Application of biorelevant saliva-based dissolution for optimisation of orally disintegrating formulations of felodipine

Unmet technological demands in orodispersible films for age-appropriate paediatric drug delivery

Age-appropriateness of a formulation is the ability to deliver variable but accurate doses to the paediatric population in a safe and acceptable manner to improve medical adherence and reduce medication errors. Paediatric drug delivery is a challenging area of formulation research due to the existing gap in knowledge. This includes the unknown safety of excipients in the paediatric population, the need for an age-appropriate formulation, the lack of an effective taste-masking method and the lack of paediatric pharmacokinetic data and patient acceptability. It is equally important to establish methods for predicting the biopharmaceutical performance of a paediatric formulation as a function of age. Overcoming the challenges of existing technologies and providing custom-made solutions for the development of age-appropriate formulation is, therefore, a daunting task. Orodispersible films (ODF) are promising as age-appropriate formulations, an unmet need in paediatric drug delivery. New technological improvements in taste masking, improving solubility and rate of dissolution of insoluble drugs, the flexibility of dosing and extemporaneous preparation of these films in a hospital good manufacturing practises (GMP) setup using 3D printing can increase its acceptance among clinicians, patients and caregivers. The current review discusses the problems and possibilities in ODF technology to address the outstanding issues of age-appropriateness, which is the hallmark of patient acceptance and medical adherence in paediatrics.

Optimization of the Preformulation and Formulation Parameters in the Development of New Extended-Release Tablets Containing Felodipine

Herein, new extended-release tablets containing felodipine were developed. For the orally administered formulations, optimization of the preformulation and formulation parameters was performed to assess the performance of the dosage form. Initially, the morphological and physical characterization of two forms of felodipine (microcrystalline and macrocrystalline) using Fourier transform infrared spectroscopy, differential scanning calorimetry and optical microscopy was performed. The pharmaco-technical properties of the two felodipine forms were also determined. Subsequently, formulation studies for felodipine extended-release tablets were performed. Mathematical modelling of release kinetics of felodipine from developed formulations using a power law model was also performed. Based on the influence of formulation factors on the in vitro availability of felodipine in experimental tablets, a new extended-release tablet formulation was established.

Formulation and in-vitro characterization of fast-disintegrating herbal extract sublingual immunotherapy tablet for peanut-induced allergic asthma

Background

Allergen immunotherapy (AIT) involves the regimen of gradually incrementing doses of the allergen, thereby inducing desensitization and tolerance. Sublingual Immunotherapy tablets (SLIT-tablets) have been formulated for several allergies and had manifested efficacy for allergic rhinitis and allergic asthma. SLIT promises an alternative method to other routes of AIT enabling patients to self-administer AIT.

Objective

The study aimed to formulate fast disintegrating SLIT containing crude peanut extract for peanut-induced allergic asthma.

Methods

The crude peanut extract was prepared by a simple extraction method and was subjected to quantitative and qualitative analysis. The extract was also characterised for its physical properties. The preformulation study for the extract and excipients of the tablet was performed using FT-IR spectroscopy and Differential scanning calorimetry. The tablet powder blends were characterised for pre-compression properties. The SLIT tablets were developed by direct compression and the post-compression evaluation was performed.

Results

The results of the quantitative and qualitative analysis of extract confirmed the presence of peanut proteins in the extract. The preformulation studies using FT-IR spectroscopy and Differential Scanning Calorimetry revealed that there is no significant interaction between the CPE and excipients. The pre-compression characterisation showed that the powder blends had good flowproperties. Three doses of SLIT tablets were formulated with each dose containing four batches and the tablet of each dose was optimized by studying the effect of varying concentrations of super disintegrants on disintegration time and dissolution rate. The post compression characterization of the tablets was performed and the optimized batch of the three doses with the concentration of 5% crospovidone and 2% croscarmellose sodium showed less wetting time and high-water absorption ratio, shorter disintegration time of 14secs and maximum drug release of >90% within 2-3 min.

Conclusion

The results indicated the suitability of formulated SLIT tablets for peanut induced allergic asthma.

Utilising Co-Axial Electrospinning as a Taste-Masking Technology for Paediatric Drug Delivery

The present study describes the use of two taste-masking polymers to fabricate a formulation of chlorpheniramine maleate for paediatric administration. Co-axial electrospinning was utilized to create layered nanofibres; the two polymers, Eudragit® E PO and Kollicoat® Smartseal, were alternated between the core and the shell of the system in order to identify the optimum taste-masked formulation. The drug was loaded in the core on all occasions. It was found that the formulation with Kollicoat® Smartseal in the core with the drug, and Eudragit® E PO in the shell showed the most effective taste-masking compared to the other formulations. These fibres were in the nano-range and had smooth morphology as verified by scanning electron microscopy. Solid-state characterization and thermal analysis confirmed that amorphous solid dispersions were formed upon electrospinning. The Insent E-tongue was used to assess the taste-masking efficiency of the samples, and it was found that this formulation was undetectable by the bitter sensor, indicating successful taste-masking compared to the raw version of the drug. The E-tongue also confirmed the drug's bitterness threshold as compared to quinine HCl dihydrate, a parameter that is useful for formulation design and taste-masking planning.

Comparative Study of Dissolution for Cannabidiol in EU and US Hemp Oil Products by HPLC

For the first time, a simple and robust HPLC method has been developed for dissolution studies for cannabidiol (CBD) in hemp oil products. An isocratic elution of samples performed on SOLAS™ C18 150 mm x 4.6 mm, 5 μm column with a mobile phase consisting of 75:25 acetonitrile-water v/v, delivered at a flow rate 1.5 mL/minutes to variable wavelength detector using 214 nm. An in-house validated assay test was executed for calculating the purity of hemp oil products and also for considering the dissolution medium to be used. For dissolution studies, equivalent of 5 mg and/or 10 mg of the active was introduced into 500 mL of simulated gastric and intestinal fluids separately, and dissolution was performed at 50 rpm using paddles for 180 min. Dissolution profiles for hemp oil products purchased from the United States and Europe were compared. Additionally, dissolution testing was conducted to study the effect of percentage CBD release on increased agitation speed of 75 and 100 rpm and also, on extended dissolution runtime of 240 min.

Development and optimisation of simulated salivary fluid for biorelevant oral cavity dissolution

Drug release within the oral cavity can be of paramount importance for formulations that are designed for specific purposes such as taste-masking, faster onset of therapeutic action, localization of treatment or avoidance of first-pass metabolism. Preclinical methods for assessment of dissolution in the oral cavity are necessary for design and development of these formulation but currently there is no consensus on what variables should be defined to achieve biorelevance in these tests. In this study, biorelevant simulated salivary fluids (SSFs) that can be uniformly applied for oral cavity dissolution testing were developed. Unstimulated saliva (US) SSF and stimulated saliva (SS) SSF were separately developed since the two states significantly differ. Physicochemical properties including pH, buffer capacity, surface tension and viscosity were assessed during development and optimised to mimic human saliva (HS). In order to account for the salivary proteins in HS, use of bovine submaxillary mucin (BSM) and porcine gastric mucin (PGM) in SSFs was evaluated. Following optimisation of the SSFs, biorelevance of the developed SSFs to HS was assessed by their comparative physicochemical properties as well as dissolution profiles of three diverse model compounds (sildenafil citrate, efavirenz, and caffeine) which showed comparable profiles between the SSFs and HS. This work addresses the lack of uniformed biorelevant dissolution media for oral cavity dissolution studies and provides a basis for standardised dissolution tests that provide consistency and harmonisation in future oral cavity dissolution studies. We envisage that this will have a positive impact on the development of new medicines that require functionality in the oral cavity.

Utilization of Ethylcellulose Microparticles with Rupatadine Fumarate in Designing Orodispersible Minitablets with Taste Masking Effect

Minitablets in orodispersible form constitute a flexible drug delivery tool for paediatric and geriatric population as they eliminate the risk of chocking and do not require drinking water in the application. Due to their direct contact with taste buds, taste sensation is an important factor. Preparing microparticles with taste masking polymers utilizing spray drying is an efficient technique for reducing the bitterness of drugs. Ethylcellulose is a hydrophobic polymer widely used as a taste masking material. Rupatadine fumarate, one of the newest antihistamines, features an intensive bitter taste, hence in designing orodispersible formulations, achieving an acceptable taste is a crucial issue. The main objective of this work was to formulate orodispersible minitablets containing taste masked ethylcellulose-based microparticles with rupatadine fumarate and evaluation of their quality, especially in terms of taste masking efficacy. The accessed data indicated that all obtained minitablets were characterized by beneficial pharmaceutical properties. Three independent methods: in vivo with healthy volunteers, in vitro drug dissolution, and “electronic tongue” confirmed that all designed formulations provided satisfactory taste masking rate and that formulation F15 (prepared with Pearlitol^® Flash and Surelease^® microparticles with rupatadine fumarate) was characterized by the lowest bitterness score.

A physiologically-based drug absorption modeling for orally disintegrating tablets

The aim of this research was to simulate oral pharmacokinetic (PK) profiles of atorvastatin from orally disintegrating tablets (ODTs) dosed without water ingestion in fasted humans. The in vitro dissolution profiles of three different formulations of ODTs were evaluated with fasted state biorelevant media using a paddle dissolution apparatus, and the results were coupled with an in silico model to simulate the in vivo oral PK profiles of ODTs following administration to humans. Since the dissolution rates of the ODTs in the intestinal medium (FaSSIF-V2) were highly affected by pre-exposure of the tablets to the stomach medium (FaSSGF), the simulation model took account of the relationship between the gastric emptying time and the dissolution performance of the tablets in the small intestine. The ODTs were formulated with drug-containing pellets. After oral dosing of the ODTs without water ingestion, gastric emptying of the pellets was assumed to follow first order kinetics. Thus, rate constants ranging between 0.69 and 8.3 h^-1 were applied in the PK simulations. The simulation model was built using Stella Professional® software. The results of the PK simulations suggest that the plasma concentration profiles of the ODTs can be described using the prediction model, but that different gastric emptying parameters for each ODT formulation are needed in humans.

Development of medicated chewing gum of taste masked levocetirizine dihydrochloride using different gum bases: in vitro and in vivo evaluation

Objective: The aim of this study was to develop medicated chewing gum (MCG) formulation for taste-masked levocetirizine dihydrochloride (LCZ) that can provide fast drug release into the salivary fluid.Methods: Taste-masked LCZ was first prepared by two methods: cyclodextrin complexation using Kleptose or Captisol and formation of drug resin complex using Kyron T-154 or Kyron T-314 to overcome poor LCZ palatability. MCGs were then prepared using the taste-masked drug, gum base (Artica-T, Chicle, or Health In Gum (HIG), plasticizer (glycerol or soy lecithin at 6 or 8% of the final gum weight). The developed MCGs were evaluated for physical properties, content uniformity, and drug release. Best release MCGs were evaluated thermally to investigate the plasticizer effectiveness and for ex vivo chew out study to confirm adequate drug release. Drug bioavailability was determined for selected formula compared to commercial tablets.Results: Based on taste-masking efficiency, drug/Kleptose complex (1:3 molar ratio) was chosen for incorporation into chewing gums. Physical properties and drug release showed that gum base type, plasticizer type, and level affected not only physical properties but also drug release from MCGs. Thermal study showed decreased glass transition temperature (Tg) with increased plasticizer level. Chew out study confirmed almost complete drug release after a few minutes of chewing. Pharmacokinetic results showed shorter t_max (0.585 vs. 1.375 h) and higher C_max (0.113 vs. 0.0765 μg/mL) for MCGs than conventional tablets.Conclusion: Results provided evidence that MCGs could be a better alternative to conventional tablet formulations with improved bioavailability and enhanced palatability.

Is rat a good model for assessment of particulate-based taste-masked formulations?

Recently there has been an increased interest to develop specialised dosage forms that are better suited to specific patient populations, such as paediatrics and geriatrics. In these patient populations the acceptability of the oral dosage form can be paramount to the products success. However, many Active Pharmaceutical Ingredients (APIs) are known to cause an aversive taste response. One way to increase the acceptability and to enhance the palatability of the formulation is to design coated taste-masked particulate-based dosage forms. The masking of poorly tasting drugs with physical barriers such as polymer coatings can be utilised to prevent the release of drug within the oral cavity, thus preventing a taste response. However, currently, there are few assessment tools and models available to test the efficiency of these particulate-based taste-masked formulations. The rat brief access taste aversion model has been shown to be useful in assessment of taste for liquid dosage forms. However, the applicability of the rat model for particulate-based taste masked formulations is yet to be assessed. It is not understood whether dissolution, solubility and thus exposure of the drug to taste receptors would be the same in rat and human. Therefore, rat saliva must be compared to human saliva to determine the likelihood that drug release would be similar within the oral cavity for both species. In this study rat saliva was characterised for parameters known to be important for drug dissolution, such as pH, buffer capacity, surface tension, and viscosity. Subsequently dissolution of model bitter tasting compounds, sildenafil citrate and efavirenz, in rat saliva was compared to dissolution in human saliva. For all parameters characterised and for the dissolution of both drugs in rat saliva, a substantial difference was observed when compared to human saliva. This discrepancy in saliva parameters and dissolution of model drugs suggests that preclinical taste evaluation of particulate-based taste-masked formulations suggests rat is not a good model for predicting taste of solid dosage forms or undissolved drug where dissolution is required. Alternative preclinical in vivo models in other species, or improved biorelevant in vitro models should be considered instead.