Effect of Ethanol and pH on the Adsorption of Diazepam from Simulated Gastric Fluid and Simulated Intestinal Fluid on Activated Charcoal In Vitro

Author(s):  
S K Sah ◽  
D Joshi ◽  
S Pathak ◽  
N Marasini
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. 


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.


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Shobha Regmi ◽  
Balmukunda Regmi ◽  
Sajan Lal Shyaula ◽  
Shiva Pathak ◽  
Bishnu Prasad Bhattarai ◽  
...  

Adsorption kinetics of dextromethorphan (DXM) syrup in simulated gastric and intestinal fluids onto activated charcoal (AC) were investigated in an in vitro model. The adsorption studies were performed as a function of time, initial concentration, and temperature. The quantification of DXM adsorbed onto AC was obtained from the Langmuir adsorption isotherms using HPLC. The maximum adsorption capacities (at 95% confidence limits) of AC for DXM were 111.615 [106.38; 126.85] mg in simulated intestinal environment (pH 6.8) and 78.314 [86.206; 70.422] mg in simulated gastric environment (pH 1.2). The adsorption capacity of AC for DXM in simulated gastric fluid (pH 1.2) was not significantly different from the adoption capacity of AC for DXM in simulated intestinal fluid (pH 6.8). Moreover, the adsorption kinetics behavior of dextromethorphan onto AC followed pseudo-second-order kinetics. Our results show that AC in therapeutically acceptable doses can be beneficial in the majority of oral overdose of DXM.


Author(s):  
Putra Imwa ◽  
Kusumawati Igaw

Objective: As an antidiabetic drug, metformin hydrochloride (HCl) has been well known to possess low oral bioavailability and short half-life. In this study, we prepared the drug delivery system (DDS) of metformin HCl and clinoptilolite as its carrier. The in vitro drug release profile was further investigated.Methods: DDS was made by encapsulating metformin HCl on clinoptilolite using the wet impregnation method at various pH and initial concentration of metformin HCl. Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), and N2 Sorption Analyzer were used to characterize the as-synthesized DDS. Drug release study was conducted by stirring the DDS in simulated gastric fluid and simulated intestinal fluid over 12 h.Results: The encapsulation process was achieved optimally at pH 7.0 and initial concentration of metformin HCl of 300 mg/l (CLI2-300 denoted DDS). The results of FTIR and N2 sorption analyzer confirmed the existence of metformin HCl on clinoptilolites. Meanwhile, the XRD result showed that the crystallinity of clinoptilolites remained unchanged after the encapsulation process. The cumulative drug release in the simulated gastric fluid was found to be higher than that in the simulated intestinal fluid, which indicated the potent influence of pH on the release properties of the drugs. The drug release kinetics of metformin HCl from clinoptilolite was best fitted into the Korsmeyer-Peppas model with non-Fickian transport mechanism.Conclusion: We found that clinoptilolite was suitable for DDS application, particularly as a carrier of metformin HCl.


2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Nur Syahirah Sallehudin ◽  
Khalilah Abdul Khalil ◽  
Maslinda Musa ◽  
Hifa Nazirah Mohd Yazid ◽  
Anida Yusof

Probiotic encapsulation approach has the potential to protect microorganisms and to deliver them into the gut. Because of the promising preclinical and clinical results, probiotics have been incorporated into a range of products. However, there are still many challenges to overcome with respect to the encapsulation process and the conditions prevailing in the gut. Thus in this study, the release activity of encapsulated L. plantarum NBRC 3070 and Aloe vera gel within alginate coated chitosan matrices during simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) exposure were investigated. There were four groups of beads prepared in this study: 1) Encapsulated probiotic and Aloe vera within alginate beads (chitosan coated), 2) Encapsulated probiotic within alginate beads (chitosan coated), 3) Encapsulated probiotic and Aloe vera within alginate beads (uncoated) and 4) Encapsulated probiotic alone within alginate beads (uncoated). Encapsulation process was carried out using extrusion method. The optimized composition of alginate matrix (1.34% w/v) and Aloe vera gel (1.99% w/v) were used.  In order to investigate their release activity, all beads were exposed in Simulated Gastric (SGF) at pH 2.5 and Simulated Intestinal Fluids (SIF) at pH 6.5 for 120 min and 270 min, respectively. Based on the findings, alginate-Aloe vera beads with chitosan coated was able to protect L. plantarum NBRC 3070 during SGF exposure with only 1 log10 cfu/mL reduction. The presence of Aloe vera gel in the beads improved the survivability of the cells. Encapsulated cells were observed successfully slow released of cells from the beads after exposure in SIF. Scan Electron Microscope (SEM) result had shown that cross link activity of the optimum alginate-Aloe vera with chitosan coating resulted in better survival of cells after simulated gastro and able to deliver sufficient probiotic dose to intestinal region. The combinations were able to improve encapsulated cells survivability during low acidic environment passage and release activity into the intestinal target region.   


Author(s):  
Truong Duc Thang ◽  
Le Thi Hanh Quyen ◽  
Hoang Thi Thuy Hang ◽  
Nguyen Thien Luan ◽  
Dang Thi KimThuy ◽  
...  

Bread is a popular food in the world because of its variety and convenience. Currently, studies on the adding probiotics to bread are limited due to the adverse effects of processing, such as baking temperature, aerobic environment to the probiotic bacteria. The objective of this study was to produce probiotic cream bread, in which Lactobacillus acidophilus was microencapsulated with Alginate 2% (A); Alginate 2% + maltodextrin 1% (AM); Alginate 2% + xanthan gum 0.1% (AX); and Alginate 2% + maltodextrin 1% + xanthan gum 0.1% (AMX). Microcapsules were added to the kernel, conducting encapsulation yield investigations, survival in baking, preservation of bread, and in simulated gastric fluid and simulated intestinal fluid conditions after 8 days of storage. The results showed that the addition of xanthan gum enhanced the encapsulation yield, it reached 92.9% and 92.37% in AMX and AX samples, respectively. The viability of L. acidophilus during baking was decreased by 3.64 and 3.75 Log (CFU/bread) in AMX and AM samples, compared to A and AX which were decreased by 4.75 and 4.44 Log (CFU/ bread). In SGF (Simulated Gastric Fluid) and SIF (Simulated Intestinal Fluid) conditions, the AMX microcapsules provide the best probiotic protection among the four tested carriers. The combination of xanthan gum and maltodextrin in alginate matrix, eventually leading to having dual efficiency: First, xanthan gum would act as buffers that reduce acid activity; Second, maltodextrin acting as a protective agent of L. acidophilus against high temperature as well as potential prebiotic that improve the viability of probiotic.


Author(s):  
Juliati Br Tarigan ◽  
Djendakita Purba ◽  
Cut Fatimah Zuhra

 Objective: This study demonstrated the incorporation of Vitamin E from palm fatty acid distillate onto crosslinked galactomannan phosphate (CGP) matrix.Methods: CGP was obtained from the crosslinking reaction of galactomannan from Arenga pinnata (GAP) with tri-sodium metaphosphate (TMF) ranging from 1:1 to 4:3 while incorporation of Vitamin E was conducted in two steps to form films. The reliability study of Vitamin E in CGPVE was conducted using a solution of pepsin and sodium chloride and also in solution of pancreatin and buffer phosphate.Results: The Fourier-transform infrared spectrum indicated the presence of phosphate in CGP while the scanning electron microscope images depicted the changes of surface morphology from smooth (GAP) to rough and hollow (CGP) which confirmed that crosslink had occurred. The swelling study of CGP showed that the swelling indexes were similar and decreased with the increase of TMF. The efficiency of CGP to absorb Vitamin E ranged from 89.66% to 91.09%. The in vitro releasing study of Vitamin E in simulated gastric fluid and simulated intestinal fluid showed that only a small amount of Vitamin E was released.Conclusions: This study demonstrated that CGP can be prepared and is potentially useful for drug delivery to the colon.


2016 ◽  
Vol 695 ◽  
pp. 284-288 ◽  
Author(s):  
Simona Cavalu ◽  
Vasile Laslo ◽  
Florin Banica ◽  
Simona Ioana Vicas

The aim of this study is to develop a lyophilized matrix (microspheres) as a controlled delivery system for nanoselenium particles, using different formulation based on alginate or agar. Elemental selenium is considered as the least toxic of all selenium forms and in the same time supplementation with its nanosize particles has the same or better bioavailability compared to its salts. In our study, nanosized elemental selenium was obtained by fermentation technology using probiotic lactic acid bacteria (Lactobacillus casei). The microspheres have been characterized from structural point of view by using different techniques: FTIR spectroscopy, X-ray Diffraction and SEM. Each individual natural polymer has its own characteristic advantages and disadvantages; it is commonly accepted that naturally derived matrix often show an excellent balance between the mechanical properties, swelling and dissolution capacity. The optimized formulation was proposed upon in vitro dissolution study using Diferential Pulsed Voltammetry in order to measure the concentration of selenium released in simulated gastric fluid (pH=1.2) and simulated intestinal fluid (pH=8.1). The cumulative release of selenium from different formulations showed large differences with respect to matrix composition. We demonstrated that both alginate and agarose-based formulations are suitable to be used in basic environment such as small or large intestine. The results might be of high importance as absorption of selenium occurs mainly in the duodenum, caecum and colon (more than 85%).


2021 ◽  
Vol 21 (7) ◽  
pp. 3651-3655
Author(s):  
Woo Chang Kwon ◽  
Moonhee Choi ◽  
Kyung Chan Kang ◽  
Dong Hyun Kim

A formulation for controlled delivery of ibuprofen (IBU) involving montmorillonite (MMT) nanoclays has been proposed. The present work has investigated the beneficial effect of MMT in improving controlled delivery of IBU. The intercalation of IBU into the interlayer of MMT was studied under different processing conditions such as reaction time and initial concentration of IBU. To characterize the IBU/MMT composites, X-ray diffraction (XRD) and Fourier transform infrared spectra (FTIR) were performed. The release behavior of IBU from IBU/MMT composites have been investigated under vitro conditions using buffer media of simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 7.4) at 37 °C. Controlled release of IBU from IBU/MMT composite has been observed during in vitro release experiments. Different mathematical models were used for fitting our experimental results, among them the best fitting was found for Higuchi equation based on the parabolic diffusion process.


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