Transdermal administration routes

In conclusion, SERMs exhibit changes in inflammatory markers that do not match those found with oral HT. Some variability exists within HT itself, depending on the compound (estrogens or tibolone) and on the administration route (oral vs. transdermal). There is sufficient background to hold the value... 

In recent years, much of the research work in the pharmaceutical sciences was focused on the development of effective vehicle systems, such as micelles, microemulsions, and liposomes, for drugs that are critical with respect to bioavailability. Knowledge of this subject is a prerequisite to developing vehicle systems for special administration routes, such as dermal, transdermal, intravenous, and nasal. 

While the above-mentioned examples cannot be considered an exhaustive representation of all the possible uses of membranes in the delivery field, they serve to give an idea of how many and how variegated the applications can be. The aim of this chapter is to first describe the basic principles mhng mass transport through membranes. Then, in the light of the administration route (oral, transdermal, and implantable), some of the most important applications are presented and discussed. Finally, future applications of membranes in the dehvery field are briefly treated. 

Choosing a medicine that uses an alternative administration route (oromucosal, rectal or transdermal, or parenteral if the administration by doctor or nurse can be organised)... 

One major complicating factor is the question of biodistribution—where does the drag go in the body How much arrives at the site where it is required at any particular time This in turn depends on factors such as the location and/or route of administration (oral, transdermal, parenteral, etc.), blood flow (tissues with the... 

Given the preferred route or routes of administration, what administration-route-specific risks are anticipated in patients (e.g., injection site reactions for injectables, skin or mucosal irritation for topicals or transdermals, etc.) ... 

As excipients, CDs have been widely used to cover the bitter taste of drugs, to increase their dissolution rates, to reduce irritation reactions and in low concentrations to suppress the haemolysis induced by some drugs [180]. Great effort has been made to develop CD-based drug formulations with different administrative routes, including parenteral, oral, pulmonary, nasal [181], transdermal, rectal [182] and ophthalmic [183] drug delivery [184]. 

The term parenteral drug delivery covers a number of administration routes which have little in common other than the fact that they generally involve the use of a hypodermic needle to inject the drag into the body. This route of administration bypasses a number of physiological barriers. The constraints on the composition and formulation of the medicine are much more rigorous than for less invasive routes such as oral or transdermal delivery. Despite this, a surprising range of materials can be injected into various tissues if the appropriate precautions are taken. 

Use the oral route of administration if the patient has mild nausea with minimal or no vomiting. Seek an alternative route (e.g., transdermal, rectal suppository, or parenteral) if the patient is unable to retain oral medications due to vomiting. 

Opioids maybe administered in a variety of routes including oral (tablet and liquid), sublingual, rectal, transdermal, transmucosal, intravenous, subcutaneous, and intraspinal. While the oral and transdermal routes are most common, the method of administration is based on patient needs (severity of pain) and characteristics (swallowing difficulty and preference). Oral opioids have an onset of effect of 45 minutes, so intravenous or subcutaneous administration maybe preferred if more rapid relief is desired. Intramuscular injections are not recommended because of pain at the injection site and wide fluctuations in drug absorption and peak plasma concentrations achieved. More invasive routes of administration such as PCA and intraspinal (epidural and intrathecal) are primarily used postoperatively, but may also be used in refractory chronic pain situations. PCA delivers a self-administered dose via an infusion pump with a preprogrammed dose, minimum dosing interval, and maximum hourly dose. Morphine, fentanyl, and hydromorphone are commonly administered via PCA pumps by the intravenous route, but less frequently by the subcutaneous or epidural route. 

The transdermal route of drug administration offers several advantages over other methods of delivery. For some cases, oral delivery may be contraindicated, or the drug may be poorly absorbed. This would also include situations for which the drug undergoes a substantial first-pass effect [173] and systemic therapy is desired. 

As pharmaceutical scientists gain experience and tackle the primary challenges of developing stable parenteral formulations of proteins, the horizons continue to expand and novel delivery systems and alternative routes of administration are being sought. The interest in protein drug delivery is reflected by the wealth of literature that covers this topic [150-154]. Typically, protein therapeutics are prepared as sterile products for parenteral administration, but in the past several years, there has been increased interest in pulmonary, oral, transdermal, and controlled-release injectable formulations and many advances have been made. Some of the more promising recent developments are summarized in this section. 

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