Volume 4, Issue 2, September – October 2010; Article 012 ISSN 0976 – 044X
International Journal of Pharmaceutical Sciences Review and Research
www.globalresearchonline.net
optimal formulation it is possible to decrease the release
rate, choose highly lipophilic substances and increase the
release rate of lipophillic substances.
9-10
To succeed in the market, a chewing gum formulation
must have a pleasant taste and texture. The gum base
determines the basic characteristics of the product like
the texture, its softness, hardness, elasticity,
crumbleness, stickiness, mouthfeel etc. It also determines
the release profile of active ingredients and flavors.
Formulation:
Chewing gum consists basically of a neutral and tasteless
masticatory gum base (15-40%) and several non-
masticatory ingredients such as fillers, softeners,
sweetening agents, flavouring agents and texture
regulating agents.
10-14
The main components of medicated
chewing gum are shown in Table 1. In addition to above
ingredients various additives are also used to improve
properties of chewing gum, like plasticizers, elastomers,
lipids (soyabil), emulsifiers (lecithin), softeners (partially
hydrogenated fatty acids esters, e.g., hydrogenated
soybean oil.) and fillers, texture agents (talc), coating and
binding agents, film formers, coloring agents etc. Corn
syrup keeps the gum flexible and fresh. Xylitol has been
investigated to play a significant role in dental caries.
9-16
Manufacturing process:
13-16
A typical process of manufacturing chewing gum is as
follows. The gum base would be softened or melted
(between 50 and 70°C) and placed in large kettles and
ground thoroughly. Then mixture is purified by using a
straining apparatus and high speed centrifuges. The
flavorings, softeners and sweeteners, mixed with the gum
base in machines with strong rotating blades, produce a
mass with the consistency of stiff bread dough. The gum
mass is sent through a series of rollers, formed into a thin,
wide ribbon, lightly coated with powder sugar (to prevent
sticking) and scored (cut and broken) into single sticks.
The gum is conditioned to increase shelf life. The product
is packaged and readied for distribution. The entire
procedure takes from 5-15 min, but longer mixing time
may be depending on the texture and function of gum
base used.
1
In-vitro Apparatus:
An apparatus was specially designed and constructed for
release testing of medicated chewing gums. The
adjustable instrumental settings such as temperature,
chewing frequency, chewing time, volume of test
medium, distance between the jaws and twisting angle
increased the versatility of the apparatus. Selection of the
test medium was also an important parameter. Each
sample was kneaded mechanically in separate test
chambers and the drug release was followed by sampling
and HPLC analysis. Different gum formulations were
tested and the obtained results demonstrated
satisfactory release curves for a variety of formulations
and active ingredients. The tested gum formulations
include nicotine, meclizine, dimenhydrinate and xylitol.
The apparatus proved to be suitable in product control of
commercial batches but also a useful tool in the research
and development of medicated chewing gum
formulations.
16-18
In-vitro testing:
The absorption of active substances through the buccal
mucosa can be examined by both in vitro and in vivo
methods. The most common method utilizes using
chamber where excised buccal mucosa (either from
human or animal) is placed as a barrier between two
chambers. The transport of active substances across the
mucosa is measured by withdrawal of samples from each
chamber. Porcine oral cavity is recommended, as it is
morphologically similar to human oral cavity.
16
Likewise, a human TR146 cell culture model has proven a
good in-vitro model for investigating permeability,
permeability mechanisms, effects of chemical enhancers,
and toxic effects.
19
Applications:
9, 16, 20, 21, 22, 23
1. Dental caries:
a. Prevention and cure of oral disease are targets for
chewing gum formulations.
b. It can control the release rate of active substances
providing a prolonged local effect.
c. It also re-elevates plaque pH which lowers intensity
and frequency of dental caries.
d. Fluoride containing gums have been useful in
preventing dental caries in children and in adults with
xerostomia.
e. Chlorhexidine chewing gum can be used to treat
gingivitis, periodontitis, oral and pharyngeal
infections.
f. It can also be used for inhibition of plaque growth.
g. Chlorhexidine chewing gum offers numerous
flexibility in its formulation as it gives less staining of
the teeth and is distributed evenly in the oral cavity.
h. The bitter taste of chlorhexidine can be masked quite
well in a chewing gum formulation.
2. Systemic therapy:
a) Pain- chewing gum can be used in treatment of minor
pains, headache and muscular aches.
b) Smoking cessation- Chewing gum formulation
containing nicotine and lobeline have been clinically
tested as aids to smoking cessation.
c) Obesity- Active substances like chromium, guaran and
caffeine are proved to be efficient in treating obesity.
Chromium is claimed to reduce craving for food due to an
improved blood-glucose balance. Caffeine and guaran
stimulate lipolysis and have a thermogenic effect
(increased energy expenditure) and reduce feeling of
hunger.
d) Other indications- Xerostomia, Allergy, Motion
sickness, Acidity, Cold and Cough, Diabetes, Anxiety, etc