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© 2018 Informa UK Limited, trading as Taylor & Francis Group Objective: Novel antibiotic Ramizol ® is advancing to clinical trials for the treatment of gastrointestinal Clostridium difficile associated disease. Despite this, previous studies have shown a rapid plasma clearance upon intravenous administration and low oral bioavailability indicating pure drug is unsuitable for systemic infection treatment following oral dosing. The current study aims to investigate the development of poly-lactic-(co-glycolic) acid (PLGA) particles to overcome this limitation and increase the systemic half-life following subcutaneous and intramuscular dosing. Significance: The development of new antibiotic treatments will help in combatting the rising incidence of antimicrobial resistance. Methods: Ramizol ® was encapsulated into PLGA nano and microparticles using nanoprecipitation and emulsification solvent evaporation techniques. Formulations were analyzed for particle size, loading level and encapsulation efficiency as well as in vitro drug release profiles. Final formulation was advanced to in vivo pharmacokinetic studies in Sprague-Dawley rats. Results: Formulation technique showed major influence on particle size and loading levels with optimal loading of 9.4% and encapsulation efficiency of 92.06%, observed using emulsification solvent evaporation. Differences in formulation technique were also linked with subsequent differences in release profiles. Pharmacokinetic studies in Sprague-Dawley rats confirmed extended absorption and enhanced bioavailability following subcutaneous and intramuscular dosing with up to an 8-fold increase in Tₘₐₓ and T₁/₂ when compared to the oral and IV routes. Conclusions: Subcutaneous and intramuscular dosing of PLGA particles successfully increased systemic half-life and bioavailability of Ramizol ® . This formulation will allow further development of Ramizol ® for systemic infection eradication. Refereed/Peer-reviewed

Many highly effective chemotherapeutic agents can only be administered intravenously as their oral delivery is compromised by low gastro-intestinal solubility and permeability. SN-38 (7-ethyl-10-hydroxycamptothecin) is one such drug; however, recently synthesized lipophilic prodrugs offer a potential solution to the low oral bioavailability issue. Here we introduce a microfluidic-based intestine-on-A-chip (IOAC) model, which has the potential to provide new insight into the structure-permeability relationship for lipophilic prodrugs. More specifically, the IOAC model utilizes external mechanical cues that induce specific differentiation of an epithelial cell monolayer to provide a barrier function that exhibits an undulating morphology with microvilli expression on the cell surface; this is more biologically relevant than conventional Caco-2 Transwell models. IOAC permeability data for SN38 modified with fatty acid esters of different chain lengths and at different molecular positions correlate excellently with water-lipid partitioning data and have the potential to significantly advance their preclinical development. In addition to advancing mechanistic insight into the permeability of many challenging drug candidates, we envisage the IOAC model to also be applicable to nanoparticle and biological entities. Refereed/Peer-reviewed

Oral absorption of weakly basic drugs (e.g. cinnarizine (CIN)) is limited by their pH dependent precipitation in intestinal conditions. To overcome this challenge, a novel drug delivery system composed of solid lipid and porous silica, namely silica encapsulated solid lipid (SESL) particles, was developed via hot homogenization of melted lipid dispersion, followed by ultra-sonication of the silica stabilized homogenized melted lipid dispersion. Scanning electron microscope (SEM) images of the SESL formulation revealed non-spherical and aggregated hybrid particles, with rough exterior and structured nanoparticles visible on the surface. A 1.5, 2.2 and 7-fold improvement in the dissolution of CIN was observed for the SESL particles, under simulated intestinal non-digesting conditions, in comparison to the drug loaded in solid lipid (CIN-SL) matrix, drug loaded in porous silica (CIN-PS) and pure drug powder. Under simulated intestinal digestive condition, significant improvement in the drug solubilization was reported for the SESL formulation in compared to the individual drug loaded systems i.e. CIN-PS and CIN-SL. Thereby, silica encapsulated solid lipid system provides a promising oral delivery approach for poorly water soluble weakly basic drugs. Refereed/Peer-reviewed

Biocompatible lipid hybrid particles composed of montmorillonite and medium chain triglycerides were engineered for the first time by spray drying oil-in-water emulsions stabilized by montmorillonite platelets to form montmorillonite-lipid hybrid (MLH) microparticles containing up to 75% w/w lipid. In vitro lipolysis studies under simulated intestinal conditions indicated that the specific porous nanoarchitecture and surface chemistry of MLH particles significantly increased the rate (>10-fold) and extent of lipase-mediated digestion compared to that of coarse and homogenized submicrometer triglyceride emulsions. Proton nuclear magnetic resonance studies verified the rapid and enhanced production of fatty acids for MLH particles; these are electrostatically repelled by the negatively charged montmorillonite platelet faces and avoid the "interfacial poisoning" caused by incomplete digestion that retards lipid droplet digestion. MLH particles are a novel biomaterial and encapsulation system that optimize lipase enzyme efficiency and have excellent potential as a smart delivery system for lipophilic biomolecules owing to their exceptional physicochemical and biologically active properties. These particles can be readily fabricated with varying lipid loads and thus may be tailored to optimize the solubilization of specific bioactive molecules requiring reformulation. Refereed/Peer-reviewed

Antibiotic-resistant bacteria is a major threat to human health and is predicted to become the leading cause of death from disease by 2050. Despite the recent resurgence of research and development in the area, few antibiotics have reached the market, with most of the recently approved antibiotics corresponding to new uses for old antibiotics, or structurally similar derivatives thereof. We have recently reported an in silico approach that led to the design of an entirely new class of antibiotics for the bacteria-specific mechanosensitive ion channel of large conductance: MscL. Here, we present the preclinical development of one such antibiotic, Ramizol, a first generation antibiotic belonging to that class. We present the lack of interaction between Ramizol and other mammalian channels adding credibility to its MscL selectivity. We determine the pharmacokinetic profile in a rat model and show

Ziprasidone is a poorly water-soluble antipsychotic drug that demonstrates low fasted state oral bioavailability and a clinically significant two-fold increase in absorption when dosed postprandially. Owing to significant compliance challenges faced by schizophrenic patients, a novel oral formulation of ziprasidone that demonstrates improved fasted state absorption and a reduced food effect is of major interest, and is therefore the aim of this research. Three lipid-based drug delivery systems (LBDDS) were developed and investigated: (a) a self-nanoemulsifying drug delivery system (SNEDDS), (b) a solid SNEDDS formulation, and (c) silica-lipid hybrid (SLH) microparticles. SNEDDS was developed using Capmul MCM® and Tween 80®, and solid SNEDDS was fabricated by spray-drying SNEDDS with Aerosil 380® silica nanoparticles as the solid carrier. SLH microparticles were prepared in a similar manner to solid SNEDDS using a precursor lipid emulsion composed of Capmul MCM® and soybean lecithin. The performance of the developed formulations was evaluated under simulated digesting conditions using an in vitro lipolysis model, and pure (unformulated) ziprasidone was used as a control. While pure ziprasidone exhibited the lowest rate and extent of drug solubilization under fasting conditions and a significant 2.4-fold increase in drug solubilization under fed conditions, all three LBDDS significantly enhanced the extent of drug solubilization under fasting conditions between 18- and 43-folds in comparison to pure drug. No significant difference in drug solubilization for the fed and fasted states was observed for the three LBDDS systems. To highlight the potential of LBDDS, mechanism(s) of action and various performance characteristics are discussed. Importantly, LBDDS are identified as an appropriate formulation strategy to explore further for the improved oral delivery of ziprasidone. Refereed/Peer-reviewed

Novel antibiotic RamizolThe development of new antibiotic treatments will help in combatting the rising incidence of antimicrobial resistance.RamizolFormulation technique showed major influence on particle size and loading levels with optimal loading of 9.4% and encapsulation efficiency of 92.06%, observed using emulsification solvent evaporation. Differences in formulation technique were also linked with subsequent differences in release profiles. Pharmacokinetic studies in Sprague-Dawley rats confirmed extended absorption and enhanced bioavailability following subcutaneous and intramuscular dosing with up to an 8-fold increase in TSubcutaneous and intramuscular dosing of PLGA particles successfully increased systemic half-life and bioavailability of Ramizol

Psychiatric illnesses are a leading cause of disability and morbidity globally. However, the preferred orally dosed pharmacological treatment options available for depression, anxiety and schizophrenia are often limited by factors such as low drug aqueous solubility, food effects, high hepatic first-pass metabolism effects and short half-lives. Furthermore, the discovery and development of more effective psychotropic agents has stalled in recent times, with the majority of new drugs reaching the market offering similar efficacy, but suffering from the same oral delivery concerns. As such, the application of nanomedicine formulation approaches to currently available drugs is a viable option for optimizing oral drug delivery and maximizing treatment efficacy. This review focuses on the various delivery challenges encountered by psychotropic drugs, and the ability of nanomedicine formulation strategies to overcome these. Specifically, we critically review proof of concept in vitro and in vivo studies of nanoemulsions/microemulsions, solid lipid nanoparticles, dendrimers, polymeric micelles, nanoparticles of biodegradable polymers and nanosuspensions, and provide new insight into the various mechanisms for improved drug performance. The advantages and limitations of current oral nanomedicine approaches for psychotropic drugs are discussed, which will provide guidance for future research directions and assist in fostering the translation of such delivery systems to the clinical setting. Accordingly, emphasis has been placed on correlating the in vitro/in vivo performance of these nanomedicine approaches with their potential clinical outcomes and benefits for patients. Refereed/Peer-reviewed

A Pluronic-functionalized silica-lipid hybrid (Plu-SLH) microparticle system for the oral delivery of poorly water-soluble, weak base drugs is reported for the first time. A highly effective Plu-SLH microparticle system was composed of Labrasol as the lipid phase, Pluronic F127 as the polymeric precipitation inhibitor (PPI), and silica nanoparticles as the solid carrier. For the model drug cinnarizine (CIN), the Plu-SLH delivery system was shown to offer significant biopharmaceutical advantages in comparison with unformulated drug and drug in the silica-lipid hybrid (SLH) system. In vitro two-phase dissolution studies illustrated significantly reduced pH provoked CIN precipitation and an 8- to 14-fold improvement in the extent of dissolution in intestinal conditions. In addition, under simulated intestinal digesting conditions, the Plu-SLH provided approximately three times more drug solubilization than the SLH. Oral administration in rats resulted in superior bioavailability for Plu-SLH microparticles, i.e., 1.6- and 2.1-fold greater than the SLH and the unformulated CIN, respectively. A physical mixture of Pluronic and SLH (Plu&SLH), having the same composition as Plu-SLH, was also evaluated, but showed no significant increase in CIN absorption when compared to unmodified CIN or SLH. This work represents the first study where different methods of incorporating PPI to formulate solid-state lipid-based formulations were compared for the impact on the biopharmaceutical performance. The data suggest that the novel physicochemical properties and structure of the fabricated Plu-SLH microparticle delivery system play an important role in facilitating the synergistic advantage of Labrasol and Pluronic F127 in preventing drug precipitation, and the Plu-SLH provides efficient oral delivery of poorly water-soluble weak bases. Refereed/Peer-reviewed

Solid-state lipid-based formulations offer great potential for the improved oral delivery of poorly watersoluble drugs. This study investigates the use of the high surface-area clay materials, montmorillonite and laponite, as solid carriers for lipid-based formulations. The unique cationexchange properties of clay platelets were exploited to preload the ionizable hydrophobic compound, blonanserin, prior to encapsulating a drug-loaded lipid solution. Thus, solid-statelipid-based formulations with dual-loading capabilities were developed and studied. These formulations were compared with simple clay-based lipid formulations, where blonanserin was loaded in the lipid phase only. The drug release behavior of all clay-based formulations was assessed during in vitro dissolution studies under simulated gastric conditions and in vitro fast ingintestinal lipolysis studies. Montmorillonite- and laponite-based lipid formulations significantly reduced blonanserin solubilization relative to a control lipid solution and silica−lipid hybrid particles, owing to incomplete drug release from the clay cation-exchange sites. This phenomenon was replicated during in vivo pharmacokinetic studies, whereby the bioavailability of simple clay-based lipid formulations was decreased relative to controls. Importantly, the solid-state dual-loaded montmorillonite-based lipid formulation provided an optimal pharmacokinetic performance, achieving the same degree of bioavailability enhancement as the control lipid solution. These findings indicate the potential of solid-state dual-loaded clay based lipid formulations for increasing drug loading levels and enhancing the oral absorption of poorly soluble weak base compounds. Refereed/Peer-reviewed

The method of supersaturation for achieving high drug loads in lipid-based formulations is under exploited and relatively unexplored, especially in the case of solid-state lipid-based formulations. Silica-lipid hybrids are solid-state lipid-based formulations designed for improving the oral delivery of poorly water-soluble drugs. However, their application to compounds of low potency and requiring large doses is limited by their low drug loading capacity. Here, an innovative technique to fabricate supersaturated silica-lipid hybrid formulations (super-SLH) has been established and the relationship between drug load and performance investigated. Using the model poorly water-soluble drug, ibuprofen, super-SLH was fabricated possessing drug loads ranging from 8 to 44% w/w, i.e. greater than the previously developed standard ibuprofen silica-lipid hybrids (5.6% w/w). Drug crystallinity of the encapsulated ibuprofen ranged from non-crystalline to part-crystalline with an increase in drug load. Super-SLH achieved improved rates and extents of dissolution when compared to pure ibuprofen, regardless of the drug load. The percentage increase in dissolution extent at 60 min varied from 200 to 600%. The results of the current study indicate that supersaturation greatly improves drug loading and that 16–25% w/w is the optimum loading level which retains optimal dissolution behaviour for the oral delivery of ibuprofen, which has the potential to be translated to other poorly water-soluble drugs. Refereed/Peer-reviewed

A highly efficient three-component Povarov reaction for the synthesis of tetrahydroquinoline derivatives was reported. The reaction of aldehyde, aniline, and alkene was carried out in the presence of Sn(IV), which was generated in situ from the redox reaction of SnCl2 and FeCl3, to afford tetrahydroquinoline derivatives in good to excellent yields. This discovery showed a sharp difference from the direct use of unstable SnCl4. Both aliphatic and aromatic aldehydes could be applied for the synthesis of the heterocycle in the reaction. The structure of the product 6-chloro-4-methyl-4-neopentyl-2-propyltetrahydroquinoline and 6-bromo-4-methyl-4-neopentyl-2-propyltetrahydroquinoline was confirmed by X-ray diffraction analysis.

The diversity of lipid excipients available commercially has enabled versatile formulation design of lipid-based drug delivery systems for enhancing the oral absorption of poorly water-soluble drugs, such as emulsions, microemulsions, micelles, liposomes, niosomes and various self-emulsifying systems. The transformation of liquid lipid-based systems into solid dosage forms has been investigated for several decades, and has recently become a core subject of pharmaceutical research as solidification is regarded as viable means for stabilising lipid colloidal systems while eliminating stringent processing requirements associated with liquid systems. This review describes the types of pharmaceutical grade excipients (silica nanoparticle/microparticle, polysaccharide, polymer and protein-based materials) used as solid carriers and the current state of knowledge on the liquid-to-solid conversion approaches. Details are primarily focused on the solid-state physicochemical properties and redispersion capacity of various dry lipid-based formulations, and how these relate to the in vitro drug release and solubilisation, lipid carrier digestion and cell permeation performances. Numerous in vivo proof-of-concept studies are presented to highlight the viability of these dry lipid-based formulations. This review is significant in directing future research work in fostering translation of dry lipid-based formulations into clinical applications. Refereed/Peer-reviewed

Lipid-based formulations (LBFs) are a popular strategy for enhancing the gastrointestinal solubilization and absorption of poorly water-soluble drugs. In light of this, montmorillonite-lipid hybrid (MLH) particles, composed of medium-chain triglycerides, lecithin and montmorillonite clay platelets, have been developed as a novel solid-state LBF. Owing to the unique charge properties of montmorillonite, whereby the clay platelet surfaces carry a permanent negative charge and the platelet edges carry a pH-dependent charge, three model poorly water-soluble drugs with different charge properties; blonanserin (weak base, pKa 7.7), ibuprofen (weak acid, pKa 4.5) and fenofibrate (neutral), were formulated as MLH particles and their performance during biorelevant in vitro lipolysis at pH 7.5 was investigated. For blonanserin, drug solubilization during in vitro lipolysis was significantly reduced 3.4-fold and 3.2-fold for MLH particles in comparison to a control lipid solution and silica-lipid hybrid (SLH) particles, respectively. It was hypothesized that strong electrostatic interactions between the anionic montmorillonite platelet surfaces and cationic blonanserin molecules were responsible for the inferior performance of MLH particles. In contrast, no significant influence on drug solubilization was observed for ibuprofen- and fenofibrate-loaded MLH particles. The results of the current study indicate that whilst MLH particles are a promising novel formulation strategy for poorly water-soluble drugs, drug ionization tendency and the potential for drug-clay interactions must be taken into consideration to ensure an appropriate performance. Refereed/Peer-reviewed

Objectives The aim of this study was to assess the potential of a novel delivery device for administering drugs that suffer from a high degree of first-pass metabolism. Methods A tri-layered buccal mucoadhesive patch, comprising a medicated dry tablet adhered to a mucoadhesive film, was prepared and characterized by its physicochemical properties and mucoadhesive strength. Nicotine was used as a model drug for the characterization of drug release and drug permeation. The influence of different adsorbents on the release of nicotine base from the patches was evaluated in vitro. Different molecular forms of nicotine (base and complex salt) were evaluated for their effect on release performance and permeation in vitro. Key findings Results demonstrated acceptable physicochemical and mucoadhesive properties for the tri-layered patch. Rapid release of nicotine was observed when nicotine base was incorporated with calcium sulfate dihydrate as the adsorbent. Patches incorporating nicotine base showed distinct advantages over those containing nicotine polacrilex, in terms of drug release (complete drug release achieved at 30 vs 60 min) and transmucosal permeation (37.28 ± 4.25 vs 2.87 ± 0.26% of the dose permeating through mucosa within 120 min). Conclusions The novel tri-layered patch can effectively adhere to, and deliver an active ingredient through the buccal mucosa, confirming its potential for buccal mucoadhesive drug delivery.

A three-dimensional (3D) quantitative pharmacophore model was developed from a training set of structurally diverse substituted ureas against Raf-1 kinase, which was well validated to be highly predictive by two methods, namely, test set prediction and Cat-Scramble method. Then a virtual database searching was performed with the pharmacophore model as a 3D query, and the bioactivities of the retrieved hits were predicted by the pharmacophore. Subsequently, molecular docking was carried out on the selected hits whose estimated IC50 was less than 1 μM. Finally, 29 hits were identified as potential leads against Raf-1 kinase, which exhibited good estimated activities, high docking scores, similar binding mode to experimentally proven compounds and favorable drug-like properties. The study may facilitate the discovery and rational design of novel leads with potent inhibitory activity targeting Raf-1 kinase. Refereed/Peer-reviewed

Introduction: A number of biobarriers limit efficient oral drug absorption; both polymer-based and lipid-based nanocarriers have demonstrated properties and delivery mechanisms to overcome these biobarriers in preclinical settings. Moreover, in order to address the multifaceted oral drug delivery challenges, polymer-lipid hybrid systems are now being designed to merge the beneficial features of both polymeric and lipid-based nanocarriers. Areas covered: Recent advances in the development of polymer-lipid hybrids with a specific focus on their viability in oral delivery are reviewed. Three classes of polymer-lipid hybrids have been identified, i.e. lipid-core polymer-shell systems, polymer-core lipid-shell systems, and matrix-type polymer-lipid hybrids. We focus on their application to overcome the various biological barriers to oral drug absorption, as exemplified by selected preclinical studies. Expert opinion: Numerous studies have demonstrated the superiority of polymer-lipid hybrid systems to their non-hybrid counterparts in providing improved drug encapsulation, modulated drug release, and improved cellular uptake. These features have encouraged their applications in the delivery of chemotherapeutics, proteins, peptides, and vaccines. With further research expected to optimize the manufacturing and scaling up processes and in-depth pre-clinical pharmacological and toxicological assessments, these multifaceted drug delivery systems will have significant clinical impact on the oral delivery of pharmaceuticals and biopharmaceuticals. Refereed/Peer-reviewed

SN38 (7-ethyl-10-hydroxycamptothecin) is a highly potent anti-cancer compound. However, it is poorly soluble in pharmaceutically acceptable excipients, thus the direct formulation and delivery are restricted. The current study focused on lipid-based formulation design to enable oral delivery of SN38 at high doses and at therapeutic levels. The pH dependent ionisation property of SN38 was utilised to form a molecular complex with the cationic surfactant, oleylamine and this increased (>200-fold) solubility/loading in Labrasol (the optimally determined lipid carrier). A SN38 loaded silica-lipid hybrid (SN38-SLH) particle delivery system was prepared by lyophilisation of mesoporous silica nanoparticle stabilised lipid emulsions. The subsequent free-flowing, SLH solid dosage form contained high loading levels of molecularly dispersed SN38 (5% w/w) and significantly enhanced in vitro dissolution in simulated gastrointestinal media. Furthermore, SN38 was chemically stable for at least 12 months at 25 °C. Orally dosed pharmacokinetics in a rat model demonstrated a 176% increase in SN38 blood plasma exposure in comparison with a raw drug suspension and a significant increase in the period where therapeutic levels are established. SN38-SLH shows potential for enabling injection-to-oral transformation in cancer chemotherapy. Refereed/Peer-reviewed

Oral chemotherapy with SN38 is restricted by its poor solubility in gastrointestinal (GI) fluids and low permeability. Here we report the oral delivery of SN38 by a combined lipophilic prodrug and lipid-based formulation strategy. A lead lipophilic prodrug of SN38, SN38-undecanoate (SN38-unde20), was incorporated into a self-microemulsifying drug delivery system (SMEDDS) for improved in vitro and in vivo performance. The formulation was purposefully designed and optimized with long chain lipids and lipid-based nonionic surfactants to maximize drug solubilization in GI conditions, facilitate trans-membrane permeation, and hence improve oral absorption. SN38-unde20-SMEDDS significantly increased (>7 fold) drug solubilization in the aqueous phase compared to unformulated drug during in vitro lipolysis and drug solubilization studies. In an orally dosed in vivo pharmacokinetics study in a Dark Agouti rat model, the SN38-unde20-SMEDDS formulation confirmed oral absorption of SN38-unde20 and subsequent reconversion to SN38. Importantly, the overall plasma exposure of SN38 (AUC0→∞) was equivalent for orally dosed SN38-unde20-SMEDDS in comparison with a parenteral dose of SN38-unde20-SMEDDS and SN38 at an identical dose (10 mg/kg). The combination of lipophilic prodrug along with an optimal delivery carrier is demonstrated to enable effective oral delivery of challenging chemotherapeutic compounds that are conventionally dosed by injection. Refereed/Peer-reviewed

Lipid-based drug delivery systems (LBDDS) have gained significant attention in recent times, owing to their ability to overcome the challenges limiting the oral delivery of poorly water-soluble drugs. Despite the successful commercialization of several LBDDS products over the years, a large discrepancy exists between the number of poorly water-soluble drugs displaying suboptimal in vivo performances and the application of LBDDS to mitigate their various delivery challenges. Conventional LBDDS, including lipid solutions and suspensions, emulsions, and self-emulsifying formulations, suffer from various drawbacks limiting their widespread use and commercialization. Accordingly, solid-state LBDDS, fabricated by adsorbing LBDDS onto a chemically inert solid carrier material, have attracted substantial interest as a viable means of stabilizing LBDDS whilst eliminating some of the various limitations. This review describes the impact of solid carrier choice on LBDDS performance and highlights the importance of appropriate solid carrier material selection when designing hybrid solid-state LBDDS. Specifically, emphasis is placed on discussing the ability of the specific solid carrier to modulate drug release, control lipase action and lipid digestion, and enhance biopharmaceutical performance above the original liquid-state LBDDS. To encourage the interested reader to consider their solid carrier choice on a higher level, various novel materials with the potential for future use as solid carriers for LBDDS are described. This review is highly significant in guiding future research directions in the solid-state LBDDS field and fostering the translation of these delivery systems to the pharmaceutical marketplace. Refereed/Peer-reviewed

Shasha Rao, Yunmei Song, Frank Peddie, Allan M EvansSansom Institute for Health Research, Division of Health Sciences, University of South Australia, Adelaide, South Australia, AustraliaAbstract: Poorly water-soluble drugs, such as phenylephrine, offer challenging problems for buccal drug delivery. In order to overcome these problems, particle size reduction (to the nanometer range) and cyclodextrin complexation were investigated for permeability enhancement. The apparent solubility in water and the buccal permeation of the original phenylephrine coarse powder, a phenylephrine–cyclodextrin complex and phenylephrine nanosuspensions were ­characterized. The particle size and particle surface properties of phenylephrine nanosuspensions were used to optimize the size reduction process. The optimized phenylephrine nanosuspension was then freeze dried and incorporated into a multi-layered buccal patch, consisting of a small tablet adhered to a mucoadhesive film, yielding a phenylephrine buccal product with good dosage accuracy and improved mucosal permeability. The design of the buccal patch allows for drug incorporation without the need to change the mucoadhesive component, and is potentially suited to a range of poorly water-soluble compounds.Keywords: buccal drug delivery, nanosuspension, solubility, permeation enhancement, mucoadhesion

The burden of drug resistance emerges in the wake of chronic and repeated antibiotic use. This underpins the importance of discovering alternatives to current antibiotic regimens. In chronic rhinosinusitis (CRS), topical therapy such as nasal douches and steroid sprays is the mainstay of treatment. However, bacterial sinusitis such as those with Staphylococcus aureus biofilm infection point to more recalcitrant CRS subtypes, focusing research efforts into topical antimicrobial therapies. In the sinuses, both local mucosal and systemic effects must be considered in designing any new topical medication. Nitric oxide (NO), an endogenous antimicrobial agent, is found at extremely low levels in CRS sinuses and high levels in healthy sinuses. As a novel treatment modality, we have designed a liposomal formulation of an NO donor (LFNO) using isosorbide mononitrate, as a topical sinus wash in a sheep model of S. aureus biofilm rhinosinusitis. Heart rate (HR), blood pressure, mean arterial pressure (MAP), and histologic and ciliary analyses were assessed in the safety component. Efficacy was assessed by quantifying biofilm biomass post-treatment. LFNO-treated sheep had lesser inflammation (P = 0.02), and comparable ciliary preservation (P = 0.86) than the control group. A transient increase in HR and decrease in MAP were observed in the LFNO group (P < 0.05), but this was not accompanied by observable side effects. LFNO sheep had significantly lower biofilm biomass vs controls (P = 0.044). Our findings demonstrate the localized and systemic safety of LFNO in an animal model despite using high NO concentrations, thus warranting further investigation for its possible therapeutic role in CRS. Refereed/Peer-reviewed

The study aims to develop and optimise lipid-based colloidal carriers (LBCC) for enhancing solubilisation and reducing fed/fasted variation for the poorly water-soluble danazol (DAN). Oil-based and self-microemulsifying delivery systems (SMEDDS) were developed, and the effect of solidification was investigated. Liquid SMEDDS (L-SMEDDS, Capmul MCM:Tween 80:Transcutol HP 1:2:1, w/w) and emulsion (Capmul MCM:soya lecithin 100:0.6, w/w) were developed. Solid-state formulations were prepared via (i) physical adsorption of L-SMEDDS (P-SMEDDS) or (ii) spray drying of emulsion (silica-lipid hybrid, SLH) and L-SMEDDS (spray-dried SMEDDS, S-SMEDDS) using Aerosil 380 silica nanoparticles as the solid carrier. In vitro lipid digestion and drug solubilisation under simulated intestinal conditions in both fasted and fed states were investigated. Solubilisation of unformulated DAN under both fasted and fed conditions was low, and a large fed/fasted variation was observed, i.e. 6.6-fold difference. All LBCC formulations provided enhanced drug solubilisation and significantly reduced the fed/fasted variation. For self-emulsifying LBCC, the fasted state drug solubilisation was ranked as L-SMEDDS > PSMEDDS > S-SMEDDS, suggesting that solidification reduced the capability of SMEDDS in presenting DAN to the aqueous phase. However, in the case of oil-based LBCC, improved drug solubility was observed with the solid form SLH under both fasted and fed state in comparison to that of the equivalent liquid form. Overall, the SLH, which provided the highest drug solubilisation in the fasted state (i.e. 10-fold higher than the pure DAN) and the smallest fed/fasted variation, was considered an optimised solid LBCC to enhance the solubilisation of DAN and reduce the fed/fasted variation. Refereed/Peer-reviewed

The diversity of lipid excipients available commercially has enabled versatile formulation design of lipid-based drug delivery systems for enhancing the oral absorption of poorly water-soluble drugs, such as emulsions, microemulsions, micelles, liposomes, niosomes and various self-emulsifying systems. The transformation of liquid lipid-based systems into solid dosage forms has been investigated for several decades, and has recently become a core subject of pharmaceutical research as solidification is regarded as viable means for stabilising lipid colloidal systems while eliminating stringent processing requirements associated with liquid systems. This review describes the types of pharmaceutical grade excipients (silica nanoparticle/microparticle, polysaccharide, polymer and protein-based materials) used as solid carriers and the current state of knowledge on the liquid-to-solid conversion approaches. Details are primarily focused on the solid-state physicochemical properties and redispersion capacity of various dry lipid-based formulations, and how these relate to the in vitro drug release and solubilisation, lipid carrier digestion and cell permeation performances. Numerous in vivo proof-of-concept studies are presented to highlight the viability of these dry lipid-based formulations. This review is significant in directing future research work in fostering translation of dry lipid-based formulations into clinical applications.

Aim: To investigate the role of self-emulsifying lipids and porous silica particles in enhancing supersaturated drug loading and biopharmaceutical performance of nanostructured silica–lipid hybrid (SLH) systems. Materials & methods: Two lovastatin (LOV)-SLHs were engineered from self-emulsifying lipid (Gelucire® 44/14; Gattefossé, Lyon, France) and Aerosil® 380 (SLH-A; Evonik Industries, Essen, Germany) or Syloid® 244FP silica (SLH-S; Grace Davison Discovery Sciences, Rowville, Australia). Results & discussion: The LOV-SLHs encapsulated LOV at 10% w/w, which is ≥3-fold higher than typical lipid formulations in the absence of porous silica. The LOV-SLHs retained self-emulsifying lipid-associated solubilization benefits and improved drug solubilization by twofold in simulated intestinal condition. SLH-S, with larger surface area (299 m2/g), was superior to SLH-A (184 m2/g) in optimizing oral bioavailability, suggesting a critical role of the silica geometry. Bioavailability of SLH-S was 2.8- and 1.3-fold higher than pure drug and drug suspension in Gelucire 44/14, respectively. Conclusion: In conclusion, SLHs profit from advantages associated with both self-emulsifying lipids and porous silica, and provide potentially improved therapy against coronary artery disease.

Clinical trials addressing the viability of lipid and nanoparticle-based solid dosage forms for the oral delivery of poorly water-soluble drugs are limited to date. This Phase I study aimed to assess the comparative tolerability and oral pharmacokinetics of a novel silica nanoparticle-lipid hybrid formulation encapsulating ibuprofen (i.e., Lipoceramic-IBU) with reference to a commercial tablet (i.e., Nurofen®). The test (Lipoceramic-IBU) and reference (Nurofen®) ibuprofen formulations were characterised for physicochemical properties and in vitro solubilisation performance prior to the clinical study. A randomised, double-blinded, one-period single oral dose (20 mg ibuprofen) study was performed in 16 healthy male subjects under fasting conditions. Encapsulation of ibuprofen in a molecularly dispersed form in the Lipoceramic nanostructured silica-lipid matrices was shown to produce superior drug solubilisation in comparison to Nurofen® and the pure drug during a two-step dissolution (or solubilisation) study in aqueous buffers of pH 1.2 followed by pH 6.5. Pharmacokinetic profiles revealed an approximately 1.95-fold increased bioavailability (p=0.02) and a 1.5-fold higher maximum plasma concentration (p=0.14) for Lipoceramic-IBU with reference to Nurofen®. Review of the safety assessments, including physical examinations, clinical laboratory tests and reports of adverse events, confirmed negligible acute side effects related to the administration of blank and ibuprofen-loaded Lipoceramic formulations. This first in man study of a dry lipid and nanoparticle-based formulation successfully demonstrated the safe use and effectiveness of the nanostructured Lipoceramic microparticles in mimicking the food effects for optimising the oral absorption of poorly water-soluble compounds. Refereed/Peer-reviewed

SN38 (7-ethyl-10-hydroxy camptothecin) is a prominent and efficacious anticancer agent. It is poorly soluble in bothwater and pharmaceutically approved solvents; therefore, the direct formulation of SN38 in solution formis limited. Currently, thewater soluble prodrug of SN38, irinotecan (CPT-11), is formulated as a lowpH solution and is approved for chemotherapy. However, CPT-11, along with most other water-soluble prodrugs shows unpredictable inter-patient conversion to SN38 in vivo, instability in the physiological environment and variable dose-related toxicities. More recently, macromolecular prodrugs (i.e. EZN-2208, IMMU-130) and nanomedicine formulations (i.e. nanoemulsions, polymeric micelles, lipid nanocapsule/nanoparticle, and liposomes) of SN38 have been investigated for improved delivery to cancer cells and tissues. Specifically, these carriers can take advantage of the EPR effect to direct drug preferentially to tumour tissues, thereby substantially improving efficacy andminimising side effects. Furthermore, oral delivery has been shown to be possible in preclinical results using nanomedicine formulations (i.e. dendrimers, lipid nanocapsules, polymeric micelles). This review summarizes the recent advances for the delivery of SN38 with a focus on macromolecular prodrugs and nanomedicines. Refereed/Peer-reviewed

Aims: The aim of present study was to investigate the effects of isosteviol on hyperglycemia and hyperlipidemia in rats fed with high-fat emulsion (HFE). Key findings: FSG, FSI, TC and LDL levels and insulin resistance index (IRI) were decreased and HDL level was increased by all doses of isosteviol. During IVGTT, serum glucose levels were decreased by isosteviol and no significant differences were observed in insulin release between isosteviol-treated and control groups. The effects of isosteviol were attenuated by palmitate. Damage to pancreatic islet cells was partially attenuated, and expression profile of hepatic PPARα mRNA was enhanced by isosteviol. Main methods: Hyperglycemia and hyperlipidemia in rats was induced by daily ingestion of HFE for 14 days. Iso- steviol (0.2, 1.0, or 5.0 mg/kg/day) was orally administered for 7 days, with rosiglitazone maleate (5.0 mg/kg/ day) used as the positive control. The levels of fasting serum glucose (FSG), fasting serum insulin (FSI), total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), and low density lipoprotein (LDL) in serum were assayed. Intravenous glucose tolerance test (IVGTT) was performed with serum glucose and insulin levels monitored. The effect of the supplement of palmitate in HFE on the activity of isosteviol was investigated. Ultra- structural changes in islet β-cells and peroxisome proliferator-activated receptor α (PPARα) mRNA expression profile were determined. Significance: Antihyperglycemic effects of isosteviol could enhance utilization of glucose in the periphery and reduce β-cell damage induced by dyslipidemia. Modulating-lipidemic effects of isosteviol might be related to the potential enhancement of liver PPARα mRNA expression. Refereed/Peer-reviewed

Oncogenic B-Raf has been identified in a variety of cancers with high incidence, especially in malignant melanoma and thyroid cancer. Most B-Raf mutations elicit elevated kinase activity and the constitutive activation of Ras/Raf/MEK/ERK pathway, which induces proliferation and promotes malignant transformation. Therefore, B-Raf inhibitors, targeting B-Raf or mutated B-Raf, have received increasing momentum in oncology drug discovery arena. This review focuses on the diverse small-molecule inhibitors of B-Raf kinase recently reported in the literature, including those currently in clinical and preclinical phase. They are described as two categories, type I or type II kinase inhibitors, based on their different mechanism of action with active or inactive conformations of the B-Raf kinase derived from the available crystal structures or molecular docking analysis. A particular emphasis is placed on their binding modes and the structure-activity relationship (SAR) of each chemical structure class. Refereed/Peer-reviewed