How Are Dosage Forms Used By Pharmacists?
Before drugs became available through mass production, pharmacists compounded medications for patients. Today, they still play a vital role in ensuring patients derive the most benefit from their medications. They dispense medicines in line with doctors’ prescriptions after safety-checking them to ensure they are no contraindications with the patient’s other drugs.
As the go-between for doctors and patients, pharmacists act as a support hub for both. They are familiar with the physicians’ methodologies and patients’ complete medical history. They may discuss the healing path with either party and alter the dosage form of the drugs. But what are dosage forms, and how do pharmacists use them?
This article defines dosage forms, describes the various types and examines the pharmacists’ role in altering and creating dosage forms from scratch.
Table of Contents
What are dosage forms?
The active ingredients of medicines are seldom administered in pure form. Instead, pharmaceutical manufacturers and pharmacists formulate them differently to ensure maximum patient efficacy. A variety of dosage forms are available, meaning patients take and absorb medicines in various formulations. The United States Pharmacopeia (USP) summarizes the available dosage forms as follows:
- Oral drugs: Medicines you swallow
- Transdermal or topical drugs: Medicines you apply via a skin cream or patch
- Inhaled drugs: Medications you inhale, such as asthma medications
- Mucosal drugs: Drugs that enter the body via the mucous membranes
The FDA lists nearly 200 dosage forms, which illustrates how pharmacists and medicine manufacturers ensure the active ingredients reach the appropriate areas with optimum safety and efficacy.
Dosage forms denote the delivery method by which the drugs reach the body, ensuring that absorption is easy for patients and that the medicine undergoes no alteration during the delivery. Drug manufacturers and pharmacists choose and create dosage forms to achieve the best treatment outcomes.
When formulating dosage forms, they want to achieve two goals:
- Make it as easy as possible for patients to take or use the drugs.
- Ensure the active ingredients maintain their efficacy during the delivery and reach and treat the target area easily and speedily.
Dosage form types
Think of the drug types you find in your local pharmacy or the drugs your physician has prescribed over the years. They come in different varieties, including:
- Tablets; chewable, soluble and insoluble
- Powders, crystals and granules
- Creams, gels, ointments, oils and lotions
- Elixirs, syrups and tinctures
- Patches and dressings
- Lozenges and pastilles
Pharmacists’ role in creating appropriate dosage forms
Pharmacists study drug administration in depth during their studies, whether through a pharmacy degree online, such as the one offered by the University of Findlay, or an on-campus degree program. Online programs, such as the University of Findlay’s Distance Doctor of Pharmacy, allow students to develop the expertise and skills to improve the quality of life for patients in their communities. Innovatively designed for distance learners, this program combines synchronous and asynchronous online coursework with experiential learning and on-campus immersions to build practical skills.
Pharmacists are likely to discover that, although efficient and convenient, mass-produced drugs do not always meet a patient’s needs. They know patients’ complete medical histories, so they may encounter cases where the prescribed dosage form isn’t appropriate. Physicians also come across the limitations of manufactured drugs and choose to customize dosage forms.
Why pharmacists may modify dosage forms
Pharmacists have several reasons for modifying dosage forms. If a patient presents with back pain and the doctor prescribes anti-inflammatory tablets, unaware of the patient’s stomach problems, the pharmacist will likely opt for the same anti-inflammatory agent but recommend a topical dosage form, such as a gel or cream instead. Pharmacists consider patients’ overall health and choose the most suitable option.
Pharmacists are often called on to change the dosage forms for patients on feeding tubes or with swallowing difficulties. Stroke patients, people with esophageal cancer, older people with reduced saliva production and children may find swallowing tablets impossible. In such cases, pharmacists’ step in and alter the dosage form.
They may deliver the active ingredients in a cream, liquid, suppository, patch, injection, inhalation, nebulization or via a lozenge.
Alternatively, they may recommend crushing tablets or opening capsules to allow patients to take the medicines in a more easily swallowable powder.
What pharmacists must consider when modifying dosage forms
Modifying dosage forms comes with a new set of responsibilities and parameters for pharmacists. For starters, they must be sure that the modification does not negatively impact the efficacy of the medicine. Secondly, the patient benefit must remain the same or improve to allow them to proceed with the modification. Thirdly, the dosage form modification must not produce any adverse effects.
If pharmacists recommend opening capsules or crushing tablets, they become liable because doing so falls outside the manufacturer’s field of responsibility.
Any modification may lead to a different absorption rate and potential adverse effects.
The behavior of the medicine’s active ingredient during the new delivery method plays a vital role in the dosage form choice. Here are some questions pharmacists must answer before opting to modify a dosage form:
- Is the new dosage form safe?
- Will the new dosage form produce the intended therapeutic outcomes?
- Is the new dosage form the most suitable and efficient delivery method?
- Is the new dosage form suitable for long-term application?
- Is the chosen dosage form therapeutically suitable for the patients in question when their overall health/mediation profile is considered?
- Does the new dosage form produce adverse reactions?
- Does the new dosage form cause contraindications with the patients’ other medicines?
- Will crushing tablets or opening capsules reduce the drug’s efficacy or cause adverse reactions?
Opening capsules or crushing tablets produces a range of risks, including contamination and loss of substance.
When switching from oral to transdermal delivery via an ointment or cream, pharmacists must calculate the absorption rate of the active ingredient. This process requires considerable expertise to ensure patients absorb and maintain the appropriate amounts.
Dosage form modification: A little-discussed everyday issue for pharmacists
Although pharmacists are often the first point of contact and determine the dosage form for patients, little research exists to document their experiences and perspective, especially on dosage form modification. They tackle complex patient issues daily, considering all aspects of health, illness and recovery. Understanding dosage forms and altering them to optimize patient benefits is just one challenge pharmacists encounter daily.