Natural Polymers in Pharmaceuticals: A Literature Review Analysis (2025)

Running head: LITERATURE REVIEW
LITERATURE REVIEW
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Introduction
Natural polymers, besides, their increased nutritional value, provides an added medicinal
or health benefit and are therefore advertised and marketed for treatment and prevention of
certain health conditions. Although, the nutraceuticals are rich in natural nutrients presented
generally in the form of dietary supplements or functional foods, but some of the natural
ingredients are disposed to degradation by gastric acid or may trigger nausea or vomiting on
administration orally. The coatings used in drugs for gastroresistant application contain polymers
with enteric release properties that are not considered as natural products or ingredients are not
usually regarded as safe for use by the regulatory bodies governing in this area and therefore,
cannot be used as nutraceuticals (Barbosa, Conway and Merchant 2017). Natural polymers are
employed in pharmaceuticals because of their compatibility, ability of chemical modification and
readily availability (Ananthakumar, Chitra and Satheshkumar 2018). Drug formulation using
natural polymers or polymers from natural origin has gained the prime important in the
pharmaceutical industry in addition with pharmaceutical ingredients. Natural polymers helps to
sustain and improve health both directly and indirectly (Patil 2014). With the advancement of
research and studies, there has been a development in the dosage forms for both existing as well
as new drug designed, formulated or invented with the natural or semi synthetic products. Gums,
husks and mucilages are commonly and most widely used natural products for the conventional
as well as novel drug forms (Patil 2014). In several studies, it has been found that natural or
plant-derived polymers are widely used in the pharmaceutical industry as binder, diluent, or
thickeners in liquids that are taken orally, as disintegrants in tablets and as suppository and
gelling agents (Choudhary and Pawar 2014). Besides, the pharmaceutical applications, they also

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have a wide range of applications in the cosmetics industry, textiles, paper making and paints.
Since, they are biocompatible, natural, easily available, have no toxicity when compared to the
semi-synthetic and synthetic polymers, they are more employed in the pharmaceutical industry
(Deogade, Deshmukh and Sakarkar 2012).
When active ingredients are not meant for releasing in the stomach, the dosage are
formulated with enteric release profile offering maximum functionality. The drug released with
enteric release profile, delays in releasing until the dosage form reaches the intestine. Enteric
coated tablets are designed to bypass the stomach and facilitate the release of drug in small
intestine. These are formulated for oral administration. Enteric coatings helps in preventing the
release of medication prior to reach to the small intestine. Most of the enteric coatings provides a
coated surface that has high stability at acidic pH (Singh et al. 2012). Natural materials that are
used as coatings are derived from fatty acids, plastics, plant fibres, waxes, shellac and others
(Singh et al. 2012). The study provides a literature review on some of the natural polymers used
in the pharmaceutical industry offering a wide range of applications including the gastroresistant
aspects as well.
A review on applications of natural polymers in Pharmaceutical science:
The study on the applications of natural polymers in gastroretentive drug delivery system
by Ananthakumar, Chitra and Satheshkumar, provides an overview of function of the natural
polymers in gastroretentive drug delivery system including its application, current research and
future development in this area. It was found through research that applications of natural
polymers in various filed such as medicines, agriculture and other similar areas have been
increased progressively. It was also found that, since natural polymers are biodegradable and

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non-toxic, they are found to have a wide range of application in the pharmaceutical field. Using
natural polymers in the drug delivery formulation aids in drug transport with therapeutic efficacy
and an improved bioavailability. Natural polymer, when used in the pharmaceuticals in
gastroresistant drug for mucoadhesive in the gastric system and possess floating to increase the
gastric resistant time and improve therapeutic efficacy, specifically in those drugs which have a
lower therapeutic index like itopride, cavediol and glipizide (Ananthakumar, Chitra and
Satheshkumar 2018). Physical characteristics of the natural polymers contributes to their
swelling, sustained and mucoadhesive nature, thus, enabling them to be chosen in gastroretentive
drug delivery formulation (Ananthakumar, Chitra and Satheshkumar 2018).
Gum karaya:
Gum karaya, also known as Sterculia gum is obtained from Sterculia urens Roxburgh and
other species of Sterculia (Family – Sterculiaceae). Gum Karays is a vegetable gum produced by
trees of genus Sterculia. It is a polysaccharide comprised of sugar galactose, galacturonic acid
and rhamnose and used as an emulsifier and thickener in foods as a laxative and denture
adhesive. It has been found that gum karaya generally produces D-galactose, D-galacturonic
acid, L-rhamnose, and a little amount of D-glucuronic acid, after acid hydrolysis. It is known to
be sparingly in water and poorly soluble in 0.1 N HCl and gastric fluid simulated and a little
insoluble in ethanol (95%) and other organic solvents similar. It is also slightly soluble in alkali
solutions which has pH above 6.5. Since, gum karaya has a nature of swelling in water and
therefore in various formulations, it is used as a polymer for controlling the release rate (Setia,
Goyal and Goyal 2010).

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Figure 1: Chemical structure of Gum Karaya.
Source: (Thabet et al. 2018)
Pharmaceutical applications of Gum karaya:
Gum karaya has a varied industrial application because of its characteristics like
absorbing water or moisture, film and gel forming and its adhesive nature. Recent researches are
focusing on the application of gum karaya as a release controlling agent. Because of the swelling
nature of these hydrophilic gums, these are found to be used for controlling the release of
primarily two drugs, diclofenac sodium and caffeine, which have dissimilar solubility in the
aqueous medium (Setia, Goyal and Goyal 2010). Karaya gum has shown a low capacity for
hydration and an increasing rate of erosion, when studies were conducted using dissolution
apparatus for determining factors such as hydration, gum erosion and drug release. It was found
in the study that karaya gums showed zero order drug release along with its erosion mechanism
(Munday and Cox 2000).
Gum karaya acts like an effective bulk laxative since the gum particles have the ability of
absorbing water and swell up to 60 to 100 times than their original volume. Gum karaya must be
taken with sufficient fluid and continue to take it for some days to make it notable. Gum karaya
is also used as an ostomy equipment and as adhesives in dental fixtures and also used as base for
salicylic acid patches. Karaya coating is used to prevent accretion of denture plaque and to

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prevent other related problems like denture induced stomatitis, unpleasant odours and staining. It
is also used as drug carriers like caffeine and diclofenac-sodium in ratios of gum: drug of 3:1 and
1:1. Studies have also shown that gum karaya can be used as a potential carrier in enhancing the
dissolution rate of nimodipine (Goswami and Naik 2014).
Applications of Gum karaya in the Drug Delivery System:
Gum karaya is used in formulation of drugs because of its adhesive nature. They shows
cohesiveness to power mass by converting them into granules. They are also used as
disintegrates in tablets. The disintegrating property of gums is contributed by the swelling nature
and absorption capacity of gums. For example- The binding agent Buteamonospermalam.gum
act like a binder in ibuprofen tablet, the binding agent Magnifer indica gums as binder in
paracetamol tablets, and the binding agent Cassia roxbughii seed as a binder in paracetamol
tablets, cashew tree gums as binder in metronidazole tablets (Goswami and Naik 2014).
Jujube:
Jujube is considered as a neutraceutical food. It is evident from the Pharmacological and
Pharmaceutical studies that one of the main biologically active component in the jujube fruits are
the polysaccharides have a multiple biological applications and effects that includes,
hepatoprotective, antitumor, antioxidant, hypoglycemic activities, immunomodulatory and
gastrointestinal protective effects (Ji et al. 2017). It is found from the studies that functional food
plays an important role to protect the gastrointestinal mucosa. Polysaccharides are known to
protect and repair tissue damage with growth factors and also generates anti-inflammatory
effects through the mechanism of suppressing the cytokine or neutrophil cascade in the
gastrointestinal tract (Silva et al. 2012).

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Figure 2: Chemical structure of Jujube

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Source: (Jmiai et al. 2018)
Caseine milk from bovine:
Studies have shown that Beta-casein milk proteins have physiological effect on the
gastrointestinal tract and also have been reported to have an important role in modifying
intestinal transit and inflammation. There are different types of beta caseins present in milk,
which, in addition to the whey proteins are a major source of protein present in yogurt and
cottage cheese. Evidences have shown yoghurt to have shown an advancement of digestion of
both the Beta-casein as well as Beta-Lg used together with pepsin 30 minutes later after
stimulated gastric digestion (Chia et al. 2018).
Since, pH of human stomach is highly acidic, however, it is neutral in the duodenum, and
casein has a pH dependent behaviour which is useful for controlled release of substance that are
orally administered. Moreover, caseins have the ability to penetrate the plasma membrane by an
energy-independent way that enhances the cellular uptake by means of oral administration. In
addition to this, casein can also take part in proteolysis because of their unfolded structure that
facilitates the release of proteolytic enzymes in the gastrointestinal tract. It is also found in the
studies that the reassembled nanoparticles present in the casein are digested easily by the
gastrointestinal proteases that make it beneficial for easy stomach delivery and reduces gastric
digestion (Głąb and Boratyński 2017).

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Figure 3: Chemical structure of Bovine
Source: (Holt 2016)
Psyllium husk:
Psyllium husk, also known as Isphagula (Isabgul) husk is a very common, well known
and mostly used laxative for relieving constipation. Studies have shown that isabgul has been
also found to be effective in treating colon cancer. In addition to that, scientists have found
Psyllium husk is biocompatible, easily available, and inert and a cheap drug to be used like a
carrier for controlling the delivery of other or drugs or chemicals. Studies have suggested the use
of psyllium husk as a novel carrier in drug delivery (Bindu, Bharat and kumar 2012).

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Psyllium is a derivative from plant Plantagopsyllium, the husk and the seed of
Plantagoovata (Plantaginaceae) relates to psyllium which is widely used as a supplement for
fiber used for treating constipation. Some researchers have used seeds instead of husk that is
commercially available. It has been found that husk contains a large amount of hemicellulose
which is composed of a xylan backbone and linked with rhamnose, arabinose, galacturonic acid
units (arabinoxylans) (Patil 2014). However, some studies have suggested that although,
psyliium and isabgol are used interchangeably, they vary in the source and doses. Psyllium is
derivative of dried ripe seeds of Plantago psyllium and P. indica, the isabgol husk is derived from
the ripe seed of Plantago ovata. The seed and seed coat of P. ovata are studied for their chemical
composition and their gelling nature that contributes to their pharmaceutical applications. It is
evident from the studies that psyllium husk is a widely used natural polysaccharide and
medicinally active for the treatment of constipation and diarrhea (Bindu, Bharat and kumar
2012).
Figure 4: Chemical structure of Psyllium husk
Source: (Gamage et al. 2018)

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Pharmaceutical application of Psyllium husk:
Studies have shown that dietary fibre reduces the gastrointestinal transit time thereby
increasing stool weight. When psyllium husk is given, 18 grams of psyllium husk daily increases
fecal weight and boosts short chain fatty acids production. The husk has shown resistant property
towards fermentation. Studies have proven the role the psyllium husk to increase moisture in the
stool and also increases dry and weight stool weight. The soluble and non-starch polysaccharide
present in the seed of psyllium husk undergoes anaerobic fermentation producing short chain
fatty acids like butyrate, acetate and propionate in the intestines. Psyllium husk is rich in
epidermis of the seed, whereas, the actual seed contains the fermentable fiber at a higher amount
that causes the psyllium seed to degrade slower compared to pectin and known to produce an
adequate amount of acetate and butyrate. Butyric acid shows antineoplastic activity against
colorectal cancer that is the mostly preferred oxidative substrate for colonocytes and helps in the
treating ulcerative colitis.
Psyllium husk has been found to be useful as a therapeutic agent for treatment of
constipation, irritable syndrome, colon cancer, diarrhea, ulcerative colitis, inflammatory bowel
disease and even hypercholesterolemia and diabetes. Psyllium husk has mild and natural laxative
property, thereby, facilitating digestion. It changes to a sticky and gelatinous consistency on
soaking in water to facilitate their characteristic functioning. Some studies have also shown that
the dietary fiber obtained from psyllium husk may help in management of weight and control fat
loss by its role as a bulking agent (Kumar et al. 2017).

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Application of Psyllium husk in the drug delivery system:
Psyllium husk can be utilized as an excipient for preparing controlled release systems
because of its mucilaginous property. Studies have suggested the use of natural polymer,
psyllium for fabricating in a variety of drug delivery system. A number of formulations was
previously prepared by using theophylline as a model drug and investigations were done with the
aim to achieve an ideal slow drug release profile. Though hydroxypropyl methylcellulose
(HPMC) is a synthetic derivative of cellulose, but is usually preferred in producing sustained
release matrix tablets because of its good compression capacity, gelling characteristics, rapid
hydration and a low toxicity. When hydroxypropyl methylcellulose (HPMC) is added to
psyllium, it considerably reduces the burst release, though, the amount of drug release for a 12
hour period was slower and thereby, inadequate. To overcome this, lactose has been added as a
hydrophilic filler enabling a slow release of drug, which is approximately 80% in 12 hours. The
addition of HPMC into the psyllium formulation altered the kinetics of drug release from Fickian
diffusion to anomalous transport (Kaialy et al. 2013). When granulated formulation is used, it
demonstrates a slow release of drugs compared to an ungranulated or physical mixture that
causes a change in dissolution kinetics. Mild granules have been found to show more efficient
controlled drug release and no burst release. Even though, psyllium has been proved to be a
natural polymer to drug release, but, a combination of both psyllium and HPMC with the
formulation process must be considered in order to attain a zero-order release (Kaialy et al.
2013).

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Soy protein:
Seeds and oils are mainly from soybean because of a wide range of benefits. It is a
cooling, sedative and a somewhat bitter herb with anti-pyretic and diaphoretic properties and
benefits to the circulation and liver. It is used in Chinese medicine for headache, restlessness,
fever, insomnia and chest discomfort with measles and colds. Soy lecithin, a food additive,
lowers serum cholesterol levels and soy phospholipids are used to combat chronic liver disease
and also chronic hepatitis. Incorporating soy in the diet helps to generate positive impulses in the
atherosclerosis, by reducing the formation of blood clot in the artery blocking. Soy is also known
to relieve menopausal symptoms. It reduces heart diseases and minimizes the risk developing
heart diseases. Soy is known to improve bone health. Soy also reduces the risk of endometrial
cancer. It is also known to decrease the risk of breast cancer. Studies have shown the use of soy
to prevent baldness as well (Shidhaye et al. 2008).

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Figure 5: Chemical structure of Soy isoflavone
Source: (Kang et al. 2016)
Pharmaceutical application of soy protein:
Soy polysaccharides have high molecular weight cell wall, the structural components of
soybean cotyledons are usually used in combination with a substance which is therapeutically
active. The mixture can also be made into tablets through conventional means like dry or wet
granulation or by direct compression procedures. It has been found that the tablets obtained from
this methods have sufficient hardness and have a beneficial degradation properties. It makes a
good component of easy release jelly comprising of an emulsified polyunsaturated fatty acid like
alpha-linolenic acid or its derivatives amounting to greater than 10%, a gelling and an
emulsifying agent (Shidhaye et al. 2008).
The applications of soy protein in the pharmaceutical and biomedical industry have
gained prime interest because of being relatively inexpensive, tailorable biodegradability and for
being structurally similar to the extracellular matrices of the tissues. Studies have suggested the
fact that soy protein can be fabricated in many different shapes. This is possible to organise them
into different shapes because they are comparatively easier to manage and process with the help
of melt or solvent based techniques (Tansaz and Boccaccini 2016).
Pharmacokinetic studies of soybean isoflavones have shown oral ingestion. The two
major isoflavones, genistin and daidzin have shown their effect in the intestine by hydrolysing
and absorbing rapidly into the peripheral circulation. It is found to be eliminated from the bosy
with a half-life of 7-8 hours. The characteristic features of isoflavones enables them to make

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maintainence of steady state plasma isoflavone concentrations which is a new and slow release
formulation of a soybean isoflavone extract prepared by micro encapsulation with a mixture of
hydroxypropylcellulose and ethylellulose for altering its dissolution characteristics (Setchell et
al. 2005).
It was found from the above survey that due to a huge range of benefits, natural polymers
such as gum karaya, jujube and caseine milk from bovine, psyllium husk and soy protein are
used in gastroresistant applications. Since, natural polymers are biodegradable and have nontoxic
nature they are usually preferred and employed in the pharmaceutical industries (Deogade,
Deshmukh and Sakarkar 2012). Natural polymers have been employed in the gastroretentive
drug delivery to process floating or due to their mucoadhesive nature in the gastric system to
increase therapeutic efficacy. The physical characteristics of natural polymers enables them
facilitate swelling and mucoadhesive nature that helps in the gastroresistant activity and also
enhances therapeutic efficacy and bioavailability of drugs like synthetic or semi synthetic
polymers. Drug formulation using natural polymers or polymers from natural origin has gained
the prime important in the pharmaceutical industry in addition with pharmaceutical ingredients
(Deogade, Deshmukh and Sakarkar 2012). Natural polymers helps to sustain and improve health
both directly and indirectly. With the advancement of research and studies, there has been a
development in the dosage forms for both existing as well as new drug designed, formulated or
invented with the natural or semi synthetic products . The surface of the tablets are covered with
enteric coating to avoid first pass metabolism, degradation, gastric irritation and direct the drugs
to the target intestines (Pole et al., 2016). The choice of the polymer to be used as enteric
formulation and control the thickness of the enteric coated drug (Pole et al., 2016). Drugs having
a lower oral bioavailability that is less than 50%, an adequate protein binding is preferred during

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the enteric coated dosage form of the drugs that have a short half-life of around 3 hours. The
above stated dosage for is usually preferred since these can be easily formulated and are very
convenient, cost effective and these does not require the use of expensive equipment (Singh et al.
2012).

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References:
Ananthakumar, R., Chitra, K. and Satheshkumar, S. (2018). A review on applications of natural
polymers in gastroretentive drug delivery system. Drug Invention Today, 10(3).
Barbosa, J.A., Conway, B.R. and Merchant, H.A., 2017. Going natural: using polymers from
nature for gastroresistant applications. British Journal of Pharmacy, 2(1).
Bindu, D., Bharat, p. and kumar, C. (2012). Psyllium: A potential carrier to control drug
delivery. International Research Journal of Pharmacy, 3(7).
Chia, J., McRae, J., Enjapoori, A., Lefèvre, C., Kukuljan, S. and Dwyer, K., 2018. Dietary
Cows’ Milk Protein A1 Beta-Casein Increases the Incidence of T1D in NOD Mice. Nutrients,
10(9), p.1291.
Choudhary, P.D. and Pawar, H.A., 2014. Recently investigated natural gums and mucilages as
pharmaceutical excipients: An overview. Journal of pharmaceutics, 2014.
Deogade, U., Deshmukh, V. and Sakarkar, D. (2012). Natural Gums and Mucilage’s in NDDS:
Applications and Recent approaches. International Journal of PharmTech Research, 4(2),
pp.799-814.
Gamage, H.K., Tetu, S.G., Chong, R.W., Bucio-Noble, D., Rosewarne, C.P., Kautto, L., Ball,
M.S., Molloy, M., Packer, N.H. and Paulsen, I.T., 2018. Fibre supplements derived from

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sugarcane stem, wheat dextrin and psyllium husk have different in vitro effects on the human gut
microbiota. Frontiers in microbiology, 9, p.1618.
Głąb, T.K. and Boratyński, J., 2017. Potential of casein as a carrier for biologically active agents.
Topics in Current Chemistry, 375(4), p.71.
Goswami, S. and Naik, S., 2014. Natural gums and its pharmaceutical application. Journal of
Scientific and Innovative Research, 3(1), pp.112-121.
Holt, C., 2016. Casein and casein micelle structures, functions and diversity in 20
species. International Dairy Journal, 60, pp.2-13.
Ji, X., Peng, Q., Yuan, Y., Shen, J., Xie, X. and Wang, M., 2017. Isolation, structures and
bioactivities of the polysaccharides from jujube fruit (Ziziphus jujuba Mill.): A review. Food
chemistry, 227, pp.349-357.
Jmiai, A., El Ibrahimi, B., Tara, A., Chadili, M., El Issami, S., Jbara, O., Khallaayoun, A. and
Bazzi, L., 2018. Application of Zizyphus Lotuse-pulp of Jujube extract as green and promising
corrosion inhibitor for copper in acidic medium. Journal of Molecular Liquids, 268, pp.102-113.
Kaialy, W., Emami, P., Asare-Addo, K., Shojaee, S. and Nokhodchi, A., 2014. Psyllium: a
promising polymer for sustained release formulations in combination with HPMC polymers.
Pharmaceutical development and technology, 19(3), pp.269-277.
Kang, H., Wang, Z., Zhang, W., Li, J. and Zhang, S., 2016. Physico-chemical properties
improvement of soy protein isolate films through caffeic acid incorporation and tri-functional
aziridine hybridization. Food Hydrocolloids, 61, pp.923-932

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Kumar, D., Pandey, J., Kumar, P. and Raj, V., 2017. Psyllium Mucilage and Its Use in
Pharmaceutical Field: An Overview. Curr Synthetic Sys Biol, 5(134), pp.2332-0737.
Munday, D. and Cox, P. (2000). Compressed xanthan and karaya gum matrices: hydration,
erosion and drug release mechanisms. International Journal of Pharmaceutics, 203(1-2).
Patil, P. (2014). Natural Excipients: Uses of Pharmaceutical Formulations. International Journal
of PharmTech Research, 6(1), pp.21-28.
Pole, S., Maurya, S., Hasnale, P., Rathod, N., Bendale, S. and Khutle, D. (2016). A DETAIL
UNDERSTANDING OF ENTERIC COATED TABLET: MANUFACTURING AND
EVALUATION. EUROPEAN JOURNAL OF PHARMACEUTICAL AND MEDICAL
RESEARCH, 3(4), pp.135-144.
Setchell, K.D., Brzezinski, A., Brown, N.M., Desai, P.B., Melhem, M., Meredith, T., Zimmer-
Nechimias, L., Wolfe, B., Cohen, Y. and Blatt, Y., 2005. Pharmacokinetics of a slow-release
formulation of soybean isoflavones in healthy postmenopausal women. Journal of agricultural
and food chemistry, 53(6), pp.1938-1944.
Setia, A., Goyal, S. and Goyal, N. (2010). Applications of Gum Karaya in Drug Delivery
Systems: A Review on Recent Research. [online] 2(5), Available at:
(http://scholarsresearchlibrary.com/archive.html) [Accessed 11 Aug. 2019].
Shidhaye, S., Malke, S., Mandal, S., Sakhare, N. and Kadam, V. (2008). Soy - A Hidden
Treasure For Therapeutic, Cosmetic And Pharmaceutical Use. The Internet Journal of
Alternative Medicine, 7(2).

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Silva, R., Santana, A., Carvalho, N., Bezerra, T., Oliveira, C., Damasceno, S., Chaves, L.,
Freitas, A., Soares, P., Souza, M., Barbosa, A. and Medeiros, J. (2012). A Sulfated-
Polysaccharide Fraction from Seaweed Gracilaria birdiae Prevents Naproxen-Induced
Gastrointestinal Damage in Rats. Marine Drugs, 10(12), pp.2618-2633.
Singh, D., Roychowdhury, S., Verma, P. and Bhandari, V. (2012). A review on recent advances
of enteric coating. Journal of Pharmacy, 2(6).
Tansaz, S. and Boccaccini, A.R., 2016. Biomedical applications of soy protein: A brief
overview. Journal of Biomedical Materials Research Part A, 104(2), pp.553-569.
Thabet, A.A., Youssef, F.S., El‐Shazly, M. and Singab, A.N.B., 2018. Sterculia and
Brachychiton: a comprehensive overview on their ethnopharmacology, biological activities,
phytochemistry and the role of their gummy exudates in drug delivery. Journal of Pharmacy and
Pharmacology, 70(4), pp.450-474.