orabase and shellac

This study focuses on the synergistic formulation of environmentally friendly blended materials based on carboxymethyl cellulose (CMC) for advanced interactive wound dressing. New CMC hydrogels were prepared with two degrees of functionalization and chemically crosslinked with citric acid (CA) to fine-tune their properties. Additionally, CMC-based hybrids were created by blending with shellac (SHL) and incorporating self-antibacterial hydroxyapatite (HA) to inhibit bacterial growth and promote wound healing. The results demonstrate the successful production of superabsorbent hydrogels with typical swelling degrees ranging from 81% in water to 82% in phosphate-buffered saline (PBS). These hydrogels exhibit distinct morphological features and remarkable improvements in surface mechanical properties, specifically in their tensile properties, which show a significant increase from approximately 0.03 to 2.2 N/mm

Topics: Animals; Anti-Bacterial Agents; Bandages; Carboxymethylcellulose Sodium; Dogs; Durapatite; Humans; Hydrogels

The present work was devoted to prepare novel natural composite films based on carboxymethyl cellulose (CMC), gelatin and/or shellac. Four composites films series were prepared by altering the film compositions from CMC and gelatin or shellac. The composite films were prepared by solution casting in presence of glycerol (30% weight). Films were characterized by SEM, air permeability (porosity), tensile strength, burst strength, TGA and WVP. Antimicrobial activity in opposition to E. coli, B. mycoides and C. albicans were also investigated. The results revealed that, films exhibit flexibility with good antimicrobial, tensile strength, homogeneity, transparency, elongation properties, reduce porosity & air permeability and without signs of particles aggregation. Gelatin/CMC (50/50%) film was the most important one with respect to thermal stability, which exhibit a high thermal stability up to 800 °C. This study opens the door to use cellulosic composite materials to produce environmentally friendly, low-cost and sustainable packaging materials.

Topics: Anti-Infective Agents; Biocompatible Materials; Candida albicans; Carboxymethylcellulose Sodium; Escherichia coli; Gelatin; Mechanical Phenomena; Molecular Weight; Nanostructures; Permeability; Porosity; Product Packaging; Resins, Plant; Safety; Steam; Tensile Strength

The use of naturally derived excipients to develop enteric coatings offers significant advantages over conventional synthetic polymers. Unlike synthetic polymers, they are biodegradable, relatively abundant, have no daily intake limits or restrictions on use for dietary and nutraceutical products. However, little information is available on their dissolution properties under different gastrointestinal conditions and in comparison to each other. This work investigated the gastric resistance properties of commercially available GRAS-based coating technologies. Three coating systems were evaluated: ethyl cellulose+carboxymethyl cellulose (EC-CMC), ethyl cellulose+sodium alginate (EC-Alg) and shellac+sodium alginate (Sh-Alg) combinations. The minimum coating levels were optimized to meet USP pharmacopoeial criteria for delayed release formulations (<10% release after 2h in pH 1.2 followed by >80% release after 45 min of pH change). Theophylline 150 mg tablets were coated with 6.5%, 7%, and 2.75% coating levels of formulations EC-CMC, EC-Alg and Sh-Alg, respectively. In vitro dissolution test revealed a fast release in pH 6.8 for ethyl cellulose based coatings: t80% value of 65 and 45 min for EC-CMC and EC-Alg respectively, while a prolonged drug release from Sh-Alg coating was observed in both pH 6.8 and 7.4 phosphate buffers. However, when more biologically relevant bicarbonate buffer was used, all coatings showed slower drug release. Disintegration test, carried out in both simulated gastric and intestinal fluid, confirmed good mechanical resistance of EC-CMC and EC-Alg coating, and revealed poor durability of the thinner Sh-Alg. Under elevated gastric pH conditions (pH 2, 3 and 4), EC-CMC and EC-Alg coatings were broken after 70, 30, 55 min and after 30, 15, 15 min, respectively, while Sh-Alg coated tablets demonstrated gastric resistance at all pH values. In conclusion, none of the GRAS-grade coatings fully complied with the different biological demands of delayed release coating systems.

Topics: Alginates; Carboxymethylcellulose Sodium; Cellulose; Delayed-Action Preparations; Dietary Supplements; Drug Approval; Gastric Juice; Glucuronic Acid; Hexuronic Acids; Hydrogen-Ion Concentration; Intestinal Secretions; Resins, Plant; Tablets; Theophylline

Survival of the coliform bacteria Enterobacter aerogenes and Escherichia coli was monitored in a neutral carboxymethylcellulose formulation and in shellac formulations with various pH and concentrations of ethanol and the preservative paraben; populations were subsequently measured from the surface of citrus fruit coated with these formulations. Numbers of the two bacteria increased over 24 h from 10(6) CFU/ml to approximately 10(8) CFU/ml in the carboxymethylcellulose solution, but over this time numbers remained little changed in the neutral solution of shellac. The Enterobacter was more tolerant of alcohol over a 3-h period: although its numbers in a shellac solution with 10% ethanol dropped from more than 10(6) CFU/ml to just over 10(3) CFU/ml. E. coli and a third species. Klebsiella pneunoniae, declined toward the limit of detection (5 CFU/ ml) during this time. The addition of morpholine to increase the formulation pH to 9.0 caused numbers of bacteria to plummet to an undetectable level within 30 to 60 min. On Ruby Red grapefruit and Valencia oranges in storage at 13 degrees C numbers of E. aerogenes and E. coli declined over 2 weeks from 10(5) CFU/cm2 to less than 2.5 x 10(1), but most of the loss in numbers occurred within 1 day. Numbers remained significantly less on shellacked fruit compared with those applied in the carboxymethylcellulose coating, and a shellac coating prepared from a pH 9 solution was more toxic to these species than one in which 12% ethanol had been added to the neutral formulation. The addition of the preservative paraben in the basic shellac was further inhibitory.

Topics: Carboxymethylcellulose Sodium; Citrus; Colony Count, Microbial; Enterobacter aerogenes; Escherichia coli; Ethanol; Food Preservatives; Hydrogen-Ion Concentration; Parabens; Resins, Plant