Stabilization of Eye and Ear Drops - Coursework Example

Stabilization of Eye And Ear Drops by Eye drops are drops that are saline in nature and are administered through the ocular route. They may contain different ingredients depending on the condition being treated. Some of these ingredients are steroids, symppathomimetics, antihistamines, beta receptor blockers, parasympatholytics, parasympathomimetics, prostaglandins, antibiotics, non-steroidal anti-inflammatory drugs abbreviated as NSAIDS, antifungal, and topical anaesthetics (Nottingham.ac.uk, 2010). Some eye drops do not contain medications but are just meant for lubrication and replacing tears. Eye drops do not have as much risk as oral medicines and such risk can be further minimized through occlusion of the lacrimal punctum –this is pressing the inner corner of the eye in- for some time after administering the eye drops. It is recommended by pharmacists that most types of eye drops be disposed after 28 days as they are only stable for 28 days in solution. Eye drops are just as similar but now for ears. They are mostly used to treat ear infections particularly the infection of the outer ear or the ear canal, otitis externa. The half-life of a drug is the period of action of the drug. It is the time taken for the concentration of the drug in the body to reduce by half. The half-life of a drug is considered in terms of the amount of it in the plasma. If a drug molecule leaves the plasma, it can be eliminated from the body or can be relocated to another compartment of body fluid in the body such as in the intracellular fluid or can undergo destruction in the blood. The process of removing the drug from the plasma is called clearance while its distribution in the various tissues of the body is called volume distribution. These are the important pharmakokinetic parameters in determining the half-life of a drug (Nottingham.ac.uk, 2010). In order to figure out how to improve the stability of a drug, we have to ask ourselves why the drug is unstable and has a short half-life. It is definitely because of the compounds contained in the drug. Sometimes, you might find a compound that partitions itself and hides into tissues while on the most part, a compound that disappears is getting consumed and eliminated. If this is the case, one might want to check the blood for metabolites and in the urine for the same and the parent compound and see how this can be accounted for. There is no need to check the faeces or bile contents because the drug as not dosed orally. Looking for metabolites is really something magical. There are a lot of standards that are checked for example addition of multiples of sixteen. Examining structures can also give you clues. One can consider the cleavage of amide bonds. Bromine and iodine can also help track things coupled with iodine to the mass spec. The pharmaceutical market of today is being challenged by a few pressures particularly in movement of drugs through clinical trials and in faster marketing and in a more cost-effective manner. This is as a result of thinner budgets and enlarging financial burdens in the industry. In recent times, there has been development of biological drugs that are targeted to make tailored to market faster than before. The increase in interest in these therapies is because they have reduced side effects to patients which renders them ideal for treating illnesses that require frequent medication such as eye and ear allergies. Biological drugs are hampered however by their sort halve lives, meaning that after they have been administered, they are cleared from the body within minutes. As a result, those suffering from conditions that require frequent medication are required to administer on themselves higher doses more frequently which can lead to reduced compliance, increased costs and more risk of side effects. Drugs that are promising in therapeutic value more often than not are limited by this consideration. Because of this reason, pharmaceutical companies are becoming increasingly interested in mechanisms to strategies that can increase the half-lives of these drugs. Quite a number of research centres are part of the growing focus to extend the half-life of proteins and peptides. A lot of researchers have responded to this issue by concentrating their efforts to develop technologies that can extend half-lives that can modulate aspects like serum half-life of proteins and protein-based medicines to the desired specifications. Researchers have been successful in extending the serum half-life but have been unable to design protein half-lives that are flexible enough to deliver proper pharmacokinetics. The recent strategies are those involving increasing hydrodynamic volume or the use of albumin fusions. Real progress has been made in developing technologies that increase serum half-life the industry is struggling to tailor therapies in a way that meets specific medical specification s (Pipeline.corante.com, 2012). Advances in albumin fusion technology Recent technologies that can be used to enable extension of half-life are based on the serum albumin which is a non-immunogenic plasma carrier protein that is natural. Albumin is a preferred material to base technologies for extending half-life because of its long half-life in bodies of humans of 19 days compared with protein therapeutics that are cleared from the body in hours. In addition to its size, it is a PH-dependent recycling through neonatal FcRn receptor that offers protection to the albumin from clearance through the kidneys. This is what extends its half-life. Albumin is taken up by cells by nonspecific pinocytosis and protected from being degraded intracellularly when pH-dependent receptor binds to FcRn receptor in acidic endosomes. This is similar to IgGs. The interaction allows the albumin to be recycled to the cell surface. Here it is released into the bloodstream owing to the physiological pH of blood. This pH-dependent interaction between the albumin and the FcRn receptor provides a basis for the advancement in this technology of albumin fusion. Our comprehension of its impact on half-life of albumin fusion has facilitated the engineering of the interaction to increase the half-life. The pharmatokinetics of the IgG have been impacted by previous studies which altered the interaction. If these same principles of kinetics are applied, technologies for extending the half-life can be able to modulate the half-life by constructing albumin variants that have their affinity to FcRn altered. The enabling technologies can also stabilize blood levels to patients and reduces side effects that come from too much usage since lower dose rates translate to the toxicity level not being reached. The technologies allow the dose to remain at the therapeutic range which increases the tolerance of the patient to the drug (Pipeline.corante.com, 2012). Broad platform applicability The current approach on albumin use is in extending the half-life by conjugation or genetic fusion. The two methods can be effective depending on specific requirements of the delivery of the drug. Lysine, tyrosine and free thiol of the albumin molecule are used in chemical conjugation to the product with the most used conjugation route as the free thiol on the albumin molecule. This approach is specifically useful in peptides that contain maleimide groups that react with the free thiol permitting formation of a thioether stable bond between the peptide and the ether (Pipeline.corante.com, 2012). The market demands adoption or creation of technologies that allow for development of drugs that have novel properties. However, researchers need to come up with solutions that provide competitive solutions for manufacturers. There is limited number of biological drugs in the market but researchers are working on improving the ones available. Recently, there has been considerable dedication of resources to the improvement of half-life of drugs; success has been significant in the elongation of half-lives of proteins and peptides but the specific area of tailoring the pharmatokinetics of particular drugs to the medical needs has been minimal. Enabling technologies for half-life extension solve these issues because they provide a platform for developers to fine-tune the half-lives of drugs in specific therapeutic circumstances (Pipeline.corante.com, 2012). After focusing on technologies that can be used to extend the half-life of albumin serums, let us now consider the use of albumin in eye drops. Unterlauft et al., 2014 talk about how serum manufactured from autologous serum have been used for more than ten years and have been used in therapies for curing corneal wounds and ocular surfaces. Examples of these conditions are dry eye and persistent epithelial defects. Serum eye drops can however only be distributed by companies that have licenses to do so from proper authorities. Albumin is the major component of serum although its availability is in form of a quality controlled product in the pharmaceutical product in autologous serum eye drops. The wound healing capability of serum eye drops has been demonstrated in vitro (Unterlauft et al., 2014). There needs to be carried more research in the field of increasing the half-life of eye drops and ear drops so as to reduce the dosage and reduce the side effects of the drugs. This paper has focused more on the use of biological methods as a possibility because considerable research has been done and strides made. If the use of serum eye drops can be explored, the fruits of this research would be enjoyed. References Nottingham.ac.uk, (2010). Pharmacology: Half-life of Drugs. [online] Available at: http://www.nottingham.ac.uk/nursing/sonet/rlos/bioproc/halflife/02.html [Accessed 14 May. 2014]. Perkins, M. (2013). The need for improved half-life extension technologies. [online] Ddn-news.com. Available at: http://www.ddn-news.com/index.php?newsarticle=6914 [Accessed 14 May. 2014]. Pipeline.corante.com, (2012). Improving Half-Life. In the Pipeline:. [online] Available at: http://pipeline.corante.com/archives/2012/10/23/improving_halflife.php [Accessed 14 May. 2014]. Unterlauft, J., Geerling, G., Hofbauer, I., Kasper, K. and Kohlhaas, M. (2014). Unbound MEDLINE : [Albumin eye drops for treatment of ocular surface diseases. [online] Unboundmedicine.com. Available at: http://www.unboundmedicine.com/medline/citation/19813016/[Albumin_eye_drops_for_treatment_of_ocular_surface_diseases]_ [Accessed 14 May. 2014]. Read More