What are the two factors that influence bioavailability?

• Drug concentration at site of administration.
• Surface area of the absorptive site.
• Drug pKa.
• Drug molecule size.
• pH of the surrounding fluid.

How do you increase the bioavailability of a drug?

The bioavailability of poorly absorbed drugs can be improved by formulating the drugs into nanosuspensions, solid lipid nanoparticles, polymeric nano- and microparticles, liposomes, niosomes, phytosomes, self-micro emulsifying drug delivery system and microemulsion.

What are the pharmacological factors that affect bioavailability?

• Absorption.
• Food Effect.
• Drug metabolism/ biotransformation.
• Energy dependent efflux transporters.
• Physico-chemical factors.
• First pass metabolism.
• CYP450 isozymes.

What is the most important factor affecting bioavailability?

The route of administration (ROA) and the dose of a drug have a significant impact on both the rate and extent of bioavailability.

What aspects of formulation design are used to increase a drug’s oral bioavailability?

The prodrug design can improve the oral bioavailability of drugs by enhancing their water solubility and gastrointestinal permeability and overcoming first-pass metabolism. Prodrugs can improve the carrier-mediated absorption of charged or polar drugs with negligible passive absorption (Shah et al., 2020).

How does solubility affect bioavailability?

Solubility plays a critical role in drug effectiveness. Without it, a drug substance cannot be absorbed, leading to low bioavailability. Poor solubility of drugs also leads to other issues, such as challenges with metabolism or permeability, interactions with other drugs or the need to extend drug release.

Which form of the drug has highest bioavailability?

Drug in liquid form have more bioavailability than those of solids, while gases have the highest bioavailability. This is why inhalation is used in bronchial asthma.

Are there any nutrients that may improve bioavailability?

Protein, calcium, biotin, magnesium and zinc can increase ALA bioavailability[88],[89], and a good quality plant-based diet is sufficient in these nutrients.

Which route shows the highest bioavailability?

Therefore, a drug given by the intravenous route will have an absolute bioavailability of 100% (f = 1), whereas drugs given by other routes usually have an absolute bioavailability of less than one.

How does absorption affect bioavailability?

1 Definition. Absorption is the movement of drug from the site of drug administration to the systemic circulation. Bioavailability is the extent to which absorption occurs. In other words, bioavailability is the fraction of the administered drug that reaches the systemic circulation in the unchanged form.

What is bioavailability in pharmacology?

(BY-oh-uh-VAY-luh-bul) The ability of a drug or other substance to be absorbed and used by the body. Orally bioavailable means that a drug or other substance that is taken by mouth can be absorbed and used by the body.

What factors affect the bioavailability of nutrients?

• Gender.
• Age.
• Body composition.
• Health status.
• Life stage (e.g. pregnancy / children)
• Our own nutrient store of a particular nutrient.
• Cooking & processing.
• The chemical form a nutrient is delivered in.

What is physicochemical properties that affect bioavailability?

The physicochemical properties of the drug that will influence its passage into solution and transfer across membranes include its dissolution rate, pKa, lipid solubility, chemical stability and complexation potential.

How can the bioavailability of poorly soluble drugs be improved?

1. Particle size reduction.
2. Nanosuspension technology.
3. Surfactant.
4. Salt formation.
5. pH adjustment.
6. Hydrotrophy.
7. Solid dispersion.

How do you increase oral absorption?

Prodrugs. The most clinically successful strategy to improve the oral bioavailability of a poorly permeable drug has been the use of prodrugs. Prodrugs are useful in overcoming several drug absorption barriers such as poor solubility, instability, insufficient absorption, rapid first-pass metabolism etc [64].

What does increased bioavailability mean?

A higher bioavailability generally means more nutrients are being absorbed than through conventional methods. A number of different influences can affect this, from timing, age, sex and lifestyle to the format used to take the supplement and when it was taken in the day i.e. before a meal.

How does pH affect drug bioavailability?

GI pH is an important factor that can markedly affect oral drug absorption and bioavailability as it may have significant influence on drug dissolution & solubility, drug release, drug stability, and intestinal permeability. Different regions of the GI tract have different drug absorptive properties.

What are the 4 factors affecting solubility?

• Temperature. Basically, solubility increases with temperature.
• Polarity. In most cases solutes dissolve in solvents that have a similar polarity.
• Pressure. Solid and liquid solutes.
• Molecular size.
• Stirring increases the speed of dissolving.

What determines bioavailability?

Bioavailability of a drug is largely determined by the properties of the dosage form, which depend partly on its design and manufacture. Differences in bioavailability among formulations of a given drug can have clinical significance; thus, knowing whether drug formulations are equivalent is essential.

What are the two types of bioavailability?

• Absolute Bioavailability: When the drug is administered through the intravenous route, the bioavailability of the drug achieved will be 100 percent.
• Relative Bioavailability: It is the bioavailability of the drug when obtained and it is compared with a reference standard.

What causes low bioavailability?

Causes of low bioavailability Low bioavailability is most common with oral dosage forms of poorly water-soluble, slowly absorbed drugs. Insufficient time for absorption in the gastrointestinal (GI) tract is a common cause of low bioavailability.

Why is drug bioavailability important?

Bioavailability is a key indicator of drug absorption. It represents the administered dose fraction which achieves success in reaching the systemic circulation when administered orally or through any other extravascular dosing route.

What is an example of nutrient bioavailability?

Vitamin C And Iron The effect of vitamin C on iron absorption is an example of a positive effect on nutrient bioavailability. In the gut, vitamin C coverts non-haem iron (the less easily absorbed form of iron) into a more bioavailable form that the body prefers, which helps absorption.

What is bioavailability in chemistry?

Bioavailability is defined as the portion of the total quantity of concentration of a chemical that is available for biological action.

What is difference between bioavailability and bioequivalence?

For a drug to be highly bioavailable it should be fast and completely absorbable. Bioequivalence is Just a comparison of the bioavailability of two identical products. For example, we compare two brands of paracetamol (Acetaminophen) for their bioavailability.