Solid Dosage Forms: (Tablets, Capsules)
Impact on Stability:
Particle size affects dissolution and absorption.
Poor flow properties can result in content uniformity issues.
Moisture-sensitive drugs may degrade; therefore, desiccants and coatings are required.
Polymorphism must be controlled to prevent recrystallization.
Key Formulation Approaches:
Granulation to improve flow properties.
Addition of lubricants and binders to improve compressibility.
Use of coating agents to protect against moisture and oxidation.
Liquid Dosage Forms: (Solutions, Suspensions, Emulsions)
Impact on Stability:
Drugs prone to hydrolysis need pH adjustment and buffers.
Oxidation requires antioxidants and chelating agents.
Solubility enhancers like cosolvents or surfactants are often added.
Key Formulation Approaches:
Use of preservatives to prevent microbial contamination.
Selection of pH modifiers to enhance solubility and stability.
Addition of viscosity enhancers to maintain suspension uniformity.
Parenteral Dosage Forms: (Injections, Infusions)
Impact on Stability:
Sterility and pyrogen-free requirements are crucial.
Hydrolysis and oxidation are significant challenges due to aqueous media.
Physical stability (precipitation) and chemical stability must be ensured.
Key Formulation Approaches:
Use of cryoprotectants for freeze-dried formulations.
Incorporation of antioxidants and buffers to maintain stability.
Use of isotonic agents to match osmolarity with biological fluids.