Risako Onodera

Topical Use of Angiopoietin-like Protein 2 RNAi-loaded Lipid Nanoparticles Suppresses Corneal Neovascularization

Corneal neovascularization (CNV) is a sight-threatening condition that is encountered in various inflammatory settings including chemical injury. We recently confirmed that angiopoietin-like protein 2 (ANGPTL2) is a potent angiogenic and proinflammatory factor in the cornea, and we have produced a single-stranded proline-modified short hairpin anti-ANGPTL2 RNA interference molecule that is carried in a lipid nanoparticle (ANGPTL2 Li-pshRNA) for topical application. In this study, we have further examined the topical delivery and anti-ANGPTL2 activity of this molecule and have found that fluorescence-labeled ANGPTL2 Li-pshRNA eye drops can penetrate all layers of the cornea and that ANGPTL2 mRNA expression was dramatically inhibited in both epithelium and stroma at 12 and 24 hours after administration. We also examined the inhibitory effect of ANGPTL2 Li-pshRNA on CNV in a mouse chemical injury model and found that the area of angiogenesis was significantly decreased in corneas treated with ANGPTL2 Li-pshRNA eye drops compared to controls. Together, these findings indicate that this modified RNA interference agent is clinically viable in a topical formulation for use against CNV.

Feasibility of drug delivery to the eye's posterior segment by topical instillation of PLGA nanoparticles

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Prediction of effects of punch shapes on tableting failure by using a multi-functional single-punch tablet press

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Formulation design of granules prepared by wet granulation method using a multi-functional single-punch tablet press to avoid tableting failures

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In Vitro and In Vivo Characterization of Drug Nanoparticles Prepared Using PureNano™ Continuous Crystallizer to Improve the Bioavailability of Poorly Water Soluble Drugs

PurposeThe aim of this study was to enhance the dissolution and oral absorption of poorly water-soluble active pharmaceutical ingredients (APIs) using nanoparticle suspensions prepared with a PureNano™ continuous crystallizer (PCC).MethodNanoparticle suspensions were prepared with a PCC, which is based on microfluidics reaction technology and solvent–antisolvent crystallization. Phenytoin, bezafibrate, flurbiprofen, and miconazole were used as model APIs. These APIs were dissolved in ethanol and precipitated by the addition of water and polyvinyl alcohol. Batch crystallization (BC) using a beaker was also performed to prepare the suspensions. Both PCC and BC formulations were freeze-dried before being characterized in vitro and in vivo.ResultsThe particle sizes of the nanoparticle suspensions prepared with the PCC were smaller than those prepared by BC. The dissolution rate of each API in vitro significantly increased after crystallization. Reducing the particle size of either the BC or PCC formulation led to increased API flux across Caco-2 cell monolayers. PCC preparations showed higher plasma concentrations after oral administration, demonstrating the advantages of a fast dissolution rate and increased interaction with the gastrointestinal tract owing to the smaller particle size.ConclusionsPCC can continuously produce nanoparticle APIs and is an efficient approach for improving their oral bioavailability.

Pulmonary liposomal formulations encapsulated procaterol hydrochloride by a remote loading method achieve sustained release and extended pharmacological effects.

Drug inhalation provides localized drug therapy for respiratory diseases. However, the therapeutic efficacy of inhaled drugs is limited by rapid clearance from the lungs. Small hydrophilic compounds have short half-lives to systemic absorption. We developed a liposomal formulation as a sustained-release strategy for pulmonary delivery of procaterol hydrochloride (PRO), a short-acting pulmonary β2-agonist for asthma treatment. After PRO-loaded liposomes were prepared using a pH gradient (remote loading) method, 100-nm liposomes improved residence times of PRO in the lungs. PRO encapsulation efficiency and release profiles were examined by screening several liposomal formulations of lipid, cholesterol, and inner phase. Although PRO loading was not achieved using the conventional hydration method, PRO encapsulation efficiency was >60% using the pH gradient method. PRO release from liposomes was sustained for several hours depending on liposomal composition. The liposomal formulation effects on the PRO behavior in rat lungs were evaluated following pulmonary administration in vivo. Sustained PRO release was achieved using simplified egg phosphatidylcholine (EPC)/cholesterol (8/1) liposome in vitro, and greater PRO remnants were observed in rat lungs following pulmonary administration. Extended pharmacological PRO effects were observed for 120min in a histamine-induced bronchoconstriction guinea pig model. We indicated the simplified EPC/cholesterol liposome potential as a controlled-release PRO carrier for pulmonary administration.

Topical Diclofenac-Loaded Liposomes Ameliorate Laser-Induced Choroidal Neovascularization in Mice and Non-Human Primates

This study aimed to evaluate the effect of liposomes loaded with diclofenac, a potent cyclooxygenase (COX)-1 and COX-2 inhibitor, on laser-induced choroidal neovascularization (CNV) in mice and non-human primates (common marmosets). CNV was induced by laser irradiation on the unilateral or bilateral eye of each mouse or common marmoset, respectively, under anesthesia. The CNV was visualized using fluorescence labeling with intravenous injection of fluoresceinconjugated dextran (molecular weight = 2,000 kDa), and quantified in the retinal pigment epithelia (RPE)-choroidal flatmounts. Diclofenac-loaded liposome or diclofenac ophthalmic solution was instillated to the eye surface daily for 14 days and 21 days in mice and common marmosets, respectively. In the mouse CNV model, 0.1% diclofenac-loaded liposome eye drops administered four times a day (q.i.d.) significantly reduced CNV formation in the RPE-choroidal flatmounts compared with those in empty liposome eye drops. Diclofenac-loaded liposome (0.1%) eye drops, administered once a day (s.i.d.), twice a day (b.i.d.), and three times a day (t.i.d.), also reduced CNV formation in a frequency-dependent manner. Furthermore, diclofenac-loaded liposome (0.03% and 0.1%) eye drops administered t.i.d. reduced CNV formation in a dose-dependent manner, significantly so at 0.1%. In the common marmoset CNV model, late hyperfluorescence and leakage by fluorescein angiograms was observed within or beyond the lesion borders at 17 days after laser irradiation, and diclofenac-loaded liposome eye drops (0.1% t.i.d.) tended to attenuate the late hyperfluorescence and leakage. Diclofenac-loaded liposomes had significantly reduced CNV formation in the RPE- choroidal flatmounts at 21 days after laser irradiation. In conclusion, diclofenac-loaded liposome eye drops enhance penetration to the RPE-choroid, and reduce the CNV formation. These results suggest that a drug-loaded liposome is a useful tool for drug delivery into the posterior segment of the eye.

Effects of cationic liposomes with stearylamine against virus infection

&NA; In this study, we demonstrated that cationic liposomes with incorporated stearylamine (SA) inhibit viral infectivity without preloaded active pharmaceutical ingredients. Specifically, we correlated physiochemical properties of liposomes, such as zeta potentials and particle sizes, with virus infectivity using the BacMam™ reagent, which is based on recombinant baculovirus (BV). Compared with neutral or negatively‐charged liposomes, SA liposomes suppressed BV infectivity in several mammalian cell lines, including A549 cells. SA liposomes inhibited BV infection over 80% by optimizing the liposomal concentration and exposure time with cells. Moreover, these antiviral SA liposomes were not cytotoxic, and reducing the embedded cholesterol contents intensified the antiviral effects and simultaneously increased the binding of SA liposomes to the cell membranes. These data indicate that binding of SA liposomes to cell membranes may block virus entry. Finally, we also demonstrated the antiviral effects of SA liposomes on herpes simplex virus type 1 in A549 cells, and showed comparable efficacy to that of the antiviral drug acyclovir. Graphical abstract Figure. No caption available.

Gelation Factors of Pectin for Development of a Powder Form of Gel, Dry Jelly, as a Novel Dosage Form

Jellies for oral administration are dosage forms that contain water, as stipulated in the Japanese Pharmacopeia, and heat is generally applied to the jellies during the manufacturing process. Therefore, it is difficult to formulate drugs that may be affected adversely by water and/or heat. To solve this problem, we tried to develop a powder form of gel as a novel dosage form (dry jelly: jelly medicine extemporaneously prepared) that is converted to jelly after addition of water at the time of administration. For this purpose, a basic gel formulation consisting of pectin, glucono-δ-lactone, dibasic calcium phosphate hydrate, and sucrose was investigated to evaluate the critical factors affecting gelation phenomena. The gel form was developed by adjusting the amount of each component of the formulation and of water added. Gelation occurred even with hard water containing metal ions (hardness of approximately 304 mg/L), and no changes in gel hardness occurred. The desired gel hardness could be controlled by adjusting the amount of water. The gel hardness changed over time after the addition of water, but this change did not affect the dissolution behavior of drugs formulated in the dry jelly.