Tuesday, August 20, 2013

TECH SPECIAL ...Medicated chewing gum:



Medicated chewing gum: A versatile vehicle for
delivery of APIs

Abstract
Medicated chewing gums (MCGs) are solid, single dose preparations with a base con-
sisting mainly of gums that are intended to be chewed, but not swallowed. They contain one or
 more active ingredients, which are released by chewing and are intended for use for local treatment of mouth diseases or systemic delivery after absorption through buccal mucosa
Several ingredients are now incorporated in MCGs, e.g. fluoride for prophylaxis of dental caries, chlorhexidine as disinfectant, nicotine for smoking cessation, aspirin (acetylsalicylic acid)
as a pain-relieving, dimenhydrinate for motion sickness or travel illness, and caffeine for alertness. There are many other conditions and diseases where there is a potential for the use of
medicated chewing gum.
Children, in particular, may consider chewing gumas a preferred method of drug administration compared with oral liquids ortablets. The use of MCG is feasible as a local treatment of diseases of the oral cavity, as well as a treatment of systemicconditions.
MCGs consist of a masticatory gum core with a coating that can be a film of polymers, waxes, sweeteners, sugar, flavours or colours. The pharmacologically active ingredient can be present in
the core, in the coating, or in both. The degree of oromucosal absorption depends on the condition of the mucosa, the contact time and the physicochemical properties of the active ingredient.
A small unionized lipophilic molecule dissolved in saliva that is enzymaticallystable is likely to be absorbed most readily. Regarding local actions, it is possible to achieve beneficial effects
with medicated chewing gum that mightbe superior to those achieved with lozenges.
A saliva-soluble ingredient will be almost completely released within 10-15 minutes of chewing, whereas a lipid-soluble ingredient will dissolve in the gum base and thereafter be slowly
and incompletely released. As mastication increases the production of saliva,the active ingredient (depending on its characteristics) is dissolved into the saliva and thereafter swallowed with a
consequent systemic absorption.

Introduction
Modern chewing gum products appeared in 1869. Mexican General, Antonio Lopez de Santa Anna, conqueror of the Alamo, hired New York inventor Thomas Adams to develop a new
form of rubber using chicle – a gummy substance people in Mexico had been chewing for centuries. Adams was unsuccessful in developing rubber, but he did succeed in producing the first modern chewing gum. He called it Adams New York No. 1.Gum made with chicle and  similar latexes soon became more popular than spruce gum or paraffin gum. Chicle-base chewing gum was smoother, softer and held its flavour better than any previous type of chewing gum.
By the 1900s chewing gum was manufactured in many different shapes and sizes(long pencil-shaped sticks, ball form, flat sticks and blocks) and flavours (peppermint, fruit and spearmint).
Today, synthetic materials replacenatural gum ingredients to create a chewing gum with better quality, texture and taste. There are literally thousands of varieties of gum manufacturedand sold around the world. You can find gum filled with liquid or speckled with crystals; gum that won’t stick or is made without sugar; gum with wild flavour combinations (like mango and watermelon); or gum in crazy shapes like long rolls of tape.
Chewing gum has been used for centuries to clean the mouth or freshen up the breath. The first patent on chewing gum was filed in 1869 and the first MCG containing acetyl salicylic
acid was commercially introduced in 1928. In 1991, chewing gum was approved as a pharmaceutical dosage form by the European Commission. The European Pharmacopoeia defined the intended use of MCGs as local reatment of mouth diseases or for systemic delivery after absorption through the buccal mucosa or from the gastrointestinal tract.
Applications
MCGs can also be used as a substitute to buccal and sublingual tablets, which are intended to take action systemically because the active constituent is released more uniformly and cover
greater area of absorption in oral cavity. MCGs can be used for systemic effect in conditions like Vitamin C deficiency, pain & fever, alertness, motion sickness, smoking cessation, as well as local effect like plaque acid neutralization, fresh breath, dental caries, antiplaque, fungal and bacterial infection.
Prevention and cure of oral diseases is a prime target for chewing gum formulations.
Providing a prolonged local effect MCGs can control the release rate of active constituents. It also maintains the plaque pH, which lowers the intensity and frequency of dental caries.
Chlorhexidine chewing gum can be used to treat gingivitis, periodontis, oral, pharyngeal infection and inhibition of plaque growth. Fluoride (sodium fluoride) containing gums help to prevent dental caries.
Green tea concentrated extract can be used as mouth deodorizer with anti-plaque activity.
Benzenthonium chloride can be used as antibacterial product for oral hygiene.
Chewing gum formulated with aspirin can be use in treatment of pains (headache & muscular aches).
Chewing gum formulation containing nicotine, lobeline and silver acetate have been clinically tested as aids to smoking cessation.
Active constituents like chromium (reduce craving for food due to improved blood-glucose
balance), guaran and caffeine (stimulate lipolysis and increase energy expenditure and reduce feeling of hunger) have been proved to be effective in treating obesity.
APIs like dextromethorphan and dropropizine have been used as an anti-cough and dimenhydrinate can be used for combating motion sickness.
Most recently, alternative medicine has prompted the incorporation of agents such as ginseng, ginkgo, propolis, guarana, etc. in chewing gum.
Future trends
Chewing gum not only offers clinical benefits, but also is an attractive, discrete and efficient drug delivery system. A few decades ago, the only treatment for some disease was surgical procedure but now more and more disease can be treated with Novel Drug Deli-very Systems. Generally, it takes time for a new drug delivery system to establish itself in the market and gain
acceptance by patients. However, chewing gum is seen as a convenient and advantageous drug delivery system, as it meets the high quality standards of pharmaceutical industry and can be formulated to obtain different release profiles of active substances.
The potential of MCG for buccal delivery, fast onset of action and the opportunity for product line extension makes it an attractive delivery form.
Reformulation of an existing product is required for patent protection, additional patient benefits and conservation of revenues.
Conclusion
MCG is probably the most successful innovation in medical science in recent years.
Combining a tooth-friendly image with a softer, chewy texture and a cleaner refreshing
taste, it appeals to the desire of today’s consumer for healthier and tastier sweets.
In coming years MCGs will be more common and popular because it is convenient, easy to administer – anywhere, any time – and its pleasant taste improves patient compliance.

FOR THE FULL ARTICLE SEE CHEMICAL WEEKLY  JULY 30,2013

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