Surface thermodynamics of mucoadhesive dry powder formulation of zolmitriptan

A narrative review investigating the potential effect of lubrication as a mitigation strategy for whey protein-associated mouthdrying

Whey is consumed by active adults to aid muscle recovery and growth, the general population as a nutritious convenient food, and by older adults to prevent sarcopenia due to its high leucine content. However, whey protein has poor consumer acceptance in this latter demographic, partially due to mouthdrying. This is thought to result from electrostatic interactions between whey and salivary proteins, mucoadhesion to the oral mucosa, and the inherent astringency of acidity. Previous unsuccessful mitigation strategies include viscosity, sweetness and fat manipulation. This literature review reveals support for increasing lubrication to reduce mouthdrying. However, of the 50 papers reviewed, none have proposed a method by which whey protein could be modified as an ingredient to reduce mouthdrying in whey-fortified products. This review recommends the use of modern technologies to increase lubrication as a novel mitigation strategy to reduce mouthdrying, with the potential to increase consumer acceptance.

Prevention of esophageal stenosis via in situ cross-linkable alginate/gelatin powder in a new submucosal exfoliation model in rats

Endoscopic submucosal dissection (ESD) for the treatment of esophageal mucosal lesions often leads to postoperative stenosis, causing difficulty in swallowing, known as dysphagia. In this study, we developed an in situ cross-linkable powder composed of alginate, gelatin, transglutaminase (TG), and calcium chloride ions (Ca2+), which can be administered through a 1.5 m-long and 3.2 mm-diameter endoscopic instrument channel. The powdered mixture of alginate and gelatin quickly formed a hydrogel by absorbing body fluids and was cross-linked by TG and Ca2+, which adhered ex vivo to porcine submucosal layers for over 2 weeks. In addition, we developed a new submucosal exfoliation model in rats that induced severe stenosis, similar to the ESD-induced stenosis models in clinical practice. When administered to the new rat model, the powder system effectively reduced the severity of esophageal stenosis based on body weight change monitoring, anatomical findings, and histological analysis. The body weight of the rats was maintained at the initial weight on postoperative day 14 (POD14), and epithelialization on POD7 and 14 improved to almost 100%. Additionally, collagen accumulation and the number of α-SMA-positive cells decreased due to powder administration. Therefore, these findings indicate that the in situ cross-linkable powder can prevent esophageal stenosis after ESD.

Mucoadhesive drug delivery systems: a promising non-invasive approach to bioavailability enhancement. Part I: biophysical considerations

INTRODUCTION

Mucoadhesive drug delivery systems (MDDS) are specifically designed to interact and bind to the mucosal layer for localized, prolonged, and/or targeted drug delivery. Over the past 4 decades, different sites have been explored for mucoadhesion including the nasal, oral, and vaginal cavities, the gastrointestinal tract and ocular tissues.

AREAS COVERED

The present review aims to provide a comprehensive understanding of different aspects of MDDS development. Part I focuses on the anatomical and biological aspects of mucoadhesion, which include a detailed elucidation of the structure and anatomy of the mucosa, the properties of mucin, the different theories of mucoadhesion and evaluation techniques.

EXPERT OPINION

The mucosal layer presents a unique opportunity for effective localization as well as systemic drug delivery via MDDS. Formulation of MDDS requires a thorough understanding of the anatomy of mucus tissue, the rate of mucus secretion and turnover, and the physicochemical properties of mucus. Further, the moisture content and the hydration of polymers are crucial for interaction with mucus. A confluence of different theories used to explain the mechanism of mucoadhesion is useful for understanding the mucoadhesion of different MDDS and their evaluation is subject to factors, such as the site of administration, type of dosage form, and duration of action. [Figure: see text].

Spray dried powders for nasal delivery: Process and formulation considerations

Powders for nasal delivery have been recognized as advantageous dosage forms over liquids due to increased stability and residence time on nasal mucosa, with improved bioavailability. They can be manufactured by spray-drying, allowing the optimization of the particle properties that are critical to guarantee nasal deposition, as size and shape. It is also a scalable and flexible method already explored extensively in the pharmaceutical industry. However, it is important to understand how process parameters, particle physical properties and formulation considerations affect the product performance. Hence, this review aims to provide an overview of nasal powder formulation and processing through spray drying, with an emphasis on the variables that impact on performance. To this purpose, we describe the physical, biological and pharmacological phenomena prior to drug absorption as well as the most relevant powder properties. Formulation considerations including qualitative and quantitative composition are then reviewed, as well as manufacturing considerations including spray drying relevant parameters.

Tailored Doxycycline Hyclate Loaded In Situ Gel for the Treatment of Periodontitis: Optimization, In Vitro Characterization, and Antimicrobial Studies

Currently, periodontitis is treated by oral dosage forms (antibiotics) which shows systemic side effects and failed to reach the therapeutic concentration (above minimum inhibitory concentration, MIC) in the periodontal pocket. The present study aimed to overcome the above issues, by designing tailored doxycycline hyclate laden in situ gel by Poloxamer 407, chitosan, and polyethylene glycol 600. The in situ gel-forming system has attracted attention owing to its ability of sustained drug release above MIC, easy administration (syringeability), and high drug retention (localization) in the periodontal cavity. The Box-Behnken design (BBD) was used to tailor and optimize the concentration of Poloxamer 407 (X₁ = 14.3%), chitosan (X₂ = 0.58%), and polyethylene glycol 600 (X₃ = 1.14%) to achieve sufficient syringeability (149 N), t_90% (1105 min), and viscosity at non-physiological condition (512 cps) and physiological condition (5415 cps). The optimized in situ gel was clear and isotonic (RBCs test). The gelation temperature of the optimized in situ was 34 ± 1°C with sufficient mucoadhesive strength (26 ± 2 dyn/cm²), gel strength (29 ± 2 sec), and texture profile for periodontal application. The in vitro drug release studies showed sustain release from optimized in situ gel (24h) in comparison to marketed gel (7h). The antimicrobial activity (cup plate technique) of the in situ gel was equivalent to the marketed doxycycline gel, which suggests that the doxycycline hyclate retained its antimicrobial efficacy when formulated as in situ gelling system. In conclusion, BBD was effectively utilized to optimize in situ gel with minimum level of polymers to achieve the required characteristics of the in situ gel for sustaining drug delivery to treat periodontitis.

Development of in situ gel containing asiaticoside/cyclodextrin complexes. Evaluation in culture human periodontal ligament cells (HPLDCs)

Asiaticoside (AS), an active herbal compound isolated from Centella asiatica, has the potential benefit in promoting type I collagen (COL I) synthesis and osteogenic differentiation in human periodontal ligament cells (HPDLCs). However, it has low aqueous solubility which may hamper the bioavailability. Thus, the aim of this study was to develop thermoresponsive in situ gel containing AS/cyclodextrin (CD) complexes. The non-encapsulated formulations consisted of AS/hydroxypropyl β-CD (HPβCD) complexes and encapsulated formulations containing AS loaded sulfobutylether β-CD/chitosan nanoparticles (SBEβCD/CS NPs) were prepared. The appearance, pH and viscosity of all formulations were within the acceptable range. All formulations formed relatively rapid sol-to-gel transition when contacted with simulated salivary fluid at body temperature. Compared to non-encapsulated formulations, in vitro gelation and rheological studies of encapsulated formulations displayed gel formation that remained longer with high mechanical strength. In vitro mucoadhesion and in vitro release studies revealed that nanoencapsulated in situ gel had excellent mucoadhesive property and could release AS in a sustained manner. These formulations exhibited no cytotoxic effects to HPDCLs. The SBEβCD/CS NPs containing low AS content could express the COL I synthesis. Thus, nanoencapsulated platform could serve as a promising carrier to deliver AS for periodontal tissue regeneration.

Physical stability of dry powder inhaler formulations

Introduction: Dry powder inhalers (DPIs) are popular for pulmonary drug delivery. Various techniques have been employed to produce inhalation drug particles and improve the delivery efficiency of DPI formulations. Physical stability of these DPI formulations is critical to ensure the delivery of a reproducible dose to the airways over the shelf-life.Areas covered: This review focuses on the impact of solid-state stability on aerosolization performance of DPI drug particles manufactured by powder production approaches and particle-engineering techniques. It also highlights the different analytical tools that can be used to characterize the physical instability originating from production and storage.Expert opinion: A majority of the DPI literature focuses on the effects of physico-chemical properties such as size, morphology, and density on aerosolization. While little has been reported on the physical stability, particularly the stability of engineered drug particles for use in DPIs. Literature data have shown that different particle-engineering methods and storage conditions may cause physical instability of dry powders for inhalation and can significantly change the aerosol performance. A systematic examination of physical instability mechanisms in DPI formulations is necessary during formulation development in order to select the optimum formulation with satisfactory stability. In addition, the use of appropriate characterization tools is critical to detect and understand physical instability during the development of DPI formulations.

Opportunity and challenges of nasal powders: Drug formulation and delivery

In the field of nasal drug delivery, among the preparations defined by the European Pharmacopoeia, nasal powders facilitate the formulation of poorly water-soluble active compounds. They often display a simple composition in excipients (if any), allow for the administration of larger drug doses and enhance drug diffusion and absorption across the mucosa, improving bioavailability compared to nasal liquids. Despite the positive features, however, nasal products in this form still struggle to enter the market: the few available on the market are Onzetra Xsail® (sumatriptan) for migraine relief and, for the treatment of rhinitis, Rhinocort® Turbuhaler® (budesonide), Teijin Rhinocort® (beclomethasone dipropionate) and Erizas® (dexamethasone cipecilate). Hence, this review tries to understand why nasal powder formulations are still less common than liquid ones by analyzing whether this depends on the lack of (i) real evidence of superior therapeutic benefit of powders, (ii) therapeutic and/or commercial interest, (iii) efficient manufacturing methods or (iv) availability of suitable and affordable delivery devices. To this purpose, the reader's attention will be guided through nasal powder formulation strategies and manufacturing techniques, eventually giving up-to-date evidences of therapeutic efficacy in vivo. Advancements in the technology of insufflation devices will also be provided as nasal drug products are typical drug-device combinations.

Mucoadhesive therapeutic compositions: a patent review (2011-2014)

INTRODUCTION

With the introduction of mucoadhesion in 1980, pharmaceutical researchers have gained interest in mucoadhesive compositions. This interest has led to the development of mucoadhesive drug delivery systems aiming (I) to target a specific tissue, (II) to overcome barriers to absorption as well as (III) to control drug release of the therapeutic compositions.

AREAS COVERED

In this review, the term mucoadhesion and a variety of targetable mucosa are described through review of the literature. Mucoadhesive drug delivery systems and mucoadhesive polymers, such as thiomers, which are reported within the patent literature or in related publications are described in detail, including their therapeutic uses.

EXPERT OPINION

Mucoadhesion is associated with benefits such as controlled, sustained release, prolonged residence time at the site of action, the ability to target specific mucosae and ease of application which leads to higher rates of patient compliance. Although many research groups are investigating in this domain, not many drug delivery systems based on mucoadhesive polymers have got from bench to market. The most promising and advanced applications seen in patent literature within the last five years seems to be for oral application.

Modification Effect of Cellulase on the Physicochemical Characteristic of Polysaccharides Edible Films

This study was conducted to assess hydrolytic influence of cellulase (C) on the physicochemical stability of chitosan (CH)/hydroxypropyl methylcellulose (HPMC) films in time of storage (T). Initially, nine films were physically characterized by contact angle, water vapour permeability (WVP), water activity(aw), tensile test, dynamic mechanical thermal analysis (DMTA), and thermogravimetric analysis (TGA) and chemically by Fourier Transform Infrared Spectrometry (FTIR). The contact angle results varied from 53.67° to 78.33°. The presence of the enzyme and passing time reduced the WVP from8.46E-09to7.41E-09 g/s·m·Pa. The enzyme treatment improved elasticity but decreased tensile strength of films. After adding cellulaseTgwas shifted to a higher temperature. Thermal stability of the films decreased with addition of cellulase and after prolonging storage time. FTIR analysis proved that chemical changes in polysaccharides structure were caused by cellulase incorporation in films composition, which may be observed in appearance of 1656 cm−1band. Theawvalues did not change.

Theophylline cocrystals prepared by spray drying: physicochemical properties and aerosolization performance

The purpose of this work was to characterize theophylline (THF) cocrystals prepared by spray drying in terms of the physicochemical properties and inhalation performance when aerosolized from a dry powder inhaler. Cocrystals of theophylline with urea (THF-URE), saccharin (THF-SAC) and nicotinamide (THF-NIC) were prepared by spray drying. Milled THF and THF-SAC cocrystals were also used for comparison. The physical purity, particle size, particle morphology and surface energy of the materials were determined. The in vitro aerosol performance of the spray-dried cocrystals, drug-alone and a drug-carrier aerosol, was assessed. The spray-dried particles had different size distributions, morphologies and surface energies. The milled samples had higher surface energy than those prepared by spray drying. Good agreement was observed between multi-stage liquid impinger and next-generation impactor in terms of assessing spray-dried THF particles. The fine particle fractions of both formulations were similar for THF, but drug-alone formulations outperformed drug-carrier formulations for the THF cocrystals. The aerosolization performance of different THF cocrystals was within the following rank order as obtained from both drug-alone and drug-carrier formulations: THF-NIC>THF-URE>THF-SAC. It was proposed that micromeritic properties dominate over particle surface energy in terms of determining the aerosol performance of THF cocrystals. Spray drying could be a potential technique for preparing cocrystals with modified physical properties.

Influence of polymeric microcarriers on the in vivo intranasal uptake of an anti-migraine drug for brain targeting

The objective of this study was to investigate the effect of polymeric microcarriers on the in vivo intranasal uptake of an anti-migraine drug for brain targeting. Mucoadhesive powder formulations consisted of antimigraine drug, zolmitriptan, and chitosans (various molecular weights and types) or hydroxypropyl methylcellulose (HPMC). Their suitability for nasal administration was evaluated by in vitro and ex vivo mucoadhesion and permeation tests. The formulations based on chitosan glutamate (CG) or HPMC were tested in vivo because they showed good mucoadhesive properties and altered the permeation rate of the drug. The in vivo results from intravenous infusion and nasal aqueous suspension of the drug or nasal particulate powders were compared. The plasmatic AUC values obtained within 8h following intravenous administration appeared about three times higher than those obtained by nasal administration, independent of the formulations. Zolmitriptan concentrations in the cerebrospinal fluid obtained from nasal and intravenous administrations were, respectively, 30 and 90 times lower than the concentrations of the drug in the blood. Thus, nasal administration potentiated the central zolmitriptan activity, allowing a reduction in the drug peripheral levels, with respect to the intravenous administration. Among nasally administered formulations, CG microparticles showed the highest efficacy in promoting the central uptake of zolmitriptan within 1h.