What is the Role of Over 100 Excipients in Over the Counter (OTC) Cough Medicines?

Abstract

Most medicines are white bitter powders that are formulated as tablets and capsules but cough medicines are an exception where the taste and appearance of the medicine are more important to the patient than the pharmacology of the active ingredient. Excipients are generally defined as any ingredient in a medicine other than the active ingredient. In most medicines excipients play a supportive role in delivering the medicine, but in the case of cough medicines, excipients have more important and complex roles and they can also be the main active ingredient of the cough medicine as menthol, glycerol, and sugars, which are declared as active ingredients. This review searched the United Kingdom electronic medicines compendium (emc) and found over 100 excipients in 60 different liquid formulations of over the counter cough medicines. The excipients were divided into functional groups: sweeteners, thickeners, flavors, colors, antimicrobials, and buffers, and the incidence and function of the different excipients is discussed. When considering the efficacy of a cough medicine, clinicians and pharmacists tend to think of the pharmacology of antitussives such as dextromethorphan or expectorants such as guaifenesin, and they rarely consider the role of excipients in the efficacy of the medicine. This review discusses the functions and importance of excipients in cough medicines and provides some new information for clinicians, pharmacists, and all interested in the treatment of cough when considering the composition and efficacy of a cough medicine.

Cumulative Risks of Excipients in Pediatric Phytomucolytic Syrups: The Implications for Pharmacy Practice

“…Sweeteners are the key component of pediatric medications that significantly contribute to compliance and palatability [7,8]. However, the use of sweeteners is related to a range of safety issues.…”

“…Some syrups may substitute sucrose-based syrup with a solution of polyols, such as sorbitol, or a mixture of polyols, such as sorbitol and glycerin [7]. Overall, the key functional components of a cough syrup include active ingredients and excipients: thickeners, flavors, colors, antimicrobials, and buffers [8]. Most of these excipients are additives used in the food and beverage industry [9].…”

“…The safety of excipients included in pediatric medicines will continue to be a concern for many years and has been discussed by a range of authors. The comprehensive review of Eccles presents the analysis of over 100 excipients in OTC cough medicines including pediatric ones [8]. The use of excipients in the pediatric population is critically reviewed by Rouaz et al [16], the issues of using coloring agents are reviewed by Pérez-Ibarbia et al [9], and the potential side effects of sweeteners are thoroughly discussed in works of Eccles, Humaid, Christensen, Ruiz-Ojeda et al, Saraiva et al [7][8][9][17][18][19][20][21][22][23][24][25].…”

“…Physicians, pediatricians, and pharmacists are traditionally concerned with the efficacy of active ingredients in cough syrup and rarely consider the safety aspects of excipients that, however, are not completely "inactive" and are proved to initiate some negative reactions and interactions with other drugs [8]. The latter becomes highly significant, as in practice respiratory infections in children are treated with the usage of several drugs in complex therapy.…”

LUNG Year in Review: 2020

“…Thankfully, the last decade has seen a great increase in cough-related research which has led to multiple antitussive drug development programs currently underway [ 9 ]. Cough-related articles featured in 2020 included State-of-the-Art reviews on the placebo effect in cough clinical trials [ 2 ], the role of excipients in antitussive preparations [ 11 ], and an update on the status of chronic cough in China [ 3 ]. Other topics covered were drug-associated cough [ 82 ], therapeutic strategies for chronic cough [ 79 , 83 ], the role of cough assessment in monitoring patients with asthma [ 36 ] and COPD [ 47 ], the question of whether there will be an emergence of a post-COVID-19 chronic cough [ 23 ], and abstracts from the Seventh American Cough Conference [ 84 ].…”