Ionic Equilibria Concepts

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What primarily determines a drug's physicochemical properties?

The drug's administration route

The drug's molecular structure (correct)

The drug's distribution in the body

The drug's dosage form

Why is the ionization of a drug significant?

It influences the drug's color

It impacts the drug's physical, chemical, and biological performance (correct)

It determines the drug's shelf life

It affects the drug's taste

What process describes a compound dissociating into ions in an aqueous solution?

Ionization (correct)

Evaporation

Saturation

Precipitation

What does the acronym ADME represent in pharmacology?

Absorption, Distribution, Metabolism, Excretion Signup and view all the answers

What is a defining characteristic of weak electrolytes?

They ionize partially in solution Signup and view all the answers

What distinguishes strong electrolytes from weak electrolytes?

Strong electrolytes ionize completely in solution Signup and view all the answers

Which statement accurately describes amphiprotic solvents?

They can either accept or donate protons. Signup and view all the answers

According to Arrhenius's definitions, what do acids yield in water?

H+ ions Signup and view all the answers

What is a conjugate base?

An ion that remains after an acid donates a proton Signup and view all the answers

What does the ionization constant (Ka) indicate about a weak acid?

Its tendency to donate protons Signup and view all the answers

What does a higher Ka value indicate about an acid?

The acid is stronger. Signup and view all the answers

At what pH is a solution considered neutral?

pH 7 Signup and view all the answers

What is the Henderson-Hasselbalch equation for weak acids?

pH = pKa + log([A-]/[HA]) Signup and view all the answers

What is the effect of lower pH on the solubility of weak bases?

It increases their ionization. Signup and view all the answers

What type of pH results from a salt formed from a weak acid and a strong base?

Alkaline pH Signup and view all the answers

How does increasing urinary pH affect the excretion of weak acids?

It increases ionization and enhances excretion. Signup and view all the answers

What does pH + pOH equal?

14 Signup and view all the answers

What is the significance of ionization regarding drug absorption?

Unionized drugs are more soluble in aqueous solutions. Signup and view all the answers

What is hydrolysis in relation to salts?

It is the reaction of salt ions with water. Signup and view all the answers

Which aspect does the pH partition hypothesis emphasize regarding drug absorption?

The ionization of drugs depending on pH conditions. Signup and view all the answers

Study Notes

Ionization and Drug Properties

Drug ionization influences absorption, distribution, metabolism, and excretion (ADME).
Most drugs are weak electrolytes, meaning their ionization depends on the environment's pH.
Strong electrolytes completely ionize in solution (NaCl, HCl, NaOH).
Weak electrolytes partially ionize in solution (aspirin, phenobarbital, sulfadiazine).
The Henderson-Hasselbalch equation predicts the ionization state of weak acids and bases based on pKa and pH.

pH and Ionization

pH affects drug ionization and solubility.
Ionized drugs are more soluble in aqueous solutions.
Unionized drugs are more lipid-soluble, favoring absorption through cell membranes.
Weak acids ionize more at higher pH (above their pKa).
Weak bases ionize more at lower pH.

Salts and pH

Salts formed from strong acids and weak bases create acidic solutions (e.g., ephedrine HCl).
Salts formed from weak acids and strong bases create alkaline solutions.
The hydrolysis of salt ions in water can influence the solution's pH.

Ionization and Drug Absorption

The pH partition hypothesis explains that drug absorption depends on ionization and pH gradients in different body compartments.
Ionized drugs are poorly absorbed because they are less lipid-soluble.
Unionized drugs are more readily absorbed due to their higher lipid solubility.

Examples

Sulfisoxazole is more effective than sulfadiazine for urinary tract infections (UTIs) due to its lower pKa, resulting in more ionization in urine and enhanced excretion.

Key Concepts

Understanding drug ionization and its dependence on pH is crucial for predicting drug behavior in the body.
pKa and pH are critical factors influencing drug absorption, distribution, and elimination.
The Henderson-Hasselbalch equation is a valuable tool for predicting drug ionization.
Adjusting urinary pH can impact drug excretion by influencing ionization.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the crucial role of drug ionization in pharmacology, including its impact on absorption, distribution, metabolism, and excretion. This quiz covers concepts like pH effects, the Henderson-Hasselbalch equation, and the solubility of weak electrolytes. Test your knowledge on how these principles apply to various drugs and their formulations.