Hydrogels based Drug Delivery System.pptx

Hydrogels based Drug Delivery System
Dosage Form
Drug Delivery System
Novel Drug Delivery System

1. Hydrogels based Drug Delivery System By: Abdul Rafay Ahmad MSPH-F20-009 M.Phil Pharmaceutics Mentor: Dr Rashida Parveen

2. Definition: “Hydrogels are polymeric networks that take in and keep huge quantities of water. There are hydrophilic groups in the polymeric network which become hydrated in aqueous media thus forming hydrogel structure.” Hydrogels are highly absorbent (they can contain over 90% water) natural or synthetic polymeric networks. Hydrogels also possess a degree of flexibility very similar to natural tissue, due to their significant water content

3. Characteristics Of Hydrogels: Both solid like and liquid like properties High biocompatibility Can trap large quantity of water in the network structure (“hydro”) Shrink when dried Environmental stimuli respondent

4. Classification: On the basis of Preparation: 1- homo-polymer 2- copolymer 3- Semi-interpenetrating network 4- interpenetrating network On the basis of cross linking: 1- Chemical hydrogels 2- Physical hydrogels

5. Homo-Polymer: Derived from single species of monomer. Cross linked homopolymers are used in drug delivery system and in contact lenses. Polyethylene glycol (PEG) based hydrogels are responsive towards external stimuli and hence these smart hydrogels are widely used in drug delivery system

6. Co-polymeric hydrogel Composed of two types of monomer in which at least one is hydrophilic in nature Synthesized the biodegradable triblock poly( ethylene glycol )-poly( caprolactone )- poly( ethylene glycol ) (PEG) co-polymeric hydrogel for the development of drug delivery system . The mechanism involve here is the ring-opening copolymerization of caprolactone (Nylon 6)

7. Semi- Inter Penetrating Network (Semi-IPN): If one polymer is linear and penetrates another cross-linked network without any other chemical bonds between them, it is called a semi-inter penetrating network. Semi-IPNs can more effectively preserve rapid kinetic response rates to pH or temperature due to the absence of restricting interpenetrating elastic network. Provides benefits like modified pore size & slow drug release etc. This pH sensitive semi-IPN was synthesized by co-polymerization in the presence of N, N′-methylene bis-acrylamide as a cross-linking agent. The network contained both covalent and ionic bonds . The covalent bonds retained the 3-D structure of hydrogel and the ionic bonds imparted the hydrogel with higher mechanical strength and pH responsive reversibility

8. Inter Penetrating Network (IPN): It’s an intimate combination of two polymers, at least one of which is synthesized or cross-linked in the immediate presence of the other. This is typically done by immersing a pre-polymerized hydrogel into a solution of monomers and a polymerization initiator. IPN method can overcome thermodynamic incompatibility occurring due to the permanent interlocking of network segments and limited phase separation can be obtained. The main advantages of IPNs are relatively dense hydrogel matrices can be produced which feature stiffer and tougher mechanical properties, controllable physical properties and more efficient drug loading compared to other hydrogels.

9. Properties of Hydrogels: Swelling property: hydrogels are the swollen polymeric networks, interior of which is occupied by drug molecules, therefore, release studies are carried out to understand the mechanism of release over a period of application Swelling property is influenced by: • Type and composition of monomers • Other environmental factors such as : temperature, pH, ionic strength • Cross-linking (mechanical strength and permeability)

10. Continued… Mechanical properties: These are very important for pharmaceutical applications. For example property of maintaining its physical texture during the application of drug delivery. Changing the degree of crosslinking has been utilized to achieve the desired mechanical property of the hydrogel. Biocompatible properties: It is important for the hydrogels to be biocompatible and nontoxic in order to make it applicable in biomedical field. - Cell culture methods, also known as cytotoxicity tests, can be used to evaluate the toxicity of hydrogels.

11. Applications of Hydrogels in Drug Delivery: Benefits of controlled drug delivery • More effective therapies with reduced side effects • Numerous applications Stem Cells, Tissue Engineering, Cell Therapy, Contact Lenses and Cancer Treatment. • The maintenance of effective drug concentration levels in the blood • Patient’s convenience as medicines hence increased patient compliance

12. Continued… Hydrogels that are responsive to specific molecules, such as glucose or antigens, can be used as biosensors as well as drug delivery systems. Sensitive hydrogels like temperature, pH sensitive, which are used for the targeted delivery of proteins to colon, and chemotherapeutic agents to tumours.

13. Advantages of Hydrogels: Hydrogels possess a degree of flexibility very similar to natural tissue, due to their significant water content. Entrapment of microbial cells within Hydrogel beads has the advantage of low toxicity. Environmentally sensitive Hydrogels have the ability to sense changes of pH, temperature, or the concentration of metabolite and release their load as result of such a change. Timed release of growth factors and other nutrients to ensure proper tissue growth.

14. . Hydrogels have good transport properties. Hydrogels are Biocompatible. Hydrogels can be injected. Hydrogels are easy to modify.

15. Disadvantages of Hydrogels: Hydrogels are expensive. Hydrogels causes sensation felt by movement of the maggots. Hydrogels causes thrombosis at Anastomosis sites. The surgical risk associated with the device implantation and retrieval. Hydrogels are non-adherent; they may need to be secured by a secondary dressing.

16. . Hydrogels used as contact lenses causes lens deposition, hypoxia, dehydration and red eye reactions. Hydrogels have low mechanical strength. Difficulty in handling, loading and Sterilization.

17. APPLICATIONS OF HYDROGELS IN DRUG DLEIVERY: A number of strategies have been proposed to achieve drug delivery systems for efficient therapy. Among them, hydrogels have attracted considerable attention as excellent candidates for controlled release devices, bio adhesive devices, or targetable devices of therapeutic agents .

18. 1- Peroral drug delivery: Drug delivery through the oral route has been the most common method in the pharmaceutical applications of hydrogels. In peroral administration, hydrogels can deliver drugs to four major specific sites ; mouth, stomach, small intestine and colon . By controlling their swelling properties or bio adhesive characteristics in the presence of a biological fluid, hydrogels can be a useful device for releasing drugs in a controlled manner at these desired sites. Additionally, they can also adhere to certain specific regions in the oral pathway, leading to a locally increased drug concentration, and thus, enhancing the drug absorption at the release site

19. A- Drug delivery in the oral cavity : Drug delivery to the oral cavity can have versatile applications in local treatment of diseases of the mouth, such as periodontal disease, stomatitis, fungal and viral infections, and oral cavity cancers . Long-term adhesion of the drug containing hydrogel against copious salivary flow, which bathes the oral cavity mucosa, is required to achieve this local drug delivery

20. B- Drug delivery in the GI Tract: The GI tract is unquestionably the most popular route of drug delivery because of the facility of administration of drugs for compliant therapy, and its large surface area for systemic absorption. It is, however, the most complex route, so that versatile approaches are needed to deliver drugs for effective therapy. Like buccal delivery, hydrogel-based devices can be designed to deliver drugs locally to the specific sites in the GI tract. For example, stomach-specific antibiotic drug delivery systems for the treatment of Helicobacter pylori infection in peptic ulcer disease. For localized antibiotic delivery in the acidic environment of the stomach, they developed cationic hydrogels with pH-sensitive swelling and drug release properties. The hydrogels were composed of freeze-dried chitosan-poly (ethylene oxide) (PEO) IPN. pH-dependent swelling properties and the release of two common antibiotics, amoxicillin and metronidazole,

21. C- Rectal delivery: The rectal route has been used to deliver many types of drugs, although patient acceptability is variable due to the discomfort arising from administered dosage forms. Its primary applications have been for local treatment of diseases associated with the rectum, such as haemorrhoids. Additionally, it is well known that drugs absorbed from the lower part of the rectum drain into the systemic circulation directly. Thus, the rectal route is a useful administration route for drugs suffering heavy first-pass metabolism. Conventional

22. D- Ocular delivery In ocular drug delivery, many physiological constraints prevent a successful drug delivery to the eye due to its protective mechanisms, such as effective tear drainage, blinking and low permeability of the cornea. Thus, conventional eye drops containing a drug solution tend to be eliminated rapidly from the eye, and the drugs administered exhibit limited absorption, leading to poor ophthalmic bioavailability.

23. Transdermal delivery: Drug delivery to the skin has been traditionally conducted for topical use of dermatological drugs to treat skin diseases, or for disinfection of the skin itself. In recent years, a transdermal route has been considered as a possible site for the systemic delivery of drugs. The possible benefits of transdermal drug delivery include that drugs can be delivered for a long duration at a constant rate

24. Conclusion: Recent developments in polymer technology has led to the development of various stimuli sensitive hydrogels like pH, temperature sensitive hydrogels A new way to create hydrogels has been developed by immobilizing different proteins at the same time. Hydrogels with novel properties will continue to play important role in drug delivery. New synthetic methods have been used to prepare homo- and co-polymeric hydrogels for a wide range of drugs, peptides, and protein delivery applications. Hydrogels are also used in regenerating human tissue cells