Howida Kamal, Ph.D Ass. Prof. of Pharmaceutics, Cairo University

Transcription

1 Pharmacy Howida Kamal, Ph.D Ass. Prof. of Pharmaceutics, Cairo University

2 Pharmacy

3 Pharmacy Pharmaceutics The science of dosage form design.

4 Pharmacy Dosage forms Information Resources Use of computer in pharmacy

5 The gross physical form in which the drug is used by the patient The means through which drug molecules reach the target site inside the body to give their actions

6 Target Site

7 Drug Action Systemic the drug acts in the whole body Local the drug only acts in the area where it is administered Absorbtion Tissue Plasma water Site of Action Metabolism Excretion

8 Route of administration (Location of drug application)? The United States Food and Drug Administration recognizes 111 distinct routes of administration.

9 Route of administration (Location of drug application) Enteral INTO Parenteral ONTO Topical

10 Oral po (from the Latin per os) Swallowed First pass effect

11 Oral Advantages Most convenient for the patient (chronic disease). -Non invasive -Ease and safety of administration -No sterile procedures required Possibility of controlled release delivery Disadvantages First pass metabolism Not for drugs inactivated by GIT Not for drugs irritant to the GIT Not for patients with unconsciousness, vomiting, malabsorption or surgery

12 Buccal Oral transmucosal Sublingual Not swallowed

13 Buccal Sublingual Parentral Oral Rest of body

14 Buccal Sublingual Advantages Rapid transport to the systemic circulation No first pass hepatic metabolism Non invasive Possibility of controlled release delivery (buccal) Disadvantages Some drugs can not pass the mucosa (permeation enhancers) Not for bitter drugs Some drugs are irritant to the mucosa Eating and drinking may be restricted Possibility of the patient to swallow the dosage form

15 Rectal Advantages Suitable for unconscious patients Suitable for patients with vomiting Suitable for drugs irritant to the GIT Most of the absorbed drug by-passes the first pass metabolism Disadvantages Less convenient Small absorption surface area Not for patients suffering from diarrhea

16 Injections Primary routes Specialized routes Intravenous (I.V.) Made into a vein (introduced directly into the blood stream) Intramuscular (I.M.) Made into the striated muscle fibers that lie beneath the subcutaneous layer Subcutaneous (s.c.) Made under the skin, into the subcutaneous tissue

17 Injections Primary routes Specialized routes

18 Injections Intravenous injections

19 Injections Intramascular injections

20 Injections subcutaneous injections side of the arm back of the arm. abdomen front of the thigh

21 Injections Primary routes Specialized routes Intradermal (I.D.) Intra-Abdominal Intraspinal Intra ocular Intracardiac Intra-arterial (I.A) Intraventricular

22 Injections Advantages Rapid onset of action 100% absorption No first pass hepatic metabolism Possibility of controlled release delivery (eg. IM and SC) For patients with unconsciousness, vomiting or post surgery For drugs not absorbed, deactivated or harmful to the GIT Disadvantages Invasive Strict antiseptic techniques are required Not for self administration Not convenient for the patient, painful Possibility of complications (embolism, phlebitis, infection ) No antidote.

23 Transdermal Drug is applied to the skin and absorbed through its layers Advantages Rapid transport to the systemic circulation No first pass hepatic metabolism Non invasive Possibility of controlled release delivery Disadvantages Not all drugs can be absorbed transdermally Transdermal absorption is much poor than intestinal absorption. More expensive More difficult to manufacture

24 Inhalation drug is taken by nose or mouth and deeply inhaled into the lungs Advantages Rapid absorption (high blood flow and large surface area of the alveoli) Rapid onset of action. No first pass effect. Disadvantages Special apparatus is required. Irritation of the respiratory tract may take place. Cooperation of the patient is required.

25 Topical Dermal Occular Vaginal Nasal Auditory Urethral

26 Factors affecting the choice of route of administration 1. Ease of administration 2. Desired onset (rapid, slow) 3. Duration of action (short, prolonged) 4. Duration of drug use (acute, chronic) 5. Site of therapeutic action 6. Quantity of drug to be administered 7. Drug characteristics (taste, stability, metabolism, excretion and toxicity). 8. Status of patient (post surgery, comatose, co-operative, ) 9. Age of the patient 10. Setting where drug is administered (home, hospital, )