#Drugs #Medicine

1. Tauseef Ahmed

2. Contents
 Drug Delivery Intro.
 Dosage Form Definition
 Delayed Released Drug Delivery
 Targeted Drug Delivery

3. Drug Delivery
 Refers to approaches, formulations, technologies for transporting a
pharmaceutical substances.
 As needed to safely achieve desired therapeutic effect.
 Involve scientific site targeting within the body/might involve
facilitating.

4. Dosage Form (Unit Doses)
 Dosage forms are pharmaceutical drug products in the form in which
they are marketed for use.
 Specific mixture of active ingredients and excipients.
 Particular configuration (such as Capsule shell)
 Appointed in particular dose.

5. Delayed Released Drug Delivery System.
 A dosage form that releases a discrete portion, portion of drug at the
time or at the time other than promptly after administration.
 Although one portion may be released promptly after administration.
e.g. Enteric Coated dosage forms are common delayed release products.

6. Delayed Released Drug Delivery System.
 For example, aspirin irritates the gastric mucosal cells of the stomach.
An enteric coating on the aspirin tablet prevents the tablet from
dissolving and releasing its contents at the low pH in the stomach.
 Mesalamine (5-aminosalicylic acid) tablets (Asacol, Proctor & Gamble) is a
delayed-release tablet coated with an acrylic-based resin that delays the
release of mesalamine until it reaches the terminal ileum and colon.
Mesalamine tablets could also be considered a targeted-release dosage
form.

7. Reasons
 Stomach irritation
 GIT Side effects
 Patient acceptance and compliance
 More uniform drug effect
 Improved efficacy/safety ratio.

8. Targeted drug delivery system
Targeted drug delivery system is a special form of drug delivery system
where the medicament is selectively targeted or delivered only to its site
of action or absorption and not to the non-target organs or tissues or cells.
The drug may be delivered to
 To the capillary bed of the active sites.
 To the specific type of cell (or) even an intracellular region. Ex: Tumor
cells but not to normal cells.
 To a specific organ (or) tissues by complexion with the carrier that
recognizes the target.

9. Objective
 To achieve a desired pharmacological response at a selected sites
without undesirable interaction at other sites, there by the drug have a
specific action with minimum side effects & better therapeutic index.
 Ex- In cancer chemotherapy and enzyme replacement therapy.

10. Advantages
• Drug administration protocols may be simplified.
• Toxicity is reduced by delivering a drug to its target site, there by reducing
harmful systemic effects.
• Drug can be administered in a smaller dose to produce the desire effect.
• Avoidance of hepatic first pass metabolism.
• Enhancement of the absorption of target molecules such as peptides and
particulates.
• Dose is less compared to conventional drug delivery system.
• No peak and valley plasma concentration.
• Selective targeting to infections cells that compare to normal cells.

11. Disadvantages
• Rapid clearance of targeted systems.
• Immune reactions against intravenous administered carrier systems.
• Insufficient localization of targeted systems into tumor cells.
• Diffusion and redistribution of released drugs.
• Requires highly sophisticated technology for the formulation.
• Requires skill for manufacturing storage, administration.
• Drug deposition at the target site may produce toxicity symptoms.
•Difficult to maintain stability of dosage form. E.g.: Resealed erythrocytes have
to be stored at 40 C.
• Drug loading is usually law. E.g. As in micelles. Therefore it is difficult to
predict /fix the dosage regimen.

12. Carrier or Markers
 Targeted drug delivery can be achieved by using carrier system.
 Carrier is one of the special molecule or system essentially required for effective
transportation of loaded drug up to the pre selected sites.
 They are engineered vectors, which retain drug inside or onto them either via encapsulation
and/ or via spacer moiety and transport or deliver it into vicinity of target cell.
Pharmaceutical carriers :
 Polymers
 Microcapsules
 Micro particles
 Lipoproteins
 Liposomes
 Micelles

13. Types of Targeted drug delivery System
 Nano Tubes (Fig. 1)
 Nano Wires (Fig. 2)
 Nano Shells (Fig. 3)
 Quantum Dots (Fig. 4)
 Nano Pores (Fig. 5)
 Gold Nano (Fig. 6)
 Dendrimers (Fig. 7)
 Liposomes (Fig. 8)
 Niosomes (Fig. 9), etc.

14. Images
Fig.1 Fig.4 Fig.5
Fig.8Fig.7Fig.6
Fig.3Fig.2
Fig.9

15. References
 Swarbrick, J., Swarbrick, J. (Ed.). (2007). Encyclopedia of Pharmaceutical
Technology, Third Edition. Boca Raton: CRC Press.
 Micelles from lipid derivatives of water-soluble polymers as delivery
systems for poorly soluble drugs, Advanced Drug Delivery Reviews,
Volume 56, Issue 9,2004.
 Wikipedia

16. THANK YOU