Digestion and absorption of food: usefulness and limitations of in vitro models

1994 ◽  
Vol 72 (4) ◽  
pp. 407-414 ◽  
Author(s):  
L. Savoie
Keyword(s):  
Release Kinetics ◽  
In Vitro Models ◽  
Physiological Adaptation ◽  
Reaction Products ◽  
Gastric Digestion ◽  
Mode Of Operation ◽  
One Step ◽  
Acid Release ◽  
Kinetics Of

The digestion and absorption of food is a spatiotemporal and dynamic process involving complex enzymatic and transport reactions, and it is illusive to try to reproduce in a single model all these biochemical and physiological events. A more practical and realistic approach is to separately evaluate the specific contributions of oral and gastric digestion, intestinal digestion by pancreatic enzymes, brush-border hydrolysis, and eventually intestinal absorption and enterocyte metabolism. The models proposed must be versatile enough to be able to modify their conditions of operation according to physiological adaptation to food. Enzymatic preparations must be kept close to physiological conditions in regard to their nature and their mode of operation. A digestion cell and a peptidase bioreactor were developed for this purpose. The challenge is to find a way to integrate all these data. This can be partially achieved by selecting techniques that allow the collection and isolation of reaction products from one step for use as substrates for the next event. Various models are presented to illustrate this concept as applied to food protein.Key words: digestion, proteolysis, in vitro models, amino acid release, kinetics of digestion.

scholarly journals Impact of UV sterilization and short term storage on the in vitro release kinetics and bioactivity of biomolecules from electrospun scaffolds

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Olivera Evrova ◽  
Damian Kellenberger ◽  
Chiara Scalera ◽  
Maurizio Calcagni ◽  
Pietro Giovanoli ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Growth Factor ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Storage Conditions ◽  
Bioactive Scaffolds ◽  
Acid Release ◽  
And Storage ◽  
Kinetics Of

Abstract To effectively translate bioactive scaffolds into a preclinical setting, proper sterilization techniques and storage conditions need to be carefully considered, as the chosen sterilization technique and storage condition might affect the structural and mechanical properties of the scaffolds, as well as the bioactivity and release kinetics of the incorporated biomolecules. Since rarely tested or quantified, we show here in a proof-of-concept study how these parameters are affected by UV sterilization and one week storage at different temperatures using bioactive electrospun DegraPol scaffolds that were specifically designed for application in the field of tendon rupture repair. Even though UV sterilization and the different storage conditions did not impact the morphology or the physicochemical properties of the bioactive scaffolds, UV sterilization caused significant attenuation of the growth factor release kinetics, here platelet derived growth factor (PDGF-BB) release (by approx. 85%) and slight decrease in ascorbic acid release (by approx. 20%). In contrast, 4 °C and −20 °C storage did not have a major effect on the release kinetics of PDGF-BB, while storage at room temperature caused increase in PDGF-BB released. All storage conditions had little effect on ascorbic acid release. Equally important, neither UV sterilization nor storage affected the bioactivity of the released PDGF-BB, suggesting stability of the bioactive scaffolds for at least one week and showing potential for bioactive DegraPol scaffolds to be translated into an off-the-shelf available product. These parameters are expected to be scaffold and protein-dependent.

Fabrication and Release Kinetics of Liposomes Containing Leuprolide Acetate

2021 ◽  
Vol 7 (1) ◽  
pp. 35-38
Author(s):  
Sudipta Das ◽  
Arnab Samanta ◽  
Koushik Bankura ◽  
Debatri Roy ◽  
Amit Nayak
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Zero Order ◽  
Leuprolide Acetate ◽  
Lipid Film ◽  
In Vitro Drug Release ◽  
Liposomal Formulations ◽  
Kinetics Of

The present work is focused on the preparation and in vitro release kinetics of liposomal formulation of Leuprolide Acetate. In this work, “Thin Lipid Film Hydration Method” was used for preparation of Leuprolide Acetate loaded liposomes. Prepared liposomal formulations of Leuprolide acetate was evaluated by drug entrapment study, in-vitro drug release kinetics and stability studies. The percentage drug entrapment of Leuprolide acetate for F1 and F2 formulations were found to be 78.14 ± 0.67 and 66.70 ± 0.81% respectively. In-vitro drug release study of liposomal formulations had shown zero order release pattern. Regression co-efficient (R2) value of Zero order kinetics for F1 and F2 formulations were 0.9912 and 0.9676 respectively. After storing formulations for 1 month, stability testing was done at 40C.It was found that all batches were stable. These liposomal formulations of Leuprolide acetate can be formulated for parenteral application to treat prostate cancer and in women, to treat symptoms of endometriosis (overgrowth of uterine lining outside of the uterus) or uterine fibroids.

Formulation and In Vitro Release Kinetics of Mucoadhesive Blend Gels Containing Matrine for Buccal Administration

2017 ◽  
Vol 19 (1) ◽  
pp. 470-480 ◽  
Author(s):  
Xiaojin Chen ◽  
Jun Yan ◽  
Shuying Yu ◽  
Pingping Wang
Keyword(s):  
Release Kinetics ◽  
In Vitro Release ◽  
Kinetics Of ◽  
Vitro Release

scholarly journals Development of a reservoir type prolonged release system with felodipine via simplex methodology

2015 ◽  
Vol 89 (1) ◽  
pp. 128-136
Author(s):  
Rareș Iuliu Iovanov ◽  
Ioan Tomuță ◽  
Sorin Emilian Leucuța
Keyword(s):  
Simplex Method ◽  
Release Kinetics ◽  
Prolonged Release ◽  
Lauryl Sulfate ◽  
Pore Former ◽  
Release System ◽  
Reservoir Type ◽  
Model Drug ◽  
Kinetics Of

Background and aims. Felodipine is a dihydropyridine calcium antagonist that presents good characteristics to be formulated as prolonged release preparations. The aim of the study was the formulation and in vitro characterization of a reservoir type prolonged release system with felodipine, over a 12 hours period using the Simplex method.Methods. The first step of the Simplex method was to study the influence of the granules coating method on the felodipine release. Furthermore the influence of the coating polymer type, the percent of the coating polymer and the percent of pore forming agent in the coating on the felodipine release were studied. Afterwards these two steps of the experimental design the percent of Surelease applied on the felodipine loaded granules and the percent of pore former in the polymeric coating formulation variables were studied. The in vitro dissolution of model drug was performed in phosphate buffer solution (pH 6.5) with 1% sodium lauryl sulfate. The released drug quantification was done using an HPLC method. The release kinetics of felodipine from the final granules was assessed using different mathematical models.Results. A 12 hours release was achieved using granules with the size between 315 – 500 µm coated with 45% Surelease with different pore former ratios in the coating via the top-spray method.Conclusion. We have prepared prolonged release coated granules with felodipine using a fluid bed system based on the Simplex method. The API from the studied final formulations was released over a 12 hours period and the release kinetics of the model drug substance from the optimized preparations fitted best the Higuchi and Peppas kinetic models. 

scholarly journals Drug Release Kinetics of Electrospun PHB Meshes

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1924 ◽  
Author(s):  
Vojtech Kundrat ◽  
Nicole Cernekova ◽  
Adriana Kovalcik ◽  
Vojtech Enev ◽  
Ivana Marova
Keyword(s):  
Release Kinetics ◽  
Entrapment Efficiency ◽  
Toxic Substances ◽  
Antimicrobial Efficiency ◽  
Vis Spectroscopy ◽  
Model Drug ◽  
Phosphate Buffered Saline ◽  
Kinetics Of

Microbial poly(3-hydroxybutyrate) (PHB) has several advantages including its biocompatibility and ability to degrade in vivo and in vitro without toxic substances. This paper investigates the feasibility of electrospun PHB meshes serving as drug delivery systems. The morphology of the electrospun samples was modified by varying the concentration of PHB in solution and the solvent composition. Scanning electron microscopy of the electrospun PHB scaffolds revealed the formation of different morphologies including porous, filamentous/beaded and fiber structures. Levofloxacin was used as the model drug for incorporation into PHB electrospun meshes. The entrapment efficiency was found to be dependent on the viscosity of the PHB solution used for electrospinning and ranged from 14.4–81.8%. The incorporation of levofloxacin in electrospun meshes was confirmed by Fourier-transform infrared spectroscopy and UV-VIS spectroscopy. The effect of the morphology of the electrospun meshes on the levofloxacin release profile was screened in vitro in phosphate-buffered saline solution. Depending upon the morphology, the electrospun meshes released about 14–20% of levofloxacin during the first 24 h. The percentage of drug released after 13 days increased up to 32.4% and was similar for all tested morphologies. The antimicrobial efficiency of all tested samples independent of the morphology, was confirmed by agar diffusion testing.

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