pH-II: Filtration & BiopHarmaceutics

Filtration is the process used to separate insoluble particles from liquids. It involves passing the mixture through a filter medium, such as a porous material or a membrane, which allows the liquid to pass through while trapping the solid particles. This method is commonly used in various industries and laboratories to separate solids from liquids, purify substances, and remove impurities. Filtration is effective in separating particles of different sizes, making it a suitable choice for separating insoluble particles from liquids.

Biopharmaceutics is the study of how the physical and chemical properties of a drug, as well as the formulation and dosage form, affect its absorption, distribution, metabolism, and excretion in the body. The factors influenced by biopharmaceutics include the protection and stability of the drug within the product, the rate of dissolution of the drug, and the availability of the drug at its site of action. Therefore, the correct answer is "All of the above."

The term "bioavailability" refers to the rate and extent at which a drug is absorbed by the body and its subsequent utilization. This statement directly mentions the key components of bioavailability, which are the rate and extent of drug absorption and its utilization by the body. Therefore, this statement accurately represents the concept of bioavailability.

The explanation for the given correct answer is that in first order pharmacokinetic processes, the rate of the process is directly proportional to the drug concentration. This means that as the drug concentration increases, the rate of the process also increases, and vice versa. This fundamental characteristic is important in understanding how drugs are absorbed, distributed, metabolized, and eliminated in the body. It helps in predicting the time it takes for a drug to reach its maximum effect and the rate at which it is cleared from the body.

The statement is false because drug metabolism actually converts chemicals into more polar metabolites, making them easier to excrete. This process typically involves adding functional groups to the drug molecule, which increases its water solubility and facilitates elimination from the body.

The statement is true because in zero-order kinetics, the drug is eliminated at a constant rate regardless of its concentration. This means that the plasma drug concentration decreases by a fixed amount over time, resulting in a linear curve when plotted against time.

Intravenous administration is the route of administration where the medication is directly injected into the bloodstream. Absorption refers to the process by which a medication is taken up by the body and enters the bloodstream. Since intravenous administration bypasses the need for absorption, it is not found in this route of administration.

The rate of drug transport across a cell membrane by lipid diffusion depends on the concentration gradient, surface area of absorption, and lipid partition coefficient. These factors determine the driving force, availability of the membrane surface for absorption, and the solubility of the drug in the lipid bilayer. However, the density of transporters does not directly affect lipid diffusion as it is a passive process that does not involve specific transport proteins.

Pyrex is the correct answer because it is a type of glass that is known for its durability and resistance to thermal shock. It is commonly used in laboratory equipment, including filtration funnels, because it can withstand high temperatures without breaking or shattering. Soda ash, quartz, and limestone are not typically used to make glass filtration funnels.

As the wall of the vessel is increased during filtration, the available space for the liquid to flow through decreases. This results in a decrease in the velocity of the liquid, and consequently, a decrease in the centrifugal force acting on the particles in the liquid. Therefore, the centrifugal force is decreased when the wall of the vessel is increased during filtration.