under the compression of a large tangential force and a small radial force, the rock mass in the maximum stress zone was in an approximate uniaxial loading state, which could lead to a split failure in the rock mass.

Micro-Mechanism of Disintegration of RE-Silicide Alloy Containing Phosphorus

The microstructure of the RE silicide alloy was studied by SEM. The feature of the phase and the distribution of Ca, P, Al were analyzed, especially the distribution of micro-cracks and its composition were determined. The result demonstrates that only a few phosphides contribute to the spontaneous crumbling of the RE silicide alloy by reacting with water and forming oxide or phosphorus oxide. The phosphorus content is not the critical factor of disintegration in the alloy studied.