Niosomes are Carier Systems that can Deliver Hydrophilic and Lipophilic Drugs

Transdermal medications come in the form of patches that are applied to the skin normally to the chest or upper arm. They work by allowing the medication to be released slowly and then absorbed. For example, Hormone Replacement Therapy (HRT) patches and nicotine patches.

It can be employed both orally and as a transdermal patch. The patch is more

Many molecules, particularly peptides and polypeptides are physically embedded in polymers to create a complex network of interconnecting pores through which the drug could subsequently diffuse. The pore structure and polymer composition is controlled in order to design systems that release the drug at nearly any rate and for nearly

3Transdermal delivery of fentanyl has a variety of advantages compared to other delivery systems. Unlike oral administration, transdermal fentanyl avoids first–pass hepatic effect of the liver, which can prematurely metabolize drugs. In comparison with oral opioids, transdermal fentanyl has a lower incidence and impact of adverse effects such as constipation and vomiting, it also enhances patience compliance (as administration is every 72 hours). Transdermal delivery of fentanyl is also more convenient in comparison to hypodermic injection which can be very painful but also exert dangerous medical waste and increase disease transmission with the re use of needles (which is very common in developing countries).

Within the epidermis is the stratum corneum which is the hardest layer for the drugs to pass through. The stratum corneum is only 20% water and is classified as a lipophilic membrane which is why a lipophilic opioid such as Remifentanil is needed to be able to pass through. Since a a drug delivered through a transdermal patch would have to move through all these layers before reaching the dermis where it would be absorbed, there is a delay from the time that the patch would be applied until enough of the drug had been concentrated to get the desired results (Nelson, 2013). For some patients, an initial dose of orally or IV opioid may be introduced into the system until such time that the transdermal patch has begun to be

When a prohormone or steroid is absorbed into the epithelial cell it is then partitioned (or directed) into either the portal vein or the lymphatic system. The process that determines this partitioning (choosing of one or the other disposition) is called “superlipophilicity”. Creating a system of delivery that will cause partitioning in the right direction is part of the equation, but not the whole picture.

Microspheres formulated using 0.1 M calcium chloride exhibited the highest drug loading at 14%, with 66.5% encapsulation efficiency. Less than 4% and 35% propranolol release occurred from hydrated and dried microspheres, respectively, in 2 hours in simulated gastric fluid (SGF). 90% of the drug load was released in increments of 5 hours and 7 hours from hydrated and dried microspheres, respectively, in simulated intestinal fluid (SIF). Prior incubation of hydrated microspheres in SGF extended the time of release in SIF to 10 hours. Restricted propranolol release in SGF and complete extraction in SIF demonstrate the potential of alginate gel microspheres for oral delivery of

Pharmacokinetic analysis suggests that the orally administered nanoemulsions had a higher rate of absorption and the concentration of the drug in the brain and plasma was the highest. Formulation: The drug nanoemulsion was prepared by adding 50% of the drug solution (with dehydrated ethanol) to one ml of safflower oil and it was stirred for the oil drug mixture to distribute homogenously and for all the ethanol to evaporate. Deionized distilled water (contains egg phosphatidylcholine) and deoxycholic acid.(40mg) make up the aqueous phase. Both the phases are heated at 70oc separately. The oil phase was slowly added to the aqueous phase and stirred well. The mixture was then sonicated (21% amplitude and 50%duty cycle). The mixture formed (drug containing nanoemulsion) was then filtered and stored at 4oc.Preparation of aqueous suspension was made using 3H Labeled drug and unlabeled drug in ethanol along with Deionized distilled water (contains egg phosphatidylcholine) and deoxycholic acid. The suspension was sonicated in order to lessen the particle size [2]. An example is Saquinavir (anti-HIV inhibitor) showed enhanced oral absorption and increased concentration of drug in the brain when incorporated in a nanoemulsion

Transdermal Patches ensure simple, painless procedure of drug usage even in patients with needle phobia. they are on par with sustainable plasma levels comparable with that of oral medication. With the local drug delivery method, hepatic first pass metabolism is bypassed. Offering increased flexibility in placing and removing the transdermal patch better patient compliance is achieved.7,8

This novel method of administration involves thin needles which penetrate the stratum corneum to deliver the drug (101). This method is painless and increases

Administration: Oral mucosal drug delivery systems are easy to administer. This quality of ease of administration is of most importance to health care providers

It was proven that surface active agents which are the backbone of the formulated lipid vesicles can enhance the transdermal delivery of drugs by lowering the permeability barrier of the skin and interacting with the SC in vitro [45]. On the other hand, Studies also reported that the drug molecules to be effectively transported across the SC they must be entrapped within the lipid vesicles suggesting that the vesicles act as drug carrier systems and not as penetration enhancers [46].

Iontophoresis is one of many modalities used in Physical Therapy. The method behind Iontophoresis was first described in 1747 when two well know scientist, Galvani and Volta put together the knowledge that electricity can move different metal ions and that movements of ions can produce electricity. Over time, transdermal administration of drugs has grown and found its place in modern medicine. Two methods of transdermal administration are passive and active. Passive administration uses a non-ionized drug that passes through the semi-permeable membrane of the skin. Consequently, due to the fact that the skin is semi-permeable, only a small amount of the drug molecules penetrates the skin. In contrast to non-ionized drugs, ionized drugs do not penetrate and generally not considered suitable for transdermal application. However, when combined with an external source of energy such as a direct low-level electrical current, ionized drug are quite effective at reaching the tissue. The principle behind

"Absorption depends on the drug’s ability to cross cell membranes and resist extensive breakdown by the stomach, liver, and intestines.

Eudragit RS and RL 100 polymers have been selected as a carrier for fabrication of nanofibers due to their nice stability, biocompatibility, and nice adhesion over skin due to excellent swelling property, and presence of surface charge. These charges can facilitate prolonged residence time and adhesion over targeted site (Haznedar et al, 2004). Their combination customize drug release, moreover presence of quaternary ammonium compound further check reoccurrence of microbial infection. Chemically these are copolymers of poly (ethylacrylate, methyl methacrylate and chlorotrimethyl-ammonioethyl methacrylate).