Welcome to George Eby's ColdCure.com!

Click below to order the only product ever found to cure the common cold.

Over the years, George Eby has become the world's leading authority on curing common colds with zinc according to this eTBLAST independent analysis. He pioneered the subject with his breakthrough 1984 research. In 2008, significant confirmation resulted with the publication of this report which showed that common colds were shortened and symptoms improved and most importantly, InterCellular Adhesion Molecule-1 (ICAM-1) was inhibited by zinc lozenges. Inhibition of ICAM-1 is considered essential by scientists for a common cold cure.

Eby's ColdCure zinc lozenges use the only formulation ever demonstrated in the history of common cold research to reduce dramatically the duration and severity of all common cold symptoms in three independent, non-company, double-blind, clinical trials published in peer reviewed medical journals. His 4-gram peppermint flavored ColdCure zinc lozenges release 14.0 mg zinc ions - and they are pleasant tasting.

See these journal articles for evidence of efficacy:

Prasad 2008

Prasad 2000

Petrus 1998

Family-size bottles of these zinc lozenges are inexpensively priced at US $28.00 for a bottle of 100 lozenges, while cases of 12 bottles (as gifts to your friends, relatives and co-workers) are only $144.00. Place your order for Eby's ColdCure zinc lozenges now for your next common cold (you know it's going to occur) using our exclusive ORDER FORM.

View Eby's ColdCure zinc lozenge bottle label here.

If you want to know why there are no other zinc lozenges that can cure the common cold, it is a matter of his patents! George Eby patented all of the zinc lozenge formulations that would shorten or cure common colds, thus all of the other zinc lozenges in stores use non-infringing formulas that can not cure common colds.

A cure for the common cold? No way! You have been thoroughly indoctrinated to know there is no such thing! Right? There are too many rhinovirus types; and too many other excuses have been thrown at you by everyone from your mother to government research scientists. It's just unthinkable. Not to belabor the point, see what Eby's ColdCure zinc lozenges with their zinc ion availability (ZIA) of 100 do to reduce the average duration of common colds by 7 days, and to reduce the severity of all common cold symptoms to the point that very few people have common cold symptoms of any consequence after the third day. They do it by taking advantage of the inhibitor effects of ionic zinc on intercellular adhesion molecule-1 (ICAM-1), by antiviral means and other means described in this website.

What does the ZIA of zinc lozenges mean? Strength! Power! Efficacy! The strength of zinc lozenge in its ability to shorten common colds, or terminate incipient common colds is directly related to the ZIA of the lozenges. A zinc lozenge having a strong ZIA value will release hydrated zinc ions (Zn²⁺) at physiologic pH evinced by oral drying (astringency) and major reduction in duration of common colds. Zinc lozenges having a ZIA value of 100 are strong enough to terminate incipient common colds in less than a day or reduce the average duration of existing common colds by a week. They are pleasant tasting, flavor stable and cause no objectionable aftertaste. Zn²⁺ ions at physiologic pH are powerful - but totally natural - antirhinoviral agents, ICAM-1 inhibitors, immune system aids, interferon inducers, cell plasma/membrane pore closing agents, anti-inflammatory agents, antioxidants, protease inhibitors, and strong drying agents.

On the other hand, other zinc lozenges having a zero or low ZIA value do not release zinc ions and are not astringent. Zinc lozenges with low positive ZIA values are not very useful and may not be sufficiently astringent to notice. Zinc lozenges having a negative ZIA value (ZnL^N-) also are not astringent, often taste acidic and may worsen common colds. It is the lozenge ZIA value -- not the total amount of zinc -- that results in duration changes in common colds. These non astringent, ineffective zinc lozenges are the type found in stores and elsewhere. See these tragic products in the table of http://zinc-lozenges.com.

Astringency is the mouth's way of detecting ionic zinc. Compare the astringency of other zinc lozenges with Eby's ColdCure zinc lozenges and use the most astringent zinc lozenges you can find (Eby's ColdCure) for maximum benefit. Purchase Eby's ColdCure zinc lozenges before you develop a common cold and start use as soon at the first indication of common cold coming on. Treating a common cold very early may terminate the common cold in less than a day. Why? Viral replication inhibition and ICAM-1 inhibition by ionic zinc occurs best during the first signs of a common cold symptom! Eby's ColdCure zinc lozenges used in the early stage of a common cold have a much better chance of terminating a common cold in a day than if their use is started after viral damage has occurred.

Young people experience more common colds and worse common colds, and often give them to their parents. If you wait until you, or your loved ones, develop a common cold, it will be too late to take best advantage of the amazing power of these zinc lozenges although they will still be of significant value.

Allergy Season?

Zinc lozenges are fabulous for seasonal allergies too! Usually only one or two lozenges are needed per day for complete nasal relief. Check out this annual allergy chart for more information about what allergens are in the air on a seasonal basis.

The Flu?

Remember, flu (influenza) is totally different from common colds and allergies and may require special medication from a physician.

George Eby's ColdCure.com web site abides by the Health on the Internet Code of Conduct for Medical and Health Websites. George Eby, the inventor of Eby's^TM ColdCure Zinc Lozenges and web master, does not hold himself to the public to be a physician, and he provides information in this site only as a public service, and not as medical advice which can be given only by a licensed physician. George Eby and Eby Pharma, LLC are not responsible for misuse of zinc or ColdCure^TM lozenges or any other item sold through this facility. All information presented in this web site is provided for educational purposes only. The only warranties made in this web site are all information is: (a) believed to be given with full and open disclosure, (b) believed to be accurate, truthful, and unbiased, and (c) believed to adhere to the National Academy of Sciences' principles of responsible scientific research.

© 1995 - 2008 All rights reserved. Permission is granted to all to make paper copies for fair use, including evaluation, research, and teaching purposes if text is maintained in its original context and if proper copyright credit is given. Written permission is required to publish for profit, or make available for sale copyrighted material from this site. Under current U.S. copyright laws and federal court interpretations, technical figures and tables are considered to be unadorned facts. Facts can not be copyrighted and may be used and distributed freely as long as proper credit is given.

Last Updated: March 20, 2008

Lots of people have asked what George Eby looks like, so here is his picture. He is 67 years old and lives in the hill country west of Austin, Texas. He is a ~~retired~~ scientist/inventor.

Questions? Contact him. Questions, kudos, complaints and comments are always welcome.

George Eby
Eby Pharma, LLC
P.O. Box 1142
Dripping Springs, Texas 78620 USA
telephone/fax (512) 263-0805

Handbook for Curing the Common Cold
The Zinc Lozenge Story

George A. Eby

Copyright Page

Published by:
Publications Division
George Eby Research
Austin, Texas U.S.A.

Copyright (c) 1994 by George A. Eby

All rights reserved. With the exception of factual figures presented, no part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise without prior written permission from the author. Absolutely no unauthorized reproduction is allowed under penalty of law.

As long as the source is properly credited, the publisher gives permission to all to reproduce figures within this publication, as most technical figures are equated with unadorned facts and they -- and most other technical figures and support data regardless of source -- are not copyrightable under existing United States case law.

Copyright (c) 1994 by Charles A. Pasternak - Foreword
Copyright (c) 1994 by David A. J. Tyrrell - Foreword
Copyright (c) 1994 by Widad Al-Nakib - Foreword

Copyrights for articles in Appendix:

Library of Congress Catalog Card Number: 93-090841

ISBN: 0-9638967-0-9

Printed in Austin, Texas, United States of America.
First edition, first printing: February 14, 1994,

Internet publication: December 3, 2002

Dedicated to my daugther,

Karen Lynn Eby

and

serendipity

· Chapter 1. Introduction - page 1

· Magnitude of Health Problem

· Etiologic Agents

· Seasonal Variation in Etiologic Agents

· New Evidence for Rhinoviruses as Principal Cause of Colds

· Immune Response of the Nose

· Overview of Common Cold Treatments

· Introduction of Zinc Gluconate Lozenges

· Stability Constants

· Calculating Availability of Zn²⁺ Ions

· Consideration of Body Acid-Base Balance

· Chapter 1. References

· Chapter 2. In Vitro Effects Of Zn²⁺ Ions - page 9

· Antiviral Effects of Zinc Ions

· Antibacterial and Antifungal Activity

· Astringency

· Non-Specific Membrane Protection

· Cytolysin

· Complement

· Mast Cells

· Histamine or Kinins in Colds?

· T-cell Lymphocytes

· Interferon Induction

· Anti-Inflammatory Action

· Zinc, Stress, and Common Colds

· Overview of Effects of Zn²⁺ Ions in Common Cold Therapy

· Chapter 2. References

· Chapter 3. Zinc Lozenge Method of Treating Colds - page 25

· Nasal Administration and Systemic Absorption

· Oral Cavity Absorption

· Mouth-Nose Electric Circuit

· Fick's First Law

· Ionic Diffusion

· Zinc Ion Availability (ZIA) Values

· Mathematics Of Common Cold Duration

· Chapter 3. References

· Chapter 4. Effects of Zinc Lozenges on Duration of Common Colds page - 33

4.A. Effects Of Hydrated Zn²⁺ Ions on Duration of Common Colds

4.A.1. Original 1984 Eby Study

4.A.2. Great Britain Medical Research Council Common Cold Unit 1987 Study

4.A.3. McNeil 11.5-Mg Zinc Gluconate Lozenge Study

4.B. Effect of Strong Zinc Complexes on Duration of Common Colds

4.B.1 Zinc Orotate Lozenges with Zinc Gluconate Nasal Spray Study

4.B.2. Zinc Aspartate Lozenge Study

C. Effects of Strong Complexes with Ligand in Excess on Duration of Common Colds

4.C.1. Citric Acid Flavor Masked Zinc Gluconate Lozenge Study

4.C.2. Australian 10 mg Zinc Acetate Effervescent Lozenge Study

4.C.3. Zinc Gluconate-Glycine Lozenge Study

· Chapter 5. Central Finding of Linear Relation between ZIA and Efficacy - page 63

· ZIA Factors

· Comparative ZIA Values

· Projection of Negative ZIA Values

· Taste Scale and ZIA

· Concession to Taste Through Use of a Double Loading Dose

· Zn²⁺ Ions and Zinc Compound Molar Concentration with ZIA Values

· Chapter 5. References

· Chapter 6. Effects of Flavor-Masking on Efficacy - page 71

· Strong Chelation of Zinc

· Various Non-Chelating Flavor Masks

· Anethole as Flavor Mask

· Low ZIA Value for 5-Gram Zinc Gluconate Lozenge

· Search for Efficacy and Pleasant Taste

· Chapter 6. References

· Chapter 7. Zinc Acetate Lozenges, Successor to Zinc Gluconate Lozenges - page 77

· Zinc Acetate as Source of Zn²⁺Ions

· Flavor Stability

7.A. General Lozenge Considerations

7.B. Standard Design Lozenges

7.C. Advanced Design Lozenges

· Other Formulations

· Eliminating Astringency from Zinc Lozenges

· Chapter 7. References

· Chapter 8. Zinc Biochemistry - page 88

· Zinc in Genetics

· General Zinc Biochemistry

· Zinc, HIV, and AIDS

· GRAS Status Assessment

· Recent Human Safety and Toxicologic Data

· Lack of Toxicity in Common Cold Studies

· Possible Adverse Effect in Pregnancy

· Industrial Safety and Material Safety Data Sheet for Zinc Acetate

· Concluding Comments on Toxicity

· Chapter 8. References

· Chapter 9. Conclusions and Recommendations - page 97

· Changes in Formulation Allowable

· Minimum Effective Dose

· Manufacturing Variables Affecting ZIA

· Importance of Placebo Matching

· Differences in Lozenge Taste Perception in Well and Ill Volunteers

· Placebo Lozenge Formula Considerations

· Recommended Placebo Lozenge Formula

· Recommended Clinical Trial Protocols

· Improving Clinical Result

· Expected Clinical Results from Advanced Design Lozenges

· Full Circle

· Expected Side Effects and Contraindications

· Use of Zinc Acetate Lozenges to Treat Upper Respiratory Allergy

· Use of Zinc Acetate Lozenges to Treat Mononucleosis

· Concluding Remarks

· Chapter 9. References

List of Figures

· Figure 1. Distribution of zinc ionic species in the Zn²⁺ and gluconic acid system

· Figure 2. Effect of different half-lives on percent of patients with symptoms on various days, showing weighted average durations

· Figure 3. Duration of common colds in ZIA 100 zinc gluconate- and placebo-treated groups

· Figure 4. Average total severity of colds in ZIA 100 zinc gluconate- and placebo-treated groups

· Figure 5. Daily clinical score of ZIA 43.9 zinc gluconate- and placebo-treated groups

· Figure 6. Daily nasal secretion weights in grams for ZIA 44 zinc gluconate- and placebo- treated groups

· Figure 7. Duration of common colds using bitter ZIA 25 zinc gluconate and placebo

· Figure 8. Effect of very low dosage ZIA 13.4 zinc gluconate and placebo

· Figure 9. Effect of ZIA 0 zinc orotate and placebo lozenges and zinc gluconate nasal spray

· Figure 10. Estimated effect of ZIA 0 zinc aspartate and placebo lozenges

· Figure 11. Mole fraction Zn²⁺ species versus pH for solution with Zn²⁺ and excess citric acid (H₃L)

· Figure 12. Mole fraction for equimolar zinc and citric acid at 10 mMol

· Figure 13. Estimated effect of ZIA -12.5 zinc gluconate-citrate and placebo lozenges

· Figure 14. Estimated effect of ZIA -54 zinc acetate- tartarate-carbonate lozenges and placebo

· Figure 15. Letter from R. J. E. Williams showing procedure and method for producing effervescence in zinc acetate lozenges

· Figure 16. Estimated effect of zinc gluconate-glycine and placebo on duration of colds

· Figure 17. Effect of pretreatment cold duration for zinc gluconate-glycine treated sub-groups

· Figure 18. Concentration of Zn²⁺, and various zinc glycinate and zinc hydroxide species in the zinc gluconate-glycinate system

· Figure 19. Relationship of zinc ion availability (ZIA) values and reduction in duration of common colds

· Figure 20. Concentration of Zn²⁺ ion in the zinc and acetate system by pH

· Figure 21. Effect of compressive force upon dissolution times

· Figure 22. Effect of compressive force upon ZIA values

· Figure 23. Effect of zinc content on ZIA and Zn²⁺ mMol concentration

· Figure 24. Relationship of lozenge zinc content to saliva production.

· Figure 25. Relationship of lozenge zinc content to lozenge dissolution rate

· Figure 26. Effect of force applied to lozenge thickness

· Figure 27. Expected effect of ZIA 100 and ZIA 400 lozenges

List of Tables

· Table 1. Characteristics of 80 subjects

· Table 2. Number of patients reporting common cold symptoms at various times

· Table 3. Average severity of 10 common cold symptoms at various times

· Table 4. Side effects and complaints

· Table 5. 11.5-mg zinc lozenge formulation tested by McNeil Consumer Products Company

· Table 6. Examples of citric acid - sodium bicarbonate in effervescent formulations from Mohrle

· Table 7. ZIA factors (zinc, fraction Zn²⁺, dissolution times, doses per day and saliva generated)

· Table 8. Study lozenges, ZIA values, electronic charge, and reduction in duration of colds.

· Table 9. Lozenge taste, salivary pH, near aftertaste and overnight aftertaste

· Table 10. Zinc²⁺ ion and zinc compound salivary molar concentration compared with ZIA values

· Table 11. Characteristics for preliminary 23-mg zinc (zinc acetate) 5-gram lozenges having different directly compressible bases

· Table 12. Medicinal ingredients for incorporation into common cold lozenge

· Table 13. Advanced design 15 mg zinc (zinc acetate) lozenge characteristics (3.5 and 5.0 gram)

· Table 14. Average zinc content, ZIA, Zn²⁺ ion concentration and saliva production from zinc acetate lozenges

· Table 15. Source and cost of zinc acetate lozenge ingredients

· Table 16. Possible daily intake of zinc in milligrams per kilogram of body weight

Foreward by Charles A. Pasternak, PhD, MD

Today, zinc supplements are found on the health-food shelves of pharmacies and drug stores, alongside ginseng, yeast extract, and oil of wintergreen. But let us not forget that today's alternative or homeopathic medicine -- complementary is probably a better word -- is tomorrow's orthodox medicine. There are plenty of examples to illustrate this point: from the use of digitalis to prevent heart attack or quinine to prevent malaria, to the technique of vaccination to prevent infectious disease. The latter is a particularly striking example. Three centuries ago the practice of variolation (inhaling the pus from a small-pox victim to protect oneself against the onset of this disfiguring disease) was not so much an old wives' tale as a young mistress's tale: having been used for centuries earlier by the Chinese, it was prescribed for the Circassian maidens who inhabited the sultan's seraglio in the Ottoman Empire to protect their luscious skins. Today, following on from the success story of the small-pox vaccine, billions of dollars are being spent by the most respected research establishments of the world to develop vaccines against malaria, influenza, HIV, and a host of other infectious agents. If we had a vaccine against rhinoviruses, we might not need to fight the common cold with Zn²⁺ ions from zinc lozenges.

The trouble with zinc is that, like vitamin C, it is present in most of our diets in quantities sufficient to prevent major deficiency disease (rare enough, anyway, in the case of zinc). Why should we take more? The answer lies in the way in which vitamins and other essential nutrients such as iron, copper, zinc, or iodine work: with the possible exception of iodine, whose function seems to be confined to the thyroid gland, most other vitamins and nutrients play a role in practically every tissue of the body. For example, while the dietary intake of vitamin C or zinc by healthy people of the Western world may be sufficient to prevent scurvy or the skin disease of Acrodermatitis enteropathica, respectively, this does not mean that a little bit extra may not be beneficial in fighting a number of different infectious diseases. For not only do vitamin C and zinc function in many different tissues, but the natures of those functions are manifold. Zinc, for example, is required for dozens of quite different molecular interactions within cells: it is easy to envisage that at a particular dietary intake most of these work normally, but one or two are below par; this would place the individual at risk for the onset of disease. Moreover, the imposition of a particular stress such as a viral infection places additional demands on certain cells within the body, and no one should be surprised that a higher concentration than normal of a critical nutrient such as zinc turns out to be beneficial.

George Eby is a courageous man. He is neither scientist nor physician, yet he has battled with the medical establishment and pharmaceutical companies for a decade to persuade them to take seriously his proposal regarding throat lozenges releasing Zn²⁺ ions as an effective treatment for common colds. There is room in all walks of life for astute and intelligent men like George Eby: the challenge from inquiring and critical laymen is often immensely beneficial to scientists and physicians set in their ways. And who in the United States can doubt the contributions made by their most eminent layman -- President Thomas Jefferson? While George Eby's suggestion 15 years ago that his hospitalized leukemic daughter be given additional nutrients that included zinc may have not been as dramatic as the decision 250 years ago of Lady Mary Worley Montague -- wife of the British Envoy in Constantinople -- to administer a small dose of live small pox to her son to protect him against subsequent exposure, George Eby may nevertheless have stumbled onto more than one novel form of therapy using zinc. Read what follows and judge for yourself.

Charles A. Pasternak, Ph.D., D.Sc., Hon M.D.
Professor of Biochemistry
University of London at
St George's Hospital Medical School
London (UK)
and
Director of the Oxford International
Biomedical Centre

Foreword by David AJ Tyrrell, MD, Director

Some years ago George Eby noted that using zinc gluconate lozenges apparently benefited his daughter's colds, so he organized a clinical trial to test the idea. The results showed that such treatment improved the outcome. Although the trial did have some faults, we conducted a further test of his formulation in volunteers given experimental colds at the Common Cold Unit at Salisbury. The results of the test seemed to show benefit if the lozenges were given before or during the cold, yet similar studies at the excellent unit at the University of Virginia failed to confirm our findings.

Mr. Eby has taken expert advice and investigated the possibility that it isn't merely the presence of zinc in the lozenge which matters, but the amount and duration of the Zn²⁺ ions released that determines whether there is an effect or not. He has combined his own studies of the characteristics of the formulations used with the published results of trials in a type of meta-analysis. It is not possible to present the amount of benefit in formally the same terms, but the results do support his case that the differences might be due to the release characteristics of the Zn²⁺ ions.

Of course this doesn't settle the problem. It has been suggested that our trials failed to control adequately for the volunteers guessing whether they had active or placebo lozenges, and so produced a spurious positive result. There is also the problem that there is no evidence that Zn²⁺ ions actually reach the infected mucous membranes in the nose; however, in a sense that does not matter as there are many examples of active treatments being discovered when there was no evidence of how they worked.

It is therefore worthwhile keeping the debate open in spite of the negative results in some trials and other much less plausible claims for benefits from zinc. This book helps in that debate by bringing together summaries of the biology of zinc, the results of the trials in common colds and the results of the analyses of the formulations used. The texts of original papers are also there to help the careful reader.

I welcome this book. The best result of its publication would be at least one vigorous trial using zinc lozenges formulated with precisely the characteristics of those used and recommended by Mr. Eby, and with vigorous monitoring of the double-blind precautions and the clinical course of the patients.

David A. J. Tyrrell, M.D.,
retired Director Common Cold Unit
British Medical Research Council,
Salisbury (UK)

and currently with the:
British Medical Research Council
AIDS Directed Programme Public Health Laboratory Service
Centre for Applied Microbiology and Research
Porton Down, Salisbury, UK

Foreword by Widad Al-Nakib, MD

In 1994, there continues to be a debate as to the efficacy of zinc in the prevention and/or treatment of the common cold. The initial studies conducted by Eby et al (1984) did suggest some efficacy although the trials were not perhaps as vigorously controlled as they should have been. We conducted double blind placebo-controlled studies at the MRC Common Cold Unit in Salisbury and found some benefit if the lozenges were given just before or after the onset of colds. One of the main criticisms of our trials was that there was not a sufficient number of volunteers in the second phase of the study which was the treatment with zinc lozenges. Studies in the USA and Australia however, failed to confirm these findings. This book attempts to review the role of zinc lozenges in the prevention and treatment of the common cold and summarizes the biology of zinc. I, like David Tyrrell, therefore welcome this book and hope that it would continue to debate the subject further with the hope that it may encourage further controlled trials.

Widad Al-Nakib, MA FRCPath PhD
Principal Investigator, Common cold Unit
British Medical Research Council CCU
currently at Advanced Pathology Services
London UK

Preface

In an effort to provide a unifying hypothesis, this handbook analyzes all reports of zinc lozenge for common cold research reported since publication of my 1984 article in Antimicrobial Agents and Chemotherapy which documented a way of reducing the average duration of common colds by seven days using zinc gluconate lozenges. Common colds are mostly caused by rhinoviruses, and zinc gluconate is a good source of Zn²⁺ ions which are antirhinoviral.

The story has been told around the world of how in 1979 my leukemic 3-year old daughter, Karen, started a revolution. She had refused to swallow her 50-mg zinc supplement because she had a severe common cold. Instead, she allowed the zinc gluconate tablet to dissolve slowly in her mouth during an afternoon nap, resulting in the termination of her cold within several hours -- without further treatment or relapse. After this serendipitous discovery, I found similar results in other family members, friends, and co-workers.

Swallowed tablets, nasal ointments, nasal sprays, and nose drops were also tested. Nose drops were expected to work better than lozenges; however, no reduction in duration of common colds was observed. The dichotomy was difficult to understand, as colds are an infection of the nose, not the mouth. In retrospect, these findings are consistent with published literature dating from 1901 on zinc treatment of nasal catarrh via the nasal route as a short-lived nasal decongestant.

Why? A biologically closed electric circuit (BCEC) between the mouth and nose controls local movement of metallic ions. Of the many BCECs described in 1984 by Björn E. W. Nordenström, the mouth-nose BCEC is the most readily observable.

Over a two-year experimental period from 1979 to 1981, I formalized what I thought to be the best protocol for using zinc gluconate lozenges. William W. Halcomb (a general practice physician and allergist now in Mesa, Arizona), Donald R. Davis (a nutrition scientist who worked for National Academy of Science member Roger J. Williams [deceased] at the Clayton Biochemical Institute Foundation at the University of Texas at Austin), and I conducted the original double-blind study using slow-dissolving zinc gluconate tablets -- as lozenges -- in the fall of 1981 to treat wild common colds.

The results showed the expected efficacy. Zinc gluconate lozenges reduced the average duration of common colds by seven days, with exceptionally strong statistical significance from the first few hours, again without relapse of colds. Our article caused others to attempt to replicate our findings.

In 1984, the Medical-Scientific Director of RBS Pharma-Milan (now part of Rôhne-Poulenc Pharma, Italia, S. P. A.), Rinaldo Pellegrini sought my team's advice on how to compound zinc gluconate lozenges. By that time, my team had completed a no-effect zinc orotate (non-ionizable) lozenge for common colds study. On the basis of the conflicting zinc gluconate and zinc orotate results, we recommended avoidance of zinc chelators in lozenges. The pleasant-tasting, fructose-based RBS Pharma lozenges were tested on experimental colds by David A. J. Tyrrell and co-workers at the Great Britain Medical Research Council (MRC) Common Cold Unit. Analysis of the data from the MRC study showed nasal secretions essentially returned to normal in the zinc-treated group by day 4, while colds in the placebo-treated group continued. Analysis of mean clinical scores showed colds were essentially absent in six days with zinc treatment. Compared to the historic average of 10.8 days for untreated colds, a reduction of 4.8 days in common cold duration occurred. For the first time, an internationally recognized common cold research group verified a clinical treatment to shorten common cold symptoms. The positive results were discomfiting to the MRC scientists, because the operative mechanism remained elusive.

The issue became confounded when other studies came up with different findings from the Texas and MRC studies. Some zinc gluconate lozenges had objectionable taste and long-lasting aftertaste, seriously impairing patient compliance. Zinc gluconate developed a reputation for being bitter, and lozenges needed flavor-masking. Actually, bitterness results only when zinc gluconate is combined with dextrose. Zinc gluconate in fructose -- as in the MRC lozenges -- tastes pleasant when flavored and has a mild aftertaste. The wide disagreement between studies caused researchers to assume the positive findings to be faulty. In 1988, letters to the editor of Antimicrobial Agents and Chemotherapy suggested differences in stability constants as being responsible for failures. The letters produced both insightful, and misleading information.

In apparent defense of citric acid flavor-masked zinc gluconate lozenge work, one letter asserted zinc gluconate-citrate lozenges produced a salivary pH of 2.3 (stomach acid pH), contending one hundred percent of the zinc was released as Zn²⁺ ions.

Realizing the improbability of a salivary 2.3 pH from use of the zinc gluconate-citrate lozenges and the improbability of availability of Zn²⁺ ions at physiologic pH, Guy Berthon, Director of Research at INSERM Unit 305 in Toulouse, France, entered the fray. One responsibility of INSERM Unit 305 is to determine the bioavailability of drugs at physiological pH 7.4, the only relevant pH for antivirals and many other chemotherapeutic agents. Determination of bioavailability is a complex and difficult effort involving solution chemistry. After a close collaboration between Guy Berthon and myself from 1988 to 1993, a report was produced thoroughly examining bioavailability of Zn²⁺ ions from the conflicting zinc lozenge articles. The resulting report, -- The "Zinc Lozenge and Common Cold Story" -- is published separately by Marcel Dekker, Inc. in Handbook of Metal-Ligand Interactions in Biological Fluids, edited by Guy Berthon. We all owe Guy Berthon our gratitude. Had he not intervened, the work would have died, and I would have gone on to do something else, disillusioned and disappointed. Worse, an effective cure to the common cold would have been buried and probably never resurrected.

Presentation of comprehensive solution chemistry data is part of the analysis of the various conflicting reports in this handbook. Guy Berthon's research demonstrated Zn²⁺ ions were available at physiologic pH