About Novel Drug Delivery Systems
Subject Code
BP704T
Semester
Semester 7
Credits
4 Credits
Novel Drug Delivery Systems (BP704T) deals with advanced methods and approaches to deliver pharmaceutical active ingredients to achieve specific therapeutic effects, targeted local action, or prolonged release. This subject covers the concepts and formulation strategies behind systems that transcend conventional dosage forms. You will study controlled release systems, microencapsulation, mucosal and implantable devices, transdermal patches, target-specific carriers (like liposomes and nanoparticles), gastroretentive techniques, and specialized routes like ocular and intrauterine delivery. Understanding NDDS is essential for modern pharmaceutical product development.
Key Learning Objectives
- Controlled Release: Understand the basic concepts, terminology, rationale, and design principles (diffusion, dissolution) of controlled drug delivery systems.
- Microencapsulation & Implants: Master the methods of microencapsulation and the principles of bioadhesion, transmucosal delivery, and formulation of implants (e.g., osmotic pumps).
- Transdermal & Gastroretentive Systems: Explore the formulation approaches for transdermal patches (TDDS), gastroretentive systems (GRDDS), and nasal/pulmonary inhalers.
- Targeted Delivery: Comprehend the concepts of targeted drug delivery and the role of carrier systems like liposomes, nanoparticles, and monoclonal antibodies.
- Ocular & Intrauterine Systems: Learn the specific challenges and formulation strategies for ocular drug delivery (ocuserts) and intrauterine devices (IUDs).
Syllabus & Topics Covered
Unit 1: Controlled Drug Delivery Systems & Polymers
- Introduction, terminology, rationale of CDDS.
- Advantages, selection of candidates, design based on diffusion, dissolution, ion exchange.
- Physicochemical and biological properties relevant to controlled release.
- Polymers: classification, properties, applications in CDDS.
Unit 2: Microencapsulation, Mucosal & Implantable Systems
- Microencapsulation: methods, microspheres, applications.
- Mucosal Delivery: bioadhesion/mucoadhesion, transmucosal permeability, buccal delivery.
- Implantable Systems: concepts, advantages, osmotic pump.
Unit 3: Transdermal, Gastroretentive & Nasopulmonary Systems
- TDDS: permeation, enhancers, basic components, formulation approaches.
- GRDDS: floating, high-density, inflatable, gastroadhesive systems.
- Nasopulmonary Delivery: inhalers, nasal sprays, nebulizers.
Unit 4: Targeted Drug Delivery
- Concepts, approaches, advantages of targeted delivery.
- Carrier systems: liposomes, niosomes, nanoparticles.
- Monoclonal antibodies and their applications.
Unit 5: Ocular & Intrauterine Drug Delivery Systems
- Ocular Drug Delivery: intraocular barriers, ocuserts.
- Intrauterine Drug Delivery: IUD development, applications.
How to Score High in Novel Drug Delivery Systems
- 1
Diagrams are Crucial: Practice drawing clear diagrams of drug delivery devices (e.g., osmotic pump, transdermal patch layers, liposome structure, ocusert).
- 2
Comparative Studies: Differentiate clearly between sustained release and controlled release, liposomes and niosomes, microcapsules and microspheres.
- 3
Mechanisms of Release: Thoroughly understand Higuchi’s model (diffusion), Noyes-Whitney applicability (dissolution), and how polymers influence release rates.
- 4
Focus on Examples: For every novel delivery system, memorize at least two commercially available examples (e.g., Progestasert for IUD, Ocusert-Pilo for ocular).
Why it Matters for Career
NDDS is highly relevant for careers in Formulation Research and Development (F&D). As the pharmaceutical industry shifts from discovering new chemical entities (NCEs) – which is expensive and risky – to lifecycle management of existing drugs via novel delivery methods (e.g., developing a sustained-release once-daily tablet from an immediate-release thrice-daily drug), expertise in NDDS principles, polymer science, and advanced formulations is highly sought after.
Exam Weightage
Unit 1 (Fundamentals of CDDS and Polymers) forms the basis and is frequently asked. Microencapsulation methods (Unit 2), Transdermal patch design (Unit 3), Liposomes (Unit 4), and Osmotic pumps/Ocuserts are high-yield topics. The exam typically tests your understanding of mechanisms (how exactly does the drug release happen) and formulation components.
Frequently Asked Questions (FAQs)
What is the difference between Sustained Release (SR) and Controlled Release (CR)?
Sustained Release (SR) prolongs the release of the drug but does generally not guarantee a constant release rate (usually follows first-order kinetics where release rate decreases over time). Controlled Release (CR) systems maintain a constant drug concentration in the blood/tissues over a specific period, typically following zero-order kinetics (a truly constant release rate independent of concentration).
Why are polymers so important in NDDS?
Polymers act as the backbone of most novel delivery systems. They serve as matrices to trap drugs, membranes to control the rate of drug diffusion, mucoadhesives to stick to biological surfaces, and biodegradable scaffolds (like PLGA) that safely break down in the body after releasing the drug. The choice of polymer determines the exact release profile of the formulation.
What is the principle of an osmotic pump?
An elementary osmotic pump consists of a core containing the drug and an osmotically active agent, surrounded by a semipermeable membrane (allows water in, but not the drug out). A small laser-drilled delivery orifice is present. Water from the GI tract diffuses in, dissolves the drug/osmogen, creates osmotic pressure inside, and this pressure pumps the drug solution out through the orifice at a constant, controlled rate (zero-order).