Lecture 11 Platforms Particulate systems Flashcards
Describe liposomes.
Microscopic vesicles made of lipid bilayers, typically composed of phospholipids and cholesterol, that self-assemble into spherical structures with an aqueous core.
What are some advantages of particulate systems?
Enhanced therapeutic efficacy, minimization of side effects, improved patient compliance, optimization of biopharmaceutical properties, enablement of novel therapies, tailored treatment approaches, facilitation of personalized medicine.
How do liposomes serve as carriers for therapeutic agents?
Liposomes encapsulate drugs in their lipid core, lipid bilayers, or both.
Define the application areas of liposomes.
Vaccination, cancer therapy, gene therapy, photodynamic therapy, transdermal delivery, pulmonary delivery, imaging, and oral drug delivery.
List some advantages of liposomes.
Broad spectrum of agents, organ targeting, potential for long-acting effects, drug protection, overcoming biological barriers, enhancing immune response, improved pharmacokinetics, decreased toxicity.
What are some disadvantages of liposomes?
High production cost, leakage and fusion of encapsulated drugs/molecules, susceptibility to oxidation and hydrolysis, short half-life, low solubility.
Describe PLGA micro/nanoparticles.
PLGA micro/nanoparticles are composed of a biodegradable and biocompatible polymer designed to encapsulate therapeutic agents for targeted delivery. They break down into non-toxic components and are eliminated from the body naturally.
Do PLGA microspheres have any advantages?
Yes, advantages of PLGA microspheres include biodegradability, biocompatibility, controlled release, versatility, targeted delivery, protection of encapsulated drugs, tunable properties, reduced toxicity, and enhanced pharmacokinetics.
Define burst release in the context of PLGA micro/nanoparticles.
Burst release refers to the rapid and immediate release of the encapsulated drug from PLGA micro/nanoparticles, which can lead to potential issues in drug delivery.
How is PLGA utilized in Vivitrol® formulation?
Vivitrol® is an extended-release formulation of naltrexone for alcohol and opioid dependence that uses PLGA microspheres for sustained drug release.
Describe the disadvantages of PLGA micro/nanoparticles.
Disadvantages of PLGA micro/nanoparticles include burst release, acidic microenvironment, polymer degradation, incomplete release, particle aggregation, manufacturing complexity, size limitations, immunogenicity, and cost implications.
Describe the importance of particle size in nanocrystal technology.
Particle size plays a crucial role in nanocrystal technology as smaller size leads to a bigger A factor, impacting factors like adhesion, concentration gradient, and drug delivery.
What are the advantages of long-acting nanosuspensions in drug delivery?
Advantages include prolonged release, enhanced bioavailability, targeted delivery, stability, reduced side effects, flexibility in formulation, ease of administration, and manufacturing scalability.
How does milling impact drug delivery in nanocrystal technology?
Milling helps in delivering drug nano particles orally, leading to finely dispersed nano-crystals that exhibit pronounced adhesion, reproducibility, and a high concentration gradient.
Define the Noyes-Whitney equation and its relevance in drug formulation.
The Noyes-Whitney equation relates the rate of dissolution of a solid material to its surface area and solubility. In drug formulation, it signifies that smaller particle size results in a larger surface area, affecting dissolution and bioavailability.
