Bioequivalence of rimegepant, a small molecule CGRP receptor antagonist, administered as an oral tablet, a sublingual orally disintegrating tablet, and a supralingual orally disintegrating tablet: two phase 1 randomized studies in healthy adults

BACKGROUND

Rimegepant is an orally administered small molecule calcitonin gene-related peptide receptor antagonist indicated for the acute and preventive treatment of migraine.

METHODS

Two single-center, phase 1, open-label, randomized bioequivalence studies were conducted in healthy adult non-smokers, aged 18-55 years. One study compared the rate and extent of absorption of the marketed formulation of rimegepant 75 mg orally disintegrating tablet (ODT) administered sublingually with rimegepant 75 mg oral tablet, an earlier development formulation; the second compared the rate and extent of absorption of 75 mg rimegepant ODT administered supralingually with rimegepant oral tablet.

RESULTS

The ln-transformed geometric mean ratios for the area under the curve (AUC) from time 0 to the last available concentration time point (time t) (AUC0-t), AUC from time 0 to infinity (AUC0-inf), and maximum observed concentration (Cmax) of sublingual rimegepant ODT vs. rimegepant tablet were 97, 97, and 105%, respectively, and the 90% confidence intervals (CIs) were all within the predefined range (80-125%) for bioequivalence. The ln-transformed geometric mean ratios for the AUC0-t and AUC0-inf of supralingual rimegepant ODT vs. rimegepant tablet were 98%, the 90% CIs were within the predefined range (80-125%), and the geometric mean ratio for Cmax was 103% with the 95% upper confidence bound for the scaled average bioequivalence criterion of -0.0575 (within-participant coefficient of variation for the reference for Cmax > 30%) for bioequivalence.

CONCLUSIONS

Rimegepant 75 mg ODT, administered sublingually or supralingually, and rimegepant 75 mg oral tablet were bioequivalent.

Exploring the potential of pH-sensitive polymers in targeted drug delivery

The pH-sensitive polymers have attained significant attention in the arena of targeted drug delivery (TDD) because of their exceptional capability to respond to alteration in pH in various physiological environments. This attribute aids pH-sensitive polymers to act as smart carriers for therapeutic agents, transporting them precisely to target locations while curtailing the release of drugs in off-targeted sites, thereby diminishing side effects. Many pH-responsive polymers in TDD have revealed promising results, with increased therapeutic efficacy and decreased toxic effects. Several pH-sensitive polymers, including, hydroxy-propyl-methyl cellulose, poly (methacrylic acid) (Eudragit series), poly (acrylic acid), and chitosan, have been broadly studied for their myriad applications in the management of various types of diseases. Additionally, the amalgamation of pH-sensitive polymers with, additive manufacturing techniques like 3D printing, has resulted in the progression of novel drug delivery systems that regulate drug release in a controlled manner. Herein, types of pH-sensitive polymers in TDD are systemically reviewed. We have briefly discussed the nanocarriers employed for the delivery of various pH-sensitive polymers in TDD. Finally, miscellaneous applications of pH-sensitive polymers are discussed thoroughly with special attention to the implication of 3D printing in pH-sensitive polymers.

Development of α-Cyclodextrin-Based Orally Disintegrating Tablets for 4-Phenylbutyrate

Despite major improvements brought about by the introduction of taste-masked formulations of 4-phenylbutyrate (PB), poor compliance remains a significant drawback to treatment for some pediatric and dysphagic patients with urea cycle disorders (UCDs). This study reports on the development of a cyclodextrin (CD)-based orally disintegrating tablet (ODT) formulation for PB as an alternative to existing formulations. This is based on previous reports of the PB taste-masking potential of CDs and the suitability of ODTs for improving compliance in pediatric and dysphagic populations. In preliminary studies, the interactions of PB with α and βCD in the solid state were characterized using X-ray diffraction, scanning electron microscopy, dissolution, and accelerated stability studies. Based on these studies, lyophilized PB-CD solid systems were formulated into ODTs after wet granulation. Evaluation of the ODTs showed that they had adequate physical characteristics, including hardness and friability and good storage stability. Notably, the developed αCD-based ODT for PB had a disintegration time of 28 s and achieved a slightly acidic and agreeable pH (≈5.5) in solution, which is suitable for effective PB-CD complexation and taste masking. The developed formulation could be helpful as an alternative to existing PB formulations, especially for pediatric and dysphagic UCD patients.

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.

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.

Potential of graphene oxide as a drug delivery system for Sumatriptan: a detailed density functional theory study

The adsorption property of Sumatriptan drug onto graphene oxide (GO) was studied using density functional theory (DFT) calculations. All possible initial positions of drug adsorption were considered to find out which one is energetically favorable. According to the achieved findings, the stronger interactions occurred between the positively polarized parts of the Sumatriptan (i.e. hydrogen atoms of the-OH and -NH parts) and negatively polarized oxygen atoms of the GO. The presence of non-covalent interactions of GO and Sumatriptan was confirmed based on the determined geometrical parameters, electronic structure analysis results, and adsorption energies. Different parameters such as frontier molecular orbital (FMO), natural bond orbital (NBO), dipole moment, and solation energy were investigated. Global indices such as hardness, softness, chemical potential, and electrophilicity of all systems were calculated and compared. The adsorption energy values were determined within the range of -8.39 to -10.59 kcal/mol (-1.87 to -5.67 BSSE corrected) in the water solvent for different adsorption geometries. The obtained results show that GO can act as a promising carrier/sensor for Sumatriptan drug in practical application.Communicated by Ramaswamy H. Sarma.

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.

Original research paper. Characterization and taste masking evaluation of microparticles with cetirizine dihydrochloride and methacrylate-based copolymer obtained by spray drying

Taste of a pharmaceutical formulation is an important parameter for the effectiveness of pharmacotherapy. Cetirizine dihydrochloride (CET) is a second-generation antihistamine that is commonly administered in allergy treatment. CET is characterized by extremely bitter taste and it is a great challenge to successfully mask its taste; therefore the goal of this work was to formulate and characterize the microparticles obtained by the spray drying method with CET and poly(butyl methacrylate-co-(2-dimethylaminoethyl) methacrylate-co-methyl methacrylate 1:2:1 copolymer (Eudragit E PO) as a barrier coating. Assessment of taste masking by the electronic tongue has revealed that designed formulations created an effective taste masking barrier. Taste masking effect was also confirmed by the in vivo model and the in vitro release profile of CET. Obtained data have shown that microparticles with a drug/polymer ratio (0.5:1) are promising CET carriers with efficient taste masking potential and might be further used in designing orodispersible dosage forms with CET.

Preparation and characterization of a powder containing an oily liquid drug with Eudragit EPO or L100 copolymer

Oily liquid drugs are not convenient for oral administration. We developed a powder containing clofibrate (CF), a model of an oily drug, using aminoalkyl methacrylate copolymer (EPO) or methacrylic acid copolymer (L100). CF or a mixture of CF and soybean oil was emulsified with EPO or L100 aqueous solution. Using a high-pressure homogenizer, a stable emulsion was obtained, and a powder was then obtained by lyophilization of the emulsion. The content of CF in the powder depended on the formulation, with the highest contents being 24.6% and 27.1% for EPO and L100, respectively. The incorporation ratio of CF was higher for L100 than for EPO. The powder using EPO was sticky because of leaked CF and the low glass transition temperature of EPO. The powder using L100 was a typical powder obtained by lyophilization. The leakage of CF from the powder was <2%, lower than for EPO powder. The dissolution of CF from powder using EPO was fast, regardless of the pH of the medium, but the powder using L100 showed enteric-soluble characteristics, indicating that CF is well incorporated in L100.

A novel intranasal breath-powered delivery system for sumatriptan: a review of technology and clinical application of the investigational product AVP-825 in the treatment of migraine

INTRODUCTION

AVP-825, formerly 'OptiNose Sumatriptan,' is an investigational Breath-Powered(TM) Bi-Directional(TM) intranasal delivery system containing low-dose sumatriptan (22 mg intranasal powder) that avoids limitations of other types of intranasal administration by taking advantage of unique features of nasal anatomy and physiology.

AREAS COVERED

This review summarizes intranasal drug delivery for migraine, how the breath-powered technology works, and AVP-825 pharmacokinetic, efficacy and safety/tolerability findings. To identify AVP-825 clinical studies, a PubMed/MEDLINE database search was conducted with the terms AVP-825, OptiNose, OptiNose Sumatriptan, Breath-Powered Nasal Delivery or sumatriptan powder. Of 20 articles, 5 clinical studies were identified, including the head-to-head comparative COMPASS trial (AVP-825 vs oral sumatriptan) and two placebo-controlled studies.

EXPERT OPINION

AVP-825 has faster sumatriptan absorption versus oral tablets or traditional liquid nasal spray. In Phase II/III randomized, double-blind, placebo-controlled trials, AVP-825 produced early and sustained efficacy with minimal triptan-related adverse effects. In COMPASS, AVP-825 produced earlier reduction of migraine pain intensity and migraine-associated symptoms than 100 mg oral sumatriptan, and higher early rates of pain relief and pain freedom, similar sustained efficacy, and fewer atypical sensations. AVP-825 has the potential to provide migraine patients with improved intranasal administration of sumatriptan that may enhance efficacy and tolerability.

Non-ionic surfactants as novel intranasal absorption enhancers: in vitro and in vivo characterization

OBJECTIVE

To explore the potential of non-ionic surfactants as novel intranasal absorption enhancers.

METHODS

Taking sumatriptan succinate (SMS) as a model drug, influence of different non-ionic surfactants, including laurate sucrose ester (SE), cremophor EL and poloxamer 188, on the intranasal absorption of SMS was investigated using an in situ nasal perfusion technique in rats. Ciliotoxicity of the non-ionic surfactants was evaluated using an in situ toad palate model. In vivo behavior of the selected formulations was studied in rats.

RESULTS

All the non-ionic surfactants investigated increased the intranasal absorption of SMS remarkably but with varied extent and trend. Moreover, it was revealed that at the same concentration, laurate SE had better permeation-enhancing effect than that of cremophor EL and poloxamer 188. The ciliotoxicity results showed that all the non-ionic surfactants were regarded as safe at selected concentrations. Based on the in situ absorption data and ciliotoxicity results, the following three samples, 0.5% laurate SE, 0.1% cremophor EL and 0.5% poloxamer 188 were selected for in vivo absorption studies in rats. Among them, 0.5% laurate SE group presented the highest enhancing effect, followed by 0.1% cremophor EL and 0.5% poloxamer 188 group, with absolute bioavailability 29.99%, 22.64% and 20.90%, respectively.

CONCLUSIONS

Laurate SE is a promising intranasal absorption enhancer.

pH- and ion-sensitive polymers for drug delivery

INTRODUCTION

Drug delivery systems (DDSs) are important for effective, safe, and convenient administration of drugs. pH- and ion-responsive polymers have been widely employed in DDS for site-specific drug release due to their abilities to exploit specific pH- or ion-gradients in the human body.

AREAS COVERED

Having pH-sensitivity, cationic polymers can mask the taste of drugs and release drugs in the stomach by responding to gastric low pH. Anionic polymers responsive to intestinal high pH are used for preventing gastric degradation of drug, colon drug delivery and achieving high bioavailability of weak basic drugs. Tumor-targeted DDSs have been developed based on polymers with imidazole groups or poly(β-amino ester) responsive to tumoral low pH. Polymers with pH-sensitive chemical linkages, such as hydrazone, acetal, ortho ester and vinyl ester, pH-sensitive cell-penetrating peptides and cationic polymers undergoing pH-dependent protonation have been studied to utilize the pH gradient along the endocytic pathway for intracellular drug delivery. As ion-sensitive polymers, ion-exchange resins are frequently used for taste-masking, counterion-responsive drug release and sustained drug release. Polymers responding to ions in the saliva and gastrointestinal fluids are also used for controlled drug release in oral drug formulations.

EXPERT OPINION

Stimuli-responsive DDSs are important for achieving site-specific and controlled drug release; however, intraindividual, interindividual and intercellular variations of pH should be considered when designing DDSs or drug products. Combination of polymers and other components, and deeper understanding of human physiology are important for development of pH- and ion-sensitive polymeric DDS products for patients.

Preparation and evaluation of orally disintegrating tablets containing taste-masked microcapsules of berberine hydrochloride

The purpose of this study was to prepare and evaluate a taste-masked berberine hydrochloride orally disintegrating tablet for enhanced patient compliance. Taste masking was performed by coating berberine hydrochloride with Eudragit E100 using a fluidized bed. It was found that microcapsules with a drug-polymer ratio of 1:0.8 masked the bitter taste obviously. The microcapsules were formulated to orally disintegrating tablets and the optimized tablets containing 6% (w/w) crospovidone XL and 15% (w/w) microcrystalline cellulose showed the fastest disintegration, within 25.5 s, and had a pleasant taste. The dissolution profiles revealed that the taste-masked orally disintegrating tablets released the drug faster than commercial tablets in the first 10 min. However, their dissolution profiles were very similar after 10 min. The prepared taste-masked tablets remained stable after 6 months of storage. The pharmacokinetics of the taste-masked and commercial tablets was evaluated in rabbits. The Cmax, Tmax, and AUC0-24 values were not significantly different from each other, suggesting that the taste-masked orally disintegrating tablets are bioequivalent to commercial tablets in rabbits. These tablets will enhance patient compliance by masking taste and improve patients' quality of life.

Formulation and evaluation of sublingual tablets containing Sumatriptan succinate

Objective:

Sumatriptan succinate is a selective 5-hydroxytryptamine-1 receptor agonist effective in the acute treatment of migraine headaches, having low bioavailability of about 15% orally due to first-pass metabolism. The purpose of this research was to mask the intensely bitter taste of Sumatriptan succinate and to formulate fast-acting, taste-masked sublingual tablet formulation.

Materials and Methods:

Taste masking was performed by solid dispersion method with mannitol and ion exchange with Kyron T 114 because it releases the drug in salivary pH. The resultant batches were evaluated for in-vivo taste masking as well compatability study (Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC)). For a better feel in the mouth, menthol and sweetener Na saccharine were added to the tablet formulation. The tablets were prepared by direct compression and evaluated for weight variation, thickness, friability, drug content, hardness, disintegration time, wetting time, in vitro drug release, and in vitro permeation study.

Results and Discussion:

Optimized batches disintegrated in vitro within 28-34 s. Maximum drug release could be achieved with in 10 min for the solid dispersion batches and 14-15 min for the ion-exchange batches with Kyron T 114. The optimized tablet formulation showed better taste and the formulated sublingual tablets may act as a potential alternate for the Sumatriptan succinate oral tablet.

Conclusion:

Sumatriptan succinate can be successfully taste-masked by both the solid dispersion method using mannitol by the melting method and Ion exchange resin with Kyron T114. It was also concluded that prepared formulation improve bioavailability by prevention of first pass metabolism.

Development of orally disintegrating tablets of Perphenazine/hydroxypropyl-β-cyclodextrin inclusion complex

The aim of the present work was to prepare perphenazine (PPZ) orally disintegrating tablets (ODTs) based on the use of hydroxypropyl-β-cyclodextrin (HP-β-CD) forming inclusion complex with PPZ to improve the solubility and dissolution of this practically insoluble drug. Phase solubility studies were performed to evaluate the complexation of PPZ with HP-β-CD in three aqueous systems. The inclusion complex prepared by evaporation method was characterized by different physicochemical techniques, including the dissolution studies. The prepared complex was incorporated into ODTs containing different fillers and disintegrants. The ODTs prepared by direct compression were evaluated for drug content, hardness, porosity, friability, in vitro disintegration time (DT), wetting time (WT) and dissolution profiles. The solubility and dissolution rate were substantially improved compared with that of PPZ. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analyses suggested that PPZ could form true inclusion complex with HP-β-CD. The optimized formulation F6 exhibited short DT (15.5 ± 1.9 s) and WT (34.2 ± 2.3 s), sufficient hardness (30.4 ± 1.6 N/mm) and rapid drug dissolution. The developed tablet formulation could be a promising drug delivery system with improvements in PPZ bioavailability and patient compliance.