scholarly journals The effect of enzymes on the in vitro degradation behavior of Mg alloy wires in simulated gastric fluid and intestinal fluid

Author(s):  
Yue Zhang ◽  
Jian Cao ◽  
Xianli Wang ◽  
Huan Liu ◽  
Yi Shao ◽  
...  
2017 ◽  
Vol 9 (4) ◽  
pp. 54 ◽  
Author(s):  
Jose Raul Medina ◽  
Jonathan Hernandez ◽  
Marcela Hurtado

Objective: To characterize the in vitro release of carbamazepine tablets and benzoyl metronidazole suspensions using the flow-through cell apparatus and simulated gastrointestinal fluids.Methods: Tegretol® tablets, Flagyl® suspension, and generic formulations of each were tested. Release studies were performed using an automated flow-through cell apparatus. Simulated gastric fluid (with and without pepsin) and simulated intestinal fluid (without pancreatin) at 16 ml/min and fasted state simulated intestinal fluid at 8 ml/min, all at 37.0±0.5 °C, were used as dissolution media. The quantity of dissolved carbamazepine and benzoyl metronidazole was determined at 5-min intervals until 60 min at 285 and 278 nm, respectively. Percentage dissolved at 60 min, mean dissolution time, dissolution efficiency values, and t10%, t25%, t50% and t63.2% were calculated. Mean values for all parameters were compared between the reference and generic formulations using Studentʼs t-test. Dissolution data were fitted to different kinetic models.Results: Simulated gastric fluid without pepsin showed no discriminative capability for carbamazepine tablets. Significant differences were observed between the reference and generic formulations for almost all parameters (*P<0.05). In some cases, the logistic model best described the in vitro release of both drugs.Conclusion: Using an apparatus and media that best simulates the gastrointestinal environment, we identified differences in the rate and extent of dissolution of both drugs that could help to optimise the design of interchangeable formulations. Based on the physicochemical characteristics of carbamazepine and benzoyl metronidazole and the conditions in which the formulations were tested, these differences could be of clinical relevance. 


2018 ◽  
Vol 33 (9) ◽  
pp. 603-611 ◽  
Author(s):  
Praveen Kumar Nakka ◽  
Naveen Chikkala ◽  
Sujatha Desetti ◽  
Anandarao Daida ◽  
Naga Sireesha Janyavula ◽  
...  

2014 ◽  
Vol 24 (8) ◽  
pp. 2516-2528 ◽  
Author(s):  
H.R. BAKHSHESHI-RAD ◽  
E. HAMZAH ◽  
M. DAROONPARVAR ◽  
M.A.M. YAJID ◽  
M. KASIRI-ASGARANI ◽  
...  

2008 ◽  
Vol 74 (15) ◽  
pp. 4799-4805 ◽  
Author(s):  
Yongsheng Ma ◽  
Jennifer C. Pacan ◽  
Qi Wang ◽  
Yongping Xu ◽  
Xiaoqing Huang ◽  
...  

ABSTRACT This paper reports the development of microencapsulated bacteriophage Felix O1 for oral delivery using a chitosan-alginate-CaCl2 system. In vitro studies were used to determine the effects of simulated gastric fluid (SGF) and bile salts on the viability of free and encapsulated phage. Free phage Felix O1 was found to be extremely sensitive to acidic environments and was not detectable after a 5-min exposure to pHs below 3.7. In contrast, the number of microencapsulated phage decreased by 0.67 log units only, even at pH 2.4, for the same period of incubation. The viable count of microencapsulated phage decreased only 2.58 log units during a 1-h exposure to SGF with pepsin at pH 2.4. After 3 h of incubation in 1 and 2% bile solutions, the free phage count decreased by 1.29 and 1.67 log units, respectively, while the viability of encapsulated phage was fully maintained. Encapsulated phage was completely released from the microspheres upon exposure to simulated intestinal fluid (pH 6.8) within 6 h. The encapsulated phage in wet microspheres retained full viability when stored at 4°C for the duration of the testing period (6 weeks). With the use of trehalose as a stabilizing agent, the microencapsulated phage in dried form had a 12.6% survival rate after storage for 6 weeks. The current encapsulation technique enables a large proportion of bacteriophage Felix O1 to remain bioactive in a simulated gastrointestinal tract environment, which indicates that these microspheres may facilitate delivery of therapeutic phage to the gut.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 449
Author(s):  
Ahmed M. Omer ◽  
Zyta M. Ziora ◽  
Tamer M. Tamer ◽  
Randa E. Khalifa ◽  
Mohamed A. Hassan ◽  
...  

An effective drug nanocarrier was developed on the basis of a quaternized aminated chitosan (Q-AmCs) derivative for the efficient encapsulation and slow release of the curcumin (Cur)-drug. A simple ionic gelation method was conducted to formulate Q-AmCs nanoparticles (NPs), using different ratios of sodium tripolyphosphate (TPP) as an ionic crosslinker. Various characterization tools were employed to investigate the structure, surface morphology, and thermal properties of the formulated nanoparticles. The formulated Q-AmCs NPs displayed a smaller particle size of 162 ± 9.10 nm, and higher surface positive charges, with a maximum potential of +48.3 mV, compared to native aminated chitosan (AmCs) NPs (231 ± 7.14 nm, +32.8 mV). The Cur-drug encapsulation efficiency was greatly improved and reached a maximum value of 94.4 ± 0.91%, compared to 75.0 ± 1.13% for AmCs NPs. Moreover, the in vitro Cur-release profile was investigated under the conditions of simulated gastric fluid [SGF; pH 1.2] and simulated colon fluid [SCF; pH 7.4]. For Q-AmCs NPs, the Cur-release rate was meaningfully decreased, and recorded a cumulative release value of 54.0% at pH 7.4, compared to 73.0% for AmCs NPs. The formulated nanoparticles exhibited acceptable biocompatibility and biodegradability. These findings emphasize that Q-AmCs NPs have an outstanding potential for the delivery and slow release of anticancer drugs.


2006 ◽  
Vol 7 (11) ◽  
pp. 2983-2990 ◽  
Author(s):  
Karin D. F. Vlugt-Wensink ◽  
Xulin Jiang ◽  
Geert Schotman ◽  
Govert Kruijtzer ◽  
Arjen Vredenberg ◽  
...  

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