Drug Stability Flashcards
What is accelerated stability testing?
Accelerated stability testing involves subjecting a product to conditions that simulate time over a shorter period to assess its stability and estimate shelf life.
This testing is done under more severe conditions like high temperature and humidity to speed up the degradation process.
Why is accelerated stability testing important?
It helps in quickly identifying potential issues with a product before it goes to market and is essential for ensuring product quality and safety.
This is particularly crucial in industries where stability is vital.
Define amorphous solids.
Amorphous solids lack a defined shape and arrangement of particles, offering increased solubility and bioavailability compared to crystalline forms.
These solids have a disordered molecular structure.
What advantages do amorphous solids have in drug formulations?
Amorphous solids enhance dissolution rate and absorption in the body, leading to faster dissolution and higher drug concentrations in the blood.
Their increased surface area compared to crystalline solids contributes to these effects.
What is a key characteristic of amorphous solids?
Amorphous solids are thermodynamically unstable and tend to convert to more stable crystalline forms over time.
What does the Arrhenius equation describe?
The Arrhenius equation describes the relationship between temperature and reaction rates, stating that for every 10°C increase, the rate of reaction approximately doubles.
It is often used to calculate rate constants in chemical reactions.
What does the Arrhenius equation help predict?
It helps predict how environmental changes, like temperature, can impact reaction rates.
True or False: The Arrhenius equation assumes a linear relationship between temperature and reaction rate constant.
True
Fill in the blank: Amorphous forms are commonly used in drug formulations to improve _______.
[drug delivery and therapeutic effectiveness]
What does the Bronsted-Bjerrum Equation describe?
The relationship between pH, pKa, and the ratio of ionized to unionized drug molecules in solution
The equation helps in predicting drug ionization at different pH values.
How is the Bronsted-Bjerrum Equation expressed?
pH = pKa + log A-1/[HA]
This equation is fundamental for understanding drug behavior in different environments.
What is the significance of the Bronsted-Bjerrum Equation in pharmacology?
It helps in understanding drug absorption, distribution, and elimination
Knowledge of this equation can aid in optimizing drug formulations for desired pharmacokinetic properties.
Define chemical stability.
The ability of a substance to maintain its chemical composition under various environmental conditions
Factors affecting stability include exposure to light, heat, humidity, and pH.
What are common causes of chemical degradation?
- Oxidation
- Hydrolysis
- Photolysis
These processes can significantly affect the stability of chemical substances.
How can chemical stability be enhanced?
By using antioxidants to prevent oxidation
Additionally, storing substances in a cool, dry place can help maintain their stability.
What are crystalline solids?
Substances with an ordered arrangement of atoms or molecules, displaying a repeating pattern in their crystal lattice structure
They have sharp melting points due to their organized structure.
What effect do different crystalline forms have?
They can exhibit varying solubility and bioavailability
This is crucial for the effectiveness of pharmaceutical compounds.
What method is commonly used to determine the crystalline structure?
X-ray diffraction
This technique provides detailed information about the crystal lattice arrangement.
How do impurities or defects in the crystal lattice affect crystalline solids?
They can affect the physical and chemical properties of crystalline solids
This highlights the importance of purity in drug formulation.
What is the dielectric constant?
A measure of a solvent’s ability to decrease the electric field strength, indicating a solvent’s polarity
It is crucial for predicting solubility and stability of drugs.
How does the dielectric constant relate to ionic compounds?
A higher dielectric constant generally indicates better solvent ability to dissolve ionic compounds
This is important for formulating effective drug delivery systems.
What can affect the dielectric constant of a solvent system?
Temperature and pressure
Variations can impact drug solubility and overall formulation effectiveness.
How is the dielectric constant used in drug delivery systems?
To optimize drug solubility
Understanding dielectric properties helps in the formulation of effective drug delivery systems.
What is drug stability?
The ability of a drug to retain its chemical composition and effectiveness over a specific period
Influenced by factors like temperature, light, and moisture.
What does stability testing assess?
Factors like pH, degradation, and impurity formation
It helps determine the stability of the drug.
What can impact drug stability?
Incompatibilities with other drugs, container materials, and packaging
These factors can lead to reduced drug effectiveness.
What are crucial for maintaining drug stability?
Proper storage conditions, such as temperature control and protection from light
These measures help prevent degradation.
What can degradation products from instability be?
Harmful or ineffective
This affects the therapeutic outcomes.
What factors can influence drug instability?
Light, temperature, moisture, and pH levels
These factors impact drug efficacy and safety.
How does UV light exposure affect drugs?
It can degrade drugs, leading to reduced effectiveness
This is a significant factor in drug stability.
What can extreme temperatures do to drugs?
Alter drug chemical structure and decrease potency
This is critical for maintaining drug stability.
What is the effect of high humidity on drugs?
It can cause drug decomposition and affect stability
Moisture is a key factor in drug preservation.
How do changes in pH impact drugs?
They can impact drug solubility and stability, affecting absorption and bioavailability
pH levels are crucial in drug formulation.
What is ionic strength?
The concentration of ions in a solution, impacting drug solubility and stability
It affects chemical reactions and drug formulations.
How is ionic strength calculated?
By summing the concentrations of all charged ions in a solution
This measurement is important for drug performance.
What effect does higher ionic strength have on drugs?
It can lead to decreased drug solubility and stability
This is important in drug formulation and delivery.
What do salts do to ionic strength?
Increase it due to their dissociation into ions
Salts play a significant role in drug solutions.
What must drug delivery systems consider?
The ionic strength of the environment
Ensuring optimal drug performance is essential.
What does long-term stability testing involve?
Evaluating the chemical and physical properties of a drug over an extended period
This ensures quality and efficacy.
What does long-term stability testing help determine?
The shelf life of a drug
It is critical for proper drug usage.
What factors are monitored during stability testing?
Temperature, humidity, and light exposure
These factors are crucial for maintaining drug quality.
What informs proper storage conditions for a drug?
Data from stability testing
This helps in ensuring drug safety and effectiveness.
