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Objective:Based on the previous studies, to investigate the dissolution behavior of Fuzi Lizhongwan by simultaneously determining the dissolution of benzoylmesaconine, benzoylaconine and benzoylhypaconine in Aconiti Lateralis Radix Praeparata. Method:The simultaneous determination of benzoylmesaconine, benzoylaconine and benzoylhypaconine in Fuzi Lizhongwan was established by HPLC-QQQ-MS. The dissolution amounts of three compositions in 15 batches of Fuzi Lizhongwan from 5 manufacturers at different time points, the cumulative dissolution was calculated and the dissolution curve was drawn. The f2 similarity factor method was adopted to evaluate similarity of dissolution curves of index components in different batches of samples from the same manufacturer, and to evaluate similarity of dissolution curves of samples from different manufacturers based on the same index component. The dissolution model of Fuzi Lizhongwan was concluded by fitting with the dissolution data. Result:When hydrochloric acid solution with pH of 1.2 was used as the dissolution medium, the three alkaloids had the best dissolution effect. The dissolution behavior of three monoester alkaloids in Fuzi Lizhongwan was basically synchronous and the dissolution lasted for 24 h. Three batches of samples from the same manufacturer (manufacturer 1, 3, 4 and 5) appeared to be similar on dissolution behavior, indicating that the dissolution behavior of the majority of samples from different manufacturers was similar. The dissolution behavior of batch 1 sample was different from batch 2 and 3 samples in manufacturer 2, suggesting that the quality of different batches of samples in manufacturer 2 might be different. The fitting results of dissolution data of index components in samples from different manufacturers were consistent, and the Weibull model was the best. Conclusion:Index components in fifteen batches of samples from 5 manufacturers are continuously dissolved within 24 h, indicating that the samples have the characteristics of slow dissolution. The dissolution curves of samples from the same manufacturer are similar to each other, indicating that the quality of different batches of products from most manufacturers is stable. The dissolution behavior of benzoylmesaconine, benzoylaconine and benzoylhypaconine in samples form different manufacturers has some differences, which may be caused by the source of medicinal materials and preparation technology parameters.
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Objective: Establishing the model of cell bioelectrical sensing effect of Compound Danshen Tablets to study its dissolution kinetics. Methods: By means of real-time cell-based assay, the in vitro dissolution of Compound Danshen Tablets can be investigated, and then the dissolution kinetics model can also be established. In addition, the result was compared and verified by UV-Vis. Results: The cell line with specific dependence on Compound Danshen Tablets was screened by CCK-8 experiment and RTCA experiment. The dissolution kinetics model of Compound Danshen Tablets based on RTCA technology was established, and the best fitting model was obtained: Weibull model ln{ln[1/(1-Q)] =1.071 4 lnt-3.736 7; Establish a dissolution kinetic model of Compound Danshen Tablets based on UV spectrophotometry to obtain the best fitting model, Weibull model ln{ln[1/(1-Q)]}=1.080 4 lnt-3.723 4; Comparing the two Weibull models, the RTCA fitted model worked better. Conclusion: The application of RTCA in the dissolution kinetics of traditional Chinese medicine compound solid preparations is feasible, Which provides new ideas for traditional Chinese medicines and the quality evaluation of traditional Chinese medicine compunds.
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Objective: To prepare dihydromyricetin (DMY) phospholipids complex (DMY-PC) and its nanostructured lipid carriers (DMY-PC-NLC), and carry out in vitro and in vivo evaluation. Methods: DMY-PC was prepared by solvent evaporation method. High pressure homogenization method was used to prepare DMY-PC-NLC. Orthogonal test was employed to optimize the ratio of solid/liquid lipid, dose of lipids materials, dose of DMY-PC and the concentration of emulsifier of poloxamer. The lyophilized powder of DMY-PC-NLC was prepared with 5% of mannitol as protective agent. The comparation of in vitro release and pharmacokinetics between DMY-PC and DMY-PC-NLC was also studied. Results: DMY was in an amorphous state in DMY-PC. The results of 1HNMR showed that the structure of DMY was not changed. The optimized prescription of DMY-PC-NLC determined by orthogonal test was as follow: The ratio of solid/liquid lipid was 5:1, dose of lipids materials was 325 mg, dose of DMY-PC was 45 mg and the concentration of emulsifier of poloxamer was 0.9%. The average size, Zeta potential, entrapment efficiency and drug loading of DMY- PC-NLC was (197.25 ± 4.42) nm, (-18.2 ± 2.1) mV, (71.68 ± 1.36)% and (3.94 ± 0.24)%, respectively. The in vitro release model was accord with Weibull model and the equation was lnln(1-Mt/M∞)=0.700 1 lnt-1.954 1 (r = 0.971 4). The relative bioavailability of DMY-PC and DMY-PC-NLC were enhanced to 1.63 and 3.22 times compared to DMY, respectively. Conclusion: Compared with DMY-PC, the absorption was promoted by DMY-PC-NLC in further, and the bioavailability of DMY was enhanced effectively.
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OBJECTIVE: To develop a method for determination of the dissolution of inhaled drugs by using indacaterol maleate, ipratropium bromide and budesonide as model drugs, and explore the law of dissolution of inhaled drugs. METHODS: Samples were prepared and the improved paddle apparatus method (USP dissolution assay-fifth method) was used for dissolution experiment. Samples were taken at a certain time, and the drug concentration was determined by HPLC. The sample dispersion method, dissolution medium and membrane were optimized, meanwhile inhaled drugs with different properties were measured and dissolution curve was modeled. RESULTS: An improved paddle apparatus method for simulating drug dissolution in respiratory tract was developed, samples were collected using the new generation impactor and the dissolution parameters were determined to be as follows: 150 mL of dissolution medium (250 mL dissolution cup), 2% Tween 80-PBS dissolution medium, 4.5 cm watch glass (4.7 cm drug-loaded membranes and 4.7 cm mesh screen), glass microfiber filters, double-layer membranes, drug-loaded membrane fixation method (level the mesh screen) and sampling time of 3 h; Weibull model was suitable for fitting the three drugs with different solubility (r2>0.999 1). CONCLUSION: The method is simple and reproducible, and can be used to determine the dissolution of inhalation drugs; the dissolution process of inhaled drugs is consistent with Weibull model.
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The purpose of this study was to analyze the response of different initial contamination levels of Alicydobadllus acidoterrestris ATCC 49025 spores in apple juice as affected by pulsed light treatment (PL, batch mode, xenon lamp, 3pulses/s, 0-71.6 J/cm²). Biphasic and Weibull frequency distribution models were used to characterize the relationship between inoculum size and treatment time with the reductions achieved after PL exposure. Additionally, a second order polynomial model was computed to relate required PL processing time to inoculum size and requested log reductions. PL treatment caused up to 3.0-3.5 log reductions, depending on the initial inoculum size. Inactivation curves corresponding to PL-treated samples were adequately characterized by both Weibull and biphasic models (R²d j 94-96%), and revealed that lower initial inoculum sizes were associated with higher inactivation rates. According to the polynomial model, the predicted time for PL treatment increased exponentially with inoculum size.
El objetivo del presente trabajo fue evaluar la influencia de la concentración de esporas de Alicyclobacillus acidoterrestris ATCC 49025 en la respuesta de inactivación por acción de la luz pulsada (modo estanco, lámpara de xenón, 3 pulsos/s, 0-71,6 J/cm²) en jugo de manzana comercial. Para caracterizar la relación existente entre la concentración de esporas y el tiempo de tratamiento con las reducciones logarítmicas alcanzadas luego de la exposición a la luz pulsada (LP), se aplicaron 2 modelos: el de Weibull y el bifásico. Adicionalmente, se estimó la relación entre el tiempo de tratamiento con LP y la concentración inicial de inoculo en el jugo con las reducciones logarítmicas logradas mediante regresión múltiple y la metodología de superficie de respuesta (MSR). La inactivación por LP provocó entre 3 y 3,5 reducciones logarítmicas, según la concentración inicial de esporas. Las curvas de inactivación fueron adecuadamente caracterizadas por los modelos matemáticos propuestos (Restado = 94-96%). El análisis por MSR permitió predecir un aumento exponencial del tiempo de tratamiento requerido conforme se incrementa el nivel de contaminación inicial.
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Spores, Bacterial , Beverages , Malus , Alicyclobacillus , Food Contamination , Food MicrobiologyABSTRACT
Objective: Optimize to obtain the in situ gel of matrine with thermosensitivity and rectal retention of bioadhesion rectum. Methods: Thermosensitive gel was prepared by cold method, and then using gelation temperature as an indicator, central combination design-response surface method (CCD-RSM) was used to optimize the dosage of P407, P188, and CMC-Na. Texture Analyzer was used to measure the gel strength and adhesion of prescription, the rectal retention was investigated by rectal administration, and the release rate was explored by modified paddle method. Results: The optimal prescription was matrine 2%, CMC-Na 1.0%, P188 1.3%, P407 16.5%, and benzalkonium bromide 0.02%. The prescription gel did not leak after rectal administration in rats, which can remain in the body for more than 6 h, in vitro release in line with Weibull model. Conclusion: The optimized matrine-loaded thermosensitive in situ gel could meet the requirement of rectal administration.
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Objective To mitigate Lycii Fructus surface crust and save drying time during drying process, vacuum pulsed drying technology was applied to dry Lycii Fructus so as to investigate moisture diffusion regulation and build the drying model. Methods The effect of different drying temperature (50, 55, 60, and 65 ℃), vacuum pressure holding time (5, 10, 20, and 30 min), and atmosphere pressure holding time (2, 4, and 8 min) on drying characteristics, moisture diffusion coefficients and drying activation energy was explored in vacuum pulsed drying process. Weibull model distribution was used to simulate and analyze Lycii Fructus drying curves. Results All the drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time had significant influence on drying time. When drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time was 60 ℃, 4 min, and 10 min, respectively, the minimum drying time was achieved to be 284 min. Weibull distribution model can be well described the vacuum pulsed drying process of Lycii Fructus. The scale parameter was related to drying time and decreased as drying temperature increased. The drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time had little influence on the shape parameter. The shape parameter was associated with drying method. The moisture diffusion coefficient and activation energy were calculated to be 2.02 × 10-8-3.56 × 10-8 m2/s and 36.27 kJ/mol, respectively. Conclusion Weibull distribution model can well describe the moisture diffusion regulation of vacuum pulsed drying process of Lycii Fructus. The drying result had a great significance for predicting, controlling and optimizing drying process. On the other hand, the research could provide technical basis for industrial drying of Lycii Fructus by vacuum pulsed drying technology.
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OBJECTIVE: To evaluate the similarity of the mean drug dissolution or release curves by the experimental model of reformatory Weibull. METHODS: Three drugs were taken as the model drugs. With the fiber-optic in site dissolution testing equipment(FODT), the percentages of accumulated dissolution/release changing with time of the control and test preparations of every drug were respectively monitored. The mean percentages were calculated and the dissolution/release curves were drawn. The data were fitted by the reformatory Weibull model. The fitted parameters c, Ti, b, a, and the 95% confidence intervals of every parameters were extracted. The similarity of the mean drug dissolution curves between the control and test preparations was evaluated by the fitted parameters and observation of the dissolution curves. RESULTS: For the sustained-release preparations, there was no significant difference in the parameters c, Ti, b, and a of the test and control samples, and the mean drug release curves were similar. As for the non-modified preparations, whether the dosage forms of the test and control preparations were the same or not, there existed differences in the parameters fitted by the method of reformatory Weibull model. CONCLUSION: The modified method of reformatory Weibull model can be applied in the evaluation of similarity of drug dissolution behavior with satisfactory goodness-of-fit and quantitative result.
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Objective To compare the dissolution of Chuangxiong powder in different medium and discuss the dissolution characteristics in vitro of Changxiong powder. Methods The paddle method was adopted, the UV spectrophotometric method was developed to determine the in vitro dissolution quantity of Changxiong powder in five medium (water, 0.1 mol/L hydrochloric acid, acetate buffer of pH 4.5, phosphate buffer of pH 6.8, phosphate buffer of pH 7.4) with ferulic acid as index, and evaluated by drawing the dissolution curve and using the similar factor method and Weibull model. Results The dissolution quantity of Changxiong oral powder in five medium was different. The dissolution quantity in water, 0.1 mol/L hydrochloric acid, acetate buffer of pH 4.5 and phosphate buffer of pH 6.8 was similar and fit Weibull model, but it mutated in phosphate buffer of pH 7.4 and reached the maximum amount at 30 min. Conclusion The dissolution quantity of Changxiong powder is gradually increasing and the time is shorted in the medium from acidic to neutral then to alkaline. Dissolution curve is similar in the acidic and neutral medium. Changxiong powder dissolves out fast and completely in the alkaline medium.
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This paper was aimed to study the quantitation method of bitterness intensity of bitter drug, and to ex-plore the mutual relations between the bitterness intensity and the concentration of bitter drugs solution. The mod-el drug of berberine hydrochloride, which was made into a series of solutions of different concentrations, was ap-plied. Twenty volunteers, who were screened, trained and qualified, tasted the different concentration of aqueous solution, with the purpose of detecting the rank bitterness intensity. After analyzing the features of the data and testing the logarithm model and Weibull curve model, as well as nonlinear fitting, we finally set up the appropri-ate relationship curve between the concentration and the bitterness intensity. There is a good curve positive corre-lation between the bitterness intensity and the concentration, which is consistent with the Weibull curve model (R2= 0.9973, RMSE = 0.0976, RMSECV = 0.1453). The fitting degree of the model established in this paper is high, which provides a reference for quantitation and forecast of the drug bitterness.
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Conocer la cinética de deshidratación osmótica de un alimento y los factores que la afectan son aspectos importantes para diseñar un adecuado proceso. En este trabajo se investigó la aplicación del modelo de Weibull normalizado para describir la deshidratación osmótica de láminas finitas de sardina y determinar el coeficiente de difusión efectivo del agua. La deshidratación osmótica se realizó durante 4 horas utilizando salmueras de diferentes concentraciones (0,15-0,27 g NaCl/g) y temperaturas (30-38°C). Durante el proceso se midió el contenido de agua en las láminas y estos valores se ajustaron al modelo de Weibull normalizado. Los altos valores del coeficiente de regresión (R² > 0,99), la alta significancia (α < 0,001) para el coeficiente de difusión (D) y el parámetro β, y los bajos valores del ji-cuadrado reducido, indicaron la aceptabilidad del modelo para describir el proceso y determinar el coeficiente de difusión efectivo De del agua. Los valores de D variaron entre 1,01 x 10-11 m²/s y 4, 30 x 10-11 m²/s.
Knowledge of kinetics of osmotic dehydration of a food and factors that cause effects are aspects import for the appropriate design of process. In this work the application of normalized Weibull model was investigated for describing the osmotic dehydration (OD) of sardine finite sheets and determining the effective diffusion coefficient for water. The OD was carried out during 4 hours using brine at different concentrations (0.15-0.27 g NaCl/g) and temperatures (30-38°C). During process the water content of shhets was measured and these values were fitted to normalized Weibull model. The high values of regression coefficients (R² > 0.99), high significance (α < 0.001) of diffusion coefficient (D), parameter β, and low values of chi-square indicated the acceptability of Weibull model for describing the process and determining the effective diffusion coefficient De for water. The values of D ranged from 1.01 x 10-11 m²/s to 4.30 x 10-11 m²/s.
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OBJECTIVE: The objective was to compare Cox proportional hazards model and Weibull model for predicting long-term probabilities for stroke risk in the Korean Cancer Prevention Study(KCPS). METHODS: The subjects comprised of 385,279 Korean aged 55 to 64 years who received health insurance from the National Health Insurance Corporation and who had medical examinations in 1992 and 1995. 70% of the subjects were used for model building and the rest for model evaluation. The final prediction model for stroke includes age, systolic blood pressure, diabetes, total cholesterol and smoking. Subjects were follow-up for identification of incident stroke cases between 1993 and 2005. Comparisons included predicted coefficients of stroke risk factors, incidence probabilities over 10 years, and the area under a receiver operating characteristics (ROC) curve for both Cox's proportional hazard model and Weibull model. RESULTS: The average age of study population was 55.5 years in men and 56.3 years in women, respectively. Percentage of men and women in study population were 58.0% and 42.0%, respectively. The study findings satisfied proportionality according to the two models. There was no significant difference in coefficients between the two models of prediction models in men and in women. Moreover, there was no difference in incidence probabilities of stroke and c-statistics. C-statistics were 0.68 for men as same as for women. CONCLUSION: There was no difference for the prediction of the stroke risk in the Korean population using Cox's proportional hazard model and Weibull model, thus the two models were found to be efficient for this purpose.
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Aged , Female , Humans , Male , Blood Pressure , Cholesterol , Follow-Up Studies , Incidence , Insurance, Health , Korea , National Health Programs , Proportional Hazards Models , Risk Factors , ROC Curve , Smoke , Smoking , StrokeABSTRACT
Objective: To evaluate dissolution properties of 2 kinds of ambroxol hydrochloride tablets.Methods: A HPLC method was used.The column was Hypersil C 18 (10 ?m,150 mm?4.6 mm).The mobile phase was methnol water tetrahydrofuran triethylamine (71∶29∶2.5∶0.25).The wavelength of detector was 242 nm.Data were analyzed by Weibull's distribution model.Results: Both tablets dissolved rapidly and their dissolution rate reached 85% in the first 8 min.But there was significant statistic differences between the 2 tablets as for Weibull's parameters.Conclusion: Although the dissolution rate of 2 tablets is similar,there are still some differences between their dissolution parameters.The dissolution of the imported tablets is more rapid than the home made ones.