Controlled Drug Delivery System, Unit-I, BP704T: NDDS, Sem-VII, Final Year B. Pharm (SPPU 2019P).pptx

Unit I
Controlled drug delivery systems: Introduction, terminology/definitions and rationale, advantages, disadvantages, selection of drug candidates.
Approaches to design controlled
release formulations based on diffusion, dissolution and ion exchange principles.
Physicochemical and biological properties of drugs relevant to controlled release
formulations.

1. Unit-I Controlled Release Drug D elivery S ystem (CRDDS) : Introduction, terminology / definitions, rationale, advantages, disadvantages. Selection of drug candidates for CRDDS. Physico-chemical & biological properties of drugs relevant to CR formulations. Approaches to design CR formulations based on diffusion, dissolution & ion exchange principles. Polymers: Introduction, classification, properties, advantages & application of polymers in formulation of CRDDS. Ms. Kartiki M. Bhandari Assistant Professor (Pharmaceutics) CONTROLLED-RELEASE DRUG DELIVERY SYSTEM

2. INTRODUCTION S ignificant advantages of CDDS: maintain drug levels within desired range, reduce frequency of administration, optimal use of the drug, & increased patient compliance. P otential disadvantages of CRDDS: possible toxicity or non-biocompatibility of the materials used, undesirable by-products of degradation, any surgery required to implant or remove the system, chance of patient discomfort from the delivery device, & higher cost compared to traditional systems.

3. INTRODUCTION I deal DDS should be: inert, biocompatible, mechanically strong, comfortable to the patient, capable of achieving high drug loading, safe from accidental release, simple to administer & remove, & easy to fabricate & sterilize. In traditional DDS, the drug levels in blood rises after each dose administration & then decreases until the next administration. Hence, the drug levels in blood should remain between maximum safe conc. (MSC) & minimum effective conc. (MEC). G oal of CRDDS: to achieve a delivery profile that yields high drug levels in blood over prolong period.

4. INTRODUCTION

5. TERMINOLOGIES / DEFINITIONS Controlled Release Drug Delivery System (CRDDS): It is a system which releases the drug from the dosage form topically or systemically, at a predetermined specific rate for a specific period of time. Sustained Release Drug Delivery System (SRDDS): It is a system designed to achieve prolonged therapeutic effect by continuous release of medicament over an extended period of time after administration of single dose. Modified Release Drug Delivery System (MRDDS): It is a system that delivers the drug for delayed or prolonged period or at specific targeted site in the body.

6. TERMINOLOGIES / DEFINITIONS Immediate Release Drug Delivery System (IRDDS): It is a system that disintegrate & release the drug immediately for faster onset of action with no specific rate controlling features. Extended Release Drug Delivery System (ERDDS): It is a system that delivers the drug for extended period to provide predetermined amount of drug throughout the day with once or twice a day dose.

7. RATIONALE Basic rationale of CRDDS is :– T o optimize the biopharmaceutics, pharmacokinetics, & pharmacodynamics properties of a drug in such a way that its utility is maximized through reduction in side effects & cure or control of disease condition in shortest possible time by using smallest quantity of drug , administered by most suitable route .

8. ADVANTAGES

9. COMMERCIAL ADVANTAGES

10. CLINICAL ADVANTAGES

11. DISADVANTAGES

12. SRDDS v/s CRDDS SRDDS CRDDS Provides medication over prolonged period of time Release medicament at predetermined constant rate for specific period of time Follows first order kinetics Follows zero order kinetics Do not contain mechanism for localization of drug at active site Contains mechanism for localization of drug at active site

13. SELECTION OF DRUG CANDIDATE FOR CRDDS T ½ T herapeutic Window D ose S olubility A bsorption 1 st Pass M etabolism M olecular Weight P rotein Binding C ompatibility P artition Coef. Absorption M echanism R oute of Absorption Mnemonic : P2T2M3 CARD

14. PHYSICOCHEMICAL PROPERTIES OF DRUG FOR CRDDS Molecular W eight Molecular S ize D iffusion Coefficient P artition Coefficient Aqueous S olubility Drug p Ka & I onisation at Physiological pH Drug S tability M echanism of Absorption S ite of Absorption R oute of Administration Mnemonic : WS4 DP2 MRI

15. BIOLOGICAL PROPERTIES OF DRUG FOR CRDDS PHARMACOKINETIC: Dose & Release rate: - Zero order release technique - First order release technique Absorption rate: - Absorption window - Distribution - Metabolism - Elimination T ½ Biological T ½ Metabolism Drug-Protein binding Dosage form index PHARMACODYNAMIC: Therapeutic range Therapeutic index Plasma conc. response relationship K = B  D D = D  B

16. APPROACHES TO DESIGN CRDDS Mnemonic : 3D IHP Wso Cep D iffusion CDDS: - Reservoir Type - Matrix Type D issolution CDDS: - Reservoir Type - Matrix Type D iffusion & D issolution CDDS I on-Dependant CDDS W ater Penetration CDDS: - S wellable CDDS - O smotic CDDS p H-Dependant CDDS C hemically CDDS: - E rodible DDS - P endant-Chain DDS H ydrogels

17. DIFFUSION CDDS: - Reservoir - matrix DISSOLUTION CDDS: - reservoir - matrix

18. DIFFUSION CDDS

19. DISSOLUTION CDDS

20. DIFFUSION CONTROL

21. DISSOLUTION CONTROL

22. DIFFUSION & DISSOLUTION CDDS

23. ION-DEPENDANT CRDDS

24. Example : Dextromethorphan is cationic drug loaded into anionic resin Dowex 50WX

25. WATER PENETRATION crdds: - SWELLABLE CRDDS - OSMOTIC CRDDS

26. pH-DEPENDANT CRDDS

27. CHEMICALLY CRDDS: - Erodible system - pendant chain syste m

28. EXAMPLES OF BIODEGRADABLE POLYMERS Polylactides (PLA) Polyglycolides (PGA) Poly (lactide-co- glycolides ) (PLGA) Polyanhydrides Polyorthoesters

29. HYDROGELS CRDDS

30. Swelling

31. Shrinking

32. Degradation/ Hydrolysis

33. CRDDS

34. THANK YOU..!!