1. General introduction of Pharmaceutics association in Biology.pptx

Pharmaceutics association in biology

1. BIOPHARMACEUTICS  Dr. Seemab Zafar Pharm.D , Mphil , PhD (Sch.)

2. COURSE DESCRIPTION Biopharmaceutics course seeks to educate and train candidates in the principles underlining drug absorption, distribution, metabolism, and excretion (ADME) following its administration to human or animal subjects. The course places emphasis on the dependence of drug absorption on the physical and chemical nature of drug substances, the effect of a dosage form in which it is designed, and the factors related to the physiologic and pathologic conditions of the subjects to which it is administered.

3. COURSE DESCRIPTION (Cont.) The aim is to develop in the candidate the ability to integrate all these factors holistically in optimizing therapeutic benefit to the patient while minimizing adverse or untoward effects of medicinal products. In addition, the course would train the candidates in novel delivery technologies that are currently being employed for enhancing drug delivery to various targets in the body.

4. Bio Pharmaceutics BIOPHARMACEUTICS – life i.e., general area of study concerned with the formulation, manufacture, stability and effectiveness of pharmaceutical dosage forms.

5. General Overview Biopharmaceutics is concerned with the relationship between the physicochemical properties of a drug in a dosage form and the observed therapeutic response after its administration. Biologic response Expressed as the alteration of the biological process existing before the drug was administered Its magnitude is related to the concentration of the drug reaching the receptor site. The observed biological effect of a drug in a = dosage form inherent pharmacological activity of the drug + its ability to reach the receptor site in appropriate concentration + MRT

6. General Overview/Definitions (Cont.) Thus, the onset, intensity, and duration of therapeutic effect of most drugs depend on factors of the biological system and the dosage form. These factors play an important role in: bringing the drug to the biological site in the body in quantities required, sustaining it at that concentration for the desired length of time, getting the drug out of the site after it has performed the desired effect. Hence, the scope of biopharmaceutics is comprised of the path the drug must take from the dosage form to the site of action and the factors encountered en route.

7. General Overview/ Definitions (Cont.) Objectives of the Biopharmaceutics course are to gain a basic understanding of the processes of drug absorption, distribution, and elimination and the potential of dosage form effects on these processes that can be applied for optimization of therapeutic benefit for a patient. The dosage form of a drug exerts its major influence on the absorption process, that is why emphasis is usually placed on drug absorption.

8. BIOPHARMACEUTICS Biopharmaceutics simply means “ the effects of dosage form and route of administration on the biological effect of a drug” - Study of factors influencing the dissolution of drug from dosage form into biological fluids at the site of absorption and the transfer of the dissolved drug across bio-membrane into the systemic circulation.

9. Biopharmaceutical methods The application of knowledge of drug release and transport across bio-membrane to obtain the expected therapeutic effect from a product on administration to a patient .

10. DRUG Agent intended for use in the diagnosis, mitigation, treatment, cure or prevention of disease in man or in other animals. It may be: 1. synthetic 4. biological 2. semi-synthetic 5. natural 3. chemical

11. DOSAGE FORM Modern drugs are potent chemical substances that must be fabricated into a drug product before use. Generally, the drug is combined with other ingredients into a drug formulation, which may be a solution, tablet, capsule or suppository.

12. RATIONALE The development of Biopharmaceutical principles allows for the rational design of drug products, which would enhance the delivery of active drugs, and optimize the therapeutic efficacy of the drug in the patient.

13. DRUG PRODUCT A finished dosage form that contains an active drug ingredient generally, but not necessarily, in association with inactive ingredient. Formulation or matrix in which the drug is contained. The term may also include a dosage form that does not contain an active ingredient intended to be used as placebo.

14. DRUG ACTION Result of an interaction between the drug substance and functionally important cell receptors or enzyme systems. This response is due to the alteration in the biologic processes that were present prior to the drug administration.

15. In-vitro – referring to a process or reaction carried out in a culture dish or test tube. In-vivo – in the living organism Ex-vivo – is a tissue not created artificially but directly taken from a living organism.

16. EFFECTS OF BIOPHARMACEUTICS Generic equivalency (cost effectiveness) Drug availability Therapeutic efficacy Drug substitution

17. Aim The aim of biopharmaceutics is to adjust the delivery of drug to the general circulation in such a manner as to provide optimal therapeutic activity for the patient. Biopharmaceutics studies allow drugs to be formulated rationally based on pharmaceutical properties.

18. Some Pharmaceutical Properties Some drugs are intended for topical or local therapeutic action at the site of administration. For these drugs, systemic absorption is undesirable. Drugs intended for local activity generally have a direct pharmacodynamic action without affecting other body organs. These drugs may be applied topically to the skin, nose, eyes, mucous membranes, buccal cavity, throat and rectum.

19. Factors Affecting Biopharmaceutics a. Physical state of the drug - according to the 4 states of matter - The crystal or amorphous forms and/or the particle size of a powdered drug have been shown to affect the dissolution rate, and thus the rate of absorption, for a number of drugs.

20. Factors Affecting Biopharmaceutics By selective control of the physical parameters of a drug, biologic response may be optimized.

21. b. Dosage form delivery system, the drug could be available for administration. Each of the dosage units is designed to contain a specified quantity of medication for ease and accuracy of the dose administered.

22. Biopharmaceutic considerations often determine the ultimate dose and dosage form of a drug product. For example, the dosage of a drug intended for local activity, such as a topical dosage form, is often expressed in concentration or as % of the active drug in the formulation. The amount of the drug is not specified because it is the concentration of the drug at the active site that relates to the pharmacodynamic action.

23. Biopharmaceutics Biopharmaceutical studies must be performed to ensure that the dosage form does not irritate, cause an allergic response or allow systemic drug absorption when used for local effects.

24. The dosage of a drug intended for systemic absorption is given on the basis of absolute amounts, such as mg or gram.

25. C. Route of administration Each route of drug application presents special biopharmaceutic considerations in drug product design.

26. By carefully choosing the route of drug administration and properly designing the drug product, the bioavailability of the active drug can vary from rapid and complete absorption to a slow, sustained rate of absorption or even virtually no absorption, depending on the therapeutic objective.

27. Example An eye medication may require special biopharmaceutic considerations including appropriate pH, isotonicity, local irritation to the cornea, draining by tears, and concern for systemic drug absorption. The design of a vaginal tablet formulation for the treatment of a fungal infection must consider ingredients compatible with vaginal anatomy and physiology.

28. 1. Encompasses all possible effects observed following the administration of the drug in the various dosage forms. 2. Encompasses all possible effects of various dosage forms on biological response 3. Encompasses all possible physiological factors which may affect the drug in various dosage forms. SCOPE OF BIOPHARMACEUTICS

29. A primary concern in biopharmaceutics is the bioavailability of drugs. Bioavailability refers to the measurement of the rate and extent of active drug that reaches the systemic circulation. means access to the bloodstream

30. Drug in the drug product Drug in solution Solid drug particles Drug in the body