Impact of Oral, inhalable, and injectable salbutamol formulations for the treatment of asthma Asthma is a common lung condition caused by inflammation of the airways (Lallemand Pharma, 2018), which includes bronchial hyperactivity and bronchospasm due to hyper responsiveness of tracheo-bronchial smooth muscle, resulting in narrowing of the air tubes. There is about 334 million people who suffer from asthma worldwide. Salbutamol is used to relieve symptoms of asthma, which are coughing, wheezing and feeling breathless (nhs.uk, 2018). It works by relaxing the muscles of the airways into the lung which makes it easier to breathe (nhs.uk, 2018). It is the most widely used short-acting relief from sudden or unexpected attacks of breathlessness. It is a white crystalline powder, readily soluble in water, which is available as an inhaler, tablet and injection. Depending on the asthma action plan of the patient, doctor will advice how to manage one’s asthma. In this essay, it will be explained how oral, inhalable and injectable salbutamol formulation helps to relieve asthma.Salbutamol is a bronchodilator drug used alone or in conjunction with inhaled corticosteroid. The way that salbutamol work depends on the method the drug is administered. For example, if it is administered orally, it resists the acid of the stomach and enzymatic attack, it absorbed across gastrointestinal membrane through pharmacokinetics, that is what the body does to the drug. At the end, salbutamol is excreted in the urine as a mixture of unchanged drug and most of the drug is recovered in the urine (Bergés et al., 2000). Salbutamol is an inhaled form that plays an important role in the management of bronchial asthma and the most widely prescribed drug in this class. The common salbutamol side effects are feeling shaky which soon passes, headache for which a painkiller can be used. The most serious ones are nervous tension, muscle cramps and being aware of the heartbeat. However, if they are troublesome, the doctors must be informed so that the latter can look at the pharmacokinetics and set up a patient care plan that can help to facilitate decisions for dose amount and the impact of drug interaction. In the lungs, salbutamol is not fully metabolised, the proportion of drug metabolism depends on the amount swallowed.Oral tablets which are solid dosage. It is one of the methods of administrating the drug to achieve better patient compliance. When the tablet is placed on the tongue, it disintegrates instantaneously, and the drug is released within a few second without the need of water. This mode of administration is useful for dysphagia adults, pediatrics, geriatrics and mentally ill patient. The drug is absorbed from the mouth, pharynx, oesophagi as saliva passes the stomach, therefore has a good bioavailability. Salbutamol is a ?2 adrenergic receptor. The stimulation of the drug via increased cyclic adenosine monophosphatedan formation in bronchial muscle cell, which cause relaxation (KUMAR and SAHARAN, 2017). Its action starts within 15 to 20 minutes and can last up to 4 hours. Hence, it is an efficient method to terminate attacks of asthma. Each tablet contains 2.4 mg of Salbutamol Sulfate. For an adult, the effective dose is 4 mg for three to four times a day and for children, the doses should be administered depending of the age, for example for a child from 2 to 6 years old is 1 to 2 mg, 6 to 12 years is 2 mg and over 12 years is 2 to 4 mg (Medicines.org.uk, 2018). The advantages of oral tablet are that fast dissolving tablets enhance safety and efficacy of the drug molecules, the tablet can be administered without water and accurate dosage compared to liquids and easy portability. Further benefits are in terms of patient compliance, rapid onset of action and increase in bioavailability. The disadvantage for this is that some patients have trouble in swallowing the drug due to large size, shape and taste.              Figure 2 shows how asthma attack is formed in the body (Britannica.com, 2018).The second method of administering salbutamol is using inhaler, which can be in the form of aerosol inhaler, auto-inhaler or powder inhaler. Salbutamol being a bronchodilator medicine dilates the airway and opens the air passages of the lungs so that the air can flowinto the lungs more freely and hence helps to relieve symptoms of asthma. The action starts within a few minutes after administered and can last for 3 to 4 hours (nhs.uk, 2018). Salbutamol inhalers are known as ‘reliever’ inhaler or blue inhaler. It is important to note that they relieve breathlessness, but do not prevent the breathlessness from happening. Doctors may give a space device to use with an inhaler when patient struggle to co-ordinate breathing or young children. The space role is to help the medicine to travel to the lungs. Salbutamol inhalers must be kept in cool and dry place, away from direct heat and light. Adults and children need to use 1 or 2 puffs of salbutamol when needed and up to a maximum of 4 times in 24 hours. In case of sudden attack, then up to 10 puffs can be used (nhs.uk, 2018). The advantages of salbutamol inhaler are that it is safe and effective with few side effects. It gives quick relief from breathing problems and it is also safe to use in pregnancy, and while breastfeeding. The main disadvantage for this is that asthma patient can have allergic reaction to salbutamol and for patient with digestive disorder of galactose intolerance.Injection is an effective route in the therapy of asthma. It is usually given by the doctor or nurse. The drug is administered under the skin or directly into the vein or muscle. The usual dose for an adult is 4 ?g/kg body weight and it is not suitable for children under 12 years old (Medicines.org.uk, 2018). Patients receiving injections have a more rapid recovery time (Tobin, 2005). The advantages are that injection help to relieve chest tightness, wheezing and cough, and used to treat severe breathing problems. The disadvantages are increasing in heart beating rate, hyperactivity, shaky and building up of acid.The essay highlighted the importance of salbutamol in the treatment of asthma, the amount of the drug reaching the airways to relieve asthma, how the patient uses the formulation effectively and the appropriate dosage that is not complying with prescription can result in high incidence of non-compliance and ineffective therapy. An oral tablet is a promising approach with a view of obtaining faster action; however, a good balance of the thickness of the tablet, hardness, friability, disintegration, and wetting time must be considered. Inhalation being a very old method of drug delivery is still a mainstay of respiratory care to relieve asthma. The inhaled formulation allows placing the drug directly to the target organs, which relief the asthma attack faster. The inhalation route also lower the systemic drug levels and has less adverse effect. Injection of salbutamol is used during the treatment of acute attack of asthma both in domiciliary and hospital practice. It is usually used as the second line of treatment after response to inhalation is unsatisfactory. There is a limited evidence that a combine treatment using the three types of formulations would have a better impact in asthma and the potential side effects of systemic salbutamol.References:1)     Lallemand Pharma. (2018). Lallemand Pharma. [online] Available at: http://www.lallemandpharma.com/334-million-people-suffer-from-asthma-worldwide/ [Accessed 27 Oct. 2018].2)     Gsk.com.au. (2013). PRODUCT INFORMATION VENTOLIN® CFC-FREE INHALER. 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