scholarly journals Studies of Degradation Kinetics of a 5-HT3 Antagonist, Ramosetron Hydrochloride: Effects of Temperature

2018 ◽  
Vol 17 (2) ◽  
pp. 167-173
Author(s):  
Md Mokaram Hossain ◽  
Reza Ul Jalil ◽  
Mohammad A Rashid
Keyword(s):  
Reaction Rate ◽  
Arrhenius Equation ◽  
Degradation Kinetics ◽  
First Order ◽  
Reaction Rate Constants ◽  
First Order Kinetics ◽  
Antiemetic Activity ◽  
Effects Of Temperature ◽  
Kinetics Of ◽  
Subtype 3

Ramosetron hydrochloride is the hydrochloride salt of ramosetron, a selective serotonin (5-HT3) receptor antagonist with potential antiemetic activity. Upon administration, ramosetron selectively binds to and blocks the activity of 5-HT subtype 3 (5-HT3) receptors located in the vagus nerve terminal and the vomiting center of central nervous system (CNS), suppressing chemotherapy-induced nausea and vomiting. Degradation of Ramosetron HCl was conducted with 0.1N NaOH at 60°C, 70°C and 80°C to study the reaction kinetics. The reaction rate constants (k) for degradation at 60°C, 70°C and 80°C were -2.2680 molL-1s-1 , -3.3714 molL-1s-1 and -5.3686 molL-1s-1 for zero order and -1.05 x 10-2s-1, -1.60 x 10-2s-1 and -2.70 x 10-2s-1 for first order kinetics, respectively. The activation energy of Ramosetron HCl was found as 10.05 kcalmol-1 by using Arrhenius equation. Dhaka Univ. J. Pharm. Sci. 17(2): 167-173, 2018 (December)

A Study on Degradation Kinetics of Trypsin Inhibitors in Horse Gram (Dolichos biflours)

2007 ◽  
Vol 3 (3) ◽  
Author(s):  
Kavita Tarade ◽  
Rekha Singhal ◽  
Radha Jayram ◽  
Aniruddha Pandit
Keyword(s):  
Arrhenius Equation ◽  
Degradation Kinetics ◽  
Cooking Methods ◽  
Heating Process ◽  
Isothermal Temperature ◽  
Horse Gram ◽  
First Order ◽  
First Order Kinetics ◽  
Nonisothermal Heating ◽  
Kinetics Of

This study aims at developing a kinetic model for the degradation of trypsin inhibitor (TI) in horse gram (Dolichos biflours) subjected to a defined set of processing conditions. The study was carried out in isothermal conditions over a temperature range of 60-120° C. The degradation of TI followed first order kinetics. It was adequately modeled by the Arrhenius equation. Using the time temperature data of the nonisothermal heating process encountered in three different cooking methods viz. open pan, pressure cooking and cooking in a recently developed and patented fuel-efficient 'EcoCooker', and the kinetic data obtained under isothermal temperature conditions, a mathematical model has been developed to predict the degradation of TI in these three modes of cooking.

scholarly journals Comparative Study of Chemical Stability of Two H1Antihistaminic Drugs, Terfenadine and ItsIn VivoMetabolite Fexofenadine, Using LC-UV Methods

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Anna Gumieniczek ◽  
Anna Berecka-Rycerz ◽  
Rafał Pietraś ◽  
Izabela Kozak ◽  
Karolina Lejwoda ◽  
...  
Keyword(s):  
Comparative Study ◽  
Chemical Stability ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of Degradation ◽  
Effects Of Temperature ◽  
High Doses ◽  
Antihistaminic Drugs ◽  
Kinetics Of

A comparative study of chemical stability of terfenadine (TER) and itsin vivometabolite fexofenadine (FEX) was performed. Both TER and FEX were subjected to high temperature at different pH and UV/VIS light at different pH and then quantitatively analyzed using new validated LC-UV methods. These methods were used to monitor the degradation processes and to determine the kinetics of degradation for both the compounds. As far as the effects of temperature and pH were concerned, FEX occurred more sensitive to degradation than TER. As far as the effects of UV/VIS light and pH were concerned, the both drugs were similarly sensitive to high doses of light. Using all stress conditions, the processes of degradation of TER and FEX followed the first-order kinetics. The results obtained for these two antihistaminic drugs could be helpful in developing their new derivatives with higher activity and stability at the same time.

Study on Kinetics of Reaction between ZrNi5 and Water Vapor

2012 ◽  
Vol 581-582 ◽  
pp. 694-697
Author(s):  
Yong Yao ◽  
De Li Luo ◽  
Zhi Yong Huang ◽  
Jiang Feng Song
Keyword(s):  
Water Vapor ◽  
Reaction Rate ◽  
Arrhenius Equation ◽  
Tritiated Water ◽  
First Order ◽  
Order Chemical Reaction ◽  
First Order Chemical Reaction ◽  
Kinetics Of Reaction ◽  
Reaction Activation Energy ◽  
Kinetics Of

In order to evaluate the feasibility of tritium recovery from tritiated water by thermochemical decomposition using ZrNi5, the kinetics of reaction between ZrNi5 and water vapor was studied by thermogravimetric method in the temperature range from 673K to 823K. The result shows that reaction rate increased significantly with the increasing of temperature and H2O concentration; the reaction mechanism for ZrNi5 can be described by the first-order chemical reaction, and the reaction is first order for H2O concentration. The reaction activation energy of ZrNi5 is 55.8kJ/mol calculated from the Arrhenius equation.

Kinetics of the Ozonation of Tetrabromobisphenol-A in Wastewater

2011 ◽  
Vol 383-390 ◽  
pp. 2945-2950 ◽  
Author(s):  
Jie Zhang ◽  
Shi Long He ◽  
Mei Feng Hou ◽  
Li Ping Wang ◽  
Li Jiang Tian
Keyword(s):  
Rate Constants ◽  
Apparent Rate Constant ◽  
Reaction Rate ◽  
Batch Reactor ◽  
Kinetic Studies ◽  
Tetrabromobisphenol A ◽  
First Order ◽  
Reaction Rate Constants ◽  
Pseudo First Order ◽  
Kinetics Of

The kinetics of TBBPA degradation by ozonation in semi-batch reactor was studied. The reaction rate constants of TBBPA with O3 and •OH were measured by means of direct ozone attack and competition kinetics, and the values of which were 6.10 l/(mol•s), 4.8×109 l/(mol•s), respectively. Results of kinetic studies showed that TBBPA degradation by ozonation under the different conditions tested followed the pseudo-first-order. The values of apparent rate constant of TBBPA degradation increased with the increase of ozone dosage and pH, but decreased with the increase of initial TBBPA concentration.

scholarly journals PERSISTENCIA DEL ENDOSULFÁN EN MEDIO ACUOSO ESTÁTICO

2001 ◽  
Vol 11 ◽  
Author(s):  
ARGELIA M. L. LENARDÓN ◽  
PATRICIA M. DE LA SIERRA ◽  
FERNANDA MARINO
Keyword(s):  
River Water ◽  
Degradation Kinetics ◽  
Water Type ◽  
Ultrapure Water ◽  
First Order ◽  
First Order Kinetics ◽  
Predominant Factor ◽  
Two Temperatures ◽  
In The Beginning ◽  
Kinetics Of

Estudou-se a cinética de degradação da mistura dos isômeros alfa e beta Endosulfan em diferentes condições de trabalho. Os compostos foram adicionados em água ultrapura, água do rio, água de rio filtrada e água ultrapura com sais (salinidade similar à agua do rio utilizada). As condições de degradação escolhidas foram: escuridão e duas temperaturas (14+1 ºC e 26+1 ºC). As amostragens foram programadas de modo a se obter dados periódicos mais freqüentes no início da experiência e posteriormente mais espaçados até o seu final (230 dias). As amostras foram submetidas à microextração e analisadas por cromatografia em fase gasosa com detector de Ni63 e coluna Megabore DB-5. A degradação foi descrita de acordo com a cinética de primeira ordem, determinando-se os tempos de meia vida (t1/2) e as energias de ativação (Ea). Os dados obtidos evidenciaram que a temperatura é o fator preponderante, sendo possível deduzir que o alfaendosulfan, exceto para água ultrapura (AU), é mais influenciado pela temperatura do que o beta-endosulfan. O segundo efeito mais importante refere-se ao tipo de água utilizada como matriz, devido à influência da salinidade. PERSISTANCE OF ENDOSULFAN IN STATIC AQUEOUS MEDIUM Abstract Degradation kinetics of a mixture of alpha- and beta-Endosulfan isomers was studied under different conditions. The compounds were spiked in ultrapure water, river water, filtered water and ultrapure water with salts (similar salinity condition to that of the river water used). The degradation conditions chosen were: darkness, two temperatures (14+1 ºC e 26+1 ºC). Samplings were programmed in order to obtain more frequent periodical data in the beginning of the experience and after more spaced until its end (230 days). The samples were submitted to microextraction and then analyzed by gas chromatography through a Ni63 detector equipped with a Megabore DB-5 column. Degradation was described using first-order kinetics to determine half-life times (t1/2) and activation energies (Ea). The data obtained evidenced that temperature is the predominant factor, it can possibly be inferred that alfa-endosulfan is much more influenced than beta-endosulfan except for ultrapure water (UW). The second important effect is the water type used as matrix, due to the influence of salinity.

The In Vitro Degradation Kinetics of Polyurethane Prodrug Materials

2011 ◽  
Vol 399-401 ◽  
pp. 1067-1070
Author(s):  
Chun Yan Li ◽  
Cong Cong Hu ◽  
Zhi Guo Wen ◽  
Sheng Xiong Dong
Keyword(s):  
Drug Release ◽  
High Performance ◽  
Degradation Kinetics ◽  
Hplc Method ◽  
In Vitro Degradation ◽  
Erosion Mechanism ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of

The method of high performance liquid chromatography (HPLC) is established to determine the content of antibacterial agent — ciprofloxacin (CF) in the degradation solution of ciprofloxacin-polyurethane (CFPU) and investigate the in vitro degradation kinetics by plotting and fitting the cumulative release curves to inspect the effects of different medium and different concentrations on drug release. The results showed that the HPLC method is accurate, reliable and simple. The drug-release of CFPU was bioresponsive and could be accorded with first order kinetics. It was observed that CF was released from CFPU by a combination of diffusion and erosion mechanism, mainly in the manner of diffusion in the absence of infection while erosion mechanism in the presence of infection.

Effects of Carrageenan and Chitosan as Coating Materials on the Thermal Degradation of Microencapsulated Phycocyanin from Spirulina sp.

2019 ◽  
Vol 15 (5-6) ◽  
Author(s):  
H. Hadiyanto ◽  
Marcelinus Christwardana ◽  
Meiny Suzery ◽  
Heri Sutanto ◽  
Ayu Munti Nilamsari ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Thermal Degradation ◽  
Rate Constants ◽  
Reaction Rate ◽  
Order Reaction ◽  
Coating Materials ◽  
First Order ◽  
Reaction Rate Constants ◽  
Kinetics Of

AbstractPhycocyanin is a natural substance that can be used as an antioxidant and food colorant. The quality of phycocyanin deteriorates when it is exposed to heat, and such deterioration is evidenced by decreases in its antioxidant activity and color. Encapsulation, which introduces a coating material over a substance of interest, has been applied to prevent changes in substance quality. The objective of the present research is to evaluate the kinetics of thermal degradation of phycocyanin coated with carrageenan or chitosan. Encapsulated phycocyanin samples were exposed to temperatures of 40, 50, or 60 °C for 90 min, and kinetics of the resulting degradation was evaluated to determine changes in sample quality. The results showed that the thermal degradation of encapsulated phycocyanin at 40–60 °C follows first-order reaction kinetics with reaction rate constants (k) of 4.67–9.17 × 10–5 s-1 and 3.83–7.67 × 10–5 s-1 for carrageenan and chitosan, respectively, and that the k of encapsulated phycocyanin is slower than that obtained from samples without the coating materials (control). Encapsulation efficiencies (EE) of 68.66 % and 76.45 %, as well as loading capacities of 45.28 % and 49.16 %, were, respectively, obtained for carrageenan and chitosan.

scholarly journals Degradation kinetics and in vitro digestive stability of selected bioactive compounds from a beverage formulated with butterfly pea flowers

2022 ◽  
Vol 52 (5) ◽  
Author(s):  
Renata Oliveira Santos ◽  
Laura Monteiro Keller ◽  
Vanessa Sales de Oliveira ◽  
Carlos Alberto Bucher ◽  
José Lucena Barbosa Junior ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Degradation Rate ◽  
Degradation Kinetics ◽  
Model Systems ◽  
First Order ◽  
Ph Values ◽  
First Order Kinetics ◽  
Butterfly Pea ◽  
Effects Of Temperature

ABSTRACT: This study evaluated the effects of temperature on the pH of extracts of ascorbic acid and anthocyanins from petals of butterfly pea, as well as their in vitro digestive stability in model systems at 60, 70, and 80 °C. The pH values significantly decreased with an increase in the temperature (P < 0.05). The findings were similar for the degradation of anthocyanins and ascorbic acid, which followed first-order kinetics in all the systems. The samples heated at 80 °C presented the highest degradation rate (kobs), as well as higher percentages of degradation at the end of digestive stability in vitro.

Degradation Kinetics of Reactive Brilliant Red X-3B Dye by UV/Mn2+/H2O2/Micro-Aeration

2012 ◽  
Vol 441 ◽  
pp. 549-554
Author(s):  
Ying Jie Cai ◽  
Xiao Jun Yang ◽  
Dong Sheng Xia ◽  
Qing Fu Zeng
Keyword(s):  
Degradation Rate ◽  
Ph Value ◽  
Degradation Kinetics ◽  
H2o2 Concentration ◽  
Kinetics Equation ◽  
Linear Least Squares ◽  
First Order ◽  
First Order Kinetics ◽  
Pseudo First Order ◽  
Kinetics Of

Abstract. Degradation of reactive brilliant red X-3B (X-3B) by a UV/Mn2+/H2O2/micro- aeration method was investigated. The influencing factors of degradation of X-3B including UV irradiation, aeration, pH value, H2O2 concentration and X-3B concentration were examined. The results show that X-3B was effectively degraded by the UV/Mn2+/H2O2/micro-aeration method. The degradation rate of X-3B was obtained from weighted linear least squares analysis of the experimental data, and accorded with the pseudo-first order kinetics equation.

Kinetics of Reductive Dechlorination of DDT in Soil with Zero-Valent Iron

2011 ◽  
Vol 295-297 ◽  
pp. 1236-1239
Author(s):  
Yin Hai Lang ◽  
Min Jie Wang ◽  
Nan Nan Wang
Keyword(s):  
Kinetic Model ◽  
Reductive Dechlorination ◽  
Reaction Rate ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
First Order ◽  
Reaction Rate Constants ◽  
Order Kinetic Model ◽  
Pseudo First Order ◽  
Kinetics Of

In this study, reductive dechlorination of DDT compounds by zero-valent iron in Jiangxi red soil was investigated. DDT compounds were effectively dechlorinated by zero-valent iron. The pseudo-first-order kinetic model for 2,4¢-DDT and 4,4¢-DDT reduction with zero-valent iron was proposed. The reaction rate constants for 2,4¢-DDT and 4,4¢-DDT were 1.19´10-2(min-1) and 1.44´10-2(min-1), respectively. The dechlorination of 2,4¢-DDT and 4,4¢-DDT were mainly affected by the specific surface area of iron. The data from the variable-pH experiments (between 3.6 and 8.8) suggested that pH does not play a role in the rate-determination step.

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