Approaches Of Gastro-Retentive Drug Delivery System or GRDDS

Approaches Of Gastro-Retentive Drug Delivery System
Includes:
Floating and Non-Floating drug delivery system with their subtypes
Like Non-effervescent system, Effervescent system, Raft forming system,
High Density system, Expandable system, Muco-adhesive system,
Super porous hydrogel system and Magnetic Systems, etc.

1. Project of Practice School on “APPROACHES OF GASTRO-RETENTIVE DRUG DELIVERY SYSTEM” PRESENTED BY Mr. Akshay P. Patane PRN No. 51639020181382310031 UNDER THE GUIDANCE Ass.Prof. Mr. Junghare S. L. (M. Pharm in Pharmaceutics) MERULING SHIKASHAN SANSTHA’S COLLEGE OF PHARMACY, MEDHA, SATARA. MAHARASHTRA (INDIA), YEAR 2021-2022 1

2. PRESENTATION OUTLINE Introduction. Approaches of GRDDS . Factors affecting GRDDS . Advantages of GRDDS . Disadvantages of GRDDS . Conclusion. Reference 2

3. INTRODUCTION Oral administration is the most convenient and preferred means of any drug delivery to the systematic circulation. Oral controlled release drug delivery have recently been of increasing interest in pharmaceutical field to achieve improved therapeutic advantages, such as ease of dosing administration, patient compliance and flexibility in formulation. Th e development of oral sustained-controlled release formulations is an attempt to release the drug slowly into the gastrointestinal tract (GIT) and maintain an effective drug concentration in the systemic circulation for a long time. After oral administration, such a drug delivery would be retained in the stomach and release the drug in a controlled manner, so that the drug could be supplied continuously to its absorption sites in the gastrointestinal tract (GIT). The current presentation deals with various gastroretentive approaches that have recently become leading methodologies in the field of site-specific orally administered controlled release drug delivery systems. 3

4. DIFFERENT APPROACHES OF GRDDS Floating Drug Delivery System Approaches of GRDDS Non-Floating Drug Delivery System Non-Effervescent System Effervescent System Gas Generating System Volatile liquid/Vaccum System 1.High Density System 2.Expandable System 3.Mucoadhesive System 4.Super porous Hydrogel 5.Magnetic System Raft Forming 4

5. Floating Drug Delivery System Floating drug delivery system (FDDS) possess bulk density lower than the gastric fluid and because of this reason it remains in the stomach without affecting gastric emptying time for an extended period of time and responsible for controlled release of drug. (A) Effervescent FDDS This system made to float in the stomach by incorporating floating chamber, which may be filled with vacuum, air or inert gas. This system uses matrices prepared with swellable polymer and effervescent components. This system is divided in to two classes: 1) volatile liquid containing system 2) gas generating system. (B) Non- Effervescent FDDS This system is also known as Hydrodynamically Balanced System (HBS). This system remains buoyant by entrapment of air in the swelled polymer. 5

6. (C) Raft forming system This system focus more for delivery of antacid and delivery of drugs used to treat gastrointestinal infection and disorders. The basic mechanism involves formation of viscous cohesive gel when the system comes in contact with gastric fluid. In this each portion of liquid swells and forms a continuous layer of gel known as raft. The raft floats because of buoyancy created by formation of CO2. Raft Forming System 6

7. High Density System This system possesses a density of about 3 g/cm3 which are retained in the antrum part of the stomach and are capable of withstanding its peristaltic movements. This system is prepared by coating a drug on a heavy core or mixed with the inert material such as iron powder, barium sulphate, zinc oxide and titanium oxide etc. Figure represents high density system in stomach. High Density System 7

8. Expandable System This system may be of two types: unfoldable system and 2) swellable polymer. Swellable systems are retained due to their mechanical property. The swelling is resulted from absorption of water. The resultant bulk enables gastric retention and maintains the stomach in the fed condition. Expandable or swellable System 8

9. Mucoadhesive / Bioadhesive System Mucoadhesion means attachment of the drug to the mucus coat. This approach helps to increase the gastric residence time of the dosage form by binding them to the gastric mucosa. Polymers used for this purpose may include polycarbophil, carbopol, CMC, chitosan, lectin etc Mucoadhesive drug delivery system Stages of mucoadhesion : 1.Contact Stage 2.Consolidation Stage 9

10. Magnetic System Magnetic System This approach of increased gastric retention time is based on the principle that dosage form contains a small internal magnet. A magnet is placed in abdomen over the position of stomach that retains dosage form in the gastric region. 10

11. FACTORS AFFECTING GRDDS Particle size : It should be in the range of 1 – 2 mm to pass through the pyloric valve into the small intestine. Density : Density of dosage form should less than gastric fluid to float. Size : Size of the system should be in greater than 7.5 mm in diameter. Shape: Ring and tetrahedron shaped system shows better gastric retention compared with the other shapes. Food intake : Gastric retention time is increased in fed state. Age: Age greater than 70 shows longer residence time. 11

12. ADVANTAGES Enhanced bioavailability Sustained drug delivery/reduced frequency of dosing Targeted therapy for local ailments in the upper GIT Reduced fluctuations of drug concentration Site specific drug delivery DISADVANTAGES Unsuitable for drugs with limited acid solubility. E.g. Phenytoin Unsuitable for drugs that are unstable in acidic environment. E.g. Erythromycin Drugs that irritates or causes gastric lesions on slow release. E.g. Aspirin & NSAID’s Drugs that absorb selectively in colon. E.g. Corticosteroid 12

13. CONCLUSION Based on the literature survey, it can be concluded that GRDDs offers various potential advantages for drugs with poor bioavailability. The control of gastro intestinal transit of orally administered dosage forms using GRDD systems can improve the bioavailability of drugs that exhibit site specific absorption. In the future it is can be easily assumed that GRDD systems will become more popular in terms of delivering drug to the systemic circulation with improving efficiency of various type of pharmacotherapy’s. REFERENCE 1.Bhavsar D., Varde N., Shah V., “Advances in Grdds : Raft Forming System a Review”, Journal of Drug Delivery & Therapeutics; 2(5), 2012, 123-128. 2.Kaur B., Sharma S., Sharma G., Saini R., Singh S, Nagpal M., Jain UK, Sharma M., “A Review of Floating Drug Delivery System”, Asian Journal of Biomedical and Pharmaceutical Sciences, 3(24), 2013, 1-6. 13