共查询到19条相似文献,搜索用时 15 毫秒
1.
Ashmitha P. Munasur Thirumala Govender Irene Mackraj 《Drug development and industrial pharmacy》2013,39(7):709-716
ABSTRACTThis study sought to identify and quantify the effects of environmental test parameters on the mucoadhesivity of a propranolol tablet. Their effects on Maximum Detachment Force (MDF) measurements were evaluated using a Box-Behnken design matrix. Prehydration time (PT) had a statistically significant negative main effect while contact force (CF) had no significant effect on in vitro MDF measurements. While contact time (CT) had no significant main or quadratic effects, it had a positive interaction effect with PT. The mathematical model was statistically validated and a PT of 3.5 min and a CT of 5 min was proposed for mucoadhesion testing by the tensile method during formulation optimization. 相似文献
2.
In this study many parameters were screened for a small-scale granulation process for their effect on the yield of granules between 75 and 500 μm and the geometrical granule mean size (d50). First a Plackett-Burman design was applied to screen the inlet air temperature, the inlet flow rate, the spray rate, the nozzle air pressure, the nozzle spray diameter, and the nozzle position. The Plackett-Burman design showed that the key process parameters were the inlet flow rate and the spray rate and probably also the inlet air temperature. Afterward a fractional factorial design (25-2) was applied to screen the remaining parameters plus the nozzle aircap position and the spraying time interval. The fractional factorial design showed that the nozzle air pressure was also important. As the target values for the granule yield (between 75 and 500 μm) and the geometric mean granule size (between 300 and 500 μm) were reached during the screening experiments, further optimization was not considered necessary. 相似文献
3.
Goutte F Guemguem F Dragan C Vergnault G Wehrlé P 《Drug development and industrial pharmacy》2002,28(7):841-848
Experimental design studies (EDS) are already widely used in the pharmaceutical industry for drug formulation or process optimization. Rare are the situations in which this methodology is applied for validation purposes. The power of this statistical tool, key element of a global validation strategy, is demonstrated for a multilayer tablet manufacturing process. Applied to the Geomatrix® system generally composed of one compression and three granulation processes, time and strictness gains are non-negligible. Experimental design studies are not used in this work for modeling. Introduced at each important step of the process development, they allow for the evaluation of process ruggedness at pilot scale and specifications for full production. A demonstration of the complete control of key process parameters is given, identified throughout preliminary studies. 相似文献
4.
Huang YT Tsai TR Cheng CJ Cham TM Lai TF Chuo WH 《Drug development and industrial pharmacy》2007,33(11):1183-1191
Pyridostigmine bromide (PB), a highly hygroscopic drug was selected as the model drug. A sustained-release (SR) tablet prepared by direct compression of wet-extruded and spheronized core pellets with HPMC excipients and exhibited a zero-order sustained release (SR) profile. The 23 full factorial design was utilized to search an optimal SR tablet formulation. This optimal formulation was followed zero-order mechanism and had specific release rate at different time intervals (released % of 1, 6, and 12 hr were 15.84, 58.56, and 93.10%). The results of moisture absorption by Karl Fischer meter showed the optimum SR tablet could improve the hygroscopic defect of the pure drug (PB). In the in vivo study, the results of the bioavailability data showed the Tmax was prolonged (from 0.65 ± 0.082 hr to 4.83 ± 1.60 hr) and AUC0-t (from 734.88 ± 230.68 ng/ml.hr to 1153.34 ± 488.08 ng/ml.hr) and was increased respectively for optimum PB-SR tablets when compared with commercial immediate release (IR) tablets. Furthermore, the percentages of in vitro dissolution and in vivo absorption in the rabbits have good correlation. We believe that PB-SR tablets designed in our study would improve defects of PB, decrease the frequency of administration and enhance the retention period of drug efficacy in vivo for personnel exposed to contamination situations in war or terrorist attacks in the future. 相似文献
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Kym Patrick Dühlmeyer Hüseyin Özcoban 《Drug development and industrial pharmacy》2013,39(8):1233-1241
Objective: The purpose of this study was to compare the influence of two different paddle wheel geometries on the distribution behavior of a model powder within the filling chamber of the modified feed frame of a rotary tablet press. Moreover, both paddle wheels were compared regarding their influence on the resulting tablet mass during the tableting process.Significance: Insights are provided regarding the influence of the paddle wheel geometry on the powder distribution to optimize the die filling process.Materials and methods: Avicel PH 102 served as model powder. A laser triangulator was used to scan the powder surface level within the feed frame and, combined with the determination of the angle position of the paddle wheel, an in-house written software was used to calculate the powder surface profiles and filling levels. Two experimental setups, one based on the filling chamber filled with a defined amount of powder (offline) and one using the filling chamber during tableting (inline) were applied.Results: Both paddle wheel geometries caused a significantly different distribution behavior of the powder within the filling chamber. The tablets obtained with the round rod filling wheel showed significantly higher tablet masses and significantly lower standard deviations. The inflow of powder into the filling chamber appeared to be improved with the round rod filling wheel.Conclusions: Under the applied experimental conditions, the round rod filling wheel showed obvious advantages compared to that with flat rods in terms of the uniformity of tablet masses and the extent of die filling. 相似文献
7.
Karen Cacua Robison Buitrago-Sierra Bernardo Herrera Farid Chejne Elizabeth Pabón 《Advanced Powder Technology》2017,28(10):2581-2588
Nanofluids have been introduced as new-generation fluids able to improve energy efficiency in heat exchangers. However, stability problems related to both agglomeration and sedimentation of nanoparticles have limited industrial-level scaling. A fractional factorial experimental 2k?1 design was applied in order to evaluate the effects of nanoparticle concentration, surfactant type and concentration, ultrasonic amplitude as well as ultrasonic time on the stability of alumina (Al2O3) nanofluids. Commercial alumina nanoparticles (particle diameter <50 nm) were dispersed in deionized water using ultrasonic probe dispersion equipment. Sodium dodecylbenzenesulfonate (SDBS) and cetyltrimethylammonium bromide (CTAB) were used as surfactants. The stability of the nanofluids in static mode was monitored by visual inspection and UV visible spectroscopy. The results of the experimental design showed that the coupled effects between surfactant type and surfactant concentration and between ultrasonication tip amplitude and ultrasonication time had the most pronounced effects on nanofluid stability. The experimental conditions providing the best stability were 0.5 wt% of Al2O3, CTAB, critical micelle surfactant concentration, 30% ultrasonic amplitude and 30 min of ultrasonication. 相似文献
8.
G. LEVESQUE N. K. ARAKERE J. J. MECHOLSKY K. GOPALAKRISHNAN 《Fatigue & Fracture of Engineering Materials & Structures》2010,33(8):490-503
Engineering applications of ceramics can often involve mixed‐mode conditions involving both tensile and shear loading. Mixed‐mode fracture toughness parameters are evaluated for applicability to ceramics using the Brazilian disc test on silicon nitride. Semi‐elliptical centrally located surface flaws are induced on the disc specimens using Vickers indentation and compression loaded to fracture with varying levels of mode mixity. The disc specimens are modelled via 3D finite element analysis and all three modes of stress intensity factors computed along the crack front, at failure load. We present a numerical and experimental investigation of four widely used mixed‐mode fracture criteria and conclude that the critical strain energy release rate criterion is simple to implement and effective for silicon nitride under mixed‐mode conditions. 相似文献
9.
This paper presents the results of an experimental investigation as to the effects of grinding parameters on roundness error and surface roughness in cylindrical grinding. Many variables including the wheel materials, wheel loading and dressing, workpiece metallurgy, work drive mechanisms, work holding methods, coolant types, feeds and speeds, machine stiffness and age, surface conditions, centre conditions, floor vibrations all influence the quality of ground parts. However, the composite sum of these grinding parameters creates static and dynamic forces. It is obvious that the roundness error and surface roughness are created by many parameters, but in this study, only the effects of the depth of cut, work speed and feed rate which create the grinding forces in cylindrical grinding are investigated. The grinding experiments were planned according to the principles of orthogonal arrays (OAs), developed by Taguchi, and were performed so as to understand the effects of these parameters on roundness error and surface roughness. The experimental data was analysed by using statistical tools: the percent contribution from an analysis of variance (ANOVA) and the correlation between machining parameters with roundness error (R) and also surface roughness (Ra). Roundness was found to be the most related with the cutting speed, grinding force and depth of cut, while surface roughness is related to feed rate and work speed. 相似文献
10.
A test method for measuring the strength of the seal on a flexible bottle is proposed. The method measures seal strength as the compression force applied to the side of the bottle required to make the seal fail. The technique has the advantage of using standard equipment and reproduced failure conditions as closely as possible. The method was used to compare the seal strengths of a foil laminate heat-seal on a retortable gamma bottle under various sealing conditions. The results for various sealing pressures, temperatures and times are reported and optimum conditions are identified. 相似文献
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This paper presents a hybrid methodology for conceptual design of large systems with the goal of enhancing system reliability.
It integrates the features of several design methodologies and maintenance planning concepts with the traditional reliability
analysis. The methodology considers the temporal quality characteristic “reliability” as the main objective and determines
the optimal system design. Key ideas from several design methodologies, namely axiomatic design, robust design, and the theory
of inventive problem solving, have been integrated with the functional prioritization framework provided by reliability-centered
maintenance. A case study of the conceptual design of a multiphase pumping station for crude oil production is presented.
The methodology provides a new design tool for determining system configurations with enhanced reliability taking into account
maintenance resources and variability. 相似文献
13.
Ling Gong Miao Yu Yanyan Sun Ying Gao Tong An Meijuan Zou 《Drug development and industrial pharmacy》2013,39(12):1990-1999
AbstractThe purpose of this research was to develop multiple-unit gastric floating mini-tablets and to evaluate the possibility of using these mini-tablets as a delivery system to improve the drug absorption for drugs with a narrow absorption window. Mini-tablets were prepared using hydroxypropyl methylcellulose (HPMC K100M) and carbopol 971P as release retarding agents and sodium bicarbonate (NaHCO3) as gas-forming agent. The properties of the prepared mini-tablets in terms of floating characteristic parameters and in vitro release were evaluated. Furthermore, in vivo gastric retention study in rats and in vivo pharmacokinetic study in rabbits of the optimized formulation were performed. The optimized mini-tablets containing 45% HPMC K100M, 15% stearyl alcohol, 13% carbopol 971P, and 12% NaHCO3 were found to float immediately within 1?min and duration more than 9?h. The in vivo gastric retention study results indicated that the mini-tablets could retain in the stomach for more than 6.67?h. Furthermore, the AUC0?t of the floating mini-tablets (6849.83?±?753.80?h ng·mL?1) was significantly higher than that of marketed sustained-release tablets XATRAL®XL (4970.16?±?924.60?h ng·mL?1). All these results illustrated that the gastric floating mini-tablets might be a promising drug delivery system for drugs with a narrow absorption window. 相似文献
14.
R. Díez L.A. Sarabia M.S. Snchez M.C. Ortiz 《Chemometrics and Intelligent Laboratory Systems》2008,92(1):71-82
This paper deals with the selection of experimental conditions and how the signals obtained in these conditions influence the fitted Partial Least Squares calibration model. The multivariate signals come from a flow analysis system with amperometric detection when determining sulfadiazine, sulfamerazine and sulfamethazine in milk.The solution (carrier plus analyte) was pumped through the system to provide a continuous supply of analyte to the cell. The detector was programmed for a scan mode operation being the multivariate signal the hydrodynamic voltammogram. To obtain an analytical signal of enough analytical quality, the Net Analyte Signal and its standard deviation have been optimised by using an experimental design. The conflicting behaviour of the two responses has been solved by estimating the Pareto-optimal front.The multivariate signals recorded in the optimal conditions found have been calibrated by Partial Least Squares regression and their figures of merit validated according to the criteria established in European Decision 2002/657/EC.In relation to the permitted limit, 100 µg l− 1 in milk, for the total content of sulfonamides established in the Commission Regulation EC no. 281/96 the proposed method has a decision limit of 109.1 µg l− 1 and the capability of detection is 117.9 µg l− 1 for both probability of false non-compliance and of false compliance equal to 5%. A recovery of 86.5% ± 2.4% (n = 5) has been obtained. 相似文献
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P. Hogstrm J.W. Ringsberg E. Johnson 《International Journal of Impact Engineering》2009,36(10-11):1194-1203
Within sheet metal forming, crashworthiness analysis in the automotive industry and ship research on collision and grounding, modelling of the material failure/fracture, including the behaviour at large plastic deformations, is critical for accurate failure predictions. In order to validate existing failure models used in finite element (FE) simulations in terms of dependence on length scale and strain state, tests recorded with the optical strain measuring system ARAMIS have been conducted. With this system, the stress–strain behaviour of uniaxial tensile tests was examined locally, and from this information true stress–strain relations were calculated on different length scales across the necking region. Forming limit tests were conducted to study the multiaxial failure behaviour of the material in terms of necking and fracture. The failure criteria that were verified against the tests were chosen among those available in the FE software Abaqus and the Bressan–Williams–Hill (BWH) criterion proposed by Alsos et al, 2008. The experimental and numerical results from the tensile tests confirmed that Barba's relation is valid for handling stress–strain dependence on the length scale used for strain evaluation after necking. Also, the evolution of damage in the FE simulations was related to the processes ultimately leading to initiation and propagation of a macroscopic crack in the final phase of the tensile tests. Furthermore, numerical simulations using the BWH criterion for prediction of instability at the necking point showed good agreement with the forming limit test results. The effect of pre-straining in the forming limit tests and the FE simulations of them is discussed. 相似文献
17.
《Drug development and industrial pharmacy》2013,39(12):1451-1459
A large-scale design space was constructed using a Bayesian estimation method with a small-scale design of experiments (DoE) and small sets of large-scale manufacturing data without enforcing a large-scale DoE. The small-scale DoE was conducted using various Froude numbers (X1) and blending times (X2) in the lubricant blending process for theophylline tablets. The response surfaces, design space, and their reliability of the compression rate of the powder mixture (Y1), tablet hardness (Y2), and dissolution rate (Y3) on a small scale were calculated using multivariate spline interpolation, a bootstrap resampling technique, and self-organizing map clustering. The constant Froude number was applied as a scale-up rule. Three experiments under an optimal condition and two experiments under other conditions were performed on a large scale. The response surfaces on the small scale were corrected to those on a large scale by Bayesian estimation using the large-scale results. Large-scale experiments under three additional sets of conditions showed that the corrected design space was more reliable than that on the small scale, even if there was some discrepancy in the pharmaceutical quality between the manufacturing scales. This approach is useful for setting up a design space in pharmaceutical development when a DoE cannot be performed at a commercial large manufacturing scale. 相似文献
18.
Vanloot P Boudenne JL Brach-Papa C Sergent M Coulomb B 《Journal of hazardous materials》2007,147(1-2):463-470
In this paper, a multivariable approach has been applied for the selective removing of Fe(III) and Al(III), in the range 0-200 microg l(-1), in water samples onto a modified organic support (salicylic acid grafted on XAD-4). An empirical mathematical model was designed which establishes the relationship between the variation of the responses (extraction yields), and the variation of three factors (sample volume, sample percolation flow rate and amount of metallic ions present in the sample). To estimate the coefficients of the developed model, an uniform shell Doehlert design has been applied; these experiments consisted in GF-AAS determination of aluminium and iron amounts in eluates after percolation of samples through modified support. Results show a similar behaviour of the resin towards aluminium and iron with a preponderant effect of the percolation flow rate value; however this one is crucial for aluminium extraction and should be maintained below to 0.55 ml min(-1) to reach a 95% Al3+ extraction yield (versus 2.25 ml min(-1) for Fe3+). The optima determined by this experimental design approach have been further applied to the selective extraction of aluminium and iron from multielement synthetic samples and from real samples at the outlet of potable water treatment units. 相似文献
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The effects of iron (Fe) and spent mushroom substrate (SMS) arsenic (As) phytotoxicity towards lettuce in artificial soils were investigated to separate the adverse soil parameters relating to As toxicity using a response surface methodology. SMS induced the root elongation of lettuce in both control and As-treated soils. However, in phytotoxicity test using a median effective concentration (EC50) of As, Fe and the interaction between both parameters (Fe*SMS) significantly affected EC50, which explained 71% and 23% of the response, respectively. The refined model was as follows: EC50 of As (mg kg−1) = 10.99 + 60.03 × Fe − 10.50 × Fe*SMS. The results confirmed that the soil parameters relating to the As mobility in soils were important factors affecting its toxicity. In conclusion, Fe significantly reduced the As phytotoxicity. However, although SMS enhanced the root elongation, SMS in As-treated soils decreased EC50 of As on the root growth via its interaction with Fe. Despite the limitations of the artificial soils and range of parameters studied, the application of this statistical tool can be considered a powerful and efficient technique for interpretation and prediction of the complicated results caused by the interactions between many factors within the soil environments. 相似文献