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Oral formulations
In the UK, the oral route of drug administration is used commonly. Oral formulations include: tablets (including chewable, soluble and oro-dispersible tablets), capsules, liquids (including syrups and suspensions), sublingual tablets and sprays, buccal tablets and liquids, lozenges and gums, and oral granules and powders.
Tablets and capsules
This chapter outlines a practical method for swallowing tablets and capsules. However, there are a number of techniques that may be employed if this method is unsuccessful. These may include:
ā¢ adding some soft food to your mouth and swallowing the food and tablet/capsule together
ā¢ drinking water through a straw when swallowing the tablet/capsule
ā¢ inserting the tablet/capsule into a cube of bread or other soft food item, e.g. yoghurt, and swallowing together.1
Some medication interacts or is incompatible with certain foodstuffs; therefore it is important to check with the summary of product characteristics (SPC) or the patient information leaflet to ensure safe and effective administration.
Some tablets have coatings that influence their release characteristics, e.g. film, sugar, enteric or modified release. These may have been designed to release the drug in the small intestine or to bypass drug release in the stomach. Coatings may also be used to protect the stomach from the drug, e.g. NSAIDs, or protect the drug from the acidic environment in the stomach, e.g. sulfasalazine. Some may also have been designed to release drug gradually over a prolonged period of time, e.g. diltiazem modified release tablets.
Tablets are available in chewable, oro-dispersible (allowed to dissolve on the tongue) and soluble versions. Although water is not needed to take oro-dispersible tablets, a lack of saliva may affect the rate of disintegration and dissolution.2
Oro-dispersible tablets are usually delicate and should be handled carefully, to avoid damaging the tablet prior to administration. They often come in packaging that requires additional mechanical strength to protect them and for the patient to peel back the film rather than āpoppingā the tablet out.
Soluble tablets often have a high sodium content, which may be unsuitable for certain groups of patient, e.g. those with uncontrolled hypertension and renal disease.3,4
The benefits of tablets and capsules are that they are convenient and discreet; therefore they are favoured by many patients in the UK. Tablets can be designed to release drugs slowly and they are generally classed as relatively stable formulations, with regards to microbiology and their physical and chemical characteristics. They are relatively cheap to manufacture and have a long shelf-life.
A disadvantage of tablets is that they can be challenging for patient groups who have dysphagia or difficulties with swallowing. Taste masking can be difficult for certain drugs. Capsules may contain gelatine, derived from animals, which may be unacceptable to certain patient groups, e.g. vegetarians, vegans, some religious denominations.
Aids are available to crush or halve tablet formulations where necessary. This may be useful to ease administration, e.g. in patients with dysphagia, or to provide a dose that is not available commercially. Consideration should be made to formulations with coatings and special release mechanisms, as they may be less suitable for crushing and halving. In such circumstances, it is advisable to seek guidance from the relevant patient information leaflet.
Oral liquids
Oral liquids are particularly useful for administering drugs to some patient groups, e.g. the young and elderly, who have difficulties swallowing solid oral dosage forms. There are many different types of oral liquids, including: syrups, suspensions, solutions, drops, emulsions, mixtures, linctuses and elixirs. There are difficulties with oral liquids, such as increased formulation costs, manufacturing and distribution challenge. They often have short shelf-lives compared to solid oral dosage forms, and require further microbiological considerations. However, liquids do allow dosage flexibility and taste masking can be utilised.
When oral liquids are packaged in multi-dose containers, they may have different expiry dates once they have been opened. It is therefore recommended to refer to the specific manufacturerās instructions for this information. It is good practice to mark the container with the date of opening when dispensing or administering from a multi-dose container, as this will allow expiry dates to be observed.
Oral liquids, with the exception of homogenous solutions, should be shaken well before use. This will ensure uniformity of the product, and thus delivery of an accurate dose.
When liquids are poured into glass containers, they curve at the edges and down at the centre. To measure the accurate volume of a liquid, you should observe the level at which the meniscus (bottom of the curvature) sits. This should be measured at eye-line.
When pouring liquids to measure doses, it is good practice for the patient to place their hand over the label of the liquid. This helps to minimise liquid spillage, and therefore damage to the pharmacy label.
The conventional methods of administering oral liquids are via medicine spoon, oral syringe and measuring cup.
The 5mL spoon is the most commonly available medicine spoon. However, some medicine spoons are graduated and marked with doses other than the standard 5mL volume measurement. Patients should be advised to familiarise themselves with the graduations on medicine spoons to ensure optimal and safe dosing. In addition, some spoons have a smaller end with a capacity to measure a volume of 2.5mL. This may be used or, alternatively, an oral syringe may be preferred. When measuring liquid doses using a medicine spoon, it is recommended to measure a level spoonful to avoid spillages and promote accurate dosing. Patients should only use the provided medicine spoons when prescribed a dose of āa spoonfulā. This is because research has shown that household teaspoons can vary in volume capacity from 2.5mL to 7.3mL.5
Oral syringes are available in different sizes with different dosing graduations. The most common oral syringes available are 1...