Irradiation-Induced Changes in Hydroxypropyl Cellulose

1995 ◽  
Vol 394 ◽  
Author(s):  
Mark A. Petrich ◽  
Lawrence A. Rosen
Keyword(s):  
Molecular Weight ◽  
Gamma Irradiation ◽  
Pharmaceutical Formulations ◽  
Hydroxypropyl Cellulose ◽  
Water Soluble ◽  
Cross Linking ◽  
Dissolution Behavior ◽  
Subsequent Effect ◽  
Sterilization Process ◽  
Induced Changes

AbstractGamma irradiation is used to sterilize products intended for ophthalmic and parenteral use. Ideally, the sterilization process should not affect the chemical identity or physical properties of the product. We have investigated the effects of gamma irradiation on the structure and molecular weight of hydroxypropyl cellulose (HPC), and the subsequent effect on dissolution behavior of HPC. Hydroxypropyl cellulose is a commonly used excipient in pharmaceutical formulations and tablet coatings, and can be used to manufacture water soluble objects. We find that the moisture content of the HPC influences the extent to which scission and cross-linking reactions occur. At low moisture levels (<5 wt.%), cross-linking is relatively unimportant, while above 12 wt. % moisture cross-linking becomes extensive leading to formation of insoluble, rubber-like gels.

Effect of gamma irradiation on the physicochemical and rheological properties of enzyme-catalyzed tragacanth-based injectable hydrogels

2019 ◽  
Vol 39 (5) ◽  
pp. 442-449 ◽  
Author(s):  
Moslem Tavakol ◽  
Ebrahim Vasheghani-Farahani ◽  
Mohammad Amin Mohammadifar ◽  
Maryam Dehghan-Niri
Keyword(s):  
Molecular Weight ◽  
Gamma Irradiation ◽  
Rheological Properties ◽  
Storage Modulus ◽  
Coupling Reaction ◽  
Water Soluble ◽  
Solution Viscosity ◽  
Injectable Hydrogels ◽  
Gum Tragacanth

Abstract In the present study, gamma irradiation was applied to promote the mechanical properties of enzyme- mediated in situ forming hydrogels prepared with tyramine-functionalized gum tragacanth (TA-GT). For this purpose, after gamma irradiation of powder or hydrocolloid solution of gum tragacanth (GT), the physiochemical and rheological properties of GT solution, and resultant hydrogel was investigated. In situ forming hydrogels were prepared via horseradish peroxidase catalyzed coupling reaction of TA-GT in the presence of hydrogen peroxide. Gamma irradiation led to a decrease in GT molecular weight and solution viscosity. Also, the solubility of GT improved and the separation of water soluble/swellable part of gum samples became easier, using gamma irradiation. In addition, by gamma irradiation of GT powder at doses of 5–15 kGy, a polymeric solution with higher concentration could be prepared that resulted in the promotion of hydrogels storage modulus. Further increase of irradiation dose did not improve storage modulus due to the extra decrease of gum molecular weight.

scholarly journals Synthesis and Coordination Properties of a Water-Soluble Material by Cross-Linking Low Molecular Weight Polyethyleneimine with Armed Cyclotriveratrilene

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4133
Author(s):  
Yoke Mooi Ng ◽  
Paolo Coghi ◽  
Jerome P. L. Ng ◽  
Fayaz Ali ◽  
Vincent Kam Wai Wong ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydrophobic Interactions ◽  
Water Soluble ◽  
Ionic Interactions ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Hydrophilic Drugs ◽  
Drug Molecules ◽  
Soluble Material ◽  
High Coordination

In this study, a full organic and water-soluble material was synthesized by coupling low molecular weight polyethylenimine (PEI-800) with cyclotriveratrilene (CTV). The water-soluble cross-linked polymer contains hydrophobic holes with a high coordination capability towards different organic drug molecules. The coordinating capability towards hydrophilic drugs (doxorubicin, gatifloxacin and sinomenine) and hydrophobic drugs (camptothecin and celastrol) was analyzed in an aqueous medium by using NMR, UV-Vis and emission spectroscopies. The coordination of drug molecules with the armed CTV unit through hydrophobic interactions was observed. In particular, celastrol exhibited more ionic interactions with the PEI moiety of the hosting system. In the case of doxorubicin, the host–guest detachment was induced by the addition of ammonium chloride, suggesting that the intracellular environment can facilitate the release of the drug molecules.

Cross-Linked αsγt-Chain Hybrids in Plasma Clots Studied by 1D- and 2D Electrophoresis and Western Blotting

1993 ◽  
Vol 70 (03) ◽  
pp. 438-442 ◽  
Author(s):  
B Grøn ◽  
C Filion-Myklebust ◽  
S Bjørnsen ◽  
P Haidaris ◽  
F Brosstad
Keyword(s):  
Molecular Weight ◽  
Monoclonal Antibodies ◽  
Human Plasma ◽  
Western Blotting ◽  
Isoelectric Point ◽  
Factor Xiii ◽  
Cross Linking ◽  
2D Electrophoresis ◽  
Complex Phenomenon ◽  
Fibrinopeptide A

SummaryFibrinogen and fibrin related chains in reduced human plasma as well as the bonds interlinking partially cross-linked fibrin from plasma clots have been studied by means of 1D- and 2D electrophoresis and Western blotting. Immunovisualization of reduced plasma or partially cross-linked fibrin with monoclonal antibodies specific for the α-chains or the γ-chains have shown that several bands represent material belonging to both chains. In order to decide whether these bands constitute αγ-chain hybrids or superimposed α- and γ-chain dimers, the cross-linked material was separated according to both isoelectric point (pI) and molecular weight (MW) using Pharmacia’s Multiphor II system. Western blotting of the second dimension gels revealed that partially cross-linked fibrin contains αsγt-chain hybrids and γ- polymers, in addition to the well-known γ-dimers and α-polymers. The main αsγt-chain hybrid has a pI between that of the α- and the γ-chains, a MW of about 200 kDa and contains Aα-chains with intact fibrinopeptide A (FPA). It was also observed that soluble fibrinogen/fibrin complexes as well as partially cross-linked fibrin contain degraded α-dimers with MWs close to the γ-dimers. These findings demonstrate that factor XIII-catalyzed cross-linking of fibrin is a more complex phenomenon than earlier recognized.

Pharmaceutical Polymers - A Review

2019 ◽  
Vol 9 (01) ◽  
pp. 27-33
Author(s):  
Naveen Kumar ◽  
Sonia Pahuja ◽  
Ranjit Sharma
Keyword(s):  
Drug Release ◽  
Industrial Revolution ◽  
Pharmaceutical Formulations ◽  
Pharmaceutical Products ◽  
Water Soluble ◽  
Taste Masking ◽  
Natural Polymers ◽  
Pharmaceutical Dosage Forms ◽  
Pharmaceutical Applications ◽  
Pharmaceutical Industries

Humans have taken advantage of the adaptability of polymers for centuries in the form of resins, gums tars, and oils. However, it was not until the industrial revolution that the modern polymer industry began to develop. Polymers represent an important constituent of pharmaceutical dosage forms. Polymers have played vital roles in the formulation of pharmaceutical products. Polymers have been used as a major tool to manage the drug release rate from the formulations. Synthetic and natural-based polymers have found their way into the biomedical and pharmaceutical industries. Synthetic and Natural polymers can be produced with a broad range of strength, heat resistance, density, stiffness and even price. By constant research into the science and applications of polymers, they are playing an ever-increasing role in society. Diverse applications of polymers in the present pharmaceutical field are for controlled drug release. Based on solubility pharmaceutical polymers can be classified as water-soluble and water-insoluble. In general, the desirable polymer properties in pharmaceutical applications are film forming, adhesion, gelling, thickening, pH-dependent solubility and taste masking. General pharmaceutical applications of polymers in various pharmaceutical formulations are also discussed

ANALISA KANDUNGAN BETA-GLUKAN LARUT AIR DAN LARUT ALKALI DARI TUBUH BUAH JAMUR TIRAM (Pleurotus ostreatus) DAN SHIITAKE (Lentinus edodes)

2013 ◽  
Vol 13 (3) ◽  
Author(s):  
Netty Widyastuti ◽  
Teguh Baruji ◽  
Henky Isnawan ◽  
Priyo Wahyudi ◽  
Donowati Donowati
Keyword(s):  
Molecular Structure ◽  
Molecular Weight ◽  
Immune System ◽  
Pleurotus Ostreatus ◽  
Water Soluble ◽  
Low Molecular Weight ◽  
Lentinus Edodes ◽  
Beta Glucan ◽  
Oyster Mushrooms ◽  
The Difference

Beta glucan is a polysaccharide compound, generally not soluble inwater and resistant to acid. Beta glucan is used as an immunomodulator (enhancing the immune system) in mammals is usually a beta-glucan soluble in water, easily absorbed and has a low molecular weight. Several example of beta-glucan such as cellulose (β-1 ,4-glucan), lentinan (β-1 0.6-glucan) and (β-1 ,3-glucan), pleuran (β-1, 6 and β-1 ,3-glucan) are isolated from species of fungi Basidiomycota include mushrooms (Pleurotus ostreatus) and shiitake (Lentinus edodes).The purpose of thisresearch activity is to obtain beta-glucan compound that can be dissolved in water and in alkali derived from fungi Basidiomycota, i.e, Oyster mushrooms (Pleurotus ostreatus) and shiitake (Lentinus edodes). The result of beta-glucan compared to characterize the resulting beta glucan that is molecular structure . The difference of beta glucan extraction is based on the differences in solubility of beta-glucan. Beta glucan could be water soluble and insoluble water.

scholarly journals Wound Healing Promotion by Hyaluronic Acid: Effect of Molecular Weight on Gene Expression and In Vivo Wound Closure

2021 ◽  
Vol 14 (4) ◽  
pp. 301
Author(s):  
Yayoi Kawano ◽  
Viorica Patrulea ◽  
Emmanuelle Sublet ◽  
Gerrit Borchard ◽  
Takuya Iyoda ◽  
...  
Keyword(s):  
Gene Expression ◽  
Molecular Weight ◽  
Wound Healing ◽  
Hyaluronic Acid ◽  
Healing Process ◽  
Dermal Fibroblasts ◽  
Water Soluble ◽  
Wound Healing Process ◽  
And Migration ◽  
Proliferation And Migration

Hyaluronic acid (HA) has been known to play an important role in wound healing process. However, the effect of molecular weight (MW) of exogenously administered HA on the wound healing process has not been fully understood. In this study, we investigated HA with different MWs on wound healing process using human epidermal keratinocytes and dermal fibroblasts. Cell proliferation and migration ability were assessed by water soluble tetrazolium (WST) assay and wound scratch assay. We examined the effect of HA addition in a full-thickness wound model in mice and the gene expression related to wound healing. Proliferation and migration of HaCaT cells increased with the increase of MW and concentration of HA. Interleukin (IL-1β), IL-8 and vascular endothelial growth factor (VEGF) as well as matrix metalloproteinase (MMP)-9 and MMP-13 were significantly upregulated by high molecular weight (HMW) HA in keratinocytes. Together with VEGF upregulation and the observed promotion of HaCaT migration, HA with the MW of 2290 kDa may hold potential to improve re-epithelialization, a critical obstacle to heal chronic wounds.

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