Development and optimization of taste-masked orally disintegrating tablets (ODTs) of clindamycin hydrochloride

Taste-masking methods in multiparticulate dosage forms with a focus on poorly soluble drugs

In the past, the administration of medicines for children mainly involved changes to adult dosage forms, such as crushing tablets or opening capsules. However, these methods often led to inconsistent dosing, resulting in under- or overdosing. To address this problem and promote adherence, numerous initiatives, and regulatory frameworks have been developed to develop more child-friendly dosage forms. In recent years, multiparticulate dosage forms such as mini-tablets, pellets, and granules have gained popularity. However, a major challenge that persists is effectively masking the bitter taste of drugs in such formulations. This review therefore provides a brief overview of the current state of the art in taste masking techniques, with a particular focus on taste masking by film coating. Methods for evaluating the effectiveness of taste masking are also discussed and commented on. Another important issue that arises frequently in this area is achieving sufficient dissolution of poorly water-soluble drugs. Since the simultaneous combination of sufficient dissolution and taste masking is particularly challenging, the second objective of this review is to provide a critical summary of studies dealing with multiparticulate formulations that are tackling both of these issues.

Solvent-free method for masking the bitter taste of azithromycin dihydrate using supercritical fluid technology

INTRODUCTION AND PURPOSE

The unpleasant extremely bitter taste of the orally administered broad-spectrum antibiotic azithromycin decreases patient compliance, especially in pediatrics. This issue can be overcome by decreasing drug interaction with the tasting buds using insoluble polymers at salivary pH (6.8 - 7.4), like the cationic polymer Eudragit EPO. Supercritical fluid technology is a green synthesis method for preparing pharmaceutical preparations that replace organic solvents with safe supercritical CO2. This study aimed to mask the bitter taste of azithromycin using the supercritical fluid method and a pH-sensitive Eudragit EPO polymer.

METHODS

A foaming process was investigated for preparing a formulation (TEST), which comprises treating the polymer with supercritical carbon dioxide (CO2) fluid to prepare a taste-masked dosage form without employing organic solvents or flavors.

RESULTS

The use of the supercritical technique at 40 °C and 10 MPa for 2 h allowed the manufacturing of solvent-free polymeric foam with azithromycin dispersions; the average calculated percentage of apparent volume change was 62.5 ± 5.9% with an average pore diameter of 34.879 Å. The formulated sample showed low drug release in simulated salivary fluid while keeping its crystalline nature. Moreover, clinical studies on healthy subjects showed that the formula successfully masked azithromycin's bitter taste.

CONCLUSIONS

Overall, it has been shown herein that the supercritical fluid technology foaming method is promising in masking the bitter taste of bitter ingredients.

An Overview of Taste-Masking Technologies: Approaches, Application, and Assessment Methods

It is well-known that plenty of active pharmaceutical ingredients (API) inherently possess an unpleasant taste, which influences the acceptance of patients, especially children. Therefore, manufacturing taste-masked dosage forms has attracted a lot of attention. This review describes in detail the taste-masking technologies based on the difference in the taste transmission mechanism which is currently available. In particular, the review highlights the application of various methods, with a special focus on how to screen the appropriate masking technology according to the properties of API. Subsequently, we overviewed how to assess taste-masking efficacy, guiding researchers to rationally design taste-masking formulations.

Pharmacological Effects and Clinical Prospects of Cepharanthine

Cepharanthine is an active ingredient separated and extracted from Stephania cepharantha Hayata, a Menispermaceae plant. As a bisbenzylisoquinoline alkaloid, cepharanthine has various pharmacological properties, including antioxidant, anti-inflammatory, immunomodulatory, antitumoral, and antiviral effects. Following the emergence of coronavirus disease 2019 (COVID-19), cepharanthine has been found to have excellent anti-COVID-19 activity. In this review, the important physicochemical properties and pharmacological effects of cepharanthine, particularly the antiviral effect, are systematically described. Additionally, the molecular mechanisms and novel dosage formulations for the efficient, safe, and convenient delivery of cepharanthine are summarized.

Creating Acceptable Tablets 3D (CAT 3D): A Feasibility Study to Evaluate the Acceptability of 3D Printed Tablets in Children and Young People

3D printing (3DP) has been proposed as a novel approach for personalising dosage forms for children and young people (CYP). Owing to its low cost and the lack of need for finishing steps, fused deposing modelling (FDM) 3DP has been heavily researched in solid dosage forms (SDFs) manufacturing. However, the swallowability and overall acceptability of 3D printed dosage forms are yet to be established. This work is the first to evaluate the acceptability of different sized 3D printed placebo SDFs in CYP (aged 4–12 years). All participants had previously participated in a feasibility study (CAT study) that assessed the swallowability and acceptability of different sized GMP manufactured placebo conventional film-coated tablets, and therefore only attempted to swallow one 3D printed tablet. The participants assessed the swallowability, acceptability, mouthfeel, volume of water consumed, and taste of the sample using a 5-point hedonic facial scale on a participant questionnaire. A total of 30 participants were recruited, 87% of whom successfully swallowed the 3D printed tablet that they attempted to take. Attributes of the 3D printed tablets were scored as acceptable by the following percentage of participants—swallowability (80%), mouthfeel/texture (87%), the volume of water consumed (80%), taste (93%), and overall acceptability (83%). Overall, 77% of children reported they would be happy to take the tablet every day if it was a medicine. Participants were also asked which tablets felt better in the mouth—the film-coated tablets or the 3D printed tablets, and the most popular response (43%) was that both were acceptable. This study shows that FDM-based 3D printed SDFs may be a suitable dosage form for children aged 4–12 years. The results from this feasibility study will be used to inform a larger, definitive study looking at the acceptability of 3D printed tablets in children.

Formulation and Quality Control of Orally Disintegrating Tablets (ODTs): Recent Advances and Perspectives

Orally disintegrating tablets (ODTs) rapidly disintegrate or dissolve in the oral cavity without using water. Demand for ODTs has increased, and the field has overgrown in the pharmaceutical industry and academia. It is reported that ODTs have several advantages over other conventional tablets. Since some of them are absorbed from the mouth, pharynx, and esophagus as the saliva passes down into the stomach, in such cases, the bioavailability of the drug improves meaningfully. Furthermore, the immediate release property of ODTs makes them a popular oral dosage form in patients with swallowing challenges, children, and for cases with a need for rapid onset of action. The current review article explains the features of active ingredients and excipients used in the formulation of ODTs, discusses multiple ODT formulation and preparation techniques with their merits and demerits, and also, offers remedies for problems associated with ODTs. Moreover, quality control steps and required considerations are presented.

Orodispersible tablets for pediatric drug delivery: current challenges and recent advances

INTRODUCTION

Child appropriate dosage forms are indispensable in modern medicine and are a prerequisite for successful pediatric drug therapy. For years, experts have called for a paradigm shift, from liquid dosage forms to novel oral solid dosage forms. This review aims to shed light on recent developments in Orodispersible tablets (ODTs) and mini-tablets (ODMTs).

AREAS COVERED

This review focuses on the presentation and critical discussion of current challenges as well as recent advances in ODTs for pediatric drug delivery. Highlighted aspects are the evidence for acceptability by children, e.g. in comparison to other dosage forms, and limitations given by tablet size at different ages, as well as advances in special ODT formulations (taste masking, modified release, enabling formulations).

EXPERT OPINION

It is the authors' belief that OD(M)Ts have significant potential as dosage forms in pediatric therapy that has not yet been fully exploited. The reasons for this are, first, that the number of direct acceptance studies is extremely low and the resulting knowledge is therefore rather anecdotal. Despite the high relevance, there seems to be reluctance both in the therapeutic use and conduction of respective studies in children. However, if one combines the knowledge from the few existing studies, surveys, and from approved products, it becomes apparent that so far there is no evidence on limitations of the use of ODTs in pediatric patients.

Salt Engineering of Aripiprazole with Polycarboxylic Acids to Improve Physicochemical Properties

Aripiprazole (APZ) has poor physicochemical properties and bitter taste. The current study aimed to prepare salts of APZ with polycarboxylic acids (citric, malic, and tartaric acids) to improve physicochemical properties and impart sour taste to the drug. The salts were prepared by solubilization-crystallization method, and characterized by electron microscopic, spectroscopic, diffractometry, and thermal methods. The salts were assessed for pH solubility, pH-stability, dissolution, and solid-state stability. Fourier transformed infrared, X-ray powder diffraction, and differential scanning calorimetry data indicated formation of new solid phases. APZ and the salts exhibited pH-dependent solubility. The pH solubility curve shape was inverted "V," inverted "W," and inverted "U" for APZ, APZ-Citrate, and APZ-Malate and APZ-Tartrate, respectively. Compared to APZ, the solubility of salts at pH 4, 5, and 6 was 3.6-7.1, 23.9-31.5, and 143.4-373.3 folds of APZ. Increase in solubility in water by citrate, malate, and tartrate salts was 5562.8, 21,284.7, and 22,846.7 folds of APZ. The salt formation also leads to an increase in rate and extent of dissolution. The dissolution extent was 3.5 ± 0.5, 71.3 ± 1.2, 80.1 ± 6.2, and 86.1 ± 1.1% for APZ, APZ-Citrate, APZ-Malate, and APZ-Tartrate, respectively. Liquid and solid-state stabilities of the salts were comparable to APZ. In conclusion, salts of APZ with polycarboxylic acids improved solubility, and dissolution, and impart sour taste, which may improve palatability of the drug.

Lipids for Taste masking and Taste assessment in pharmaceutical formulations

Pharmaceutical products often have drawbacks of unacceptable taste and palatability which makes it quite difficult for oral administration to some special populations like pediatrics and geriatrics. To curb this issue different approaches like coating, granulation, extrusion, inclusion complexation, ion-exchange resins, etc for taste masking are employed and among them use of lipids have drawn special attention of researchers. Lipids have a lower melting point which is ideal for incorporating drugs in some of these methods like hot-melt extrusion, melt granulation, spray drying/congealing and emulsification. Lipids play a significant role as a barrier to sustain the release of drugs and biocompatible nature of lipids increases their acceptability by the human body. Further, lipids provide vast opportunities of altering pharmacokinetics of the active ingredients by modulating release profiles. In taste sensors, also known as electronic tongue or e-tongue, lipids are used in preparing taste sensing membranes which are subsequently used in preparing taste sensors. Lipid membrane taste sensors have been widely used in assessing taste and palatability of pharmaceutical and food formulations. This review explores applications of lipids in masking the bitter taste in pharmaceutical formulations and significant role of lipids in evaluation of taste and palatability.

Recent Formulation Advances and Therapeutic Usefulness of Orally Disintegrating Tablets (ODTs)

This review highlights the recent formulation advances (different methods of preparation involving various novel approaches) that have been advancing the use of ODT as a popular dosage form. Furthermore, the important characteristics of ODTs that are required for patient compliance and appropriate therapeutic benefit are discussed. In addition to conventional ODTs, ODTs formulated for controlled release of pharmaceuticals and taste masking are also discussed.

In Vivo Drug Dissolution in Human Oral Cavity from Orally Disintegrating Tablet and Comparability with in Vitro Testing

We examined the amlodipine dissolution from orally disintegrating tablets (ODTs) in vivo in the human oral cavity. Additionally, 5 different in vitro short dissolution test methods (Tricorptester, magnetic stirrer, rotating injection syringe, paddle apparatus, shaking) were used to evaluate dissolution and the results were compared to those obtained with the human volunteers. Various amlodipine ODTs with different levels of physical masking effectiveness were manufactured using the RACTAB^® technique. Quantitative findings showed that amlodipine dissolution from ODT was dependent on time in the oral cavity and the amount of coating applied for physical masking. We also found that dissolution in the oral cavity was best correlated to that in in vitro short dissolution tests with a time period of 30 s. For more detailed evaluations, mean prediction error, mean absolute error, and root mean square error values were calculated, each of which was lowest with the Tricorptester method among all of the investigated test methods. Our results indicate that mimicking of the inside of the human oral cavity is accurate with a testing time of 30 s, while the Tricorptester method was the most preferable of all in vitro tests investigated in this study.

Challenges and innovations of drug delivery in older age

Both drug delivery performance and various age-related physical, mental and physiological changes can affect drug effectiveness and safety in elderly patients. The many drug delivery systems developed over the years include recent novel transdermal, nasal, pulmonary and orally disintegrating tablets that provide consistent, precise, timely and more targeted drug delivery. Certain drug delivery systems may be associated with suboptimal outcomes in the elderly because of the nature of drug present, a lack of appreciation of the impact of age-related changes in drug absorption, distribution and clearance, the limited availability of pharmacokinetic, safety and clinical data. Polypharmacy, patient morbidity and poor adherence can also contribute to sub-optimal drug delivery systems outcomes in the elderly. The development of drug delivery systems for the elderly is a poorly realised opportunity, with each system having specific advantages and limitations. A key challenge is to provide the innovation that best meets the specific physiological, psychological and multiple drug requirements of individual elderly patients.

A novel and discriminative method of in vitro disintegration time for preparation and optimization of taste-masked orally disintegrating tablets of carbinoxamine maleate

The primary objective of this study was to mask bitter taste and decrease the disintegration time of carbinoxamine maleate (CAM) orally disintegrating tablets (ODTs). In order to screen the prescription of ODTs, a novel modified in vitro disintegration method (MIVDM) was developed to measure the in vitro disintegration time. In this method, different concentrations of ethanol served as disintegration medium in order to delay the in vitro water absorption and disintegration process of tablets. The MIVDM demonstrated good in vitro and in vivo correlation and proved more precise and discriminative than other reported methods. In this research, ion exchange resins (IERs) were used to mask bitter taste for improving mouthfeel. The drug-resin ratio and reaction temperature were investigated to obtain the optimum carbinoxamine resin complexes (CRCs). The characterization of CRCs revealed an amorphous state. ODTs were prepared by direct compression. Superdisintegrants and diluents of ODTs were screened first. Further optimization was carried out by using Box-Behnken design. The effect of (X₁) mannitol/microcrystalline cellulose ratio, (X₂) the amount of low-substituted hydroxypropylcellulose and (X₃) the hardness was investigated for achieving the lowest (Y) in vitro disintegration time. Technological characterization, wetting time, water absorption ratio, and roughness degree were evaluated. The CRCs and ODTs proved successful taste-masking efficiency. The end product improved patients' compliance. The developed MIVDM was practical for commercial use.

In vitro and in vivo investigation of taste-masking effectiveness of Eudragit E PO as drug particle coating agent in orally disintegrating tablets

CONTEXT

Considering that bitter taste of drugs incorporated in orally disintegrating tablets (ODTs) can be the main reason for avoiding drug therapy, it is of the utmost importance to achieve successful taste-masking. The evaluation of taste-masking effectiveness is still a major challenge.

OBJECTIVE

The objective of this study was to mask bitter taste of the selected model drugs by drug particle coating with Eudragit^® E PO, as well as to evaluate taste-masking effectiveness of prepared ODTs using compendial dissolution testing, dissolution in the small-volume shake-flask assembly and trained human taste panel.

MATERIALS AND METHODS

Model drugs were coated in fluidized bed. Disintequik™ ODT was used as a novel co-processed excipient for ODT preparation. Selected formulations were investigated in vitro and in vivo using techniques for taste-masking assessment.

RESULTS AND DISCUSSION

Significantly slower drug dissolution was observed from tablets with coated drug particles during the first 3 min of investigation. Results of in vivo taste-masking assessment demonstrated significant improvement in drug bitterness suppression in formulations with coated drug. Strong correlation between the results of drug dissolution in the small-volume shake-flask assembly and in vivo evaluation data was established (R ≥ 0.970).

CONCLUSION

Drug particle coating with Eudragit^® E PO can be a suitable approach for bitter taste-masking. Strong correlation between in vivo and in vitro results implicate that small-volume dissolution method may be used as surrogate for human panel taste-masking assessment, in the case of physical taste-masking approach application.

Preparation of polymer-blended quinine nanocomposite particles by spray drying and assessment of their instrumental bitterness-masking effect using a taste sensor

CONTEXT

The development of taste-masking technologies for foods and drugs is essential because it would enable people to consume and receive healthy and therapeutic effect without distress.

OBJECTIVE

In the current study, in order to develop a novel method to prepare nanocomposite particles (microparticles containing bitter nanoparticles) in only one step, by using spray drying, a two-solution mixing nozzle-equipped spray dryer that we previously reported was used. The nanocomposite particles with or without poorly water-soluble polymers prepared using our spray-drying technique were characterized.

METHODS

(1) The organic solution containing quinine, a model of bitter compound and poorly water-soluble polymers and (2) sugar alcohol (mannitol) aqueous solution were separately flown in tubes and two solutions were spray dried through two-solution type spray nozzle to prepare polymer-blended quinine nanocomposite particles. Mean diameters of nanoparticles, taste-masking effect and dissolution rate of quinine were evaluated.

RESULTS

The results of taste masking by taste sensor suggested that the polymer (Eudragit EPO, Eudragit S100 or Ethyl cellulose)-blended quinine nanocomposite particles exhibited marked masking of instrumental quinine bitterness compared with the quinine nanocomposite particles alone. Quinine nanocomposite formulations altered the quinine dissolution rate, indicating that they can control intestinal absorption of quinine.

CONCLUSION

These results suggest that polymer-blended quinine composite particles prepared using our spray-drying technique are useful for masking bitter tastes in the field of food and pharmaceutical industry.

Evaluation of the Bitterness-Masking Effect of Powdered Roasted Soybeans

The masking of bitterness is considered important because many pharmaceutical compounds have a bitter taste. The bitterness-masking effect of powdered roasted soybeans (PRS) was investigated using a bitter taste sensor. PRS was revealed to significantly suppress the bitterness of quinine hydrochloride and denatonium benzoate. Furthermore, the bitterness-masking mechanism of PRS extracts was evaluated using dynamic light scattering. These results showed that the extracted suspension consisted of particles that were several hundreds of nanometers in size. Analysis of the PRS extracts by nuclear magnetic resonance spectroscopy indicated that denatonium benzoate was entrapped in the PRS extracts. Thus, PRS may be useful as a bitterness-masking agent in orally administered pharmaceuticals.

Nanosponge-based pediatric-controlled release dry suspension of Gabapentin for reconstitution

CONTEXT

Gabapentin was selected to formulate oral controlled release dry suspension because of short biological half life of 5-7 h and low bioavailability (60%). Gabapentin is a bitter drug so an attempt was made to mask its taste.

OBJECTIVE

To formulate and evaluate controlled release dry suspension for reconstitution to increase the bioavailability and to control bitter taste of drug.

MATERIALS AND METHODS

Cyclodextrin based nanosponges were synthesized by previously reported melt method. The nanosponge-drug complexes were characterized by FTIR, DSC and PXRD as well as evaluated for taste and saturation solubility. The complexes were coated on Espheres by a suspension layering technique followed by coating with ethyl cellulose and Eudragit RS-100. A dry powder suspension for reconstitution of the microspheres was formulated and evaluated for taste, redispersibility, in vitro dissolution, sedimentation volume, leaching and pharmacokinetics.

RESULTS AND DISCUSSION

The complexes showed partial entrapment of drug nanocavities. Significant decrease in solubility (25%) was observed in the complexes than pure drug in different media. The microspheres of nanosponge complexes showed desired controlled release profile for 12 h. Insignificant drug leaching was observed in reconstituted suspension during storage for 7 days at 45 °C/75% RH. Nanosponges effectively masked the taste of Gabapentin and the coating polymers provided controlled release of the drug and enhanced taste masking. The results of in vivo studies showed increase in bioavailability of controlled release suspension by 24.09% as compared to pure drug.

CONCLUSION

The dry powder suspension loaded with microspheres of nanosponges complexes can be proposed as a suitable controlled release drug delivery for Gabapentin.