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PATIENT RELATED FACTORS AFFECTING ON DRUG ABSORPTION

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Physiologic Factors Related to Drug Absorption:   The systemic absorption of a drug is dependent on   The physicochemical properties of the drug,   The nature of the drug product, and   The anatomy and physiology of the drug absorption site.  1. Membrane Physiology A. Nature of Cell Membrane  The fluid mosaic model, proposed by , explains the transcellular diffusion of polar molecules.   According to this model, the cell membrane consists of globular proteins embedded in a dynamic fluid, lipid bilayer matrix. These proteins provide a pathway for the selective transfer of certain polar molecules and charged ions through the lipid barrier.  As shown in , transmembrane proteins are interdispersed throughout the membrane. Two types of pores of about 10 nm and 50 to 70 nma were inferred to be present in membranes based on capillary membrane transport studies. These small pores provide a channel through which water, ions, and dissol...
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Pharmaceutical factors affecting drug absorption

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Definitions Pharmacokinetics o    Evaluate the way in which a drug interacts with various barriers within a biological system Pharmacodynamics o    Study of the relationship between systemic exposure of a drug and it’s biological effects on tissue o    Absorption can be defined as the movement of active drug (or prodrug) from the site of administration across biologic barriers into a site where it is measured in the blood. This site of measurement is not specified. o    Bioavailability can be defined as the fraction of administered drug that reaches the systemic circulation. o    Note the difference in endpoint measurement sites    PHARMACEUTICAL FACTORS: It include factors relating to the- A.     Chemical Factors o    A variety of chemical options can be used to improve the stability and systemic availability of drugs. o    For example, esters can be p...
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PLANT LAYOUT FOR CAPSULE MANUFACTURING DEPARTMENT & MANUFACTURING PROCESS

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Practical: Determination of Angle of repose, Carre's Index & Hausner ratio of given powder

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Aim:  Determination of Angle of repose, Carre's Index & Hausner ratio of given powder Reference: L. Lachman CVS Subramanyam Requirements: Apparatus:  Funnel, beaker, measuring cylinder, funnel holding stand Chemicals:  Lactose, Na. carbonate, Boric acid Theory topics: Angle of Repose: Introduction, Definition, Equation, Description, various methods of determination, factors affect, Pharmacopoeia specification, effect on flow property Fig: Methods of angle of repose Carr’s consolidation Index (CI) Introduction, Definition, Equation, Description, various methods of determination, factors affect, Pharmacopoeia specification, effect on flow property Hausner’s Ratio: Introduction, Definition, Equation, Description, various methods of determination, factors affect, Pharmacopoeia specification, effect on flow property Procedure: Angle of repose: Weighed amt. of powder was taken (lactose-5gm, na. bicarbonate-10gm, Boric acid-10gm) Weighed p...
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PLASMA PROTEIN BINDING

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Introduction: It is binding of drug to plasma protein in blood component.  Binding of drugs to plasma proteins is reversible.  Various plasma protein to which drug binds includes Albumin, α1-Acid glycoprotein (orosomucoid), lipoprotein, globulins, etc.  Order of binding of drugs to various plasma proteins:  Albumin > α1-Acid glycoprotein (orosomucoid) > Lipoproteins > Globulins Such bound drug is both pharmacokinetically as well as pharmacodynamically inert i.e. a protein bound drug is neither metabolized nor excreted nor it  is pharmacologically active.  A bound drug is also restricted since it remains confined to a particular tissue for which it has greater affinity. Moreover, such bound drug because of its enormous size cannot undergo membrane transport & thus its half life is increased.  However this binding is rapidly reversible and non-specific – that is many drugs may bind to the same protein. Drug–plasma protein bindi...
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