Contents INTRODUCTION WHAT IS GRDDS ? NEED FOR GRDDS…? POTENTIAL DRUG CANDIDATES DRUGS THAT ARE UNSUITABLE FOR GASTRORETENTIVE DRUG DELIVERY SYSTEMS FACTORS AFFECTING THE GASTRORETENTIVE SYSTEM. ADVANTAGES OF GRDDS  DISADVANTAGES OF GRDDS  APPROACHES TO EXTEND GI TRANSIT INTRODUCTION Oral route has been the most convenient and accepted route of drug delivery. Gastroretentive drug delivery system is novel drug delivery systems which has an upper hand owing to its ability of prolonged retaining ability in the stomach and thereby increase gastric residence time of drugs and also improves bioavailability of drugs. WHAT IS GRDDS ? Gastroretentive drug delivery is an approach to prolong gastric residence time, thereby targeting site-specific drug release in the upper gastrointestinal tract (GIT) for local or systemic effects. NEED FOR GRDDS…? Oral drug delivery system, sustained drug delivery systems, these drug delivery systems suffer from mainly two adversities: Short gastric retention time(GRT) and Unpredictable short gastric emptying time (GET) which can result in incomplete drug release from the dosage form in the absorption zone (stomach or upper part of small intestine) leading to diminished efficacy of administered dose. To formulate a site-specific orally administered controlled release dosage form, it is desirable to achieve a prolong gastric residence time by the drug delivery. Prolonged gastric retention time (GRT) in the stomach could be advantageous for local action e.g. treatment of peptic ulcer, etc. POTENTIAL DRUG CANDIDATES FOR GASTRORETENTIVE DRUG DELIVERY SYSTEMS Drugs that disturb normal colonic microbes e.g. antibiotics against Helicobacter pylori. Drugs that degrade in the colon. e.g. Ranitidine, Metformin HCl. Drugs which are absorbed rapidly from the GI tract. e.g. Metronidazole, tetracycline. Drugs with a narrow window of absorption e.g. Cyclosporine, Methotrexate, Levodopa, etc. Drugs that are poorly soluble at alkaline pH e.g. Furosemide, Diazepam, Verapamil, etc. Drugs that are primarily absorbed in the stomach e.g. Amoxicillin. Drugs acting locally in the stomach(active in stomach) e.g. Antacids and drugs for H. Pylori viz., Misoprostol DRUGS THAT ARE UNSUITABLE FOR GASTRORETENTIVE DRUG DELIVERY SYSTEMS Drugs that have very limited acid solubility phenytoin etc. Drugs that suffer instability in the gastric environment e.g. erythromycin etc. Drugs intended for selective release in the colon e.g. 5-amino salicylic acid and corticosteroids etc. FACTORS AFFECTING THE GASTRORETENTIVE SYSTEM. Density Size Shape of dosage form Single or multiple unit formulation Fed or unfed state. Advantages of GRDDS  Increase in bioavailability and curative efficiency of drugs and economic usage of dosage. Minimised factor of risk in resistance in antibiotics owing to stabilised therapeutic levels over prolonged periods removing fluctuations.

1. PRESENTED BY: MOHIT KUMAR
M. PHARMACY
(PHARMACEUTICS)
3rd SEMESTER
SETH G. L. BIHANI S. D. COLLEGE OF TECHNICAl EDUCATION
(INSTITUTE OF PHARMACEUTICAL SCIENCES & DRUG RESEARCH)
GAGAN PATH, SRI GANGANAGAR (RAJ.) 335001, INDIA.

2.  INTRODUCTION
 WHAT IS GRDDS ?
 NEED FOR GRDDS…?
 POTENTIAL DRUG CANDIDATES
 DRUGS THAT ARE UNSUITABLE FOR GASTRORETENTIVE DRUG DELIVERY
SYSTEMS
 FACTORS AFFECTING THE GASTRORETENTIVE SYSTEM.
 ADVANTAGES OF GRDDS
 DISADVANTAGES OF GRDDS
 APPROACHES TO EXTEND GI TRANSIT

3.  Oral route has been the most convenient and accepted route of
drug delivery.
 Gastroretentive drug delivery system is novel drug delivery
systems which has an upper hand owing to its ability of prolonged
retaining ability in the stomach and thereby increase gastric
residence time of drugs and also improves bioavailability of drugs.

4.  Gastroretentive drug delivery
is an approach to prolong
gastric residence time, thereby
targeting site-specific drug
release in the upper
gastrointestinal tract (GIT) for
local or systemic effects.

5.  Oral drug delivery system, sustained drug delivery
systems, these drug delivery systems suffer from mainly
two adversities:
 Short gastric retention time(GRT) and
 Unpredictable short gastric emptying time (GET)
 which can result in incomplete drug release from the
dosage form in the absorption zone (stomach or upper
part of small intestine) leading to diminished efficacy of
administered dose.
 To formulate a site-specific orally administered controlled
release dosage form, it is desirable to achieve a prolong
gastric residence time by the drug delivery.
 Prolonged gastric retention time (GRT) in the stomach
could be advantageous for local action e.g. treatment of
peptic ulcer, etc.

6.  Drugs that disturb normal colonic microbes
e.g. antibiotics against Helicobacter pylori.
 Drugs that degrade in the colon. e.g.
Ranitidine, Metformin HCl.
 Drugs which are absorbed rapidly from the
GI tract. e.g. Metronidazole, tetracycline.
 Drugs with a narrow window of absorption
e.g. Cyclosporine, Methotrexate, Levodopa,
etc.

7.  Drugs that are poorly soluble at alkaline pH
e.g. Furosemide, Diazepam, Verapamil, etc.
 Drugs that are primarily absorbed in the
stomach e.g. Amoxicillin.
 Drugs acting locally in the stomach(active in
stomach) e.g. Antacids and drugs for H. Pylori
viz., Misoprostol

8.  Drugs that have very limited acid solubility
phenytoin etc.
 Drugs that suffer instability in the gastric
environment e.g. erythromycin etc.
 Drugs intended for selective release in the
colon e.g. 5-amino salicylic acid and
corticosteroids etc.

9.  Density
 Size
 Shape of dosage form
 Single or multiple unit formulation
 Fed or unfed state.

10.  Increase in bioavailability and curative efficiency
of drugs and economic usage of dosage.
 Minimised factor of risk in resistance in
antibiotics owing to stabilised therapeutic levels
over prolonged periods removing fluctuations.
 Optimised release in case of short half-life
drugs, causes flip flop pharmacokinetics and also
ensures patient compliance with reduced dosage
frequency.
 They are advantageous against drawbacks of the
gastric retention time (GRT) as well as the gastric
emptying time (GET). The system remains
buoyant on gastric fluid because of lower bulk
density than gastric fluids.

11.  These are efficient in repairing stomach and small
intestine related problems. Its attributed to the fact
that gastroretentive drug delivery sustains drug
release and hence, avail local therapy in these organs.
 This method provides with a systematic and
controlled drug delivery system which minimises
chances of drug over exposure at the diseased site.
 Providing a narrow curative index, the gastroretentive
dosage forms minimises variance in concentrations of
drugs and effects.
 This system provides higher efficiency due to reduced
counter activity by body.
 As the system provides with controlled rates of
fluctuation, a wider array is provided for selectivity in
receptor activation.

12.  Drugs intended for selective release in the
colon.
 Unpredictable adherence owing to state of
constant renewal of mucus wall of stomach.
 GRDDS is fed into the system after the meal
as time of stay in stomach depends on
digestive state.
 The ability of the drug to remain in the
stomach depends upon the subject being
positioned upright.

13.  Hydrogel based swelling system takes longer
time to swell.
 Upon multiple administrations, size
increasing drug delivery systems pose the
threat to life owing to possible hazard of
permanent retention in stomach.
 Superporous systems having drawback like
problematical storage of much easily
hydrolysable, biodegradable polymers.
 Need for increased level of fluids in the
stomach

14.  Unsuitable for such drugs as:
• Problematic with solubility in gastric fluid
• Causing G.I irritation
• Inefficient in acidic environment

16.  These systems can withstand peristaltic movements of the stomach by
retaining active drug molecule in the rugae of stomach.
 These dosage forms are pellets of high density.
 Effective development approach is mixing of drug coated heavy core
with barium sulphate, iron powder, zinc oxide and titanium oxide etc. act
as inert materials.

17.  If size of the dosage form is larger than size of the pyloric
sphincter of the stomach, this type of dosage form is suitable to
resist gastric transit property of the stomach.
 Three approaches:
 Swellable systems and Unfoldable systems
 Unfoldable type of gastric retentive dosage forms
 Superporous hydrogel systems

18.  Swelling systems are type of gastroretentive
systems which after contact with gastric
content swells to large size and pylorus
sphincter prevents the passage of swelled
dosage form due to large size.
 Known as plug type dosage forms because
their tendency to lodged at the pyloric
sphincter.

19.  Prepared by using biodegradable polymeric
materials.
 These systems occurs in different geometric
arrangements such as tetrahedron, ring or
planner membrane (4 – label disc or 4 –
limbed cross form) made up of bio erodible
polymers packed within a capsule

20.  Superporous hydrogels are swellable type of
drug delivery systems.
 Superporous hydrogels has pore size >100
μm.
 Rapid water uptake by capillary wetting
through numerous interconnected open
pores.

21.  Commonly used system.
 Increase site specific absorption of drugs.
 Frequently used polymeric materials for bioadhesive purpose are
chitosan, cholestyramine, sodium alginate, poly acrylic acid,
hydroxypropyl methyl cellulose, sucralfate, tragacanth, dextrin,
and polylactic acids etc.

22.  Floating systems are one of the most
effective approaches.
 Floating systems are suitable drug delivery
systems for drugs which have absorption
window constraints.
 Effective buoyancy characteristics.
 Hydroxy propyl methyl cellulose is preferred
hydrocolloidal material recommended for
floating controlled release dosage forms.

23.  Are floating controlled release dosages forms made up of
hydrophilic polymeric matrices.
 When these systems come in contact with gastric fluids, polymer
become hydrated and forms a gel like barrier at the surface and
remain buoyant in the stomach due to their low bulk density and
prolongs the gastric residence time of the systems.

24.  Formulated with effervescent excipients
and gel forming polymers.
 Localized effects.
 Effective management of gastric
esophageal reflux disease.
 They swell and form a viscous cohesive
gel leading to the formation of a continuous
layer termed as rafts.

25.  Dosage form consists of active pharmaceutical ingredient,
excipients and also a small amount of internal magnet.
 An extracorporeal magnet is placed over the stomach to
control the position of the dosage form containing internal
magnet.
 The position and the magnetic field intensity of the
extracorporeal magnet can affect the GRT.
 GRT and bioavailability are improved by magnetic tablets.

26.  Sharma A.R. , et al (2014) gastroretentive drug delivery system: an approach to enhance gastric
retention for prolonged drug release. International journal of pharmaceutical sciences and research
[Online]. Available
at<https://www.google.com/search?q=gastro+retentive+drug+delivery+system&rlz=1C1NDCM_en
IN751IN751&oq=Gastro+retentive+drug+delivery+system&aqs=chrome.0.0l8.23890j0j8&sourceid
=chrome&ie=UTF-8 [Accessed 1 july 2020]
 Jawaid N. (2015) Presentation GRDDS. Slideshare [Online]. Available at
<https://www.slideshare.net/NadiaJawaid/presentation-grdds> [Accessed 1 july 2020]
 Tripathi J. (2019) Current State and Future Perspectives on Gastroretentive Drug
Delivery Systems. MDPI [Online]. Available at
<file:///C:/Users/mohit/Downloads/pharmaceutics-11-00193-v2%20(1).pdf>
[Accessed 1 july 2020]

27.  Nayak A.K. ,et al.(2010) Gastroretentive drug
delivery system. Asian journal of pharmaceutical and
clinical research 3(1)
 Setia M, et al. (2018) Gastro-retentive floating
beads a new trend of drug delivery system.
Jddt 8(3)169-80.
 <https://d3i71xaburhd42.cloudfront.net/06
2d043f247a8c01a6384ec52c290b0664bd6a
63/6-Figure1.11-1.png>

28. THANK YOU