From Bitter to Better: How Capsules Improve Patient Acceptance of Medications
A number of factors can significantly affect medication acceptability, including product design, route of administration, dosage forms, taste, and appearance. These may sometimes be influenced by the physical and physiochemical properties of active ingredients or drugs. Among these factors, especially for the oral route of administration, taste, and odor have emerged as a major concern in pharmaceutical development, often posing a significant challenge due to the bitterness or unpleasant flavor of certain drugs and excipients. This inherent taste profile presents an often formidable task for formulators striving to create appealing products. In response to this critical aspect of healthcare, pharmaceutical companies are increasingly integrating criteria into their formulations aimed at improving medication acceptability while simultaneously preserving efficacy. These techniques involve employing strategies to mask or disguise the unpleasant taste and odor of medications, thereby enhancing their palatability and overall patient compliance.
Amidst this, capsules have emerged as a valuable tool in taste and odor masking, offering an ideal solution for administering bitter and unpleasant-tasting medications. By encapsulating medication within a protective layer, capsules prevent direct contact with the taste buds in the mouth, thereby increasing patient acceptability and - in turn - compliance.
Taste Masking in Oral Pharmaceuticals
The development of oral drug formulations demands meticulous attention to organoleptic properties, especially taste and palatability, given their significant impact on medication acceptability. They hold considerable importance not only in pharmaceuticals but also in gastronomical contexts, influencing consumer choice and adherence to medication regimens.
Pharmaceuticals typically consist of pure drugs combined with additives, some of which may impart a bitter or unpleasant taste that affects the medication’s overall palatability. This can lead to potential reluctance or even refusal to take medication, making it essential for pharmaceutical companies to address taste concerns. For instance, drugs like antibiotics, anti-inflammatories, analgesics, antiepileptics, anticoagulants, oral vaccines, and sex hormones often have a dominant taste that significantly impacts how patients experience them. This taste can create a negative perception, which can deter patients from complying with their treatment plans. Consequently, opting for better-tasting alternatives poses challenges for pharmaceutical companies in terms of maintaining patient adherence and therefore subsequent profitability.
Adherence problems are common among children and the elderly because of taste sensitivity. Children have more taste buds than adults, making them pickier about the flavor of medicines. On the other hand, the elderly often take multiple medications, which can make it harder for them to keep track and stick to their treatment plans. So, making medicines taste better is important to help them keep taking them regularly and get the best results from their treatment.
In this context, capsules stand out as vital for ensuring adherence to medication. Renowned for their long-standing presence and numerous benefits, capsules hold a top spot among traditional dosage forms. Their superiority is underscored by their exceptional palatability, valued since ancient times. Capsules offer a range of advantages, including versatility in formulation, space for innovation, an appealing appearance, and – notably - effective taste masking. With their ease of use and widespread acceptance, capsules clearly play a significant role in promoting medication adherence.
Factors Affecting the Taste of Pharmaceuticals
Taste indeed pertains to the capability to identify the flavor of a substance upon its entry into the mouth. This recognition takes place as the drug dissolves in saliva and interacts with the taste buds. Hence, even minute quantities of a drug with a potent, unpleasant taste can be discerned upon exposure to saliva. Following exposure, this perception is transmitted to the gustatory receptors, specialized cells located on the taste buds, which then trigger the sensation of taste.
In the case of pharmaceuticals there exist various parameters that can affect the overall taste of the formulation. These factors encompass the chemical structure of the active ingredient, the presence of functional groups, the solubility of the compound, its stability, concentration, and so on.
Many active pharmaceutical ingredients (APIs) inherently carry bitter or unpleasant flavors, as a result of their chemical composition. These taste attributes are intrinsic to the compound and are difficult to alter. Specific functional groups present within the molecular framework of APIs play a role in bitterness. For example, compounds featuring nitrogen or sulphur atoms may induce bitter tastes. These functional groups engage with taste receptors on the tongue, eliciting a bitter sensation. Furthermore, aromatic compounds, characterized by benzene rings or analogous structures, can also contribute to bitterness.
Certain additives or excipients possess the ability to chemically interact with the API, leading to alterations in its taste profile. These interactions may result in the formation of compounds with bitter or unpleasant tastes, thereby worsening taste-related difficulties in the formulation. Additionally, specific excipients are deliberately formulated to mask the taste of pharmaceuticals. However, there are occasions when these additives fail to adequately conceal the bitterness or unpleasantness of the drug, leading to a suboptimal taste experience for the patient.
The hydrophobicity or water-repellent nature of certain compounds can affect their taste. These molecules tend to interact more strongly with taste receptors on the tongue compared to hydrophilic molecules. When hydrophobic APIs come into contact with saliva, they may linger longer in the mouth, allowing for prolonged interaction with taste receptors.
Nevertheless, even with a comprehensive understanding of these compound characteristics, developers often encounter difficulties in significantly modifying the product to enhance its palatability, particularly during the developmental stage. This challenge is exacerbated by the paramount importance of ensuring the safety and efficacy of such compounds. This evaluation usually occurs in early-phase studies utilizing non-human primates, overlooking the palatability considerations frequently due to the absence of human subjects.
At times, the therapeutic effect takes primacy importance over palatability modifications, leading to neglect of additional enhancements. Additionally, the physicochemical attributes of the drug, including solubility, permeability, and stability, place constraints on formulation strategies aimed at taste enhancement.
However, in the current landscape, taste masking has become an essential aspect of development. Several methods are currently employed for the creation of palatable medications, some of which are outlined below.
Taste Masking Methods
Taste masking methods encompass both traditional and advanced approaches to mitigate the unpleasant taste of medications. Conventional methods typically involve incorporating sweeteners and flavor enhancers. Recent advancements offer sophisticated techniques such as pro-drugs, ion exchange resins, hot melt extrusion, solid dispersions, microencapsulation, spray drying, and coating. However, these methods often entail complex processes and additional ingredients, which can affect the development timeline and manufacturing costs.
In contrast, replacing taste masking methods with capsules offers a convenient alternative for enhancing medication palatability. By leveraging the inherent properties of capsules as a taste-masking dosage form, pharmaceutical developers can streamline formulation processes, enhance patient experience, and ultimately, promote better medication adherence and therapeutic outcomes.
Capsules for Effective Taste Masking
Capsules present a straightforward yet highly effective solution to the challenge of taste masking in pharmaceutical formulations. Their inherent capability to act as a barrier between the drug and taste receptors minimizes direct taste perception, particularly beneficial for medications with inherently bitter or unpleasant tastes. Examples include drugs like quinine, celecoxib, etoricoxib, levofloxacin, ofloxacin, sparfloxacin, ciprofloxacin, cefuroxime, erythromycin, clarithromycin, ibuprofen, where simple flavors or sweeteners may not suffice due to their overpowering taste profiles, the capsule encapsulation may provide an effective solution. Additionally, it also aids in masking odors, further enhancing patient acceptance. The design of capsules facilitates effortless carrying and administration, augmenting their attractiveness. This convenience factor plays a significant role in encouraging patients to stick to their medication regimen, contributing to improved treatment adherence and ultimately better health outcomes.
From a manufacturing standpoint, capsules stand out as the preferred choice in the pharmaceutical industry due to a number of core advantages. Their straightforward formulation process simplifies production, requiring fewer steps compared to complex taste masking processes. This reduction in complexity translates to saved time and resources during formulation development. Additionally, capsules offer cost-effectiveness, attributed to efficient manufacturing processes, making them a financially viable option for pharmaceutical companies. Furthermore, the ease of preparation enhances efficiency on the manufacturing line. Capsules can be filled with precision and consistency, minimizing production errors and maximizing output. Importantly, capsules eliminate the need for additional taste masking additives or coating agents, simplifying the formulation, and reducing the risk of potential interactions or side effects. It also maintains the bioavailability of the medication, ensuring optimal delivery of active ingredients without compromising absorption or efficacy due to their inert nature.
In medication formulation, the dose of the specific drug utilized to treat the ailment holds significant importance. For instance, with low-dose drugs, there is ample space to adjust the taste profile of the formulation by incorporating additional excipients. However, high-dose drugs pose a challenge due to limited space for supplementary excipients. In such cases, capsules emerge as the optimal choice. It offers the flexibility to accommodate the drug without the need for extra excipients, effectively fulfilling their role in taste masking and pharmaceutical delivery.
Furthermore, capsules represent a versatile option for pharmaceutical delivery, facilitating various formulation modifications to meet specific needs. In addition to providing a physical barrier, capsules can function as suitable containers to deliver the drug to the intended site of action. If necessary for the enhanced formulation need, it can encapsulate taste-masking agents or coated drug particles, further reducing the likelihood of taste detection until the capsule dissolves in the gastrointestinal tract. This additional safeguard shields patients from unpleasant pharmaceutical tastes, streamlining taste masking while bolstering patient acceptance and adherence through the familiar and more palatable dosage form.
In addition to their formulation flexibility, capsules offer a notable array of customization options. They possess the versatility to accommodate a wide range of drug formulations, encompassing immediate-release, extended-release, and modified-release variants, all while retaining their taste-masking properties. Moreover, capsules can be tailored with varying shell compositions, sizes, and colors. These present opportunities for personalized medication delivery, which aligns precisely with consumers’ preferences and requirements.
The capsule shell, typically composed of materials such as gelatin, HPMC, or acrylate polymers, serves as a protective barrier for the encapsulated drug. This polymer shell is widely favored in pharmaceutical capsules for its ability to form a sturdy, flexible, and taste-neutral enclosure. HPMC capsules, for instance, are renowned for effectively masking the taste of drugs, ensuring a seamless and pleasant swallowing experience for patients.
Moreover, with recent advancements, the capsule shell itself can undergo further modifications to incorporate flavors if desired. Capsule formulation allows for the addition of flavoring agents, enabling the outer membrane to impart a specific taste to the medication. These flavored capsules offer an additional dimension of customization, enhancing patient acceptability and compliance by catering to individual taste preferences.
Summary
In the rapidly evolving therapeutic landscape, patients are becoming increasingly discerning about their choices, even within the pharmaceutical sector. The medication acceptability is becoming essential during product development, particularly considering the taste and palatability of oral pharmaceuticals. Despite being the simplest method of pharmaceutical administration, oral formulations have demonstrated effectiveness in delivering both simple and complex molecules. However, to enhance formulation acceptability and align with industry trends focusing on palatability, numerous adaptations have been made.
A successful oral dosage form should not only be effective but also enhance palatability and garner patient acceptance. The pharmaceutical industry has significantly contributed to meeting these objectives through various methods. Among these, capsule dosage forms emerge as a straightforward yet effective solution. Leveraging their inherent properties, capsules improve taste perception and increase patient acceptance, making them a preferred option for delivering medications effectively while ensuring a positive patient experience. With the simplicity and effectiveness of capsule formulations, they have become an effective means to enhance palatability and acceptability in pharmaceuticals.
Author Details
Jnanadeva Bhat- Head-R&D-Formulation development (Pharma & Nutra), ACG; Manali Dalvi- Lead-R&D-Whitepaper and publications; (Pharma & Nutra), ACG
Publication Details
This article appeared in American Pharmaceutical Review:
Vol. 27, No. 5
July/Aug 2024
Pages: 55-57