Introduction. Drug delivery systems (DDSs) are developed to deliver the required amount of drugs effectively to appropriate target sites and to maintain the desired drug levels.
Nanotechnology drug delivery applications occur through the use of designed nanomaterials as well as forming delivery systems from nanoscale molecules such as liposomes. Improve the ability to deliver drugs that are poorly water soluble. Provide site-specific targeting to reduce drug accumulation within healthy tissue.
The present limit on duration of rate-controlled oral products is currently set by the transit of solid dosage forms through the gastrointestinal tract: the longest of the oral delivery system products has a delivery time of 18 h [7].
Active targeting is a non-invasive approach, in which the drug is transported to the target organ or tissue using site-specific ligands. The pairing of drug carriers, such as liposome, particulate nanocarrier etc., with a ligand leads to the specific targeting to selected cells.
Various mechanisms drive drug release from the carriers. For example, drug release kinetics can be controlled by diffusion of a drug molecule through a carrier matrix or a barrier surrounding the matrix.
Passive targeting is achieved by incorporating the therapeutic agent into a macromolecule or nanoparticle that passively reaches the target organ. Drugs encapsulated in nanoparticles or drugs coupled to macromolecules can passively target tumors through the EPR effect.
Due to their small size and large surface area, drug nanoparticles show increase solubility and thus enhanced bioavailability, additional ability to cross the blood brain barrier (BBB), enter the pulmonary system and be absorbed through the tight junctions of endothelial cells of the skin (Kohane, 2007).
Drug release is from: diffusion, degradation, swelling, and affinity-based mechanisms. Some of the common routes of administration include the enteral (gastrointestinal tract), parenteral (via injections), inhalation, transdermal, topical and oral routes.
The thrust behind development of NDDS has increased owing to its manifold advantages such as safety, high efficacy, improved pharmacokinetics, decreased dosing frequency, minimization side effect on account of targeting capability to specific site, patient compliance and its economical aspect; the most important
Drug delivery is the method or process of administering a pharmaceutical compound to achieve a therapeutic effect in humans or animals. For this purpose, several drug delivery systems have been formulated and are being investigated for nasal and pulmonary delivery.
Abstract. Drug delivery refers to the technology utilized to present the drug to the desired body site for drug release and absorption, or the subsequent transport of the active ingredients across the biological membranes to the site of action.
Novel drugs are often innovative products that serve previously unmet medical needs or otherwise significantly help to advance patient care and public health. NMEs have chemical structures that have never been approved before.
Nano-drug delivery systems (NDDSs) are a class of nanomaterials that have abilities to increase the stability and water solubility of drugs, prolong the cycle time, increase the uptake rate of target cells or tissues, and reduce enzyme degradation, thereby improve the safety and effectiveness of drugs (Quan et al.,
sustained release dosage forms follow first order kinetics whereas controlled forms follow zero order kinetics. In sustained forms the dosage is sustained for prolonged period of time and drug release is not definite per unit time but in controlled forms, drug release is very definite per unit time.
Sustained release's definition is more akin to a "controlled release" rather than "sustained". Extended-release dosage consists of either sustained-release (SR) or controlled-release (CR) dosage. SR maintains drug release over a sustained period but not at a constant rate.
Most conventional (immediate release) oral drug products, such as tablets and capsules, are formulated to release the active drug immediately after oral administration. In the formulation of conventional drug products, no deliberate effort is made to modify the drug release rate.
