Second Edition, Revised and Expanded
`
`Edited by Herbert A. Lieberman,
`
`eeeities)
`Dosage Forms:
`Tablets TTCae
`
`Leon Lachman, and Joseph B. Schwartz
`
`

`

`PHARMACEUTICAL
`DOSAGE FORMS
`
`Tablets
`
`SECOND EDITION, REVISED AND EXPANDED
`
`In Three Volumes
`
`VOLUME 1
`
`EDITED BY
`
`Herbert A. Lieberman
`H H Lieberman Associates, Inc
`Consultant Services
`
`Livingston, New Jersey
`
`Leon Lachman
`Lachman Consultant Services
`Westbury, New York
`
`Joseph B. Schwartz
`Philadelphia College of Pharmacy and Science
`Philadelphia, Pennsylvania
`
`ARCEL
`
`DEKKER
`
`

`

`Library of Congress Cataloging-in~Publication Data
`
`Pharmaceutical dosage forms--tablets / edited by Herbert A. Lieberman,
`Leon Lachman, Joseph B. Schwartz. -- 2nd ed., rev. and expanded.
`Pp.
`cm.
`Includes index.
`ISBN 0-8247-8044-2 (v. 1: alk. paper)
`I. Lieberman,
`1. Tablets (Medicine)
`2. Drugs--Dosage forms.
`Herbert A.
`II. Lachman, Leon.
`III. Schwartz, Joseph B.
`[DNLM:
`1. Dosage Forms.
`2. Drugs--administration & dosage. QV
`785 P535]
`RS201.T2P46
`615'.191--dc19
`DNLM/DLC
`for Library of Congress
`
`89-1629
`CIP
`
`1989
`
`Copyright © 1989 by MARCEL DEKKER, INC. All Rights Reserved
`
`Neither this book nor any part may be reproduced or transmitted in
`any form or by any means, electronic or mechanical, including photo-
`copying, microfilming, and recording, or by any information storage
`and retrieval system, without permission in writing from the publisher.
`
`MARCEL DEKKER, INC,
`270 Madison Avenue, New York, New York 10016
`
`Current printing (last digit):
`10 98 7
`6
`
`PRINTED IN THE UNITED STATES OF AMERICA
`
`

`

`PHARMACEUTICAL
`DOSAGE FORMS
`
`

`

`Preface
`
`Several years have passed since the first edition of Pharmaceutical Dosage
`Forms: Tablets was published. During this time, considerable advances
`have been made in the science and technology of tablet formulation, manu-
`facture, and testing. These changes are reflected in this updated, re-
`vised and expanded second edition.
`The tablet dosage form continues to be the most widely used drug de-
`livery system for both over-the-counter and prescription drugs. The term
`tablet encompasses: the usual compressed tablet; the compressed tablet that
`is sugar- or film-coated to provide dissolution in either the stomach or the
`intestine, or partially in the stomach and partially in the intestine; layered
`tablets for gastric and intestinal release; effervescent tablets; sustained-
`release tablets; compressed coated tablets; sublingual and buccal tablets;
`chewable tablets; and medicated lozenges. These various dosage forms are
`described in depth in the three volumes of this series.
`in the first volume,
`the various types of tablet products are discussed;
`the second volume is concerned with the processes involved in producing
`tablets, their bioavailability and pharmacokinetics; and in the third volume,
`additional processes in tablet production are discussed, as well as sustained
`drug release, stability, kinetics, automation, pilot plant, and quality as-
`surance,
`The first chapter in Volume 1 describes "Preformulation Testing." This
`second edition of the chapter contains an extensive amount of new material
`on substance purity, dissolution, the concept of permeability, and some of
`the pharmaceutical properties of solids.
`In the second chapter, "Tablet
`Formulation and Design," the plan for developing prototype formulas has
`been revised and an approach, using statistical design, is presented.
`There is consideration given to those elements in tablet formulation that are
`of importance to the operation of tablet presses with microprocessor controls.
`There have been so many advances in the technology of wet granula-
`tion and direct compression methods since the first edition that what had
`previously been one chapter has now been expanded into two chapters.
`
`iii
`
`

`

`iv
`
`Preface
`
`"Compressed Tablets by Wet Granulation" has been updated, and a new
`section on unit operations has been added.
`Information on the formulations
`of sustained-release tablets by wet granulation is included in the chapter.
`"Compressed Tablets by Direct Compression," a separate chapter new to
`this edition, contains:
`a table comparing all aspects of direct compression
`versus Wet granulation; an extensive glossary of trade names and manu-
`facturers of tableting excipients; a section on morphology of pharmaceutical
`excipients,
`including scanning electron photomicrographs; a discussion of
`direct compression of example active ingredients; and a considerably ex-
`panded section on prototype or guide formulations.
`The chapter entitled "Compression-Coated and Layered Tablets" de-
`scribes the current technology for making these types of tablets. The
`chapter "Effervescent Tablets" has been expanded to include fluid-bed
`granulation techniques, updating on stability testing methods, new packag-
`ing materials, and methodologies for checking airtightness of sealed pack-
`ets. The chapter on "Special Tablets" now contains information on long-act-
`ing and controlled-release buccal tablets as well as new sections on vaginal
`and rectal tablets, The chapter "Chewable Tablets" has increased its cov-
`erage to include microencapsulation and spray coating techniques. This
`chapter includes an update of the information concerned with excipients,
`colorants, direct-compression chewable tablets, and current manufacturing
`and product evaluation procedures related to these tablets.
`"Medicated
`Lozenges," the final chapter in Volume 1, has increased its scope to include
`liquid-center medicated lozenges and chewy-based medicated tgblets.
`Each of the tablet forms discussed requires special formulation procedures.
`Knowing how to make a particular type does not guarantee knowledge of how
`to make another, Since considerable expertise is required for the myriad
`tablet dosage forms, a multiauthored text seemed to be the only way to
`accomplish the editors' goals of providing knowledgeable and complete cov-
`erage of the subject. The editors chose authors to describe particular
`types of tablets on the basis of their experience, training, and high degree
`of knowledge of their subjects.
`The authors were charged with the task of covering their technology in
`a Way that would not be merely a review of the literature. Each chapter
`begins by assuming the reader is not very familiar with the subject.
`Gradually, as each chapter develops, the discussion becomes more advanced
`and specific.
`Following this format, we have intended the text to be a
`teaching source for undergraduate and graduate students as well as ex-
`perienced and inexperienced industrial pharmaceutical scientists. The book
`can also act as a ready reference to all those interested in tablet tech-
`nology. This includes students, product development pharmacists, hospital
`pharmacists, drug patent attorneys, governmental and regulatory scientists,
`quality control personnel, pharmaceutical production personnel, and those
`concerned with production equipment for making tablets.
`The authors are to be commended for the manner in which they cover
`their subjects ss well as for their patience with the editors’ comments con-
`cerning their manuscripts. The editors wish to express their special
`thanks to the contributors for the excellence of their works, as well as for
`their continued forbearance with our attempts to achieve our desired level
`of quality for this text. Although there has been a great deal written
`about various types of tablets,
`it is only in this multivolume treatment
`that this subject is completely described. The acceptability and usefulness
`
`

`

`Preface
`
`v
`
`of these volumes is attributable to the efforts and skills of all of the con-
`tributing authors.
`The topics, format, and choice of authors are the responsibilities of
`the editors. Any multiauthor book has problems of coordination and
`minimizing repetition.
`Some repetition was purposely retained because,
`in the editors' opinions, it helped the authors to develop their themes and
`because each individual treatment is sufficiently different so as to be val-
`uable as a teaching aid. The editors hope that the labors of the contrib-
`utors and our mutual judgments of subject matter have resulted in an up-to-
`date expanded reference that will facilitate the work of the many people who
`use it,
`
`Herbert A. Lieberman
`Leon Lachman
`Joseph B. Schwartz
`
`

`

`Contents
`
`Preface
`Contributors
`Contents of
`
`Contents of
`
`Contents of
`
`Pharmaceutical Dosage Forms: Tablets, Second Edition
`Volumes 2 and 3
`Pharmaceutical Dosage Forms: Parenteral Medications,
`Volumes I and 2
`Pharmaceutical Dosage Forms: Disperse Systems,
`Volumes I and 2
`
`Chapter 1.
`
`Preformulation Testing
`
`Deodatt A. Wadke, Abu T. M, Serajuddin, and
`Harold Jacobson
`
`Introduction
`I,
`H. Organoleptic Properties
`Ii. Purity
`IV. Particle Size, Shape, and Surface Area
`Vv.
`Solubility
`VI. Dissolution
`VII. Parameters Affecting Absorption
`VII. Crystal Properties and Polymorphism
`IX. Stability
`X. Miscellaneous Properties
`XI. Examples of Preformulation Studies
`References
`
`Chapter 2.
`
`Tablet Formulation and Design
`
`Garnet E, Peck, George J. Baley, Vincent E. McCurdy,
`and Gilbert S$. Banker
`
`1.
`Il.
`Ill.
`
`Introduction
`Preformulation Studies
`A Systematic and Modern Approach to
`Tablet Product Design
`IV. Tablet Components and Additives
`V. Regulatory Requirements for Excipients in
`the United States
`VI. References
`
`AE
`
`xV
`
`XXX
`
`75
`
`75
`%7
`
`79
`88
`
`121
`128
`
`vii
`
`

`

`viit
`
`Contents
`
`Chapter 3. Compressed Tablets by Wet Granulation
`
`Fred J. Bandelin
`
`I.
`II.
`Ill.
`IV.
`V.
`Vi.
`Vil.
`VIIl.
`
`Properties of Tablets
`Formulation of Tablets
`Tablet Manufacture
`Granulation
`Excipients and Formulation
`Multilayer Tablets
`Prolonged Release Tablets
`Manufacturing Problems
`References
`
`Chapter 4. Compressed Tablets by Direct Compression
`
`Ralph F, Shangraw
`I.
`il.
`
`Ill.
`IV.
`Vv.
`VI.
`VI.
`VIII.
`
`Introduction and History
`Advantages and Disadvantages of the Wet
`Granulation Process
`The Direct-Compression Process
`Direct-Compression Filler Binders
`Factors in Formulation Development
`Morphology of Direct-Compression Fillers
`Coprocessed Active Ingredients
`Modification and Integration of Direct-
`Compression and Granulation Processes
`Future of Direct-Compression Tableting
`Formulations for Direct Compression
`Glossary of Trade Names and Manufacturers
`References
`
`Chapter 5. Compression-Coated and Layer Tablets
`
`William C,. Gunsel and Robert G. Dusel
`
`I.
`Hl.
`lil.
`IV.
`V.
`
`Compression Coating
`Formulations (Compression Coating)
`Inlay Tablets
`Layer Tablets
`Formulations (Layer)
`References
`
`Chapter 6. Effervescent Tablets
`
`Raymond Mohrle
`
`I.
`H.
`til.
`IV.
`V.
`
`Introduction
`Raw Materials
`Processing
`Manufacturing Operations
`Tablet Evaluation
`
`131
`
`132
`133
`135
`148
`151
`179
`181
`188
`190
`
`195
`
`195
`
`197
`198
`203
`214
`220
`225
`
`227
`228
`229
`243
`245
`
`247
`
`247
`260
`273
`274
`278
`284
`
`285
`
`285
`286
`294
`300
`302
`
`

`

`Contents
`
`VI. Effervescent Stability
`VII. Effervescent Formulations
`VIII. References
`
`Chapter 7.
`
`Special Tablets
`
`James W. Conine and Michael J. Pikal
`
`I. Drug Absorption Through the Oral Mucosa
`II. Molded Sublingual Tablets
`Ili, Special Problems with Molded Nitroglycerin
`Tablets
`IV. Compressed Sublingual Tablets
`V. Buccal Tablets
`VI. Vaginal Tablets
`VII. Rectal Tablets
`VIII. Dispensing Tablets
`IX. Tablets for Miscellaneous Uses
`References
`
`Chapter 8. Chewable Tablets
`
`Robert W. Mendes, Aloysius O. Anaebonam, and
`Jahan B. Daruwala
`
`Introduction
`I.
`II. Formulation Factors
`III. Formulation Techniques
`IV. Excipients
`V. Flavoring
`VI. Colorants
`VII. Manufacturing
`VIII. Evaluation of Chewable Tablets
`IX.
`Summary
`References
`
`Chapter 9. Medicated Lozenges
`David Peters
`
`I. Hard Candy Lozenges
`Il. Processing
`II. Formulations (Hard Candy Lozenges)
`IV. Center-Filled Hard Candy Lozenges
`V. Formulations (Center Filled Lozenges)
`VI. Packaging
`VII. Chewy or Caramel Base Medicated Tablets
`VIII. Formulations (Chewy Based Confections)
`IX, Compressed Tablet Lozenges
`X. Manufacturing: Compression Sequence
`Xl. Typical Formulations (Compressed-Tablet
`Lozenges)
`
`304
`320
`326
`
`329
`
`329
`334
`
`340
`354
`356
`359
`360
`362
`363
`364
`
`367
`
`367
`368
`371
`382
`387
`392
`396
`406
`415
`415
`
`419
`
`419
`445
`497
`501
`509
`511
`520
`541
`543
`598
`
`565
`
`

`

`XII. Quality Control Procedures
`References
`Suggested Reading
`
`Index
`
`Contents
`
`567
`576
`580
`
`583
`
`

`

`9 M
`
`edicated Lozenges
`
`David Peters*
`
`Warner-Lambert Company, Morris Plains, New Jersey
`
`Lozenges are flavored medicated dosage forms intended to be sucked and
`held in the mouth or pharynx [1,85]. They may contain vitamins, anti-
`biotics, antiseptics,
`local anesthetics, antihistamines, decongestants, cortico-
`steroids, astringents, analgesics, aromatics, demulcents, or combinations
`of these ingredients [2]. The oropharyngeal symptoms which lozenges are
`intended to relieve are commonly caused by local infections and occasionally
`by allergy or drying of the mucosa from mouth breathing.
`Lozenges may take various shapes, the most common being theflat,
`circular, octagonal, and biconvex forms. Another type, called bacilli, are
`in the form of short rods or cylinders. A soft variety of lozenge, called
`a pastille,.consists of medicament in a gelatin or glycerogelatin base or in
`a base of acacia, sucrose, and water. Confections (now obsolete) are
`heavily sugared soft masses containing medicinal agents [3].
`Two types of lozenge bases have gained wide usage because of their
`ready adaptation to modern high-speed methods of product manufacture.
`These two lozenge forms, which will be discussed in detail,
`include hard
`(or boiled) candy lozenges and compressed tablet lozenges.
`
`I. HARD CANDY LOZENGES
`
`Hard candy is a mixtute of sugar and other carbohydrates that are kept in
`an amorphous or glassy condition [4]. This form can be considered a solid
`syrup of sugars generally having from 0.5 to 1.5% moisture content.
`Essentially, the preparation of hard candy lozenges can be considered
`an art. Many of the formulations used in confectionary manufacturing, and
`the rationale used for solving problem areas, are based on experience and
`intuition rather than scientific deduction. The confectionary equipment
`utilized by the manufacturer of lozenges is suitable for the preparation of
`
`*Current affiliation: Treworgy Pharmacy, Calais, Maine
`
`419
`
`

`

`420
`
`Peters
`
`Figure 1 Mixing of flavors and medicinals by hand. Preparation of 1- or
`2-kg laboratory batches enables the formulator to evaluate potential prob-
`lem areas that may develop when flavor or medicament is incorporated into
`hard candy base.
`(From Ref. 24.)
`
`candies but is not designed to produce a controlled and reproducible medi-
`cated candy with close tolerances as to size, weight, and quantity of drug
`concentration per unit dose, The formulator must gain a comprehensive
`knowledge of the physical and chemical qualities of raw materials in the
`product and become familiar with all aspects of candy base production in
`order to prepare a medicated product that conforms to the specifications
`for good manufacturing procedures (Figures 1 and 2). A review of pos-
`sible shelf life problems must be determined through stability testing after
`the product is manufactured. The formulator,
`in essence, is required to
`bring a scientific approach to an empirical art.
`
`A. Raw Materials
`
`Sugar (Sucrose)
`
`H20H
`
`Various grades and types of sugars are available in commerce that may be
`suitable for incorporation into hard candy, but the two with the greatest
`utility are cane and beet sugars [4,80].
`Sucrose is prepared commercially from sugar cane, beet root, or sor-
`ghum. The sugar cane is crushed and the juice (amounting to about 80%)
`
`

`

`Medicated Lozenges
`
`421
`
`is expressed with roller mills, treated with lime to clear the syrup and
`then with carbonic acid gas to remove excess lime. The juice is then con-
`centrated in vacuum pans until crystallization of sucrose is complete. The
`crystals and the syrup are separated by centrifugation—with the resulting
`syrup (a byproduct) known as molasses. Beet sugar is made by a similar
`process but is more difficult to purify.
`Refined sugar from either raw cane or beet sugars is prepared by dis-
`solving the sugar in water, clarifying, filtering, and finally decolorizing
`the solution by treatment with charcoal. The water-clear solution is evapo-
`rated under reduced pressure to the crystallizing point [5].
`Cane and beet sugars are now chemically and physically identical and
`therefore cannot be distinguished from each other in the refined state,
`At one time, though, there were significant differences in the purity and
`shelf life among products prepared with each type of sugar. Beet sugar
`contained many impurities, producing a final product containing batch-to-
`batch differences in color, The candies had a tendency to grain (exhibit
`sugar crystallization) and pick up excessive moisture. Advances in sugar
`refining have led most manufacturers to indicate that these differences no
`longer exist, with only geographic considerations and availability determin-
`ing which is used.
`is used
`Today liquid sugar with a solids content of 67% w/w (Table 1)
`almost exclusively in the manufacture of confections, as all continuous candy
`base manufacturing equipment requires a constant supply of sugar syrup
`and corn syrup during cooking. Manufacturers can prepare the Syrup as
`
`
`
`Figure 2 Motorized drop-former. Lozenges manufactured in the labora-
`tory are suitable for stability evaluation of medicament, flavor, and color
`prior to manufacture of production batches.
`(From Ref. 24.)
`
`

`

`422
`
`Peters
`
`Table 1
`
`Physical Constants of Sucrose Solutions
`
`Degrees
`Brix (% of
`sugar)
`
`Degrees
`Baumé
`(modulus 145)
`
`Index of
`refraction
`at 68°F
`
`Specific
`gravity
`at 68°F
`
`Weight (Ib)
`of 1 US gal.
`at 68°F
`
`67.0
`
`68.0
`
`69.0
`
`70.0
`
`71.0
`
`72.0
`
`73.0
`
`74.0
`
`75.0
`
`76.0
`
`77.0
`
`78.0
`
`79.0
`
`80.0
`
`36.05
`
`36.55
`
`37.06
`
`37.56
`
`38. 06
`
`38.55
`
`39.05
`
`39.54
`
`40.03
`
`40.53
`
`41.01
`
`41.50
`
`41.99
`
`42.47
`
`1, 4579
`
`1. 4603
`
`1. 4627
`
`1. 4651
`
`1. 4651
`
`1.4700
`
`1.4725
`
`1. 4749
`
`1.4774
`
`1.4799
`
`1.4825
`
`1.4850
`
`1.4876
`
`1.4901
`
`1.3309
`
`1.3371
`
`1.3433
`
`1.3496
`
`1.3559
`
`1.3622
`
`1.3686
`
`1.3750
`
`1.3814
`
`1.3879
`
`1.3944
`
`1.4010
`
`1.4076
`
`1.4142
`
`11.08
`
`11,13
`
`11.18
`
`11.23
`
`11.29
`
`11,34
`
`11.39
`
`11. 45
`
`11.50
`
`11.55
`
`11.61
`
`11.66
`
`11.72
`
`ELT
`
`Source: The Manufacturing Confectioner, Vol. 70, No. 7, July 1970.
`
`needed from granular sugar or purchase liquid sugar directly from their
`sugar refiners.
`
`Corn Syrup
`
`Corn syrups are produced by either acid, enzyme, or acid—enzyme com-
`bination hydrolysis of cornstarch and are generally available in several
`grades, varying in degree of conversion [dextrose equivalent (DE)] and
`solids content (degrees Baumé) [4].
`
`Manufacture
`
`The manufacture of all corn sweeteners begins with the hydrolysis
`of cornstarch, a process involving the splitting of the starch molecules
`by chemical reaction with water. During the process, a thoroughly
`agitated slurry of purified starch granules containing the required amount of
`‘dilute acid is brought to the desired temperature by the injection of steam.
`A variety of acids will affect the conversion, but in the United States hydro-
`chloric acid is used almost exclusively. Time and temperature are varied de-
`pending on the type of corn sweetener to be manufactured [6].
`As the reaction progresses,
`the gelatinized starch is converted first to
`other polysaccharides and subsequently to sugars, mostly maltose and dex-
`trose. The sugar content increases and viscosity decreases as the conver-
`sion proceeds. Complete hydrolysis produces dextrose.
`
`

`

`Medicated Lozenges
`
`423
`
`The hydrolysis of the starch is halted when partially complete—to pro-
`duce corn syrup, the exact degree depending on the type of syrup being
`made. Partial hydrolysis of starch converts part of the starch completely
`to dextrose; the remainder, which is not completely hydrolyzed to dextrose,
`consists of maltose and higher saccharides. The proportions of saccharides
`vary, depending on the extent and method of hydrolysis.
`Two methods of hydrolysis are in commercial use for the production of
`corn syrup—the acid process and the acid-enzyme process,
`In the latter,
`acid hydrolysis is followed by conversion with an amylolytic enzyme, re-
`sulting in a syrup with a higher proportion of maltose than can be obtained
`by acid hydrolysis alone. The dextrose/maltose ratio can be varied, within
`certain limits, depending on the type of enzyme used and on the extent of
`the preliminary acid conversion.
`In the acid hydrolysis process, the hydrolysis is stopped when the re-
`action has reached the desired DE range, by transferring the contents of
`the converter into a neutralizing tank where the pH is raised to the level
`necessary to stop the reaction. The acid acts as a catalyst and does not
`combine chemically with the starch, The acidified product is partially neu-
`tralized by adding a calculated quantity of sodium carbonate to the solution.
`Fatty substances which rise to the surface are skimmed and then re-
`moved in centrifuges or by precoated filters. Suspended solid matter is
`removed by filtering the hydrolyzate in vacuum filters. The filtrate is
`then evaporated to a density of about 60% dry substance.
`After this initial evaporation, the hydrolyzate is passed through either
`bone char or other carbon filters, which causes further clarification and
`decolorization so that the resulting syrup is clear and practically colorless.
`This process partially removes soluble mineral substances, which also can
`be removed by an ion exchange process.
`After final filtration, evaporation is carried out in vacuum pans at rela-
`tively low temperature to avoid damage to the syrup. The syrup is cooled
`and can be stored or loaded directly in tank cars, tank trucks, steel drums,
`or cans.
`In the production of high-conversion acid-enzyme or dual-conversion
`syrups, acid hydrolysis is carried to a level of 48-55 DE. The syrup
`then is neutralized, clarified, and partially concentrated, and the enzyme
`added.
`In other products the acid hydrolysis may be stopped at a level
`as low as 15 DE. When the enzyme hydrolysis has progressed to the de-
`sired degree,
`the enzyme is inactivated. Adjustment of the pH, further
`refining, and final evaporation follow as in the production of acid conver-
`sion syrup. A summary of the corn-refining process is described in
`Figure 3.
`
`Dextrose Equivalent
`
`Dextrose equivalent is a measure of the reducing-sugar content of a
`product calculated as dextrose and expressed as a percentage of the total
`dry substance [7,8]. Essentially, the dextrose equivalent is the percent-
`age of pure dextrose that gives the same analytical effect as is given by
`the corn syrup. Certain sugars, such as dextrose, maltose, lactose, and
`levulose, are called reducing sugars because when a copper hydroxide solu-
`tion (Fehling’s solution) is warmed with these sugars,
`they react with
`cupric hydroxide to form cuprous oxide. Sucrose is not a reducing sugar;
`thus it does not react with Fehling's solution. Generally, dextrose equiva-
`lent indicates the degree of conversion in corn syrup. The higher the
`
`

`

`
`
`
`
`AFAis,
`"eat a
`wt
`a
`
`AAStf
`a2? A}
`
`Mh my od bal
`pei
`
`i
`
`ia
`vie
`oo CASE: Hedy) ot’
`
`-
`
`
`
`at
`
`on,D.C.)
`
`Figure3
`
`

`

`_ Medicated Lozenges
`
`425
`
`dextrose equivalent, the further the conversion has been carried out, re-
`sulting in less of the higher sugars (maltotriose and maitotetrose).
`The classes of corn syrups categorized as to degree of conversion [8]
`include:
`
`Low-conversion corn syrup
`Regular conversion corn syrup
`Intermediate-conversion corn syrup
`High-conversion corn syrup
`Extra high-conversion corn syrup
`Dextrose
`
`20—38 DE
`38-48 DE
`48-58 DE
`58-68 DE
`68—99 DE
`100 DE
`
`A typical analysis of corn syrup with representative carbohydrate com-
`position and physical and chemical characteristics is included in Table 2,
`
`Physical Characteristics
`
`Corn syrups with 42—43 DE are called normal corn syrups; those with
`37-38 DE, low-dextrose-equivalent corn syrups; and those with 58-62 DE,
`high-dextrose-equivalent corn syrups. Regular- or low-conversion dextrose
`equivalent corn syrups are widely used in hard candy. For caramels, low-
`dextrose-equivalent syrup is preferred because it prevents the product
`from "flowing" in the cold state because of the high viscosity that low-dex-
`trose-equivalent corn syrups impart to products to which they are added.
`The high viscosity prevents the caramel from losing its shape when the
`product is stored at elevated temperature or high-humidity conditions.
`High-dextrose-equivalent corn syrups are generally used for filling where
`_ a low-viscosity and higher sweetness medium is required. Since the intro-
`duction of enzyme conversion, corn syrups can be varied to best suit their
`application, The properties and functional applications of corn syrups
`based on degree of conversion may be described as follows [6].
`
`Browning reaction. The typical brown color that candy base may de-
`velop during cooking results from a reaction between reducing sugars and
`proteins (Maillard reaction). As the corn syrup conversion continues, more
`reducing sugars are produced, The higher dextrose equivalent syrups are
`more prone to darkening.
`Some reducing sugars are more active than
`others. For example, dextrose is more reactive than maltose. Therefore,
`the more highly converted products containing maltose are selected in pref-
`erence to the dextrose-containing syrups. Fructose reacts more readily
`than dextrose and will give a greater amount of browning than dextrose
`at the same solids level.
`
`Fermentability. Yeast-raised goods, particularly bread, require fer-
`mentable sugars to serve as food for the yeast, and also some residual
`sugars to give good crust color and add a mild sweetness to the finished
`product. Because fermentable sugars increase with dextrose equivalent
`level, the high-DE, dextrose-rich corn syrups are always utilized in making
`yeast-raised products with crystalline dextrose as the ultimate ingredient.
`
`Foam stabilizer. Because the lower dextrose equivalent syrups have
`a greater ability to retain incorporated air, they are always chosen as the
`best foam stabilizer.
`
`

`

`426
`
`Peters
`
`Typical Analysis of Various Corn Syrup Grades
`Table 2.
`Saenreereeeeeneeee
`Representative carbohydrate composition
`
`Degree of conversion
`Type of conversion
`
`Very low
`Acid-
`enzyme
`
`Regular
`Acid
`
`Regular
`Acid-
`
`Dextrose equivalent (%)
`
`Fermentable extract (%)
`Dextrose (monosaccharides) (%)
`Maltose (disaccharides) (%)
`Maltotriose (trisaccharides) (%)
`Higher saccharides (%)
`
`26
`
`23
`5
`14
`14
`67
`
`Representative chemical and physical data
`
`Baumé at 100°F (degrees
`Total solids (%)
`Moisture (%)
`pH
`(%)
`Acidity as HCl
`Viscosity (poises at 100°F)
`Boiling point (°F)
`Weight (lb gal at 100°F)
`
`42
`77.5
`22.5
`5
`0.015
`220
`222
`11.70
`
`35
`
`32
`14
`12
`ii
`63
`
`43
`79.9
`20.1
`5
`0.015
`220
`226
`11,81
`
`43
`
`42
`20
`14
`12
`54
`
`43
`80.3
`19.7
`5
`0.015
`125
`227
`11.81
`
`Percentage ash (sulfated) of resin-refined corn syrup, less than 0.02%.
`Percentage ash of vegetable-carbon refined corn syrup, 0.3%
`eaane
`Source: A, E, Staley Manufacturing Co., Decatur, Illinois (Tech. Data
`Sheet No. 110).
`
`Freezing point depressio;, and osmotie pressure. Because freezing
`point depression and osmotic pressure are directly related to the number
`of molecules present,
`the highest dextrose equivalent products give the
`greatest freezing point depression and the highest osmotic pressure,
`
`Hygroscopicity. The more highly converted syrups have the greatest
`ability to take up water and the low-conversion products the least.
`If a
`base product for preparing a dry powder with low hygroscopicity is de-
`sired,
`then the lowest dextrose equivalent products are used, sometimes
`extending below the 20-DE range into the maltodextrins.
`
`

`

`Medicated Lozenges
`
`427
`
`
`
`Regular
`Acid-
`enzyme
`
`Intermediate
`Acid
`
`High
`Acid-
`enzyme
`
`High
`Acid-
`enzyme
`
`Very High
`Acid-
`enzyme
`
`42
`58
`7
`34
`27
`32
`
`43
`80.5
`19.5
`5
`0.015
`125
`227
`11.81
`
`54
`54
`30
`18
`13
`39
`
`43
`81.0
`19.0
`5
`0.015
`75
`229
`11,81
`
`64
`76
`39
`33
`12
`16
`
`43
`81.8
`18.2
`5
`0.015
`55
`233
`11, 81
`
`64
`76
`39
`33
`12
`16
`
`44
`83.8
`16.2
`5
`0.015
`155
`234
`11.93
`
`68
`79
`40
`39
`4
`17
`
`43
`82.0
`18.0
`5
`0.015
`55
`233
`11.81
`
`Nutritive solids. Since the caloric value of starch hydrolyzates is
`based primarily on carbon content,
`there is no significant difference among
`the various corn syrups when nutritive value is based on solids content.
`If a controlled rate of assimilation is required for specialty applications,
`such as infant foods, the lower converted products with lower rates of
`assimilation are used.
`In a special application, there could be preference
`for a corn syrup containing dextrose, maltose, or fructose.
`
`In the preparation of hard candies,
`Control of sugar crystallization.
`control of the number and size of sugar crystals is required. The higher
`
`

`

`428
`
`Peters
`
`polysaccharides of the low converted corn syrups are effective agents for
`this purpose, By selecting syrups with the correct higher polysaccharide
`eontent and distribution, control of crystallization can be obtained.
`
`Sweetness, Fructose is sweeter than dextrose, which is sweeter than
`maltose, which is sweeter than higher polysaccharides. Since the sugars,
`fructose, dextrose, and maltose are all reducing sugars,
`the higher dex-
`trose equivalent corn syrups are generally sweeter than the lower dextrose
`equivalent products. However, at any dextrose equivalent level, the corn
`syrup containing a given amount of fructose will be sweeter than a syrup
`containing an equal quantity of dextrose or maltose. Where sweetness is
`the major functional property desired, the high-dextrose-equivalent corn
`syrups, especially those containing fructose, should be selected.
`
`Viscosity. This property is basically dependent on the average mole-
`cular size. The most viscous syrups are the lowest dextrose equivalent
`products.
`
`Miscellaneous. Corn syrup is transported from the manufacturer to
`eustomers or to distribution points in rail tankers as a thick, viscous,
`water-white syrup. The tankers are usually insulated to maintain the tem-
`perature of the syrup at 90—140°F, depending on the type of syrup being
`shipped.
`<A summary of the physical characteristics available with various
`corn syrups appears in Figure 4 [6].
`
`Degrees Baumé
`
`Corn syrups are sold on a Baumé basis, which is a measure of specific
`gravity or dry substance content [8]. Since corn syrups are viscous at
`room temperature, Baumé determination is made at 140°F (60°C) with an
`arbitrary correction of 1.00° Baumé added to the observed reading to cor-
`rect the value, which would be reported at 100°F (37.7°C). This is called
`commercial Baumé [9]. Specific gravity is an important consideration when
`choosing a grade of corn syrup (43° Baumé corn syrup having about 20%
`water, 45° Baumé about 15% water, and 37° Baumé about 30% water). For
`transport by tank cars, a corn syrup of 43° Baumé is preferred over one
`of 45° Baumé because of its superior flow characteristics. Forty-three
`degree Baumé corn syrup, even with improved flow vs. 45° Baumé syrup,
`still must be heated to 100°F to effect acceptable flow. Use of 41° Baumé
`corn syrup (77% solids) eliminates the heating of corn syrup during stor-
`age. This requires longer heating during candy base preparation, thus
`resulting in longer cooking time and possibly more browning [10]. The
`overall advantages of 43° Baumé corn syrup make this the syrup of choice
`in the preparation of hard candy lozenges.
`
`Applications
`
`The primary functions of corn syrup in hard candy base are (a) to
`control crystallization; (b) to add body; (c) to supply solids at a reduced
`cost; (d) to adjust sweetness level. Control of sugar crystallization is a
`primary application of corn syrup in hard candy. Since sugar is readily
`erystallized when the water of sugar solutions is boiled off, the presence
`of the noncrystallizable corn syrup is necessary to inhibit the graining or
`recrystallization of the sucrose. This inhibition of sugar recrystallization
`is accomplished by surrounding each molecule of sucrose with a film of
`
`

`

`Medicated Lozenges
`
`429
`
`HIGH-
`HIGH.
`WHTER,-
`REG.-
`Low.
`PROPERTY OR FUNCTIONAL USE
`
`
`
`
`
`CONV conv cONY CONV(ALPHABETICALLY) CONV
`
`TYPE OF CORN SYRUP
`
`SWEETNESS MHIVISCOSITY
`
`BODYING AGENT
`
`BROWNING REACTION
`
`COHESIVENESS
`
`FERMENTABILITY
`
`FLAVOR ENHANCEMENT
`
`FLAVOR TRANSFER
`MEDIUM
`
`FOAM STABILIZER
`
`FREEZING POINT
`DEPRESSION
`
`HUMECTANCY
`
`HYGROSCOPICITY
`
`NUTRITIVE SOLIDS
`
`OSMOTIC PRESSURE
`
`PREVENTION
`OF SUGAR
`CRYSTALLIZATION
`
`PREVENTION OF COARSE
`ICE CRYSTALS DURING
`FREEZING
`
`SHEEN PRODUCER
`
`Properties and functional uses of corn syrup.
`Figure 4
`Association, Inc,, Washington, D.C.)
`
`(Corn Refiners
`
`in essence, may be characterized
`uncrystallizable corn syrup. Hard candy,
`85 a supersaturated sugar solution in corn syrup [4]. The sugar molecules
`are dissolved and separated in the corn syrup, and because of the high vis-
`eosity of the corn syrup solution, movement of sugar molecules in the corn
`syrup is slowed. Eventually,