Taste masking of paracetamol by hot-melt extrusion: An in vitro and in vivo evaluation

Innovative Strategies in the Formulation and Applications of Mouth Dissolving Films for Enhanced Oral Drug Delivery

OBJECTIVE

The main objective is to provide an overview of the advantages of mouth dissolving films by addressing the limitations of traditional oral dosage forms such as tablets and capsules, particularly for pediatric and geriatric patients with dysphagia. Also to explore its potential to revolutionize the oral drug delivery system supported by advancements in technology.

SIGNIFICANCE

Mouth dissolving films offer a transformative approach for the delivery of drugs with rapid disintegration, ease of administration, and water-free administration that improve patient compliance significantly. This review highlights the mouth dissolving films formulation strategies, applications, patent portfolio, and role of emerging technologies like 3D printing and artificial intelligence in enhancing drug absorption and bioavailability with substantial commercial potential and versatility, offering a patient-centric solution to modern pharmaceutical challenges.

KEY FINDINGS

Mouth dissolving film helps in addressing potential limitations in the traditional drug delivery system by enhancing patient compliance. This formulation relies on hydrophilic polymers and excipients to achieve desired characteristics, with techniques like solvent casting and 3D printing playing a pivotal role in their development, ensuring critical quality parameters that are essential for maintaining the efficacy and safety of the film with significant market potential. These innovative dosage forms are further supported by emerging technologies like artificial intelligence and microfabrication, offering improved drug absorption, enhancing bioavailability, and a revolutionary impact on oral drug delivery systems.

CONCLUSION

Mouth dissolving films are a transformative progress in oral drug delivery with future advancements in AI, robotics, and microfabrication that hold promise to further enhance bioavailability, targeted delivery, and sustained release solidifying their role in modern pharmaceutics.

Microbubble-encapsulation of actives for controlled release and its application to the taste-masking of acetaminophen

In this work we present a new encapsulation method that allows for the controlled release of drugs under simulated small intestinal conditions. This method consists of encapsulation within microbubbles and is characterized by an unprecedented combination of excellent barrier properties and fast and complete triggered release. The method was applied to produce a drink containing taste-masked acetaminophen as a model drug. Micronized acetaminophen (paracetamol) was dispersed in cyclohexane containing pharma-approved hydrophobized silica particles and the resulting dispersion was emulsified in an aqueous phase containing dispersed hydrophobized silica particles and dissolved maltodextrin. The resulting solid-in-oil-in-water emulsion was washed to remove unencapsulated acetaminophen and subsequently freeze-dried to remove both the water and the cyclohexane. This produced a dry material that after reconstitution in water created a suspension of microbubbles containing acetaminophen particles, i.e. a solid-in-gas-in-water dispersion. The encapsulation efficiency was well over 90% and hardly any acetaminophen escaped from the microbubbles during storage for 24 h in aqueous solution. Also, encapsulates were stable in the presence of saliva as well as during in vitro incubation with stomach juice. In line with this, sensory tests showed an excellent masking of the taste of the drug. In vitro incubation with simulated intestinal fluid containing bile salts triggered fast and near complete release of the encapsulated acetaminophen, which should assure good bioavailability in vivo. The described encapsulates that are stable for at least days, are thus expected to be suitable for taste-masking or enteric release applications in liquid formulations, including foods.

Exploring the impact of material selection on the efficacy of hot-melt extrusion

Hot-melt extrusion (HME) has emerged as a versatile and efficient technique in pharmaceutical formulation development, particularly for enhancing the solubility and bioavailability of poorly water-soluble drugs. This review delves into the fundamental principles of HME, exploring its application in drug delivery systems. A comprehensive analysis of polymers utilized in HME, such as hydroxypropyl methylcellulose, ethyl cellulose, hydroxypropyl cellulose, and polyvinylpyrrolidone, is presented, highlighting their roles in achieving controlled drug release and improved stability. The incorporation of plasticizers, such as triacetin, poly(propylene glycol), glycerol, and sorbitol, is critical in reducing the glass transition temperature (Tg) of polymer blends, thereby enhancing the processability of HME formulations. A comparison of Tg values for various polymer-plasticizer combinations is discussed using different predictive models. For researchers and industry professionals looking to optimize drug formulation strategies, this article offers valuable insights into the mechanisms through which HME enhances drug solubility and bioavailability two critical factors in oral drug delivery. Furthermore, by reviewing recent patents and marketed formulations, the article serves as a comprehensive resource for understanding both the technical advancements and commercial applications of HME. Readers will gain a deep understanding of the role of polymers and additives in HME, alongside future perspectives on how emerging materials and techniques could further revolutionize pharmaceutical development. This review is essential for those aiming to stay at the forefront of pharmaceutical extrusion technologies and their potential to improve therapeutic outcomes. The review concludes that meticulous material selection is vital for advancing pharmaceutical manufacturing processes and ensuring optimal outcomes in HME applications, thereby enhancing the overall efficacy of drug delivery systems.

Optimization of a Twin screw melt granulation process for fixed dose combination immediate release Tablets: Differential amorphization of one drug and crystalline continuance in the other

Interest in Twin Screw Melt Granulation (TSMG) processes is rapidly increasing, along with the search for suitable excipients. This study aims to optimize the TSMG process for immediate-release tablets containing two different drugs. The hypothesis is that one poorly water-soluble drug requires amorphous conversion for improved dissolution, while the other water-soluble drug, with a higher melting point (Tm), remains more stable in its crystalline form. Ibuprofen (IBU) and Acetaminophen (APAP) were chosen as the model drug combination to test this hypothesis. Various diluents, binders, and disintegrating agents were assessed for their impact on processability, crystallinity, disintegration, and dissolution during development. The temperatures used during processing were below the Tm of all components, except for IBU. Melted IBU acted as a granulating aid in addition to the binders in the formulation, facilitating granule formation. Physicochemical analyses by Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD) confirmed the complete conversion of IBU into an amorphous state and the preserved crystalline nature of APAP. Saturation solubility studies showed an improvement in IBU's solubility by ∼ 32-fold in 0.1 N HCl. Poor tablet disintegration performance led to the addition of disintegrating agents, where osmotic agents (sorbitol and NaCl) were found to significantly enhance disintegration compared to super disintegrants. The optimized formulation showed an enhanced IBU release (∼20 %) compared to the physical mixture (∼12.5) in 0.1 N HCl dissolution studies.

Role of rheology in formulation and process design of hot melt extruded amorphous solid dispersions

Hot melt extrusion (HME) has been widely used as a continuous and highly flexible pharmaceutical manufacturing process for the production of a variety of dosage forms. In particular, HME enables preparation of amorphous solid dispersions (ASDs) which can improve bioavailability of poorly water-soluble drugs. The rheological properties of drug-polymer mixtures can significantly influence the processability of drug formulations via HME and eventually the end-use product properties such as physical stability and drug release. The objective of this review is to provide an overview of various rheological techniques and properties that can be used to evaluate the flow behavior and processability of the drug-polymer mixtures as well as formulation characteristics such as drug-polymer interactions, miscibility/solubility, and plasticization to improve the HME processability. An overview of the thermodynamics and kinetics of ASD processing by HME is also provided, as well as aspects of scale-up and process modeling, highlighting rheological properties on formulation design and process development. Overall, this review provides valuable insights into critical rheological properties which can be used as a predictive tool to optimize the HME processing conditions.

3D printed tinidazole tablets coupled with melt-extrusion techniques for formulating child friendly medicines

This study investigates the feasibility of fabrication of poly(1-vinyl-2-pyrrolidone) (Kollidon®25)-mediated filaments for producing tinidazole (TNZ)-loaded, customizable, child-friendly tablets (with varying shapes and sizes) using hot melt extrusion (HME) coupled with fused deposition modeling (FDM) technology. Kollidon®25, chosen for its ability to enhance the dissolution of TNZ (a BCS Class II drug), was evaluated for polymer-drug compatibility through Hansen solubility, polarity, and interaction parameter analyses, confirming good miscibility and affinity between TNZ and Kollidon®25. Placebo- and TNZ-loaded filaments were prepared in different ratios using HME, followed by the development of 3D-printed tablets via FDM. The fabricated batches of placebo and TNZ-loaded 3D tablets were characterized, and it was found that they had an average weight variation of 270.41 ± 7.44 mg and 270.87 ± 9.33 mg, hardness of 155.01 ± 11.79 N and 265.3 ± 7.62 N, and friability of 0.1583 ± 0.0011 % and 0.2254 ± 0.0013 %. Amorphization was confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) analysis. Scanning electron microscopy (SEM) revealed a layer-by-layer pattern with tiny fractures on the tablet surfaces, which enhanced media penetration, resulting in improved dissolution profiles. The TNZ release profile showed complete 100 % release within 2.0 h in a gastric acidic medium. These findings support the potential of Kollidon®25 to create customizable, child-friendly, 3D-printed dosage forms with different shapes and sizes for TNZ delivery, offering a unique approach to paediatric medications.

Taste Sensor Assessment of Bitterness in Medicines: Overview and Recent Topics

In recent decades, taste sensors have been increasingly utilized to assess the taste of oral medicines, particularly focusing on bitterness, a major obstacle to patient acceptance and adherence. This objective and safe method holds promise for enhancing the development of patient-friendly medicines in pharmaceutical companies. This review article introduces its application in measuring the intensity of bitterness in medicine, confirming the achievement of taste masking, distinguishing taste differences between branded and generic medicines, and identifying substances to suppress bitterness in target medicines. Another application of the sensor is to predict a significant increase in bitterness when medicine is taken with certain foods/beverages or concomitant medication. Additionally, to verify the sensor's predictability, a significant correlation has been demonstrated between the output of a bitter-sensitive sensor designed for drug bitterness (BT0) and the bitterness responses of the human taste receptor hT2R14 from BitterDB (huji.ac.il). As a recent advancement, a novel taste sensor equipped with lipid/polymer membranes modified by 3-Br-2,6-dihydroxybenzoic acid (2,6-DHBA), based on the concept of allostery, is introduced. This sensor successfully predicts the bitterness of non-charged pharmaceuticals with xanthine skeletons, such as caffeine or related compounds. Finally, the future prospects of taste sensors are discussed.

Effects of nano zinc oxide and nano chitosan on the taste masking paracetamol granules

OBJECTIVE

The purpose of this study is to investigate the taste masking of Paracetamol granules in the range of 250-850 µm, coated by two nanocomposites prepared from Eudragit® E100, nanozinc oxide, and nanochitosan, respectively, from 1 to 5% by the weight of the granules.

METHODS

In this study, Paracetamol granules were coated in several formulas with two different types of nanocomposites (polymeric and mineral) on two sizes of granules to reduce bitter taste and with the FBC method and pH-sensitive polymers (Eudragit® E100).

RESULTS

The effect of nanoparticles (Nano zinc oxide and Nanochitosan) on taste-masking Paracetamol was studied with dissolution-coated granules in vitro by simulating in the oral (pH 6.8) range. Based on the results of the studies, the rate of drug release was confirmed by the taste test, and the formulated granule with 5% nano-chitosan (F14) had the best bitter taste mask function of all samples. These results were also confirmed by scanning electron microscopy (SEM) analysis, which showed a smoother and more stable surface than the samples obtained from other formulations.

CONCLUSION

In the comparison of the release of two types of nanocomposites in the dissolution test, it was shown that the type B granules of Paracetamol's 5% nano-chitosan-coated granule (F14) were released 99% less than Paracetamol's 5% nano-ZnO-coated granule (F11). and Paracetamol's 1% nano-chitosan-coated granule (F12) was released 91% less than Paracetamol's 1% nano-ZnO-coated granule (F9). The results showed that nano-chitosan-coated granules have better coverage of bitter taste instead of nano-ZnO.

Liquid API feeding in pharmaceutical HME: Novel options in solid dosage manufacturing

Hot melt extrusion (HME) is a common unit operation. It is broadly applicable in the pharmaceutical industry and can be implemented in a continuous manufacturing line. However, the conventional way of active pharmaceutical ingredient (API) feeding with a pre-blend consisting of a powdered API and a polymer does not allow the flexibility and agility to adjust the process parameters, which is generally an essential part of continuous manufacturing. In addition, this method of API feeding may result in the segregation of the individual powder components or agglomeration of highly cohesive materials, leading to an inhomogeneous API content in the extrudates, especially at low doses. In this study, the universal applicability of liquid side feeding in pharmaceutical HME was demonstrated using various APIs suspended or dissolved in water and fed as suspension or undersaturated, supersaturated, and highly concentrated solutions into anterior parts of the extruder. The extrudates were characterized in terms of their API content, residual moisture content, and solid-state of the API embedded in the polymer. The results show that a uniform API content without major deviations can be obtained via this method. Furthermore, the residual moisture content of the extrudates was low enough to have no significant influence on further processing of the final dosage form. In summary, this advanced way of feeding allows an accurate, flexible, and agile feeding of APIs, facilitating the production of personalized final dosage forms and a novel option to link the manufacturing of the drug substance and the drug product.

Effects of Flavors on Taste Sensation of Pioglitazone Orally Disintegrating Tablets

Orally disintegrating tablets (ODTs) can be easily swallowed without drinking water and are a convenient dosage form for the elderly and infirmed patients, as well as other patients, such as businesspeople. A major challenge in the development of ODTs is masking the unpleasant taste of the drug, which can make ODTs palatable. Flavors are often used for taste-masking. A few comprehensive studies have been conducted on the selection of suitable flavors for ODTs. This study aimed to evaluate the effects of different flavors on the taste sensation of ODTs using a visual analog scale (VAS). Sixteen flavors were studied for their effects on the taste sensation of pioglitazone ODTs in a randomized single-blind study involving the gustatory sensation testing of ODTs. Healthy volunteers were enrolled and asked to periodically evaluate the bitterness, sweetness, astringency, sourness, and overall palatability of ODTs, both during and after disintegration in the oral cavity, using the VAS. Most flavors improved the sweetness of ODTs without the addition of a sweetener, and some suppressed bitterness, astringency, and sourness. In particular, blueberry, and yoghurt flavors significantly improved sweetness and overall palatability during disintegration of the pioglitazone ODT. The approach of using VAS score analysis was effective in selecting the most suitable flavor for improving the overall palatability of ODT. Furthermore, the addition of a suitable flavor can successfully mask the unpleasant taste of the drug and effectively improve the overall palatability of ODT.

The quality monitoring of paracetamol medicament using a noninvasive microwave sensor

Environmental conditions, including temperature, humidity, and light, can impact the quality of drugs. Microwave-based approaches offer a fast and cost-effective way to detect quality variations, providing an alternative to traditional techniques in the pharmaceutical and cosmetic industries. This article proposes the use of a microwave sensor for monitoring the quality of pharmaceutical drugs at distinct temperature levels. A small planar sensor based on three hexagonal split ring resonators (TH-SRR) is fabricated. The design is manufactured on an FR-4 dielectric substrate. The sensor is tested on a 1000 mg paracetamol tablet, at temperatures ranging from 40 to 80 [Formula: see text]C. The Variation in the permittivity that characterizes product degradation is translated into a shift in the frequency of the scattering matrix elements. To validate the microwave approach, drug quality is examined with the laser-induced breakdown spectroscopy (LIBS) technique, an optical emission laser used for both qualitative and quantitative investigations of elements contained in a sample. The existing elements are classified using the National Institute of Standards and Technology (NIST) database and categorized according to their spectral line wavelengths. The experiments show the presence of optimal wavelength values for carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) at 247.92 nm, 656.49 nm, 244.23 nm, and 777.48 nm, respectively. The microwave experimental results show a shift frequency of approximately 1 MHz on average when the tablet is heated at 80 [Formula: see text]C for 15 min. Meanwhile, the LIBS measurement shows a remarkable shift in terms of intensity of approximately 8884 and 812 for carbon and hydrogen, respectively. Understanding how paracetamol dries under high temperatures and improving the process settings of the microwave sensor are investigated and assessed in this work.

Influence of Poloxamer on the Dissolution and Stability of Hot-Melt Extrusion-Based Amorphous Solid Dispersions Using Design of Experiments

The current study aimed to see the effects of poloxamer P407 on the dissolution performance of hydroxypropyl methylcellulose acetate succinate (AquaSolve™ HPMC-AS HG)-based amorphous solid dispersions (ASD). A weakly acidic, poorly water-soluble active pharmaceutical ingredient (API), mefenamic acid (MA), was selected as a model drug. Thermal investigations, including thermogravimetry (TG) and differential scanning calorimetry (DSC), were conducted for raw materials and physical mixtures as a part of the pre-formulation studies and later to characterize the extruded filaments. The API was blended with the polymers using a twin shell V-blender for 10 min and then extruded using an 11-mm twin-screw co-rotating extruder. Scanning electron microscopy (SEM) was used to study the morphology of the extruded filaments. Furthermore, Fourier-transform infrared spectroscopy (FT-IR) was performed to check the intermolecular interactions of the components. Finally, to assess the in vitro drug release of the ASDs, dissolution testing was conducted in phosphate buffer (0.1 M, pH 7.4) and hydrochloric acid-potassium chloride (HCl-KCl) buffer (0.1 M, pH 1.2). The DSC studies confirmed the formation of the ASDs, and the drug content of the extruded filaments was observed to be within an acceptable range. Furthermore, the study concluded that the formulations containing poloxamer P407 exhibited a significant increase in dissolution performance compared to the filaments with only HPMC-AS HG (at pH 7.4). In addition, the optimized formulation, F3, was stable for over 3 months when exposed to accelerated stability studies.

Influence of formulation variables on the processability and properties of tablets manufactured by fused deposition modelling

The present work studied the influence of different formulation variables (defined also as factors), namely, different polymers (HPC EF, PVA and HPMC-AS LG), drugs with different water solubilities (paracetamol, hydrochlorothiazide and celecoxib) and drug loads (10 or 30 %) on their processability by HME and FDM. Both filaments and tablets were characterized for physic and chemical properties (DSC, XRPD, FTIR) and performance properties (drug content, in vitro drug release). Experiments were designed to highlight relationships between the 3 factors selected and the mechanical properties of filaments, tablet mass and dissolution profiles of the model drugs from printed tablets. While the combination of hydrochlorothiazide and HPMC-AS LG could not be extruded, the combination of paracetamol with HPC EF turned the filaments too ductile and not stiff enough hampering the process of printing. All other polymer and drug combinations could be successfully extruded and printed. Models reflected the influence of the solubility of the drug considered but not the drug load in formulations. The ranking of the drug release rates was in good agreement with their solubilities. Furthermore, PVA presenting the fastest swelling rate, promoted the fastest drugs' releases in comparison with the other polymers studied. Overall, the study enabled the identification of the key factors affecting the properties of printed tablets, with the proposal of a model that has valued the relative contribution of each factor to the overall performance of tablets.

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.

Production of Bi-Compartmental Tablets by FDM 3D Printing for the Withdrawal of Diazepam

Diazepam (DZP) is a long-acting benzodiazepine to treat anxiety or acute alcohol withdrawal. Although this class of drugs should be taken for a short period of time, many patients take them for longer than recommended, which has been linked to an increased risk of dementia and dependence. The present work aimed at using the dual-nozzle system of fused deposition modeling (FDM) 3D printers to prepare tablets with gradual doses of DZP with constant mass and size. Placebo and DZP-loaded filaments were prepared by hot-melt extrusion and used to print the bi-compartmental tablets. Thermal processing allowed the conversion of crystalline DZP to its amorphous counterpart. Tablets with different DZP contents were effectively printed with a mass, thickness and diameter average of 111.6 mg, 3.1 mm, and 6.4 mm, respectively. Microscopic data showed good adhesion between the different layers in the printed tablets. The desired drug contents were successfully achieved and were within the acceptance criteria (European Pharmacopeia). The combination of a placebo and drug-loaded extrudates proved to be beneficial in the production of tablets by FDM for patients in need of drug withdrawal.

Twin-Screw Continuous Mixing Can Produce Dry Powder Inhalation Mixtures for Pulmonary Delivery

The feasibility of twin-screw corotating extruder as a continuous process mixer to prepare dry powder inhalation (DPI) powders was investigated. Interactive mixtures of 1% micronized budesonide, 0.3% magnesium stearate and 98.7% alpha-lactose monohydrate were manufactured using a Leistritz Nano-16 extruder at various processing conditions. One set of GFM (grooved mixing) elements were included in the screw profile to provide distributive mixing of conveyed powders with the goal of resulting in a homogeneous mixture. Residence time in the twin-screw mixer was modelled to quantify mixing efficiency. Comparative powders were also prepared using either low or high-shear batch mixing to compare the effect of mixing methods on the properties of the budesonide dry powder inhalation formulation. Twin screw mixing results in homogeneous mixtures with aerosol performance comparable to that of high-shear batch mixing. Scanning electron microscopy confirmed that twin screw mixing produces particles with morphology like that of low and high-shear batch mixing. X-ray diffraction (XRD) analysis verified that there was no form change of the drug due to twin-screw processing. Statistical regression was used to probe the relationship between twin screw mixing process parameters such as screw speed and feed rate and aerosol performance. The twin screw mixing process was found to be robust, as no significant differences in aerosol performance were found for various processing parameters.

Role of Nanotechnology in Taste Masking: Recent Updates

One of the important parameters in the case of dosage form is taste. Most of the drugs available in oral dosage form have an unpleasant taste which leads to patient incompliance and affects the success ratio of products in the market. Geriatric and paediatric patients suffer more with the bitter taste of medicines. According to the studies reported, it is found that 50% of the population have the problem swallowing tablets, especially the pediatric and geriatric population. Masking the taste of bitter drugs has become necessary in the pharmaceutical field and increasing interest of researchers to develop various methods for masking the bitter taste of drugs. Five major tastes, felt by our tongue are salt, sour, sweet, bitter, and umami. When the drug dissolves with saliva, drug molecules interact with taste receptors present on the tongue and give taste sensations. Although, many solid oral dosage forms like pills, and tablets have an additional advantage of masking and encapsulation of bitter taste drugs; however, they might not be effective for children because they may or may not swallow pills or tablets. There are various other methods that mask the bitter taste of drugs such as the addition of sweeteners and flavouring agents, granulation, coating, inclusion complexes, extrusion method, ion-exchange resins, etc, discussed in the first section of the article. The second part of this article consists of various nanotechnology-based drug delivery systems that were fabricated by researchers to mask the bitter taste of drugs. A brief of recent literature on various nanocarriers that were fabricated or developed for taste masking has been discussed in this part. A better understanding of these methods will help researchers and pharmaceutical industries to develop novel drug delivery systems with improved taste masking properties.

Personalised Paediatric Chewable Ibuprofen Tablets Fabricated Using 3D Micro-extrusion Printing Technology

Three-dimensional (3D) printing is becoming an attractive technology for the design and development of personalized paediatric dosage forms with improved palatability. In this work micro-extrusion based printing was implemented for the fabrication of chewable paediatric ibuprofen (IBU) tablets by assessing a range of front runner polymers in taste masking. Due to the drug-polymer miscibility and the IBU plasticization effect, micro-extrusion was proved to be an ideal technology for processing the drug/polymer powder blends for the printing of paediatric dosage forms. The printed tablets presented high printing quality with reproducible layer thickness and a smooth surface. Due to the drug-polymer interactions induced during printing processing, IBU was found to form a glass solution confirmed by differential calorimetry (DSC) while H-bonding interactions were identified by confocal Raman mapping. IBU was also found to be uniformly distributed within the polymer matrices at molecular level. The tablet palatability was assessed by panellists and revealed excellent taste masking of the IBU's bitter taste. Overall micro-extrusion demonstrated promising processing capabilities of powder blends for rapid printing and development of personalised dosage forms.

Strategies for Taste Masking of Orodispersible Dosage Forms: Time, Concentration, and Perception

Orodispersible dosage forms, characterized as quick dissolving and swallowing without water, have recently gained great attention from the pharmaceutical industry, as these forms can satisfy the needs of children, the elderly, and patients suffering from mental illnesses. However, poor taste by thorough exposure of the drugs' dissolution in the oral cavity hinders the effectiveness of the orodispersible dosage forms. To bridge this gap, we put forward three taste-masking strategies with respect to the intensity of time, concentration, and perception. We further investigated the raw material processing, the composition of auxiliary material, formulation techniques, and process control in each strategy and drew conclusions about their effects on taste masking.

Fabrication of a Shell-Core Fixed-Dose Combination Tablet Using Fused Deposition Modeling 3D Printing

Fixed-dose combinations (FDCs) achieve optimal goals for treatment with minimal side effects, decreased administration of large number of tablets, thus, greater convenience, and improved patient compliance. However, conventional FDCs do not have a guaranteed place in the future of patient-centered drug development because of the difficulty in achieving dose titration of each drug for individualized specific health needs and desired therapeutic outcomes. In the current study, FDCs of two antihypertensive drugs were fabricated with two distinct compartments using fused deposition modeling three-dimensional printing (FDM-3DP). Atorvastatin calcium and Amlodipine besylate loaded filaments were prepared by hot-melt extrusion. Shell-core FDC tablets were designed to have different infills for individualized dosing. Differential scanning calorimetry and powder X-ray diffraction revealed that both drugs were transformed into amorphous forms within the polymeric carriers. The fabricated tablets met the United States Pharmacopeia acceptance criteria for friability, content uniformity, and dissolution testing. The fabricated tablets were stable at room temperature with respect to drug content and thermal behavior over six months. This dynamic dosage form provides flexibility in dose titration and maintains the advantages of FDCs, thus achieving optimal therapeutic outcomes in different healthcare facilities.

Preparation of Azithromycin Amorphous Solid Dispersion by Hot-Melt Extrusion: An Advantageous Technology with Taste Masking and Solubilization Effects

Azithromycin (AZI) is one of the most commonly used macrolide antibiotics in children, but has the disadvantages of a heavy bitter taste and poor solubility. In order to solve these problems, hot-melt extrusion (HME) was used to prepare azithromycin amorphous solid dispersion. Preliminary selection of a polymer for HME was conducted by calculating Hansen solubility parameter to predict the miscibility of the drug and polymer. Eudragit^® RL PO was chosen as the polymer due to its combination of taste-masking effect and dissolution. Moreover, the solubility was improved with this polymer. Design of experiments (DoE) was used to optimize the formulation and process, with screw speed, extrusion temperature, and drug percentage as independent variables, and content, dissolution, and extrudates diameter as dependent variables. The optimal extrusion parameters were obtained as follows: temperature-150 °C; screw speed-75 rpm; and drug percentage-25%. Differential scanning calorimetry (DSC) and Powder X-ray Diffraction (PXRD) studies of the powdered solid dispersions showed that the crystalline AZI transformed into the amorphous form. Fourier transform infrared spectroscopy (FTIR) results indicated that the formation of a hydrogen bond between AZI and the polymer led to the stabilization of AZI in its amorphous form. In conclusion, this work illustrated the importance of HME for the preparation of amorphous solid dispersion of AZI, which can solve the problems of bitterness and low solubility. It is also of great significance for the development of compliant pediatric AZI preparation.

Personalised Tasted Masked Chewable 3D Printed Fruit-Chews for Paediatric Patients

The development of personalised paediatric dosage forms using 3D printing technologies has gained significant interest over the last few years. In the current study extruded filaments of the highly bitter Diphenhydramine Hydrochloride (DPH) were fabricated by using suitable hydrophilic carries such as hydroxypropyl cellulose (Klucel ELF^TM) and a non-ionic surfactant (Gelucire 48/16^TM) combined with sweetener (Sucralose) and strawberry flavour grades. The thermoplastic filaments were used to print 3D fruit-chew designs by Fused Deposition Modelling (FDM) technology. Physicochemical characterisation confirmed the formation of glass solution where DPH was molecularly dispersed within the hydrophilic carriers. DPH was released rapidly from the 3D printed fruit-chew designs with >85% within the first 30 min. Trained panellists performed a full taste and sensory evaluation of the sweetener intensity and the strawberry aroma. The evaluation showed complete taste masking of the bitter DPH and revealed a synergistic effect of the sweetener and the strawberry flavour with enhanced sweet strawberry, fruity and aftertaste perception. The findings of the study can be used for the development of paediatric dosage forms with enhanced organoleptic properties, palatability and medication adherence.

Preparation and characterization of aqueous vitamin E/Soluplus® dispersions for film coating applications

OBJECTIVE

The goals of this study were to (1) delineate a technique to prepare stable aqueous vitamin E/Soluplus® dispersions; (2) characterize films cast from the aqueous dispersions; and (3) demonstrate the utility of the aqueous dispersions in fluid bed coating applications. This study demonstrated the feasibility of using vitamin E in the preparation of amphiphilic film withs potential use in delayed-release coating applications.

METHODS

Low viscosity aqueous vitamin E/Soluplus® dispersions were prepared by first spray drying ethanolic vitamin E/Soluplus® solutions followed by high-shear homogenization of the solid dispersions in water. Concentrated (10%) aqueous dispersions containing 0%, 10%, 20%, and 30% of vitamin E in the binary blend with Soluplus® were then cast into films and characterized for contact angle and mechanical strength by texture analysis.

RESULTS

All films were hydrophilic and homogenous, which confirmed the utility of vitamin E as a plasticizer for the Soluplus® polymer. The 0% and 10% films were brittle whereas the 30% were tacky. The 20% dispersion was subsequently used to coat acetaminophen granules by a fluidized bed process to a dry weight gain of 10-30%. When tested by a dissolution study, a delay in acetaminophen release was observed as a function of weight gain.

CONCLUSION

The results from this study demonstrated that it is feasible to produce stable vitamin E/Soluplus® aqueous dispersions to be used as solvent-free functional film coating materials.

Twin-Screw Melt Granulation for Oral Solid Pharmaceutical Products

This article highlights the advantages of pharmaceutical continuous melt granulation by twin-screw extrusion. The different melt granulation process options and excipients are described and compared, and a case is made for expanded use of twin-screw melt granulation since it is a flexible and continuous process. Methods for binder selection are profiled with a focus on rheology and physical stability impacts. For twin-screw melt granulation, the mechanism of granulation and process impact on granule properties are described. Pharmaceutical applications of melt granulation ranging from immediate release of soluble and insoluble APIs, taste-masking, and sustained release formulation are reviewed, demonstrating the range of possibilities afforded by twin-screw melt granulation.

Aqueous and pH dependent coacervation method for taste masking of paracetamol via amorphous solid dispersion formation

Taste masking of paracetamol was achieved by preparing amorphous solid dispersion (ASD) using modified coacervation method. The method is based on dissolving the drug and polymeric carrier in water adjusted to certain pH level. Then, precipitation of ASD granules is performed by gradually changing pH level. Therefore, the chosen drug and polymer should obtain appropriate acidic or basic groups to enable pH-dependent solvation. Moreover, using solubility enhancing additives such as sodium lauryl sulphate (SLS) and low viscosity polyethylene glycol (PEG 400) found to be essential in aiding drug/polymer aqueous solvation which enhanced amorphization, hence taste masking and drug loading. Solid dispersion between Paracetamol and Eudragit E was formed and that proved by FT-IR, DSC, PXRD and SEM. Also, Paracetamol was released after 2 min in 0.1 N hydrochloric acid medium and the taste of masking forms are accepted from all volunteers. Modified coacervation method does not involve organic solvents, high temperatures, or sophisticated instruments commonly used in taste masking methods. Using PEG 400 resulted in significantly higher drug loading and dissolution rate compared to SLS granules. Moreover, using previously reported scoring system for the evaluation of taste masking methods shows that pH dependent coacervation obtained high scoring over common methods and thus display a robust potential for industrial applications.

Comparative taste-masking evaluation of microencapsulated bitter drugs using Smartseal 30D and ReadyMix for paediatric dosage forms

The taste of drug substances plays a key role in the development of paediatric formulations with suitable organoleptic properties. The aim of the study was to evaluate the taste masking effectiveness of Smartseal 30D and ReadyMix on a range of bitter drug substances such as diphenhydramine HCl (DPD), ibuprofen lysine (IBU-LS), and phenylephrine HCl (PPH) for the development of paediatric dosage forms. The drugs were microencapsulated in the polymer carriers at 10-20% loadings using spray-drying processing. Spray drying of drug formulations was optimized in terms of percent yield and encapsulation efficiency followed by physicochemical characterization in order to identify the drugs' physical state in the polymer microparticles. The in vivo taste masking efficiency was evaluated using human test panel and showed noticeable reduction of drug's bitterness at all loadings in comparison to the bulk substances.

Formulation, in vitro characterization and optimization of taste-masked orally disintegrating co-trimoxazole tablet by direct compression

Introduction

Orally disintegrating tablet (ODT) is a dosage form that overcomes the problem of swallowing which is prevalent in about 35% of the general population. Co-trimoxazole (CTX) is given for patients with HIV for the prophylaxis of opportunistic infection (OI), commonly for pneumocystis carinii pneumonia. It was reported that CTX was associated with a 25–46% reduction in mortality among individuals infected with HIV in sub-Saharan Africa. Esophageal candidiasis which usually comes along with HIV/AIDS is one of AIDS defining illness affecting up to 1 in 5 of people with AIDS. This opportunistic illness is manifested by painful or difficulty of swallowing. In this respect, CTX ODT offer the advantages of both liquid dosage forms in terms of easy swallowing thereby improve patient compliance and solid dosage forms in terms of dose uniformity, stability, lower production, and transportation costs. The objective of this study was to formulate, characterize and optimize CTX ODT which could overcome swallowing problem and improve patient compliance. Co-trimoxazole ODTs were prepared by direct compression technique using a semi synthetic super disintegrant (crospovidone) along with other excipients. Two taste masking techniques were employed, addition of sweetening agent, and solid dispersion by using a pH sensitive polymer, Eudragit E-100 at different ratios (1:1, 1:2 and 1:3). Taste masking was determined by comparing taste threshold value and in vitro drug release. Preliminary study was used to investigate the effect of crospovidone, compression force (CF) and Hydroxypropyl cellulose (HPC) on disintegration time, friability and wetting time (WT). Factorial design was used as it enables simultaneous evaluation of formulation variables and their interaction effect. From the preliminary study, the factors that were found significant were further optimized using central composite design. Design-Expert 8.0.7.1 software was employed to carry out the experimental design. The bitterness threshold concentration of Trimethoprim was found to be 150 μg/ml and the in vitro drug release of the three batches of drug to polymer ratio (F1:1, 1:2 and 1:3) was 2.80±0.05, 2.77±0.00 and 2.63±0.00 respectively. From the optimization study, the optimal concentration for the superdisintegrant was 8.60% w/w and a CF of 11.25 KN which gave a rapid disintegration and WT of 13.79 and 23.19 seconds respectively and a friability of 0.666%.

Conclusion

In this study, co-trimoxazole ODT was formulated successfully. Central composite design was effectively used to model and optimize friability, DT and WT. The method was found effective for estimating the effect of independent variables on the dependent variables by using polynomial equation and surface plots. Optimization of the response variables was possible by using both numerical and graphical optimization and the predicted optimal conditions were confirmed experimentally and were found to be in good agreement within 5% of the predicted responses. The results of the study showed that CTX ODT had significantly rapid disintegration, less than 1% friability and enhanced dissolution profiles. The successful formulation of CTX ODT can solve difficulty of swallowing of conventional tablets for some group of patients which are unable to swallow solid oral dosage form.

Quaternary enteric solid dispersion prepared by hot-melt extrusion to mask the bitter taste and enhance drug stability

To mask the bitterness of drug is profoundly important especially in children's medication. This study designed and investigated a quaternary enteric solid dispersion (QESD) by secondary hot-melt-extrusion. Erythromycin (EM) was chosen as a model drug. The optimal QESD contained enteric polymer HPMCP-55, plasticizer and water-soluble polymer copovidone VA64. Raman and Atomic force microscope has exploited that majority EM was distributed in VA64 matrix, nanometer-sized EM-VA64 system was entrapped within enteric continuous phase to form a solid emulsion-like structure. For the prepared QESD, EM released concentration was far less than bitterness threshold (7 μg/mL to 20 μg/mL) in artificial saliva within the first 30 s. And dissolution rate was increased by 10% in article intestine fluid, which dominated by water-soluble VA64. Stress testing after two months at high-humidity (75% RH) and high-temperature (60 °C) revealed, compared with traditional enteric SDs, the chemical degradation of EM was slowed down in QESD. Furthermore, hydrogen and salt bonds were respectively formed between EM and VA64 and between leaking EM and HPMCP-55, which increasing the system stability and taste-masking. The effect of masking bitter taste can be satisfied as well as enhance drug dissolution rate in the intestine, and formulation physicochemical stability during storage.

Fabrication of Taste-Masked Donut-Shaped Tablets Via Fused Filament Fabrication 3D Printing Paired with Hot-Melt Extrusion Techniques

The objective of this work was to develop taste-masked donut-shaped tablet formulations utilizing fused filament fabrication three-dimensional printing paired with hot-melt extrusion techniques. Caffeine citrate was used as the model drug for its bitter taste, and a 3-point bend test was performed to assess the printability of filaments. The stiffness constant was calculated to represent the printability by fitting the breaking distances and stress data into Hooke's law. The formulations without Eudragit E PO (F6) and with Eudragit E PO (F7) filaments exhibited the desired hardness with a "k" value of 48.30 ± 3.52 and 45.47 ± 3.51 g/mm³ (n = 10), respectively, and were successfully printed. The donut-shaped tablets were 3D printed with 10, 50, and 100% infill densities. In vitro dissolution studies were performed in simulated salivary fluid (pH 6.8, artificial saliva) to evaluate the taste-masking efficiency of the printed donuts. In the first minute, the concentrations of caffeine citrate observed in the dissolution media from all the printed donuts were less than the bitter threshold of caffeine citrate (0.25 mg/mL). Formulation F7, which contained Eudragit E PO copolymer, demonstrated better taste-masking efficiency than formulation F6. Furthermore, both formulations F6 and F7 demonstrated immediate drug release profiles in gastric medium (10% infill, > 80% release within 1 h). Taste-masked caffeine citrate formulations were successfully developed with donut shapes, which will enhance appeal in pediatric populations and increase compliance and patient acceptance of the dosage form.

Preparation of Hot-Melt Extruded Dosage Form for Enhancing Drugs Absorption Based on Computational Simulation

The aim of this study was to control the dissolution rate and permeability of cilostazol. To enhance the dissolution rate of the active pharmaceutical ingredient (API), hot-melt extrusion (HME) technology was applied to prepare a solid dispersion (SD). To control permeability in the gastrointestinal tract regardless of food intake, the HME process was optimized based on physiologically based pharmacokinetic (PBPK) simulation. The extrudates were produced using a laboratory-scale twin-screw hot-melt extruder with co-rotatory screws and a constant feeding rate. Next, for PBPK simulation, parameter-sensitive analysis (PSA) was conducted to determine the optimization approach direction. As demonstrated by the dissolution test, the solubility of extrudate was enhanced comparing cilostazol alone. Based on the PSA analysis, the surfactant induction was a crucial factor in cilostazol absorption; thus, an extrudate with an even distribution of lipids was produced using hot-melt extrusion technology, for inducing the bile salts in the gastrointestinal tract. In vivo experiments with rats demonstrated that the optimized hot-melt extruded formulation was absorbed more rapidly with lower deviation and regardless of the meal consumed when compared to marketed cilostazol formulations.

Insoluble Polymers in Solid Dispersions for Improving Bioavailability of Poorly Water-Soluble Drugs

In recent decades, solid dispersions have been demonstrated as an effective approach for improving the bioavailability of poorly water-soluble drugs, as have solid dispersion techniques that include the application of nanotechnology. Many studies have reported on the ability to change drug crystallinity and molecular interactions to enhance the dissolution rate of solid dispersions using hydrophilic carriers. However, numerous studies have indicated that insoluble carriers are also promising excipients in solid dispersions. In this report, an overview of solid dispersion strategies involving insoluble carriers has been provided. In addition to the role of solubility and dissolution enhancement, the perspectives of the use of these polymers in controlled release solid dispersions have been classified and discussed. Moreover, the compatibility between methods and carriers and between drug and carrier is mentioned. In general, this report on solid dispersions using insoluble carriers could provide a specific approach and/or a selection of these polymers for further formulation development and clinical applications.

A Comparison Between Lab-Scale and Hot-Melt-Extruder-Based Anti-inflammatory Ointment Manufacturing

Hot-melt extrusion (HME) has been extensively investigated for continuous manufacturing of amorphous solid dispersions, to improve the solubility of poorly water-soluble drug substances, impart abuse deterrence to controlled substances, taste masking for pediatric and geriatric formulations and development of cocrystal system. Much research has been conducted on the continuous manufacturing of solid dosage forms using HME, but its applicability in the manufacturing of semisolids remains an unexplored domain. This study aimed to explore the applicability of HME in the continuous manufacturing of topical semi-solid formulations with two active pharmaceutical ingredients (APIs). Ointments containing a combination of triamcinolone acetonide and lidocaine hydrochloride were screened based on a quality target product profile (QTPP) and established critical quality attributes (CQAs) using design of experiments (DoE). Three selected formulations, manufactured by a lab-scale fusion method and HME, were subjected to further characterization studies including work of adhesion, stiffness, apparent pH, content uniformity, differential scanning calorimetry, accelerated stability, and in vitro drug release testing. Selected formulations met design characteristics and demonstrated the applicability of HME in the continuous manufacturing of semi-solid formulations. Graphical abstract.

Taste masking of propranolol hydrochloride by microbeads of EUDRAGIT® E PO obtained with prilling technique for paediatric oral administration

The purpose of this study was to develop a new solid paediatric formulation for propranolol hydrochloride (PR). This drug is used to treat various paediatric diseases, and recently received clearance to treat haemangioma. However, PR has a bitter salty taste that does not facilitate high rates of compliance among children, especially in liquid formulations. In addition, the solid formulations are designed for adults and often their dosage is not suitable for children that require a flexible dose based on their weight. Therefore, matrix microbeads of EUDRAGIT® E PO containing PR were manufactured to overcome these limitations. Nine different samples were prepared using the prilling-congealing technique with high yield. Using 2 nozzles, 300 and 450 μm (code n), the diameters obtained of microbeads (from 333 to 699 μm) were homogenous and appropriate to be swallowed by children. In this study, the ratio drug:matrix for the microbeads was also examined in detail: 1:25 (F₁), 1:15 (F₂) and 1:10 (F₃) in aqueous and tert-butyl alcohol/aqueous (code t) media. Most of the examined microbeads were characterized by high percentage of encapsulation efficiency (22-100%) and drug loading (22-77 mg of drug per g of matrix) effective for the administration of low and high doses of PR. SEM analysis revealed a matrix with a radial or a spongy structure, with numerous pores that generated soft floating microbeads in aqueous solution. Release studies confirmed a low release and dissolution of the drug in artificial saliva, mainly F_1n > F₁ > F_2nt, and a prompt dissolution in simulated gastric media. Finally, electronic tongue measurements revealed the ability of these formulations to mask the bitter drug taste, especially for the sample with a ratio 1:25 (F_1n and F₁). These samples were chemically and physically stable for six months. In conclusion, the projected microbeads F₁, and F_1n reached the goal of the study, and could be proposed as new solid oral formulations dedicated to use by children.

Critical Evaluation of Laboratory Potentiometric Electronic Tongues for Pharmaceutical Analysis-An Overview

Electronic tongue systems equipped with cross-sensitive potentiometric sensors have been applied to pharmaceutical analysis, due to the possibility of various applications and developing new formulations. Many studies already proved the complementarity between the electronic tongue and classical analysis such as dissolution tests indicated by Pharmacopeias. However, as a new approach to study pharmaceuticals, electronic tongues lack strict testing protocols and specification limits; therefore, their results can be improperly interpreted and inconsistent with the reference studies. Therefore, all aspects of the development, measurement conditions, data analysis, and interpretation of electronic tongue results were discussed in this overview. The critical evaluation of the effectiveness and reliability of constructed devices may be helpful for a better understanding of electronic tongue systems development and for providing strict testing protocols.

Assessment of taste masking of captopril by ion-exchange resins using electronic gustatory system

The objective of the study was to mask the unpleasant taste of captopril (CPT). Taste masking was achieved by complexation of CPT with a basic ion exchange resin, Dowex^® 66, using the batch method. Dowex^® 66 was used for the adsorption of CPT, and physical and chemical parameters of the CPT resinates complex were evaluated. A central composite design was used to generate the experiments for the manufacture of resinates using different process and formulation variables. In vitro dissolution studies were performed for 2 h in 0.01N HCl (pH 1.6) using USP Apparatus I. The compatibility of CPT and the resin was evaluated by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD). The resinates were evaluated for micromeritic properties and further characterised using FTIR, DSC, and PXRD. Response surface methodology was used to determine the significance of input variables on the CPT content and release. The CPT resin ratio was found to have a significant impact on content of the resinates and on CPT release. The formulations were also studied for taste masking ability by means of an electronic gustatory system - electronic tongue.

Taste Masking of Nizatidine Using Ion-Exchange Resins

The purpose of this study was to mask the bitter taste of nizatidine (NZD) using cation-exchange resins. Amberlite IRP-69 and Dowex-50 containing cross-linked polystyrene backbones were used. The drug resin complexes were prepared by batch process using drug: resin ratios of 1:1, 1:3, and 1:5. The optimum drug: resin ratio and the time required for maximum percentage drug loading into the complexes were determined. The selected drug-resin complexes were evaluated for morphology, drug release, and taste. The NZD-Dowex complex was obtained at a drug: resin ratio of 1:5 using a stirring time of 1 h in order to get 100% loading of NZD. The NZD-Dowex complex had a spherical shape and smooth texture similar to Dowex resin. The NZD-Dowex complex with a ratio of 1:5 showed that in vitro drug release of 4.27% at 5 min in simulated salivary fluid of pH 6.8 and 99.67% at 1 h in simulated gastric fluid of pH 1.2. NZD’s bitter taste was effectively masked when it formed a complex with Dowex at a ratio of 1:5. This was proved by an electronic tongue and human test panel.

Oral thin films as a remedy for noncompliance in pediatric and geriatric patients

Pediatric and geriatric patients experience swallowing difficulties for traditional oral dosage forms, such as tablets. Further, microbial contamination, chemical stability, unpleasant taste and swallowing large volumes of fluids have led to low therapeutic efficacy and patient noncompliance. The emergence of oral thin films has resulted in dramatic improvements in compliance and drug therapy outcomes in pediatric and geriatric patients. Oral thin films do not require water for administration, are readily hydrated upon contact with saliva, adhere to the mucosa and disintegrate ideally under 1 min. This article provides an overview of oral thin films, modern trends in their formulation and characterization, available commercial products, information to fill knowledge gaps and future potential and economic prospects of oral thin film technology, with emphasis on their use in the pediatric and geriatric patient groups.

Chemico-calorimetric analysis of amorphous granules manufactured via continuous granulation process

The current study explores the first case of the implementation of solution calorimetry (SolCal) in order to determine the amorphous content of crystalline benzoyl-methoxy-methylindol-acetic acid (BMA)-a model poorly soluble drug, in the amorphous granules prepared via single-step continuous twin-screw dry granulations (TSG). Amorphous magnesium aluminometasilicate (Neusilin®) (US2) was used as a novel inorganic carrier via a TwinLab 10 mm twin-screw extruder. The BMA/US2 blends were processed at 180 °C and varying drug: carrier ratios of 1:4, 1:2.5 and 1:1 (w/w). Physico-chemical characterisation conducted via SEM, DSC and XRPD showed amorphous state of the drug in all granulated formulations. Reverse optical microscopy revealed a meso-porous structure of US2 in which the drug particles are adsorbed and/or entrapped within the porous network of the carrier. This phenomenon can be the underlying reason for the increase of the amorphous content in the extruded granules. Solution calorimetry (SolCal) study revealed amorphous content of the drug in all formulations quite precisely, whereas the dynamic vapour sorption (DVS) analysis complemented the results from SolCal. Furthermore, an attempt has been made for the first time to interrelate the findings from the SolCal to that of the release of the drug from the amorphous granules. It can be concluded that SolCal can be used as a novel technique to precisely quantify and interrelate the amorphous content to its physico-chemical performances such as drug release from the granulated formulations processed via TSG.

Effect of melt extrudability and melt binding efficiency of polyvinyl caprolactam polyvinyl acetate polyethylene glycol graft copolymer (Soluplus®) on release pattern of hydrophilic and high dose drugs

The present study explores the effect of melt binding of Soluplus® on in vitro release profiles of two hydrophilic drugs, metformin hydrochloride, and paracetamol. The melt viscosities of bulk polymer and physical mixtures with different concentrations of selected APIs were analyzed by using a rheometer. The rheological evaluation revealed both the suitable temperature range for melt extrusion process and drug-polymer extrudability. The effect of formulation and processing parameters (e.g. polymer/drug ratio, temperature, screw speed) on extrudability were evaluated in terms of torque and residence time analysis. The extrudates obtained via hot melt extrusion (HME) processing exhibited good flow and compressibility. Differential scanning calorimetry (DSC) and X-ray diffraction studies examined the change in glass transition temperature (Tg) and crystalline pattern of extruded formulations where all extruded formulations seemed to have retained their crystallinity. The thermogravimetric analysis determined the thermal stability (weight loss) as a function of operating temperature whereas scanning electron microscopy (SEM) showed agglomerated microstructure and rough surface with a porous network and void spaces. The tablets obtained after compression of milled extrudates showed excellent hardness with robust tablet characteristics. The in vitro release studies of individual batches performed in various USP recommended dissolution media (for paracetamol) showed the pH-independent release of the hydrophilic drugs from the polymer matrices.

Development and evaluation of taste masked dry syrup formulation of potassium chloride

Potassium chloride (KCl) syrup is widely used for the oral treatment of the hypokalemia. However, it is associated with unacceptable taste. In the present study, we sought to develop a palatable and easy to reconstitute KCl dry syrup as a commercially viable alternative to currently available KCl syrup. We explored the potential of Eudragit E100 as a taste-masking polymer to coat and improve the palatability of the KCl. With the help of fluid bed processor, KCl was coated with the solution containing varying amounts of Eudragit E100 (4, 6, 10 and 15%). Coating with 10% polymer solution enabled optimal fluid bed processing, higher entrapment of the KCl (81%) and better in vitro release profile in 0.1 N HCl and pH 6.8 phosphate buffer. A dry syrup formulation containing Eudragit E100 coated KCl with good physical and chemical stability in dry and reconstituted state was developed. The palatability of the optimized formulation and commercially available KCl syrup was evaluated using the Electronic Taste Sensing Machine. The developed formulation showed~ 2-fold better taste-masking compared to the commercial KCl syrup. Thus, present investigation describes the development of an effective alternative to the current KCl syrup that can offer better palatability, stability and patient compliance.

Developments in Taste-Masking Techniques for Traditional Chinese Medicines

A variety of pharmacologically active substances, including chemotherapeutic drugs and the substances from traditional Chinese medicine (TCM), always exhibit potent bioactivities after oral administration. However, their unpleasant taste (such as bitterness) and/or odor always decrease patient compliance and thus compromise their curative efficacies in clinical application. Therefore, the developments of taste-masking techniques are of great significance in improving their organoleptic properties. However, though a variety of taste-masking techniques have been successfully used to mask the unpalatable taste of chemotherapeutic drugs, their suitability for TCM substances is relatively limited. This is mainly due to the fact that the bitter ingredients existing in multicomponent TCM systems (i.e., effective fractions, single Chinese herbs, and compound preparations) are always unclear, and thus, there is lack of tailor-made taste-masking techniques to be utilized to conceal their unpleasant taste. The relevant studies are also relatively limited. As a whole, three types of taste-masking techniques are generally applied to TCM, including (i) functional masking via sweeteners, bitter blockers, and taste modifiers; (ii) physical masking via polymer film-coating or lipid barrier systems; and (iii) biochemical masking via intermolecular interaction, β-cyclodextrin inclusion, or ion-exchange resins. This review fully summarizes the results reported in this field with the purpose of providing an informative reference for relevant readers.

Hot Melt Extrusion: Highlighting Physicochemical Factors to Be Investigated While Designing and Optimizing a Hot Melt Extrusion Process

Hot-melt extrusion (HME) is a well-accepted and extensively studied method for preparing numerous types of drug delivery systems and dosage forms. It offers several advantages: no solvents are required, it is easy to scale up and employ on the industrial level, and, in particular, it offers the possibility of improving drug bioavailability. HME involves the mixing of a drug with one or more excipients, in general polymers and even plasticizers, which can melt, often forming a solid dispersion of the drug in the polymer. The molten mass is extruded and cooled, giving rise to a solid material with designed properties. This process, which can be realized using different kinds of special equipment, may involve modifications in the drug physicochemical properties, such as chemical, thermal and mechanical characteristics thus affecting the drug physicochemical stability and bioavailability. During process optimization, the evaluation of the drug solid state and stability is thus of paramount importance to guarantee stable drug properties for the duration of the drug product shelf life. This manuscript reviews the most important physicochemical factors that should be investigated while designing and optimizing a hot melt extrusion process, and by extension, during the different pre-formulation, formulation and process, and post-formulation phases. It offers a comprehensive evaluation of the chemical and thermal stability of extrudates, the solid physical state of extrudates, possible drug-polymer interactions, the miscibility/solubility of the drug-polymer system, the rheological properties of extrudates, the physicomechanical properties of films produced by hot melt extrusion, and drug particle dissolution from extrudates. It draws upon the last ten years of research, extending inquiry as broadly as possible.