Physiological Barriers to Drug Distribution Certain physiological barriers regulate drug distribution, protecting tissues from harmful substances but also limiting drug access: Blood-Brain Barrier (BBB) Composed of tight endothelial junctions, it prevents many drugs from entering the brain. Only highly lipophilic drugs or those using specialized transporters can cross. Blood-Testes Barrier (BTB) Protects developing sperm from … Read more
Factors Influencing Drug Absorption Through the GIT include physicochemical properties, formulation, gastric emptying, and intestinal pH. Factors Influencing Drug Absorption Through the GIT The absorption of drugs through the GIT is affected by multiple factors, which can be broadly classified into the following categories: Physicochemical Properties of the Drug The inherent chemical and physical properties … Read more
Absorption of drug from non per-oral extra-vascular routes covers intramuscular, subcutaneous, inhalation, and transdermal pathways. Absorption of drug from Non per-oral extra-vascular routes Non-peroral extra-vascular routes refer to drug administration methods outside the gastrointestinal (GI) tract. These routes offer various advantages, such as avoiding first-pass metabolism and enabling targeted drug delivery. The major routes include: … Read more
Drug Distribution in Biopharmaceutics explains how drugs move from blood to tissues, influenced by protein binding and permeability. Definition of Drug Distribution in Biopharmaceutics Drug distribution refers to the process by which a drug is transported from its administration site to target tissues and other organs in the body via the bloodstream. Factors Influencing Distribution … Read more
Physiological Properties Affecting Drug Distribution include blood flow, tissue permeability, protein binding, and body water content. Physiological Properties Affecting Drug Distribution The distribution of a drug in the body is influenced by several physiological properties: Lipid Solubility Highly lipid-soluble drugs (e.g., diazepam, propofol) distribute more readily into lipid-rich tissues like the brain and adipose tissue. … Read more
Tissue Permeability of Drugs depends on lipid solubility, ionization, molecular size, and membrane transport mechanisms. Tissue permeability refers to the ability of drugs to cross cell membranes and enter tissues, influencing drug distribution and therapeutic action. It depends on both drug properties and physiological barriers. Factors Influencing Tissue Permeability Lipid Solubility Lipid-soluble drugs easily diffuse … Read more
Binding of Drugs involves reversible interaction with plasma proteins and tissues, affecting distribution, action, and elimination. Drug binding refers to the interaction of drugs with various body components, including proteins, enzymes, receptors, DNA, and ions. This binding influences drug distribution, efficacy, metabolism, and potential drug-drug interactions. Protein binding is the most common type, where drugs … Read more
Mechanisms of Drug Absorption Through the GIT explain passive diffusion, active transport, and endocytosis in biopharmaceutics. Mechanisms of Drug Absorption Through the GIT When a drug is administered orally (peroral route), it must traverse several barriers in the gastrointestinal tract before reaching systemic circulation. The main mechanisms include: Passive Diffusion Passive diffusion is the most … Read more
Introduction to Biopharmaceutics explores drug absorption, distribution, metabolism, and excretion with focus on therapeutic effectiveness. Introduction to Biopharmaceutics Definition and Scope Biopharmaceutics studies the interrelationship between a drug’s physical, chemical, and biological properties and its absorption, distribution, metabolism, and excretion. It connects drug formulation with its therapeutic effects. Importance in Drug Development and Therapy Formulation … Read more
