In vitro Lipolysis as a Tool for the Establishment of IVIVC for Lipid-Based Drug Delivery Systems

2019 ◽  
Vol 16 (8) ◽  
pp. 688-697
Author(s):  
Ravinder Verma ◽  
Deepak Kaushik
Keyword(s):  
Drug Delivery ◽  
Ph Value ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Rapid Screening ◽  
Resonance Spectroscopy ◽  
Fed State ◽  
In Vitro Lipolysis ◽  
Ph Stat

: In vitro lipolysis has emerged as a powerful tool in the development of in vitro in vivo correlation for Lipid-based Drug Delivery System (LbDDS). In vitro lipolysis possesses the ability to mimic the assimilation of LbDDS in the human biological system. The digestion medium for in vitro lipolysis commonly contains an aqueous buffer media, bile salts, phospholipids and sodium chloride. The concentrations of these compounds are defined by the physiological conditions prevailing in the fasted or fed state. The pH of the medium is monitored by a pH-sensitive electrode connected to a computercontrolled pH-stat device capable of maintaining a predefined pH value via titration with sodium hydroxide. Copenhagen, Monash and Jerusalem are used as different models for in vitro lipolysis studies. The most common approach used in evaluating the kinetics of lipolysis of emulsion-based encapsulation systems is the pH-stat titration technique. This is widely used in both the nutritional and the pharmacological research fields as a rapid screening tool. Analytical tools for the assessment of in vitro lipolysis include HPLC, GC, HPTLC, SEM, Cryo TEM, Electron paramagnetic resonance spectroscopy, Raman spectroscopy and Nanoparticle Tracking Analysis (NTA) for the characterization of the lipids and colloidal phases after digestion of lipids. Various researches have been carried out for the establishment of IVIVC by using in vitro lipolysis models. The current publication also presents an updated review of various researches in the field of in vitro lipolysis.

scholarly journals Nitric oxide interactions with cobalamins: biochemical and functional consequences

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1857-1864 ◽  
Author(s):  
M Brouwer ◽  
W Chamulitrat ◽  
G Ferruzzi ◽  
DL Sauls ◽  
JB Weinberg
Keyword(s):  
Nitric Oxide ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
No Formation ◽  
Iron Nitrosyl ◽  
Wide Range ◽  
Functional Consequences

Abstract Nitric oxide (NO) is a paramagnetic gas that has been implicated in a wide range of biologic functions. The common pathway to evoke the functional response frequently involves the formation of an iron- nitrosyl complex in a target (heme) protein. In this study, we report on the interactions between NO and cobalt-containing vitamin B12 derivatives. Absorption spectroscopy showed that of the four Co(III) derivatives (cyanocobalamin [CN-Cbl], aquocobalamin [H2O-Cbl], adenosylcobalamin [Ado-Cbl], and methylcobalamin [MeCbl]), only the H2O- Cbl combined with NO. In addition, electron paramagnetic resonance spectroscopy of H2O-Cbl preparations showed the presence of a small amount of Cob-(II)alamin that was capable of combining with NO. The Co(III)-NO complex was very stable, but could transfer its NO moiety to hemoglobin (Hb). The transfer was accompanied by a reduction of the Co(III) to Co(II), indicating that NO+ (nitrosonium) was the leaving group. In accordance with this, the NO did not combine with the Hb Fe(II)-heme, but most likely with the Hb cysteine-thiolate. Similarly, the Co(III)-NO complex was capable of transferring its NO to glutathione. Ado-Cbl and Me-Cbl were susceptible to photolysis, but CN- Cbl and H2O-Cbl were not. The homolytic cleavage of the Co(III)-Ado or Co(III)-Me bond resulted in the reduction of the metal. When photolysis was performed in the presence of NO, formation of NO-Co(II) was observed. Co(II)-nitrosyl oxidized slowly to form Co(III)-nitrosyl. The capability of aquocobalamin to combine with NO had functional consequences. We found that nitrosylcobalamin had diminished ability to serve as a cofactor for the enzyme methionine synthase, and that aquocobalamin could quench NO-mediated inhibition of cell proliferation. Our in vitro studies therefore suggest that interactions between NO and cobalamins may have important consequences in vivo.

Using in vitro lipolysis and SPECT/CT in vivo imaging to understand oral absorption of fenofibrate from lipid-based drug delivery systems

2020 ◽  
Vol 317 ◽  
pp. 375-384 ◽  
Author(s):  
Thuy Tran ◽  
Peter Bønløkke ◽  
Cristina Rodríguez-Rodríguez ◽  
Zeynab Nosrati ◽  
Pedro Luis Esquinas ◽  
...  
Keyword(s):  
Drug Delivery ◽  
In Vivo Imaging ◽  
Drug Delivery Systems ◽  
Oral Absorption ◽  
Delivery Systems ◽  
In Vitro Lipolysis

scholarly journals Besifloxacin liposomes with positively charged additives for an improved topical ocular delivery

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Giselly Almeida dos Santos ◽  
Ricardo Ferreira-Nunes ◽  
Luciana Facco Dalmolin ◽  
Ana Carolina dos Santos Ré ◽  
Jorge Luiz Vieira Anjos ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Defense Mechanisms ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Drug Penetration ◽  
Current Application ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic ◽  
Positively Charged

Abstract Topical ophthalmic antibiotics show low efficacy due to the well-known physiological defense mechanisms of the eye, which prevents the penetration of exogenous substances. Here, we aimed to incorporate besifloxacin into liposomes containing amines as positively charged additives and to evaluate the influence of this charge on drug delivery in two situations: (i) iontophoretic and (ii) passive treatments. Hypothesis are (i) charge might enhance the electromigration component upon current application improving penetration efficiency for a burst drug delivery, and (ii) positive charge might prolong formulation residence time, hence drug penetration. Liposomes elaborated with phosphatidylcholine (LP PC) or phosphatidylcholine and spermine (LP PC: SPM) were stable under storage at 6 ºC for 30 days, showed mucoadhesive characteristics, and were non-irritant, according to HET-CAM tests. Electron paramagnetic resonance spectroscopy measurements showed that neither the drug nor spermine incorporations produced evident alterations in the fluidity of the liposome's membranes, which retained their structural stability even under iontophoretic conditions. Mean diameter and zeta potential were 177.2 ± 2.7 nm and − 5.7 ± 0.3 mV, respectively, for LP PC; and 175.4 ± 1.9 nm and + 19.5 ± 1.0 mV, respectively, for LP PC:SPM. The minimal inhibitory concentration (MIC) and the minimal bactericide concentration (MBC) of the liposomes for P. aeruginosa showed values lower than the commercial formulation (Besivance). Nevertheless, both formulations presented a similar increase in permeability upon the electric current application. Hence, liposome charge incorporation did not prove to be additionally advantageous for iontophoretic therapy. Passive drug penetration was evaluated through a novel in vitro ocular model that simulates the lacrimal flow and challenges the formulation resistance in the passive delivery situation. As expected, LP PC: SPM showed higher permeation than the control (Besivance). In conclusion, besifloxacin incorporation into positively charged liposomes improved passive topical delivery and can be a good strategy to improve topical ophthalmic treatments.

scholarly journals Estimating the Oral Absorption from Self-Nanoemulsifying Drug Delivery Systems Using an In Vitro Lipolysis-Permeation Method

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 489
Author(s):  
Mette Klitgaard ◽  
Anette Müllertz ◽  
Ragna Berthelsen
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Oral Absorption ◽  
Aqueous Suspension ◽  
Delivery Systems ◽  
Time Curve ◽  
Drug Permeation ◽  
In Vitro Lipolysis

The aim of this study was to design an in vitro lipolysis-permeation method to estimate drug absorption following the oral administration of self-nanoemulsifying drug delivery systems (SNEDDSs). The method was evaluated by testing five oral formulations containing cinnarizine (four SNEDDSs and one aqueous suspension) from a previously published pharmacokinetic study in rats. In that study, the pharmacokinetic profiles of the five formulations did not correlate with the drug solubilization profiles obtained during in vitro intestinal lipolysis. Using the designed lipolysis-permeation method, in vitro lipolysis of the five formulations was followed by in vitro drug permeation in Franz diffusion cells equipped with PermeaPad® barriers. A linear in vivo–in vitro correlation was obtained when comparing the area under the in vitro drug permeation–time curve (AUC0–3h), to the AUC0–3h of the plasma concentration–time profile obtained from the in vivo study. Based on these results, the evaluated lipolysis-permeation method was found to be a promising tool for estimating the in vivo performance of SNEDDSs, but more studies are needed to evaluate the method further.

scholarly journals Tabotamp®, Respectively, Surgicel®, Increases the Cell Death of Neuronal and Glial Cells In Vitro

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2453
Author(s):  
Sandra Leisz ◽  
Marie-Luise Trutschel ◽  
Karsten Mäder ◽  
Christian Scheller ◽  
Christian Strauss ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Schwann Cells ◽  
Cell Lines ◽  
Ph Value ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Regenerated Cellulose ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Eloquent Areas

Oxidized regenerated cellulose (ORC) is an approved absorbable hemostat in neurosurgery, and contains 18–21% carboxylic acid groups. This modification leads to a low pH in aqueous solutions. Therefore, the aim of study was to analyze the pH-dependent effects of the ORC Tabotamp® on astrocytes, Schwann cells, and neuronal cells in vitro to investigate whether Tabotamp® is a suitable hemostat in cerebral eloquent areas. The ORC-dependent pH value changes were measured with (i) a pH meter, (ii) electron paramagnetic resonance spectroscopy, using pH-sensitive spin probes, and (iii) with fluorescence microscopy. Cell lines from neurons, astrocytes, and Schwann cells, as well as primary astrocytes were incubated with increasing areas of Tabotamp®. Cytotoxicity was detected using a fluorescence labeled DNA-binding dye. In addition, the wounding extent was analyzed via crystal violet staining of cell layers. The strongest pH reduction (to 2.2) was shown in phosphate buffered saline, whereas culture medium and cerebrospinal fluid demonstrated a higher buffer capacity during Tabotamp® incubation. In addition, we could detect a distance-dependent pH gradient by fluorescence microscopy. Incubation of Tabotamp® on cell monolayers led to detachment of covered cells and showed increased cytotoxicity in all tested cell lines and primary cells depending on the covered area. These in vitro results indicate that Tabotamp® may not be a suitable hemostat in cerebral eloquent areas.

scholarly journals In Vitro Lipolysis Data Does Not Adequately Predict the In Vivo Performance of Lipid-Based Drug Delivery Systems Containing Fenofibrate

2014 ◽  
Vol 16 (3) ◽  
pp. 539-549 ◽  
Author(s):  
Nicky Thomas ◽  
Katharina Richter ◽  
Thomas B. Pedersen ◽  
René Holm ◽  
Anette Müllertz ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
In Vitro Lipolysis

scholarly journals A Second [2Fe-2S] Ferredoxin from Sphingomonas sp. Strain RW1 Can Function as an Electron Donor for the Dioxin Dioxygenase

2000 ◽  
Vol 182 (8) ◽  
pp. 2238-2244 ◽  
Author(s):  
Jean Armengaud ◽  
Jacques Gaillard ◽  
Kenneth N. Timmis
Keyword(s):  
Electron Donor ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
In Vitro Assays ◽  
Resonance Spectroscopy ◽  
Hydrogen Electrode ◽  
Visible Absorption ◽  
Paramagnetic Resonance ◽  
Reading Frame

ABSTRACT The first step in the degradation of dibenzofuran and dibenzo-p-dioxin by Sphingomonas sp. strain RW1 is carried out by dioxin dioxygenase (DxnA1A2), a ring-dihydroxylating enzyme. An open reading frame (fdx3) that could potentially specify a new ferredoxin has been identified downstream ofdxnA1A2, a two-cistron gene (J. Armengaud, B. Happe, and K. N. Timmis, J. Bacteriol. 180:3954–3966, 1998). In the present study, we report a biochemical analysis of Fdx3 produced inEscherichia coli. This third ferredoxin thus far identified in Sphingomonas sp. strain RW1 contained a putidaredoxin-type [2Fe-2S] cluster which was characterized by UV-visible absorption spectrophotometry and electron paramagnetic resonance spectroscopy. The midpoint redox potential of this ferredoxin (E′0 = −247 ± 10 mV versus normal hydrogen electrode at pH 8.0) is similar to that exhibited by Fdx1 (−245 mV), a homologous ferredoxin previously characterized inSphingomonas sp. strain RW1. In in vitro assays, Fdx3 can be reduced by RedA2 (a reductase similar to class I cytochrome P-450 reductases), previously isolated from Sphingomonas sp. strain RW1. RedA2 exhibits a Km value of 3.2 ± 0.3 μM for Fdx3. In vivo coexpression of fdx3and redA2 with dxnA1A2 confirmed that Fdx3 can serve as an electron donor for the dioxin dioxygenase.

scholarly journals Evaluation of Biological Toxicity of CdTe Quantum Dots in Trypanosoma cruzi

2020 ◽  
Vol 9 (12) ◽  
pp. e34391211274
Author(s):  
Graziella Santos Martins ◽  
Suzete Araújo Oliveira Gomes ◽  
Sônia Renaux Wanderley Louro ◽  
Eliane Wajnberg ◽  
Odivaldo Cambraia Alves ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Trypanosoma Cruzi ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Semiconductor Nanocrystals ◽  
Growth Curves ◽  
Ros Generation ◽  
Resonance Spectroscopy ◽  
Biological Toxicity

Luminescent semiconductor nanocrystals or quantum dots (QDs) emerge as important fluorescent probes for in vitro and in vivo Trypanosoma cruzi cells studies. However, to ensure applicability to living organisms, several tests still need to be done. Since several toxic events are caused by QDs, such as loss of mitochondrial membrane potential, ROS generation, DNA damage and cell death by autophagy. We performed a review of the literature on mechanisms of cellular uptake, internalization and citotoxicity of nanoparticles including our results about the evaluation of biological toxicity in T. cruzi. We evaluated the possible effects on parasite growth curves in a time - scale of control and incubated cells with different concentrations of CdTe – QDs (0.2; 2.0; 20 and 200µM) to determine the development cells changes. In addition, intracellular ROS were measured by Electron Paramagnetic Resonance Spectroscopy (EPR) technique. According our results, we can infer that the toxic effects of QDs in T. cruzi are dose-dependent and that high levels of ROS are involved in cellular toxicity promoted by higher concentrations of QDs. In summary, parasites labeled with low concentrations of nanoparticles are suitable and can be used as bioimaging tools for living parasites. However, more studies on QDs cytotoxicity need to be carried out.

scholarly journals Nitric oxide interactions with cobalamins: biochemical and functional consequences

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1857-1864
Author(s):  
M Brouwer ◽  
W Chamulitrat ◽  
G Ferruzzi ◽  
DL Sauls ◽  
JB Weinberg
Keyword(s):  
Nitric Oxide ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
No Formation ◽  
Iron Nitrosyl ◽  
Wide Range ◽  
Functional Consequences

Nitric oxide (NO) is a paramagnetic gas that has been implicated in a wide range of biologic functions. The common pathway to evoke the functional response frequently involves the formation of an iron- nitrosyl complex in a target (heme) protein. In this study, we report on the interactions between NO and cobalt-containing vitamin B12 derivatives. Absorption spectroscopy showed that of the four Co(III) derivatives (cyanocobalamin [CN-Cbl], aquocobalamin [H2O-Cbl], adenosylcobalamin [Ado-Cbl], and methylcobalamin [MeCbl]), only the H2O- Cbl combined with NO. In addition, electron paramagnetic resonance spectroscopy of H2O-Cbl preparations showed the presence of a small amount of Cob-(II)alamin that was capable of combining with NO. The Co(III)-NO complex was very stable, but could transfer its NO moiety to hemoglobin (Hb). The transfer was accompanied by a reduction of the Co(III) to Co(II), indicating that NO+ (nitrosonium) was the leaving group. In accordance with this, the NO did not combine with the Hb Fe(II)-heme, but most likely with the Hb cysteine-thiolate. Similarly, the Co(III)-NO complex was capable of transferring its NO to glutathione. Ado-Cbl and Me-Cbl were susceptible to photolysis, but CN- Cbl and H2O-Cbl were not. The homolytic cleavage of the Co(III)-Ado or Co(III)-Me bond resulted in the reduction of the metal. When photolysis was performed in the presence of NO, formation of NO-Co(II) was observed. Co(II)-nitrosyl oxidized slowly to form Co(III)-nitrosyl. The capability of aquocobalamin to combine with NO had functional consequences. We found that nitrosylcobalamin had diminished ability to serve as a cofactor for the enzyme methionine synthase, and that aquocobalamin could quench NO-mediated inhibition of cell proliferation. Our in vitro studies therefore suggest that interactions between NO and cobalamins may have important consequences in vivo.

Recent In Vitro and In Silico Advances in the Understanding of Intranasal Drug Delivery

2020 ◽  
Vol 26 ◽  
Author(s):  
John Chen ◽  
Andrew Martin ◽  
Warren H. Finlay
Keyword(s):  
Drug Delivery ◽  
In Silico ◽  
Local Drug Delivery ◽  
In Vivo Studies ◽  
Intranasal Drug Delivery ◽  
Nasal Sprays ◽  
In Silico Studies ◽  
Drug Delivery Devices

Background: Many drugs are delivered intranasally for local or systemic effect, typically in the form of droplets or aerosols. Because of the high cost of in vivo studies, drug developers and researchers often turn to in vitro or in silico testing when first evaluating the behavior and properties of intranasal drug delivery devices and formulations. Recent advances in manufacturing and computer technologies have allowed for increasingly realistic and sophisticated in vitro and in silico reconstructions of the human nasal airways. Objective: To perform a summary of advances in understanding of intranasal drug delivery based on recent in vitro and in silico studies. Conclusion: The turbinates are a common target for local drug delivery applications, and while nasal sprays are able to reach this region, there is currently no broad consensus across the in vitro and in silico literature concerning optimal parameters for device design, formulation properties and patient technique which would maximize turbinate deposition. Nebulizers are able to more easily target the turbinates, but come with the disadvantage of significant lung deposition. Targeting of the olfactory region of the nasal cavity has been explored for potential treatment of central nervous system conditions. Conventional intranasal devices, such as nasal sprays and nebulizers, deliver very little dose to the olfactory region. Recent progress in our understanding of intranasal delivery will be useful in the development of the next generation of intranasal drug delivery devices.

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