Innovations in Chewable Formulations: The Novelty and Applications of 3D Printing in Drug Product Design

Since their introduction, chewable dosage forms have gained traction due to their ability to facilitate swallowing, especially in paediatric, geriatric and dysphagia patients. Their benefits stretch beyond human use to also include veterinary applications, improving administration and palatability in different animal species. Despite their advantages, current chewable formulations do not account for individualised dosing and palatability preferences. In light of this, three-dimensional (3D) printing, and in particular the semi-solid extrusion technology, has been suggested as a novel manufacturing method for producing customised chewable dosage forms. This advanced approach offers flexibility for selecting patient-specific doses, excipients, and organoleptic properties, which are critical for ensuring efficacy, safety and adherence to the treatment. This review provides an overview of the latest advancements in chewable dosage forms for human and veterinary use, highlighting the motivations behind their use and covering formulation considerations, as well as regulatory aspects.

Chewing Gums as a Drug Delivery Approach for Oral Health

Background

Drug delivery approaches with the shortest therapeutic period and the lowest side effects have always been considered a sublime target in the medical sciences. Among many delivery methods, chewing gum could be perceived as a promising drug carrier that can carry several types of drugs for oral health. These drug carriers could represent optimal therapeutic time and lower side effects due to their sustained release capability and lower required thresholds for the drug compared with other delivery approaches. The convenient use in the oral cavity's local environment and the ability to locally carry multiple drugs are considered the main advantages of this delivery approach.

Aim

This review aimed to explore chewing gum as a promising drug carrier that can carry several types of drugs for oral health.

Materials and Methods

Articles were searched for on PubMed, ISI, SCOPUS, Google Patents, the Royal Society of Chemistry website, and electronic databases using MESH terms and the following keywords: ("Gum" OR "Chewing gum") and ("Drug delivery OR Drug delivery systems") in the English language. No time limit was applied, and all documents as of August 30th, 2020 were retrieved.

Results

Gum-drug interactions, mechanisms of release, and formulations of the drugs might all play a role in this versatile delivery method. Accordingly, chewing gum-based carriers may be presented as a plausible candidate for drug delivery in oral diseases.

Conclusion

Gum-driven drugs could be introduced as promising candidates for treating oral diseases due to their ability to deliver the proper local dosages of active ingredients, short contact time, biocompatibility, and biodegradable chemical structures.

An empirical study of the use of Chewing Gum by Youth as a replacement to Cigarette addiction

The current study aimed to add to this of knowledge by examining the effect of chewing gum on smoking withdrawal severity over a long period, as well as identifying the specific characteristics of chewing gum that may be responsible for the reported reductions in withdrawal. Chewing, flavour, and the combination of the two were all investigated separately. The study is based on quantitative research. The data has been classified on basis of smoker and non-smoker. Participants reported a significant difference in withdrawal severity across conditions using repeated measures Chi square, F(3, 69)=2.89, p.05. The flavoured gum condition had considerably lower withdrawal scores than the flavourless gum base and no product control conditions, according to follow-up analyses. These data suggest that chewing gum is effective in reducing the severity of nicotine withdrawal symptoms over a 24-hour period of nicotine abstinence, and that the impact is due to a combination of flavour and chewing. These findings, together with findings from previous laboratory studies, show that chewing gum could be a useful coping mechanism for those who are trying to quit smoking. 

Chewing gum reduces visually induced motion sickness

Visually induced motion sickness (VIMS) is a common side-effect of exposure to virtual reality (VR). Its unpleasant symptoms may limit the acceptance of VR technologies for training or clinical purposes. Mechanical stimulation of the mastoid and diverting attention to pleasant stimuli-like odors or music have been found to ameliorate VIMS. Chewing gum combines both in an easy-to-administer fashion and should thus be an effective countermeasure against VIMS. Our study investigated whether gustatory-motor stimulation by chewing gum leads to a reduction of VIMS symptoms. 77 subjects were assigned to three experimental groups (control, peppermint gum, and ginger gum) and completed a 15-min virtual helicopter flight, using a VR head-mounted display. Before and after VR exposure, we assessed VIMS with the Simulator Sickness Questionnaire (SSQ), and during the virtual flight once every minute with the Fast Motion Sickness Scale (FMS). Chewing gum (peppermint gum: M = 2.44, SD = 2.67; ginger gum: M = 2.57, SD = 3.30) reduced the peak FMS scores by 2.05 (SE = 0.76) points as compared with the control group (M = 4.56, SD = 3.52), p < 0.01, d = 0.65. Additionally, taste ratings correlated slightly negatively with both the SSQ and the peak FMS scores, suggesting that pleasant taste of the chewing gum is associated with less VIMS. Thus, chewing gum may be useful as an affordable, accepted, and easy-to-access way to mitigate VIMS in numerous applications like education or training. Possible mechanisms behind the effect are discussed.

Development of a Chewing Robot With Built-in Humanoid Jaws to Simulate Mastication to Quantify Robotic Agents Release From Chewing Gums Compared to Human Participants

Medicated chewing gum has been recognised as a new advanced drug delivery method, with a promising future. Its potential has not yet been fully exploited because currently there is no gold standard for testing the release of agents from chewing gum in vitro. This study presents a novel humanoid chewing robot capable of closely replicating the human chewing motion in a closed environment, incorporating artificial saliva and allowing measurement of xylitol release from the gum. The release of xylitol from commercially available chewing gum was quantified following both in vitro and in vivo mastication. The chewing robot demonstrated a similar release rate of xylitol as human participants. The greatest release of xylitol occurred during the first 5 minutes of chewing and after 20 minutes of chewing only a low amount of xylitol remained in the gum bolus, irrespective of the chewing method used. Saliva and artificial saliva solutions respectively were collected after 5, 10, 15 and 20 minutes of continuous chewing and the amount of xylitol released from the chewing gum determined. Bioengineering has been implemented as the key engineering strategy to create an artificial oral environment that closely mimics that found in vivo. These results demonstrate the chewing robot with built-in humanoid jaws could provide opportunities for pharmaceutical companies to investigate and refine drug release from gum, with reduced patient exposure and reduced costs using this novel methodology.

Formulation development of medicated chewing gum tablets by direct compression using the SeDeM-Diagram-Expert-System

Medicated chewing gums represent an orally administered dosage form with promising potential for local and systemic drug delivery. However, compared to other solid oral dosage forms, formulation development and release mechanism of medicated chewing gums are extremely complex, and thus only few products reached the approval for the market so far. Therefore, Quality by Design (QbD) approaches for rational formulation development of medicated chewing gums are needed to utilize their full potential. For chewing gum tablets, which are manufactured by direct compression, QbD approaches derived from tableting processes might be exerted. In this context, the SeDeM-Diagram-Expert-System implements the QbD approach while indicating whether a blend is suitable for direct compression and comprises powder properties, which need to be improved to facilitate the formulation development. Here, we present the successful application of the SeDeM-Diagram-Expert-System to the formulation development of medicated chewing gum tablets manufactured by direct compression. Furthermore, limitations of the SeDeM-System for medicated chewing gum tablets are evaluated and potential modifications of the system are suggested and discussed for future use.

Medicated Chewing Gums (MCGs): Composition, Production, and Mechanical Testing

Medicated chewing gums (MCGs) represent a unique platform for drug delivery. They have been defined as solid single-dose preparations, which may contain more than one active pharmaceutical ingredient (API) with base consisting primarily of gum that has to be chewed for a certain period of time. They mainly contain a tasteless masticatory gum base as the core with other minor nonmasticatory ingredients, such as flavors and sweeteners. Despite their advantages in drug delivery, MCGs remain a niche product due to the complexity of their formulation, lack of acceptable testing methods, and intricacy of their manufacturing. Few studies have been reported on their use, and most of the information on their composition and production could be found in patent search. The aim of this review is to provide an overview of gum composition, manufacturing process, and characterization. Due to the scarcity of studies concerning the evaluation of the mechanical properties of MCGs, greater emphasis was placed on the available performance tests and procedures for the estimation of their mechanical and textural properties. While very few tests have been recommended by the official pharmacopeias, several tests have been suggested for assessing the mechanical properties of MCGs in vitro. Properties, such as chewiness, elasticity, and firmness, of chewing gums during mastication are imperative quality attributes that have been found to strongly correlate with gum composition and mouth feel.

Formulation development and evaluation of medicated chewing gum of anti-emetic drug

Context: Medicated chewing gum (MCG) of Domperidone Maleate (DM) was developed by direct compression method with the goal to achieve quick onset of action and to improve patient compliance. Objective: Formulation development of MCG of DM and optimization of the formulation by screening of different excipients. Material and methods: MCG containing DM was prepared by screening different concentrations of sweeteners, flavouring agents, softening agents, lubricants and anti-adherents by changing one variable at a time. Performance evaluation was carried out by evaluating size, shape, thickness, taste, scanning electron microscopy, texture analysis, in vivo drug release study, ex vivo buccal permeation study and by studying statistical analysis for quality. Results and discussion: The statistical analysis showed significant improvement in organoleptic properties such as chewable mass, product taste, product consistency, product softness, total flavour lasting time and pharmaceutical properties like micromeritic properties after incorporation of appropriate excipients in an optimum amount in final optimized MCG formulation. In vivo drug release study showed 97% DM release whereas ex vivo buccal permeation study through goat buccal mucosa exhibited 11.27% DM permeation within 15 min indicating its potential for increasing bioavailability by decreasing time of onset. The optimized formulation showed good surface properties and the peak load required for drug release was found to be acceptable for crumbling action. Conclusion: The developed formulation of medicated chewing gum can be a better alternative to mouth dissolving and conventional tablet formulation. It may be proved as a promising approach to improve the bioavailability as well as to improve patient compliance.

The relative bioavailability of loratadine administered as a chewing gum formulation in healthy volunteers

OBJECTIVE

The aim of this study was to investigate the pharmacokinetics of loratadine and its active metabolite desloratadine after single-dose administration of loratadine as a conventional tablet, orally disintegrating tablet (smelt tablet) and a chewing gum formulation with and without the collection of saliva.

METHODS

Twelve healthy male volunteers participated in a four-period cross-over trial evaluating the effect of dosage forms on the pharmacokinetics of a single dose of loratadine. Loratadine was administered as two 10-mg conventional tablet, two 10-mg smelt tablet, a 30-mg portion of medicated chewing gum without collection of saliva and a 30-mg portion of medicated chewing gum with collection of saliva. Blood samples were taken at predefined sampling points 0-24 h after medication, and the plasma concentrations of loratadine and desloratadine were determined by high-performance liquid chromatography. Each study period was separated by a wash-out period of at least 7 days.

RESULTS

The mean dose-corrected area under the plasma concentration-time curve extrapolated to infinity AUC(0-infinity) for the chewing gum formulation was statistically significantly increased compared to the tablet formulation (geometric mean ratio: 2.68; 95%CI: 1.75-4.09). Desloratadine pharmacokinetic parameters from the chewing gum formulation were not statistically significantly different from the conventional tablet. Neither loratadine nor desloratadine pharmacokinetics of the smelt tablet formulation were statistically significantly different from the conventional tablet formulation. Plasma concentrations of desloratadine following the administration of loratadine as chewing gum with saliva collection were very low.

CONCLUSION

Our study showed that formulation of loratadine as a medicated chewing gum results in an almost threefold increase in relative bioavailability. This is most likely due to a bypass of first-pass metabolism as this study suggests that approximately 40% of the absorbed loratadine was absorbed via the oral mucosa.