scholarly journals Selection of Water-Soluble Chitosan by Microwave-Assisted Degradation and pH-Controlled Precipitation

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1274 ◽  
Author(s):  
Céline M. A. Journot ◽  
Laura Nicolle ◽  
Yann Lavanchy ◽  
Sandrine Gerber-Lemaire
Keyword(s):  
Molecular Weight ◽  
Average Molecular Weight ◽  
Aqueous Media ◽  
Phase Changes ◽  
Water Soluble ◽  
In Vivo Evaluation ◽  
Microwave Assisted ◽  
Selection Of

In the field of gene therapy, chitosan (CS) gained interest for its promise as a non-viral DNA vector. However, commercial sources of CS lack precise characterization and do not generally reach sufficient solubility in aqueous media for in vitro and in vivo evaluation. As low molecular weight CS showed improved solubility, we investigated the process of CS depolymerization by acidic hydrolysis, using either long time heating at 80 °C or short time microwave-enhanced heating. The resulting depolymerized chitosan (dCS) were analyzed by gel permeation chromatography (GPC) and 1H nuclear magnetic resonance (NMR) to determine their average molecular weight (Mn, Mp and Mw), polydispersity index (PD) and degree of deacetylation (DD). We emphasized the production of water-soluble CS (solubility > 5 mg/mL), obtained in reproducible yield and characteristics, and suitable for downstream functionalization. Optimal microwave-assisted conditions provided dCS with a molecular weight (MW) = 12.6 ± 0.6 kDa, PD = 1.41 ± 0.05 and DD = 85%. While almost never discussed in the literature, we observed the partial post-production aggregation of dCS when exposed to phase changes (from liquid to solid). Repeated cycles of freezing/thawing allowed the selection of dCS fractions which were exempt of crystalline particles formation upon solubilization from frozen samples.

Fenofibrate Solid Dispersion for Improving Oral Bioavailability: Preparation, and Characterization and in vivo Evaluation

2020 ◽  
Vol 13 (5) ◽  
pp. 5102-5109
Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi
Keyword(s):  
Oral Bioavailability ◽  
Oral Delivery ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Aqueous Solubility ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
In Vivo Evaluation

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.

Highly water-soluble derivatives of the anesthetic agent propofol: in vitro and in vivo evaluation of cyclic amino acid esters

2003 ◽  
Vol 20 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Cosimo Altomare ◽  
Giuseppe Trapani ◽  
Andrea Latrofa ◽  
Mariangela Serra ◽  
Enrico Sanna ◽  
...  
Keyword(s):  
Amino Acid ◽  
Water Soluble ◽  
Anesthetic Agent ◽  
Amino Acid Esters ◽  
In Vivo Evaluation ◽  
Derivatives Of ◽  
Acid Esters

In vitro and in vivo evaluation of the prebiotic activity of water-soluble blueberry extracts

2009 ◽  
Vol 25 (7) ◽  
pp. 1243-1249 ◽  
Author(s):  
Abdul Lateef Molan ◽  
Mary Ann Lila ◽  
John Mawson ◽  
Shampa De
Keyword(s):  
Water Soluble ◽  
In Vivo Evaluation ◽  
Prebiotic Activity

scholarly journals In vitro and in vivo evaluation of guar gum matrix tablets for oral controlled release of water-soluble diltiazem hydrochloride

2005 ◽  
Vol 6 (1) ◽  
pp. E14-E21 ◽  
Author(s):  
Saleh M. Al-Saidan ◽  
Yellela S. R. Krishnaiah ◽  
S. Patro ◽  
Vemulapalli Satyanaryana
Keyword(s):  
Controlled Release ◽  
Guar Gum ◽  
Water Soluble ◽  
Matrix Tablets ◽  
Diltiazem Hydrochloride ◽  
In Vivo Evaluation

scholarly journals A Simple Model for Assessment of Anti-Toxin Antibodies

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Alex Skvortsov ◽  
Peter Gray
Keyword(s):  
In Vitro Selection ◽  
Receptor Complex ◽  
Simple Mathematical Model ◽  
Antibody Affinity ◽  
In Vivo Evaluation ◽  
Degree Of Protection ◽  
Protective Antibodies ◽  
Selection Of

The toxins associated with infectious diseases are potential targets for inhibitors which have the potential for prophylactic or therapeutic use. Many antibodies have been generated for this purpose, and the objective of this study was to develop a simple mathematical model that may be used to evaluate the potential protective effect of antibodies. This model was used to evaluate the contributions of antibody affinity and concentration to reducing antibody-receptor complex formation and internalization. The model also enables prediction of the antibody kinetic constants and concentration required to provide a specified degree of protection. We hope that this model, once validated experimentally, will be a useful tool for in vitro selection of potentially protective antibodies for progression to in vivo evaluation.

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