DOCSLIB.ORG

Basic Concepts of Cellulose Polymers - a Comprehensive Review

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Basic Concepts of Cellulose Polymers - a Comprehensive Review Archives of Pharmacy Practice Review Article ISSN 2045-080X Vol 3 , Issue 3 , 2012 Basic Concepts Of Cellulose Polymers - A Comprehensive Review Harika K, Sunitha K, Pavan Kumar P, Maheshwar K and Madhusudan Rao Y* Department of Pharmaceutics, National facilities in Engineering and Technology with Industrial Collaboration (NAFETIC) centre, University College of Pharmaceutical Sciences, Kakatiya University, Warangal – 506 009, A.P. India. Citation: Harika K, Sunitha K, Pavan Kumar P, Maheshwar K and Madhusudan Rao Y. Basic Concepts Of Cellulose Polymers- A Comprehensive Review. Archives of Pharmacy Practice. 2012; 3(3)pp202-216. Abstract Man’s pursuance for new and improved materials has been should promote innovation. To assist the exploitation expanding with time and it can be said that it is unending. of novel drug delivery systems the need for polymers Though introduced very late in the chain of materials, continues to increase. polymers occupy a major place and pivotal position in our This review serves as a comprehensive source to improve materials map today. Unfolding of the science of polymers and understanding of cellulose derivative polymers and create polymer – based materials had evoked lot of interest and made new avenues in development of a delivery system. In them as a class of materials for their potential use in the field of addition, this review presents in-depth information on pharmaceuticals and industry based products. In recent years, various aspects of polymer chemistry, nomenclature, an awareness and understanding of these polymers has various polymer grades, physical characteristics of increased based upon the following factors. polymers, solubility, and the utility of polymers for As pharmaceutically active ingredients continue to become various drug delivery systems. more ‘‘potent’’ the effective controlled delivery of doses have become intriguing. As a result, polymers now often Introduction constitute the major portion of many pharmaceutical Cellulose is the most copious naturally occurring dosage forms and as such can have profound impact on the “biopolymer”. The main constituent of various natural reproducibility of drug release and overall performance of fibers such as cotton and higher plants is cellulose. It the dosage forms. consists of long chains of anhydro-D-glucopyranose units The technical complexities associated with drug (AGU) with each cellulose molecule having three hydroxyl development have increased in controlled delivery due to groups per AGU, except at the terminal ends. Cellulose is challenges such as complex drug actives, and in cases of insoluble in water and most common solvents; the poor biotech products, stabilization of the active ingredient. The solubility is accredited primarily to the strong multidisciplinary understanding of polymers is thus intramolecular and intermolecular hydrogen bonding required including technical, safety, quality, and regulatory between the individual chains. Regardless of its poor aspects, which, prior to this effort, has not been available in solubility characteristics, cellulose is used in a wide range a single resource. of applications including composites, netting, upholstery, It also proposes new and innovative ways for regulatory coatings, packing, paper, etc. Cellulose is chemically review of polymers, which, if adopted, modified to improve process ability and to produce cellulose derivatives (cellulosics) which can be tailored Key words for specific industrial applications [1-5]. Cellulosics are in Cellulose Polymers, Premium Product Grades, Viscosities, general strong, reproducible, recyclable and Solubility. biocompatible, being used in various biomedical applications such as blood purification membranes and Manuscript History the like. Thus, through derivatization, cellulosics have Article Received on: 1st Jan, 2012 opened a window of opportunity and have broadened Revised on: 30th April, 2012 their use. Approved for Publication: 10th June, 2012 Cellulose derivatives are a branch of semi-synthetic polymers used in controlled drug delivery. In this review, Corresponding Author we summarize all the critical properties of cellulose ethers Prof. Y. Madhusudan Rao that can be utilized for fulfilling the need of controlling the National facilities in Engineering and Technology with release of active ingredient from a drug delivery system. Industrial Collaboration (NAFETIC) centre, University College of Pharmaceutical Sciences, Kakatiya University Chemically modified derivatives of cellulose: Warangal- 506 009 (A.P), India Tel: +91 870 2438844, Fax: +91 870 2453508 Cellulose (Fig 1) being water insoluble, etherification and esterification at hydroxyl groups bring about drastic Email: [email protected] changes in its original properties making its derivatives Page 202 Archives of Pharmacy Practice Vol 3 , Issue3 , 2012 Archives of Pharmacy Practice soluble in organic and aqueous solvents [6]. The hydroxyl Table 2: Ester derivatives [6] groups (-OH) of cellulose can be partially or fully reacted with Cellulose Reagent Example Reagent various reagents to afford derivatives with useful properties ester like mainly cellulose esters and cellulose ethers (-OR). Organic Organic Cellulose Acetic acid and esters acids acetate acetic anhydride Cellulose Acetic acid and triacetate acetic anhydride Cellulose Propanoic acid propionate Cellulose Acetic acid and acetate propanoic acid Figure 1: Molecular structure of cellulose propionate Etherification: Cellulose ethers can be prepared by treating Cellulose Acetic acid and alkali cellulose with a number of various reagents including acetate butyric acid alkyl or aryl halides (or sulfates), alkene oxides, and butyrate unsaturated compounds activated by electron-attracting Inorganic Inorganic Nitrocellulose Nitric acid or groups (Eq 1). esters acids (cellulose another nitrate) powerful nitrating agent Cellulose Sulfuric acid or Equation 1: Etherification of cellulose. R’= organic radical (CH3- sulfate another , C2H5–, etc) powerful Table 1: Ether derivatives [6,7] sulfuring agent Cellulose Reagent Example Reagent ethers Cellulose acetate phthalate is obtained by partial Alkyl Halogeno Methylcellulose Chloromethane substitution of cellulose acetate (CA) with phthalic alkanes Ethylcellulose Chloroethane anhydride in the presence of an organic solvent and a Ethyl methyl Chloromethane basic catalyst. cellulose and chloroethane METHOD HOW THE INFORMATION WAS Hydroxy Epoxides Hydroxyethyl Ethylene oxide GATHERED/ CRITERIA FOR THE SELECTION OF alkyl cellulose ARTICLES Hydroxypropyl Propylene Information was gathered from product cellulose (HPC) oxide brochures of chemical companies (Dow, Hercules, Hydroxyethyl Chloromethane Aqualon, WeKcelo) which are synthesizing these methyl and ethylene polymers. cellulose oxide Physical description of the materials was Hydroxypropyl Chloromethane obtained from Material safety data sheet (MSDS) methyl and propylene of these particular polymers. cellulose oxide Other information was also considered from (HPMC) monographs of the different pharmacopeias. Ethyl Chloroethane Some basic concepts about the cellulosic hydroxyethyl and ethylene polymers were obtained from articles published cellulose oxide in various journals. Carboxy Halogenated Carboxymethyl Chloroacetic alkyl carboxylic cellulose (CMC) acid PROPERTIES OF CELLULOSE DERIVATIVE acids POLYMERS The sodium carboxymethyl cellulose can be cross-linked to Cellulose ethers: The factors associated with polymers, give the croscarmellose sodium (E468) for use as a such as molecular weight, viscosity, concentration, degree disintegrant in pharmaceutical formulations. of substitution and particle sizes have a significant influence on drug release. Hence, it is necessary to have thorough knowledge of the polymer properties to choose Esterification: The esterification can be considered as a the suitable polymer to control the release from a typical equilibrium reaction in which an alcohol and acid react particular dosage form. Among the known polymers, to form ester and water. Cellulose is esterified with certain cellulose ethers are materials of choice for controlled drug acids such as acetic acid, nitric acid, sulfuric acid and release which are discussed in detail in this review. phosphoric acid. Page 203 Archives of Pharmacy Practice Vol 3 , Issue3 , 2012 Archives of Pharmacy Practice Table 3: A Versatile Range of Polymer Properties [8] METHYL ETHYL HPMC CELLULOSE NITRO PROPERTIES HEC CMC CELLULOSE CELLULOSE &HPC ACETATE CELLULOSE Water soluble Organo soluble Gel forming Film forming Mucoadhesive High swelling Hydrophilic Hydrophobic Viscosifying Thermoplastic Drug solubilizer Table 1 A. Methyl cellulose and hypromellose: Nomenclature: Premium methyl cellulose and hypromellose products are a An example [10]- HPMC E 15 premium LV broad range of water soluble cellulose ethers. They enable Low viscosity pharmaceutical developers to create reliable formulas for tablet coating, granulation, controlled release, extrusion, For pharmaceutical use molding and for controlled viscosity of liquid formulations. Viscosity (15 mPa.s for a 2% solution Chemistry of methyl cellulose ethers: in water at 20°C) These products are available in two basic types: methyl cellulose (Fig 2) and HPMC (Fig 3). Methyl cellulose is made Chemistry type: E and K are using only methyl chloride. These are methocel A brand hypromellose products. For HPMC products (methocel E, F, J and K brand A is methylcellulose
Load more

Recommended publications
  • Supplemental
    Supporting Information Aqueous Multiphase Systems of Polymers and Surfactants Provide Self-Assembling Gradients in Density Charles R. Mace1, Ozge Akbulut1, Ashok A. Kumar2, Nathan D. Shapiro1, Ratmir Derda1, Matthew R. Patton1, and George M. Whitesides1,3* 1Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138, United States, 2School of Engineering and Applied Sciences, Harvard University, 29 Oxford St., Cambridge, MA 02138, United States, and 3Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford St., Cambridge, MA 02138, United States *Corresponding author: [email protected] S1 Materials and Methods Materials. The following chemicals were purchased from Sigma-Aldrich: alginic acid sodium salt, chondroitin sulfate A, dextran sulfate sodium salt, Ficoll, (hydroxypropyl)methyl cellulose, poly(2-acrylamido-2-methyl-1-propanesulfonic acid), poly(2-ethyl-2-oxazoline), polyacrylamide, poly(diallyldimethylammonium chloride), poly(ethylene glycol), polyethyleneimine, poly(methacrylic acid sodium salt), poly(propylene glycol), polyvinylpyrrolidone, Brij 35, 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS), cetyl trimethylammonium bromide (CTAB), Pluronic F68, sodium chloate, Tween 20, Triton X-100, Zonyl, lithium bromide (LiBr), cesium bromide (CsBr) and benzene-1,2-disulfonic acid dipotassium salt. The following chemicals were purchased from Polysciences: poly(acrylic acid), poly(allylamine hydrochloride), poly(styrenesulfonic acid sodium salt), and poly(vinyl alcohol). Dextran was purchased from Spectrum Chemical. Diethylaminoethyl-dextran hydrochloride was purchased from MP Biomedicals. Carboxy-modified polyacrylamide, hydroxyethyl cellulose, methyl cellulose were purchased from Scientific Polymer Products. N- octyl-β-D-glucopyranoside was purchased from Calbiochem. N,N-dimethyldodecylamine N- oxide was purchased from Fluka. Sodium dodecyl sulfate was purchased from J.T.
    [Show full text]
  • Enhancement of Some Mechanical Properties of Polyethylene Glycol by Adding Carboxymethyl Cellulose As a Blends and Applied in Wood Glue
    Available online at www.worldscientificnews.com WSN 21 (2015) 12-23 EISSN 2392-2192 Enhancement of Some Mechanical Properties of Polyethylene Glycol by Adding Carboxymethyl Cellulose as a Blends and Applied in Wood Glue Karrar Abd-Ali Obeid1,*, Abdul-Kareem J. Al-Bermany1, Majeed Ali Habeeb2 1Department of Physics, College of Science, University of Babylon, Iraq 2 Department of Physics, College of Education for Pure Science, University of Babylon, Iraq *E-mail address: [email protected] ABSTRACT The (PEG/CMC) blends were prepared by liquids mixing method, the appropriate concentrations of PEG were (0.1-0.2 to 0.8 g/mL)% are dissolved in (500 mL) of distilled water under stirring without heat for (20 min.) then added the CMC with two weights (0.25 and 0.5) g for each PEG concentrates at (288 K). In order to evaluate the mechanical properties of (PEG/CMC) blends the ultrasonic measurements were performed at these samples, these properties are ultrasonic velocity, compressibility, acoustic impedance and bulk modulus, were made at fixed frequency (f = 25 kHz), another acoustic mechanical properties were measured and calculated at a same time such as the ultrasonic wave amplitude absorption by using oscilloscope, then calculated the absorption coefficient and the transmittance ratio of the sound. It was found that there is significant relationship between ultrasonic velocity and material properties results show that adding PEG effects on the density then on the absorption of the ultrasonic waves inside the blend samples. Finally applied this blend in various concentrations as additive to imported wood glue and found that increasing the adhesion force after adding comparing with pure.
    [Show full text]
  • Comparison of Bran, Ispaghula, and Lactulose on Colon Function in Diverticular Disease
    Gut: first published as 10.1136/gut.19.12.1144 on 1 December 1978. Downloaded from Gut, 1978, 19, 1144-1147 Comparison of bran, ispaghula, and lactulose on colon function in diverticular disease M. A. EASTWOOD, A. N. SMITH, W. G. BRYDON, AND J. PRITCHARD From the Wolfson Laboratories, Gastrointestinal Unit, Departments of Medicine and Clinical Surgery, University ofEdinburgh, and Department of Clinical Chemistry, Western General Hospital, Edinburgh SUMMARY Bran, ispaghula (Fybogel), and lactulose were given to three groups of patients with diverticular disease for four weeks. Faecal weights, bile acids, fat and electrolytes, transit time, and colonic motility were estimated before and after treatment. Stool weight increased, notably with Fybogel. Cereal bran had the greatest effect on the transit time, reducing it significantly. There were no changes in faecal bile acids, fat or electrolytes. Coarse bran reduced colonic motility and the number of high pressure waves after food; Fybogel increased the basal pressure and was without effect on the food-stimulated pressures; whereas lactulose influenced neither. All agents paradox- ically equally alleviated symptoms. The symptoms of diverticular disease arise in Each patient was studied at home on his habitual patients who have, in the main, a small stool weight, diet. For one week stool was collected; at the prolonged intestinal transit time, and a raised start of the collection 40 barium impregnated intracolonic pressure (Painter, 1975). The rational markers were taken by mouth (Hinton et al., 1969). basis of the treatment of diverticular disease is Such markers not only give a crude estimate of principally to influence the raised intraluminal transit but act as indicators of the accuracy of http://gut.bmj.com/ pressure.
    [Show full text]
  • United States Patent (19) (11) 4,301,146 Sanvordeker 45) Nov
    United States Patent (19) (11) 4,301,146 Sanvordeker 45) Nov. 17, 1981 54 STABILIZATION OF 16-OXYGENATED 56) References Cited PROSTANOIC ACID DERVATIVES U.S. PATENT DOCUMENTS 3,826,823 7/1974. O'Rourke et al. .................... 424/80 75 Inventor: Dilip R. Sanvordeker, Elk Grove 3,965,143 6/1976 Collins et al. ...... 424/305 Village, Ill. 4,058,623 11/1977 Hoffmann et al. ... 424/80 4,127,647 1 1/1978. Sato et al. ............................. 424/78 73 Assignee: G. D. Searle & Co., Skokie, Ill. Primary Examiner-Sam Rosen Attorney, Agent, or Firm-Albert Tockman; W. Dennis Drehkoff Appl. No.: 173,292 21) 57 ABSTRACT A stable solid dosage form of the compound Eme 22 Filed: Jul. 29, 1980 thyl(7-3(a)-hydroxy-2-g-(4(RS)-4-hydroxy-4-methyl trans-1-octen-1-yl)-oxycyclopent-la-ylheptanoate, 51) int. Cl. ................... A61K 31/74; A61K 31/215; said solid dosage form comprising from about 50 to A61K 31/19 about 500 parts of a polymer selected from the group 52 U.S. Cl. ...................................... 424/80; 424/305; consisting of hydroxypropylmethyl cellulose and 424/317; 424/362 polyvinylpyrolidone per part of said compound. 58) Field of Search ................... 424/80, 78, 362, 305, 424/317 22 Claims, No Drawings 4,301,146 1. 2 suitable solvent; (3) adding the drug solution to the STABILIZATION OF 16-OXYGENATED polymer solution; (4) stirring for from about 1 to 5 PROSTANOIC ACID DERVATIVES hours, preferably for about 2 to 4 hours at room temper ature; (5) adding, if desired, up to 1000 parts of a filler U.S.
    [Show full text]
  • Drugs Used in Treating Constipation and IBS
    Drugs used in treating constipation and IBS Define constipation Know the different symptoms of constipation Know the different lines of treatment of constipation Identify the different types of laxatives Discuss the pharmacokinetics, dynamics, side effects and uses of laxatives Discuss the difference between different treatment including bulk forming laxatives, osmotic laxatives, stimulant laxatives And stool softeners (lubricants). Define bowel syndrome (IBS). Identify the pharmacokinetics, dynamics, side effects and uses of drugs used for IBS. extra information and further explanation important doctors notes Drugs names Mnemonics Kindly check the editing file before studying this document constipation and IBS Very useful. Don’t miss it Infrequent defecation, often with straining and the passage of hard, uncomfortable stools. - May be accompanied by other symptoms: Abdominal discomfort and rectal pain, Flatulence, Loss of appetite, Lethargy & Depression. Decreased motility in colon: Decrease in water and fiber Difficulty in evacuation: Drug-induced: contents of diet. 1. Local painful conditions: 1. Anticholinergic agents “Unbalanced diet” anal fissures, piles. 2. Opioids 2. Lack of muscular 3. Iron exercise. 4. Antipsychotics. 5. Anti-depressant, anti- histamine, has anticholinergic effect Adequate fluid intake High fiber contents in diet Use drugs (laxatives or Regulation of bowel habit. purgatives more watery effect) Regular exercise Avoid drugs causing constipation. • Drugs that hasten the transit of food through the gastrointestinal tract are called (Or we say the drugs that increase GI motility) (محركات) or purgatives(ملينات) laxatives • Loosen stools and increase bowel movement Bulk forming laxatives (increase the size of stool ) • Increase volume of non-absorbable solid residue. Osmotic laxatives (cause water withdrawal by sugar or salt) • Increase water content in large intestine.
    [Show full text]
  • Rheological Studies and in Vitro Release Evaluation for Different
    Iraqi J Pharm Sci, Vol.20(2) 2011 Clotrimazole emulgel Preparation and Evaluation of Physical and, Rheological Properties of Clotrimazole Emulgel Yehia I. Khalil*,1 , Abeer H. Khasraghi* and Entidhar J. Mohammed* *Department of Pharmaceutics , College of Pharmacy , University of Baghdad , Baghdad , Iraq . Abstract Recently, emulgel has emerged as one of the most interesting topical preparations in the field of pharmaceutics. In this research clotrimazole was formulated as topically applied emulgel ; different formulas were prepared. The prepared emulgels were evaluated for their physical appearance , rheological behaviour , and in vitro drug release . The influence of the type of gelling agent (carbopol 934 and methyl cellulose), the concentration of both the emulsifying agent (2% and 4% w/w of mixture of span 20 and tween 20) and the oil phase (5% and 7.5% w/w of liquid paraffin) and the type of oil phase (liquid paraffin and cetyl alcohol), on the drug release from the prepared emulgels was investigated. Commercially available topical canestin® cream was used for comparison. All the prepared emulgels showed acceptable physical properties concerning colour, homogeneity, consistency, and pH value. Rheological studies revealed that all emulgels formulations exhibited a shear – thinning behaviour with thixotropy, indicating structural break down of intermolecular interaction between polymeric chains. Clotrimazole emulgels exhibited higher drug release than canestin® cream. The results of in vitro release showed that methyl cellulose – based emulgel gave better release than carbopol 934 – based one. Also it was found that the emulsifying agent concentration had the most pronounced effect on the drug release from the emulgels, followed by the oil phase concentration, which has a retardation effect, and finally the type of the gelling agent.
    [Show full text]
  • Methylcellulose, a Cellulose Derivative with Original Physical Properties and Extended Applications
    Polymers 2015, 7, 777-803; doi:10.3390/polym7050777 OPEN ACCESS polymers ISSN 2073-4360 www.mdpi.com/journal/polymers Review Methylcellulose, a Cellulose Derivative with Original Physical Properties and Extended Applications Pauline L. Nasatto 1,2,*, Frédéric Pignon 2,3, Joana L. M. Silveira 1, Maria Eugênia R. Duarte 1, Miguel D. Noseda 1 and Marguerite Rinaudo 4 1 Departamento de Bioquímica e Biologia Molecular, Federal University of Paraná, P.O. Box 19046, CEP 81531-980, Curitiba, Paraná, Brazil; E-Mails: [email protected] (J.L.M.S.); [email protected] (M.E.R.D.); [email protected] (M.D.N.) 2 Laboratoire Rhéologie Procédés (LRP), University Grenoble Alpes, F-38000 Grenoble, France; E-Mail: [email protected] 3 Centre National de la Recherche Scientifique (CNRS), LRP, F-38000 Grenoble, France 4 Biomaterials Applications, 6, rue Lesdiguières, F-38000 Grenoble, France; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +55-041-3361-1663; Fax: +55-041-3266-2041. Academic Editor: Antonio Pizzi Received: 5 February 2015 / Accepted: 15 April 2015 / Published: 24 April 2015 Abstract: This review covers the preparation, characterization, properties, and applications of methylcelluloses (MC). In particular, the influence of different chemical modifications of cellulose (under both heterogeneous and homogeneous conditions) is discussed in relation to the physical properties (solubility, gelation) of the methylcelluloses. The molecular weight (MW) obtained from the viscosity is presented together with the nuclear magnetic resonance (NMR) analysis required for the determination of the degree of methylation. The influence of the molecular weight on the main physical properties of methylcellulose in aqueous solution is analyzed.
    [Show full text]
  • Horiba Scientific in Edi- Bottom to Top) of MCC, Sub-Hydroxypropyl Cellulose, Hypromellose (Hydroxypropyl Methylcellulose) Son, New Jersey
    ® Electronically reprinted from November 2016 Molecular Spectroscopy Workbench Characterizing Modified Celluloses Using Raman Spectroscopy Raman spectra of celluloses modified for use in the pharmaceutical, food, and materials industries are compared and analyzed, with the goal of determining spectroscopic features that can be of use in aiding in the determination of physical and chemical properties. Fran Adar ellulose is probably the most abun- the goal of then providing some insight restricted. The details of the modifications dant biopolymer on Earth and has into the chemical reactions between cel- (the chemistry of the substituent, percent C been exploited since the dawn of lulose and certain small molecules that can substitution, molecular weight, and so on) human civilization. Wood materials have change the physicochemical properties will determine the temperature of gelation been used in construction, and cotton of the reacted material. After that, we can and the viscosity of the products. Actually, and flax (linen) have been used for cloth- look at the Raman spectra of a few of these hydroxypropyl methyl cellulose (HPMC) ing and other textile applications. During modified celluloses to assess whether the is an interesting example because of the later times paper was manufactured from spectra can be useful in characterizing the variety of ways that it is used. In pharma- cellulosic sources and used for recording final products. ceutical tablets, HPMC can be used as a information. protective coating, and as a rate controlling Chemically, wood, cotton, and linen Cellulose Background release agent in timed-release formula- are all identified as cellulose, but their For the first use of cellulose in a modern tions.
    [Show full text]
  • CHEMICAL RESISTANCE CHART Chemical Resistance Glove Chart
    CHEMICAL RESISTANCE CHART Chemical Resistance Glove Chart P = Poor | F = Fair | G = Good | E = Excellent | X = Not Tested Chemical Latex Nitrile 1,1,1,2-Tetrachloroethane P F P 1,1,1-Trichloroethane P P P 1,1,2-Trichloroethane P P P 1,2,4,5-Tetrachlorobenzene X E P 1,2,4-Trichlorobenzene P F P 1,2-Dichlorobenzene (o-Dichlorobenzene) P P P 1,2-Dichloroethylene P P P 1,2-Propylenoxide P P P 1,3-Dioxane F P P 1,4-Dioxane P P P 1-Nitropropane G P P 2-(Dietylamino)ethanol P E P 2-Chloroethanol X P P 2-Hydroxyethyl acrylate P P P 2-Hydroxyethyl methacrylate (HEMA) X X X 2-Nitropropane P P P 2-Nitrotoluene P P P 3-Bromopropionic acid G F X 4,4-Methylenedianiline (MDA) X X X 5-Fluorouracil X X X Acetaldehyde G P P Acetamide G P P Acetate solvent G F P Acetic acid (glacial acetic acid) 99+ % G F F Acetic acid 30% E G F Acetic acid anhydride G F P Acetone F P P Acetonitrile F F P Acetyl chloride P P P Acetylene G E F Acryl Acid P F P Acrylamide, 30-70% P E F Acrylic Acid G G P Acrylonitrile P P P Adipic acid E E X Allyl alcohol P P P Allylamine P P P Allylchloride (3-Chloroporpene) P P P Aluminium Acetate E G X Aluminium Chloride E E G Aluminium Fluoride G E F Aluminium Hydroxide P E F Aluminium Nitrate E E X Aluminium Potassium Sulfate E E F Aluminium Sulfate E E G Amine G P Ammonia anhdyrous P G G Ammonia gas (cold) E E X Ammonia gas (hot) P P X Ammonia Nitrate X F X 74 Chemical Resistance Glove Chart P = Poor | F = Fair | G = Good | E = Excellent | X = Not Tested Chemical Latex Nitrile Ammonia solution, 30% P E X Ammonium Acetate E E X Ammonium
    [Show full text]
  • Influence of Additives on Ethylcellulose Coatings
    INFLUENCE OF ADDITIVES ON ETHYLCELLULOSE COATINGS ONG KANG TENG (B.Sc. (Pharm.)(Hons.), NUS) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF PHARMACY NATIONAL UNIVERSITY OF SINGAPORE 2006 ACKNOWLEDGEMENTS With great gratitude, I wish to thank my respectful supervisors, Associate Professor Paul Heng Wan Sia and Associate Professor Chan Lai Wah for devoting much time and effort in supervising and guiding me in my higher degree pursue. They have given me an education that is worth a lifetime. I could not have carried out my study without the generous financial supports from the National University of Singapore and the use of research facilities in the Department of Pharmacy and GEA-NUS Pharmaceutical Processing Research Laboratory. I wish to thank the laboratory officers in the Department of Pharmacy, especially Teresa and Mei Yin, who have never failed to render me their technical assistance whenever needed. My heartfelt thanks go to all my friends and colleagues in the Department of Pharmacy and GEA-NUS, especially Celine, Tin Wui, Chit Chiat, Liang Theng, Sze Nam, Gu Li, Wai See and Qiyun. They have not only shared with me their valuable experiences but also provided me with their friendship. My parents and siblings have showered me with much love and supports which kept me going, especially through difficult times. This journey has been blessed with many prayerful and spiritual supports of saints both at home and aboard, for whom I thank God for. All thanks and glory be to God the Father and Lord Jesus Christ, to whom I owe all things.
    [Show full text]
  • Hydroxypropylmethyl Cellulose
    HYDROXYPROPYLMETHYL CELLULOSE Prepared at the 74th JECFA (2011) and published in FAO JECFA Monographs 11 (2011), superseding the specifications prepared at the 63rd JECFA (2004), published in the Combined Compendium of Food Additive Specifications, FAO JECFA Monographs 1 (2005). A group ADI ”not specified” for modified celluloses (ethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, methyl ethyl cellulose, and sodium carboxymethyl cellulose) was established at the 35th JECFA (1989). SYNONYMS INS No. 464 DEFINITION Hydroxypropylmethyl cellulose is a methyl cellulose modified by treatment with alkali and propylene oxide by which a small number of 2-hydroxypropyl groups are attached through ether links to the anhydroglucose units of the cellulose. The article in commerce may be further specified by viscosity. Chemical names Hydroxypropylmethyl cellulose, 2-hydroxypropyl ether of methyl cellulose C.A.S. number 9004-65-3 Chemical formula [C6H7O2(OH)x(OCH3)y(OCH2CHOHCH3)z]n where z = 0.07 - 0.34 y = 1.12 - 2.03 x = 3-(z + y): (z + y = degree of substitution) Structural formula where R = H or CH3 or CH2CHOHCH3 Formula weight Unsubstituted structural unit: 162.14 Structural unit with 1.19 degree of substitution: approx. 180 Structural unit with 2.37 degree of substitution: approx. 210 Macromolecules: from about 13,000 (n about 70) up to about 200,000 (n about 1000) Assay Not less than 19% and not more than 30% of methoxy groups (-OCH3) and not less than 3% and not more than 12% hydroxypropoxy groups (-OCH2CHOHCH3), on the dried basis DESCRIPTION Hygroscopic white or off-white powder, or granules or fine fibres FUNCTIONAL USES Emulsifier, thickening agent, stabiliser CHARACTERISTICS IDENTIFICATION Solubility (Vol.
    [Show full text]
  • The Effect of Different Concentrations of Hydroxypropyl Methylcellulose on the Morphology
    The Effect of Different Concentrations of Hydroxypropyl Methylcellulose on the Morphology and Mechanical Properties of Whey Protein Isolate Edible Films Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Cyd Marie Quiñones Pérez, B.S. Graduate Program in Food Science and Technology The Ohio State University 2019 Thesis Committee Dr. Melvin Pascall, Advisor Dr. Gireesh Rajashekara Dr. Hua Wang Copyrighted by Cyd Marie Quiñones Pérez 2019 Abstract A container is a barrier between a packaged product and its external environment, and it protects the product from interaction between water, oxygen, dirt, light in some cases and microorganisms. The main types of food packaging materials are glass, plastic, metal, paper board and composites. Plastics are made from polymers. A polymer is made of a large number of monomeric units connected by covalent chemical bonds to make a large molecular weight structure. Some polymers are petroleum based while others are made from plants, animals or microorganisms. Due to increased environmental concerns about plastic waste, many researchers are currently focusing on the synthesis of bio-based sustainable plastic packaging materials. Polysaccharides such as Hydroxypropyl Methylcellulose (HPMC), and proteins such as Whey Protein Isolate (WPI) are being used in the food industry because they are widely available, nontoxic and have the capacity to produce edible films with acceptable properties. The objectives of this study were to compare the ratio of blending HPMC with WPI on physical, mechanical, thermal and permeability properties of films made with the blends. Five different blends were tested HPMC-WPI (100:0), HPMC-WPI (75:25), HPMC-WPI (50:50), HPMC-WPI (25:75) and HPMC-WPI (0:100).
    [Show full text]