Content text 7. CONTROLLED AND NOVEL DRUG DELIVERY SYSTEMS.pdf
PHARMD GURU Page 2 4. Maximum utilization of drugs. 5. Reduction in health care costs through improved therapy, less cost treatment and reduced frequency of dosing. DISADVANTAGES: 1. Decreased systemic availability. 2. Poor in vitro- in vivo correlation. 3. Possibility of dose dumping. 4. Withdrawal of drug is difficult in case of toxicity, poisonings or hypersensitivity reactions. 5. Reduced potential for dose adjustments. 6. High cost of formulations. TYPES OF PARENTERAL CONTROLLED DRUG DELIVERY SYSTEM: 1. Inject able drug delivery 2. . Implantable drug delivery system i.e., they are may be of depot type. EXAMPLES OF FEW INJECTABLE CONTROLLED RELEASE FORMULATIONS: 1. Long-acting Penicillin Preparations 2. Long-acting Vitamin B12 preparations 3. Long-acting Adreno corticotropic Hormone Preparations 4. Long-acting Steroid preparations 5. Long-acting Antipsychotic Preparations 6. Long-acting Antinarcotics Preparations 7. Long-acting Contraceptive Preparations 8. Long-acting Insulin Preparations TRANSDERMAL DRUG DELIVERY SYSTEM: DEFINITIONS: Transdermal Drug Delivery System (TDDS) are defined as self contained, discrete dosage forms which are also known as "patches" when patches are applied to the intact skin, deliver the drug through the skin at a controlled rate to the systemic circulation.
PHARMD GURU Page 4 CLASSIFICATION OF TDDS: A) Rate-Programmed systems: Drug in Reservoir Drug in matrix Drug in Adhesive Drug in Micro reservoir B) Physical stimuli-Activated systems: Structure based systems Electrically based systems: Iontophoresis Electroporation sonophoresis BASIC COMPONENTS OF TDDS: Polymer matrix / Drug reservoir Drug Permeation enhancers Pressure sensitive adhesive(PSA) Backing laminate Liner Examples: 1. Transdermal Scopolamine 2. Transdermal Nitroglycerine BUCCAL DRUG DELIVERY SYSTEMS: Buccal delivery is defined as the drug administered through the mucosal membranes lining the cheeks (Buccal mucosa). PRINCIPLE OF MUCO-ADHESION: In this system Muco-adhesive polymers acts as drug delivery vehicle. The common principle underlying this drug administration route is adhesion of the dosage form to the mucus layer until the polymers dissolves or the mucin replaces itself.