Search

Wear-resistant polymers and ceramics-based media have been used to pulverize the bulk powder of poorly water-soluble drugs to nanoscale size in conventional milling; however, contamination of such media is still an issue in the context of drug formulation manufacturing. In the present study, we developed a novel method for pulverizing the particles of a poorly water-soluble drug, ketoprofen, to nanoscale size by mixing mannitol and polypropylene glycol as a safe pulverizing medium. The ketoprofen nanoparticles were prepared using a Hoover automatic muller, equipment that traditionally has been used for the mixing of paint and ink. This process represents a novel application of this machine for the on-demand preparation of nanoparticulate formulations for use in the clinical setting. The optimal composition of the drug formulation was determined by designing an experiment consisting of the central composite design and responsive surface method. We obtained a design space that yielded ketoprofen nanoparticles with targeted particle size, poly-dispersity index, and drug release properties. We validated the manufacturing conditions by preparing ketoprofen nanoparticles in four compositions. Thus, the present study provided useful information regarding not only simple and effective contamination-free milling but also the experimental conditions need to produce nanoparticles of a poorly water-soluble drug.

Bioequivalence has been assessed using in vitro dissolution testing, such as in vivo predictive dissolution methodology. However, the assessment of bioequivalence should be performed carefully, considering the effect of the in vivo environment and according to the properties of the drug. The gastric emptying process is a key factor for the assessment of biopharmaceutics classification system class II (BCS class IIa) drugs with acidic properties since they cannot dissolve in the acidic stomach, but do dissolve in the small intestine (SI). The disintegration of a tablet in the stomach affects the distribution/dissolution in the SI due to the difference in the gastric emptying step, which in turn is a result of the varying formulation of the drugs. In this study, we used the reported dynamic pH change method and a novel gastric process simulation (GPS) model, which can compare the gastric emptying of particular-sized drug particles. The in vitro results were compared to clinical data using bioequivalent and bioinequivalent products of candesartan cilexetil. It was revealed that the dynamic pH change method was inappropriate, whereas the amount of filtered drug in GPS studies with 20 and 50 µm pore size filters could reflect the clinical results of all products. The evaluation of the gastric emptying process of drug particles less than 50 µm enabled us to assess the bioequivalence because they probably caused the difference in the distribution in the SI. This study demonstrated the utility of the GPS model for the assessment of bioequivalence of BCS class IIa drugs.

Confectionery ingredients are expected to enhance the medication adherence of pediatric patients taking bitter-tasting drugs when adequate pediatric medicines are not available in practical settings. Gum is a familiar confectionery, and several drug-loaded gums are on the market as medicated chewing gums. In this study, medical gum tablets composed of confectionery xylitol gum and a drug (ibuprofen or acetaminophen) were prepared and evaluated for the purpose of potential hospital applications. The effect of the sintering process, a heating treatment, on the physical properties of the solid materials was also examined. The sintering process markedly improved the hardness of the gum tablets. The sintering temperature and time affected the hardness of both ibuprofen- and acetaminophen-loaded gum tablets, whereas heat treatment around the melting point of ibuprofen or xylitol and longer heat treatment resulted in failure of the preparation or a reduction in hardness. The sintered gum tablets exhibited a delayed drug release profile in artificial saliva after an in vitro chewing test. The current results provide basic and useful information about the preparation of gum-containing tablets in future clinical settings.

As alveolar macrophages are attractive targets for the treatment of tuberculosis, effective methods for delivery to alveolar macrophages are under development. We investigated a pulmonary formulation for the efficient delivery of high water-soluble drugs at high concentration targeting alveolar macrophages. In this study, a surfactant-coated high water-soluble drug complex (SDC, a hydrophobic dried emulsion), which can preferably target alveolar macrophages and be expected to deliver drug at a high concentration, was prepared in the first process. OCT313, a high water-soluble sugar derivative with anti-tuberculosis activity was used. Then, a unique two-solution, mixing-type nozzle was used to prepare the SDC nanoparticles in mannitol (MAN) microparticles (SDC/MAN microparticles) because it was difficult to disperse the SDC nanoparticles in aqueous solution. The single micron size of OCT313-SDC/MAN microparticles contained OCT313-SDC nanoparticles (mean particle size of OCT313-SDC nanoparticles, 277.9 nm; drug contents, 1.31 ± 0.041 wt%). We found that the treatment of SDC/MAN microparticles exhibited significantly higher drug accumulation in macrophage cells (Raw264.7 cells, 7.5-fold, at 4 h after treatment) in vitro and in alveolar macrophages in rats (9.1-fold, at 4 h after treatment) in vivo than that of drug alone. These results suggest that the SDC/MAN microparticle formulation prepared by spray drying through a two-solution mixing-type nozzle provides efficient delivery of a water-soluble drug targeting alveolar macrophages and may be useful for tuberculosis treatment.

The use of three-dimensional (3D) printing technology is expanding in various fields. The application of 3D printing is expected to increase in the pharmaceutical industry after 3D-printed tablets were approved by the U.S. Food and Drug Administration (FDA). Fused deposition modeling (FDM), a type of 3D printing, has been extensively studied for the manufacturing of tablets. A drug-loaded polymer filament, the ink of FDM 3D printers, can be prepared using the hot melt extrusion method or a simple drug-soaking method. In the present study, we investigate the influence of the experimental conditions on the loading of curcumin (model drug with fluorescence) into a polyvinylalcohol polymer filament using the soaking method. We show that organic solvent type (isopropanol, methanol, acetone, and ethanol), temperature (25 and 80°C), and drug concentration (2-333 mg/mL) greatly affect drug loading. Around 5% curcumin can be incorporated into the polyvinylalcohol filament using the soaking method. The drug dissolution from 3D-printed tablets depends on the drug content in the polymer filament. The incorporation of a higher amount of curcumin, which has poor water solubility, greatly delays drug dissolution. These results provide useful information on the preparation of 3D-printed tablets using a drug-loaded polymer filament obtained with the soaking method.

3D printing technology is a novel and practical approach for producing unique and complex industrial and medical objects. In the pharmaceutical field, the approval of 3D printed tablets by the US Food and Drug Administration has led to other 3D printed drug formulations and dosage forms being proposed and investigated. Here, we report novel ophthalmologic patches for controlled drug release fabricated using a semi-solid material extrusion-type 3D printer. The patch-shaped objects were 3D printed using hydrogel-based printer inks composed of hypromellose (HPMC), sugar alcohols (mannitol, xylitol), and drugs, then freeze-dried. The viscous properties of the printer inks and patches were dependent on the HPMC and sugar alcohol concentrations. Then, the physical properties, surface structure, water uptake, antimicrobial activity, and drug release profile of lyophilized patches were characterized. Lyophilized ophthalmologic patches with different dosages and patterns were fabricated as models of personalized treatments prepared in hospitals. Then, ophthalmologic patches containing multiple drugs were fabricated using commercially available eye drop formulations. The current study indicates that 3D printing is applicable to producing novel dosage forms because its high flexibility allows the preparation of patient-tailored dosages in a clinical setting.

Nanomedicine is a new medical field involving the use of nanoparticles. Early examples of biocompatible nanomedicines include liposomes (Doxil®) and albumin nanoparticles (Abraxane®), and promising new nanomedicines include nanocarriers such as nanomicelles and nanoemulsions. A new trend towards the use of metal-based nanoparticles, including gold nanoparticles, has led to global clinical trials. These particles exhibit novel properties compared to conventional nanomedicines such as liposomes and albumin nanoparticles. These properties hold promise for nanomedicines, and thus the biodistribution and pharmacokinetics of metal-based nanoparticles should be carefully investigated. This had led to an increasing number of clinical trials investigating metal nanoparticles and inorganic nanoparticles. The present review evaluates multi-functional gold nanoparticles described in recent articles and shows that the unique properties of gold nanoparticles are applicable for not only drug delivery, but also for imaging. The combined therapeutic modality between therapeutics and diagnostics is called "theranostics" and is promising for future personalized cancer therapy. This review also introduces recent research from our laboratory involving the use of various kinds of molecules [polyethylene glycol (PEG), drug/cyclodextrin inclusion complexes, biosimilars and small interfering (siRNAs)] loaded onto and/or conjugated with gold nanoparticles.

The aim of this study was to prepare a liposomal formulation of a model drug (budesonide) for colonic delivery by incorporating a bile salt (sodium glycocholate, SGC) into liposomes followed by coating with a pH-responsive polymer (Eudragit S100, ES100). The role of the SGC is to protect the liposome from the emulsifying effect of physiological bile salts, while that of ES100 is to protect the liposomes from regions of high acidity and enzymatic activity in the stomach and small intestine. Vesicles containing SGC were prepared by two preparation methods (sonication and extrusion), and then coated by ES100 (ES100-SGC-Lip). ES100-SGC-Lip showed a high entrapment efficiency (>90%) and a narrow size distribution (particle size = 275 nm, polydispersity index < 0.130). The characteristics of liposomes were highly influenced by the concentration of incorporated SGC. The lipid/polymer weight ratio, liposome charge, liposome addition, and mixing rate were critical factors for efficient and uniform coating. In vitro drug release studies in various simulated fluids indicate a pH-dependent dissolution of the coating layer, and the disintegration process of ES100-SGC-Lip was evaluated. In conclusion, the bile salt-containing ES100-coated liposomal formulation has potential for effective oral colonic drug delivery.

The 3D printing of drug formulations is a promising method for preparing tailored medicines following the approval of 3D printed tablets by the US FDA in 2015. Appropriate dosage forms for pediatric patients are deficient because drugs have been developed for mainly adult patients. Here, we fabricated gummy drug formulations for pediatric patients using a 3D bioprinter compatible with semi-solid materials such as hydrogels and pastes. The gummy drug formulations were composed of gelatin, HPMC, reduced syrup, water and the antiepileptic drug lamotrigine. The formulations were extruded from the nozzle of the 3D bioprinter under air pressure and laminated from the bottom in a layer-by-layer process. The incorporation of HPMC aided smooth printing at room temperature, and gelatin and HPMC affected the viscosity of the drug formulation and the printability of the formulations. The strength of the gummy formulations was remarkably influenced by the gelatin concentration. Dissolution tests showed 85% drug release within 15 min from most formulations. The results suggest that 3D printing is an effective method for preparing gummy drug formulations with various shapes in different colors, and that the methodology may improve drug adherence of pediatric patients in future clinical settings.

The application of 3D printing technology for generating tablets is attracting the attention of the pharmaceutical industry following approval of a 3D printed tablet (Spritam) by the US Food and Drug Administration. Here we focused on hollow-type suppository formulations typically prepared as suppository shells by pharmacists in hospitals. We used a fused deposition modeling-type 3D printer and polyvinyl alcohol filament as a water soluble material to print suppository shells with various thicknesses and different inner structures by changing the printing conditions for the 3D designed objects. The hardness of the suppository shell was dependent on the thickness and designed inner structure. An active pharmaceutical ingredient ionic liquid, a novel type of liquid drug formulation, was loaded in the suppository shells. The drug dissolution profile of the suppository formulations differed depending on the type of suppository shell. Composite suppository formulations (two drugs in separate compartments in the suppository shell) were prepared as a model tailored medicine for pediatric patients. Our findings suggest that 3D printing technology is applicable to the preparation of hollow-type suppository formulations and may be compatible with on-site hospital production.

Wet type age-related macular degeneration results in the reduction and loss of eyesight and is closely correlated with angiogenesis. Small interfering siRNA (siRNA) is a functional nucleic acid used as a knockdown tool to control target gene expression in a sequence-dependent manner. In contrast, siRNA can potently inhibit angiogenesis in an “independent” manner via its interaction with Toll-like receptor 3. In this study, siRNA was conjugated with ultra-small gold nanoparticles to prevent the distribution of siRNA outside the eye, and the usefulness of this mini-carrier with siRNA against angiogenesis was investigated. Thiolated siRNA (siRNA-hexaethyleneglycol-SH) was conjugated to the surface of gold nanoparticles through a coordinate bond. The nanoparticles were small (approximately 10 nm in diameter) and carried approximately 7.6 siRNA molecules oriented vertically. These nanoparticles suppressed luciferase gene expression in a cell line stably expressing luciferase. The siRNA-gold nanoparticles inhibited tube formation by human endothelial cells on Matrigel efficiently. These siRNA-gold nanoparticles may be useful for treating angiogenesis resulting from age-related macular degeneration.

Gold nanoparticles (GNPs) have promising properties such as photothermal effects and could be useful for imaging and as multifunctional nanocarriers for various drugs. In this study, we synthesized polyethyleneglycol (PEG)-grafted GNPs and conjugated them with cyclodextrin (CD) to incorporate curcumin. Curcumin has anticancer effects but its therapeutic application is limited due to poor water solubility. Three types of CDs (α-, β-, and γ-CDs) were conjugated with PEGylated GNPs and the curcumin-containing CD/PEG-conjugated GNPs (cur-CD-GNPs) were characterized. Transmission electron microscopy and dynamic light scattering results showed that these cur-CD-GNPs have a small gold nanocore (approximately 5 nm) and the average size of the three cur-CD-GNPs was approximately 25-35 nm. Curcumin was efficiently incorporated into the β-CD solution and the loading efficiency of curcumin in β-CD-GNPs was the highest of the three types of CD-GNPs prepared. The cytotoxic effect of cur-CD-GNPs was investigated using a human lung cancer cell line. All cur-CD-GNPs exhibited cytotoxic effects comparable to that of curcumin solution and CD-GNPs without curcumin were not cytotoxic. These results suggest that cur-CD-GNPs may be a useful multifunctional nanomedicine, although in vivo investigations are required.

Microfluidics is a promising system for efficiently optimizing the experimental conditions for preparing nanomedicines, such as self-assembled nanoparticles. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles are promising drug carriers allowing sustained drug release. Here, we encapsulated the model drug curcumin, which has many pharmacological activities, into PLGA nanoparticles and investigated the effects of experimental conditions on the resulting PLGA nanoparticles using a microfluidics system with a staggered herringbone structure that can stir solutions through chaotic advection. The total flow rate and flow rate ratio of the solutions in the microfluidics system affected the diameters, polydispersity index, and encapsulation efficiency of the resulting PLGA nanoparticles and produced small, homogenous PLGA nanoparticles. The incorporation of polyethylene glycol (PEG)-PLGA into the PLGA nanoparticles reduced the particle size and improved the encapsulation efficiency. Initial burst release from the PLGA nanoparticles was prevented by the incorporation of PEG2000-PLGA. Curcumin-loaded PEGylated PLGA nanoparticles showed cytotoxicity similar to that of other formulations. This microfluidics system allows high throughput and is scalable for the efficient preparation of PLGA nanoparticles and PEGylated PLGA nanoparticles. Our results will be useful for developing novel PLGA-based polymer nanoparticles by using the microfluidics.

Triggered drug release is a promising strategy for delivering anticancer drugs to cancer cells and tissues. We found that liposomes co-encapsulating calcein (a water-soluble model drug and fluorescence marker) and talaporfin sodium (TPS, a water-soluble photosensitizer) released the drug upon irradiation with a near-infrared (NIR)-laser. The liposomes were composed of phospholipid (DSPC)/helper lipid (DOPE)/cholesterol/PEG-lipid (PEG2000-DSPE) at a molar ratio of 85/10/5/5 and released a large amount of drug (70%

The unique optical properties of gold nanoparticles have facilitated their application as novel nanomedicines in cancer therapy. In the current study, we examined the medical use of gold nanostars (GNSs), gold nanoparticles with protrusions on the surface. Under near-infrared (NIR) laser irradiation, GNSs exhibit an absorption peak at ∼700 nm, and this absorption peak can be targeted in photodynamic therapy using photosensitizers. GNSs were conjugated with polyethylene glycol (PEG) to form PEG-GNSs, which were further conjugated with a photosensitizer (talaporfin sodium, TPS) at the end of the PEG chain, forming TPS-PEG-GNSs. Energy absorption under NIR-laser irradiation increased the temperature of the TPS-PEG-GNSs and produced reactive oxygen species derived from TPS. The combination of TPS-PEG-GNSs and NIR-laser irradiation exhibited remarkable cytotoxic effects against A549 lung cancer cells in vitro upon optimization of the strength of the NIR laser. TPS-PEG-GNSs are thus effective multifunctional nanoparticles for simultaneous use in both photothermal and photodynamic therapy using single NIR-laser irradiation. The current results provide a useful model of nanomedicine for cancer therapy using NIR lasers.

We constructed gold nanoparticle-coated liposome/doxorubicin (GCL/DOX) for the purpose of combination therapy and focused on 1) controlled drug release from the thermosensitive liposomes triggered by near-infrared laser (NIR-laser) irradiation and 2) the photothermal effect of the gold nanoshell-like structures upon absorbing laser light. GCL/DOX was prepared using thiol-group-spiked liposomes containing glutathione conjugated to gold nanoparticles under reducing conditions. The absorption peak of GCL was dependent on the amount of added HAuCl4 and shifted from 636 to 795 nm, appropriate for the absorption of NIR laser light (660 nm) by GCL/DOX. Most of the encapsulated drug was released from GCL/DOX within 1 min (>80%) under NIR laser irradiation. GCL/DOX exhibited a synergistic effect compared to monotherapy (photothermal effect alone or free-DOX treatment alone) on A549 cells. GCL is thus an effective liposome carrier, and in conjunction with NIR laser irradiation its therapeutic modality holds promise for cancer treatment.

Clinical trials related to carrier-based drugs have recently attracted attention because carrier-based drugs hold promise for high efficiency drug delivery and for reducing drug-related side effects. In this commentary, we introduce recent clinical trials involving the use of various carriers, including liposomes, nano and micro particles, micelles, emulsions, and polymeric carriers. Liposomal drug carriers are currently the most intensively tested carriers in clinical trials, but other carriers such as polymeric carriers, albumin-based carriers, and metal nanocarriers have also recently been studied in clinical trials. Each carrier has specific properties, advantages, and disadvantages. The recent clinical trials introduced herein provide information critical to understanding current trends in carrier-based drug research.

small interfering RNA (siRNA) has been suggested as a potential therapeutic molecule, whereby potent gene silencing is precisely controlled by RNAi machinery. Cationic liposome-protamine-DNA (LPD) has been traditionally used as the carrier of functional nucleic acids. The cytotoxicity derived from the cationic moiety has raised a concern to safely deliver nucleic acids, such as siRNA, to the target site. In the present study, LPD was coated with the natural anionic polymer, hyaluronic acid (HA), termed LPDH. The cytotoxicity and safety of LPDH was assessed in vitro . LPD induced hemolysis of murine red blood cells and cytotoxicity in human endothelial cells, while LPDH remarkably reduced the hemolysis and cytotoxicity when compared to LPD at the same concentration of siRNA. Fluorescently-labeled LPD showed increased cellular uptake when compared to LPDH. In contrast, LPD and LPDH showed similar effects on gene silencing for the luciferase gene on the luciferase-expressing B16F0 cancer cell line. PEGylated LPD obstructed this gene silencing effect. These results indicate that LPDH can reduce the cytotoxicity associated with LPD with a comparable gene silencing response, suggesting that the coating of hyaluronic acid with cationic carriers is effective strategy to deliver siRNA with less cytotoxicity.

Ranibizumab is a first-line therapy against age-related macular degeneration. For further improvement of ranibizumab-based treatment, we developed ranibizumab biosimilar (Mab)/polyethyleneglycol (PEG)-conjugated small gold nanoparticles (core size: approximately 5 nm) as a novel platform of ranibizumab biosimilar (Mab) delivery. Mab/PEG-conjugated gold nanoparticles were successfully prepared, and the particles were characterized by transmission electron microscopy and dynamic light scattering method. The mean diameters of Mab/PEG-conjugated gold nanoparticles and PEG-conjugated gold nanoparticles were varied using different lengths of PEG chain (5 kDa and 10 kDa). The Mab conjugation efficiency was optimized by changing the amount of PEG in preparation, which showed a high conjugation efficiency (>70%). We found that Mab/PEG-conjugated gold nanoparticles effectively inhibited the tube formation of human umbilical vein endothelial cells based on Matrigel in vitro . PEG-conjugated gold nanoparticles without Mab inhibited the tube formation unexpectedly. The Mab/PEG-conjugated gold nanoparticles did not affect cell proliferation in human endothelial cells. These results suggest that Mab/PEG-conjugated gold nanoparticles can be used as a good and novel colloidal formulation against angiogenesis-related diseases in local sites such as age-related macular degeneration.

The liposome-protamine-DNA complex (LPD) is an effective cationic carrier of various nucleic acid constructs such as plasmid DNA and small interfering RNA (siRNA). Hyaluronic acid coated on LPD (LPDH) reduces cytotoxicity and maintains the silencing effect of LPD-encapsulated siRNA. Herein, we aim to develop LPD- or LPDH-containing spray-freeze-dried particles (SFDPs) for therapeutic delivery of siRNA to the lungs. LPD- or LPDH-containing SFDPs (LPD- or LPDH-SFDPs) were synthesized and their structure and function as gene carriers were evaluated using physical and biological methods. The particle size of LPDH, but not of LPD, was constant after re-dispersal from the SFDPs and the amount of siRNA encapsulated in LPDH was larger than that in LPD after re-dispersal from the SFDPs. The in vitro pulmonary inhalation properties of LPDH-SFDPs and LPD-SFDPs were almost the same. The cytotoxicity of LPDH-SFDPs in human umbilical vein endothelial cells (HUVEC) was greatly decreased compared with that of LPD-SFDPs. In addition, Bcl-2 siRNA in LPDH-SFDPs had a significant gene silencing effect in human lung cancer cells (A549), whereas Bcl-2 siRNA in LPD-SFDPs had little effect. These results indicate that compared with LPD, LPDH is more useful for developing SFDPs for siRNA pulmonary inhalation.

Pharmaceutical applications of three dimensional (3D) printing technology are increasing following the approval of 3D-printed tablets by the U.S. Food and Drug Administration. Semi-solid extrusion-type 3D printers are used to 3D print hydrogel- and paste-based materials. We previously developed tablet formulations for semi-solid extrusion-type 3D bioprinters. In the present study, we extended our study to the preparation of muco-adhesive oral film formulations to 3D bioprint mouth ulcer pharmaceuticals. We focused on hydroxypropyl methylcellulose (HPMC)-based catechin (model drug)-loaded hydrogel formulations and found that the viscosity of a hydrogel formulation is dependent on the HPMC concentration, and that viscosity is important for facile 3D printing. HPMC-based films were prepared using two different drying methods (air drying and freeze drying). The films exhibited different drug dissolution profiles, and increasing the amount of HPMC in the film delayed drug dissolution. The fabrication of HPMC-based catechin-loaded films with different shapes provides a model of individualized, on-demand pharmaceuticals. Our results support the flexible application of 3D bioprinters (semi-solid extrusion-type 3D printers) for preparing film formulations.

The application of 3D printing technology to pharmaceuticals is expanding, and 3D-printed drug formulations comprising various materials and excipients have been developed using different types of 3D printers. Here, we used a digital light processing-type 3D printer to fabricate poly(ethylene glycol) diacrylate (PEGDA)-based "ghost tablets" that release entrapped drug but do not disintegrate. Three drugs with different aqueous solubilities were incorporated separately into the tablets, and the effects of printer ink composition and printing conditions on tablet formation and drug release were investigated. We also constructed a simple and effective model to predict the drug release profiles of the 3D-printed PEGDA-based tablets based on printer ink compositions and printing conditions. Drug release profiles were constructed by combining data for the amount of drug released at a specified time (15 hr) predicted by a regression algorithm generated by machine learning (multiple linear regression) and the drug release kinetics model generated by a binary classification algorithm (support vector machine). The proposed prediction model is unique and provides information useful for the development of 3D-printed PEGDA-based tablets as future tailored medicines.

The objectives of this study are to enhance the oral bioavailability of cilostazol (CLZ), which is a poorly soluble compound, by cocrystallization and to evaluate the correlation between the calculated solubility of the cocrystal by the solubility product (Ksp) and the complexation constant (K11) and the performance of the cocrystal. Cocrystals of CLZ with 4-hydroxybenzoic acid (4HBA), 2,4-dihydroxybenzoic acid (2,4DHBA), and 2,5-dihydroxybenzoic acid (2,5DHBA) were prepared. Stoichiometric 1:1 structures were formed in the crystal packing of the three cocrystals according to single crystal X-ray diffraction. The calculated solubilities of the CLZ–4HBA cocrystal, CLZ–2,4DHBA cocrystal, and CLZ–2,5DHBA cocrystal were 9.5-fold, 14.5-fold, and 34.3-fold higher than that of CLZ, respectively. Interestingly, the supersaturated dissolution profile in the nonsink condition was inversely correlated with the calculated solubility of the cocrystals, and the CLZ–4HBA cocrystal, which mildly enhanced the solubility c...

This study evaluated the sustained release effect of clarithromycin-loaded in PLGA microspheres in a rabbit calvaria defect model. Four bone defects (o5.0) were created in the calvaria of New Zealand White rabbits (n = 21, n = 7/time point). The defects were randomly designated to four groups. Group 1: No augmentation (sham), Group 2: beta-tricalcium phosphate (β-TCP), Group 3: β-TCP with 0.12 µg clarithromycin, and Group 4: β-TCP with 6.12 µg PLGA microspheres loaded with 0.12 µg Clarithromycin. After 2, 4, and 12 weeks of healing, bone regeneration was evaluated using micro-computed tomography (µCT) and histology. Clarithromycin release from PLGA microspheres revealed sustained release for around 4 weeks with ∼50% release during the first week. Histologically, new bone formation was evident at 2 and 4 weeks of healing in all groups and bone formation increased as a function of healing time. At 12 weeks, Group 4 showed significantly higher amount of newly formed bone compared to Group 1. The µCT showed that Group 4 expressed significantly higher bone formation compared to Group 1 at all time points. The in vivo findings showed that β-TCP with clarithromycin-loaded microspheres can enhance bone formation in bone defects. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 201-208, 2018.

Three-dimensional (3D) printers have been applied in many fields, including engineering and the medical sciences. In the pharmaceutical field, approval of the first 3D-printed tablet by the U.S. Food and Drug Administration in 2015 has attracted interest in the manufacture of tablets and drugs by 3D printing techniques as a means of delivering tailor-made drugs in the future. In current study, polyvinylalcohol (PVA)-based tablets were prepared using a fused-deposition-modeling-type 3D printer and the effect of 3D printing conditions on tablet production was investigated. Curcumin, a model drug/fluorescent marker, was loaded into PVA-filament. We found that several printing parameters, such as the rate of extruding PVA (flow rate), can affect the formability of the resulting PVA-tablets. The 3D-printing temperature is controlled by heating the print nozzle and was shown to affect the color of the tablets and their curcumin content. PVA-based infilled tablets with different densities were prepared by changing the fill density as a printing parameter. Tablets with lower fill density floated in an aqueous solution and their curcumin content tended to dissolve faster. These findings will be useful in developing drug-loaded PVA-based 3D objects and other polymer-based articles prepared using fused-deposition-modeling-type 3D printers.

Phospholipase A2 (PLA2) is expressed in inflammation-related tissue, including cancer tumors. We report that a hybrid liposome composed of phospholipid (DPPC) and PEGylated block-copolymer (Poloxamer 188) can rapidly release an encapsulated hydrophilic drug in the presence of PLA2. DPPC/P188 liposomes released approximately 80% of the encapsulated calcein (a fluorescence marker) within 10min in the presence of 120 mU of PLA2 at 37°C in vitro, whereas several other liposomal compositions used for inhalation therapy did not. DPPC/P188 liposomes were stable in the absence of PLA2 at 37°C after 60min incubation and drug release by PLA2 was dependent on the amount of P188 incorporated into the DPPC liposomes. Drug release from doxorubicin (DOX, anticancer drug)-loaded DPPC/P188 liposomes was facilitated at higher PLA2 concentrations and was dependent on the temperature and the presence of calcium ion, thus partially explaining PLA2-responsive drug release. DOX release from liposomes triggered by PLA2 exhibited the same cytotoxic effects on the A549 lung cancer cell line as did DOX in free solution. These findings suggest that DPPC/P188 liposomes are a promising drug carrier for delivering drug efficiently at PLA2-expressing sites such as inflammatory lung cancer.

In the development of a drug for intra-articular administration, a sustained-release formulation is desirable since it is difficult to sustain the effects of conventional injections due to fast drug leakage from the joint cavity. In this study, we prepared sustained release gel formulations for intra-articular administration containing indocyanine green (ICG) as a model drug to follow its fate after intra-articular administration in rats with in-vivo imaging system (IVIS). ICG administered as an aqueous solution leaked from the joint cavity in a short time and was excreted out of the body within a day. On the other hand, ICG in the sustained-release formulations was retained and released in the joint cavity for a week. Next, we prepared a sustained-release formulation with hyaluronic acid (HA) as the gel base containing a pain-relief drug (Drug A). We had administered it and other formulations into the rat knee where we injected bradykinin to evaluate their walking distance after 1 and 3 d. The effect of an aqueous solution of Drug A disappeared on day 3. The HA gel formulation without Drug A was more effective than the aqueous solution. The HA gel formulation with Drug A was the most effective; the walking distance was about 85% of the baseline on day 3. This study showed that the gel formulations were effective to sustain the release of a drug in the knee joint, and that the combination of a pain-relief drug with HA gel was effective to improve the mobility of the acute pain model rats.

The trans platinum-chloroquine diphosphate dichloride (PtCQ) is a new type of antimalarial drug used to fight parasites resistant to traditional drugs. PtCQ is synthesized by mixing platinum and chloroquine diphosphate (CQ). This study examines two efficient methods for forming a nanodrug, PtCQ-loaded liposomes, for use as a potential antimalarial drug-delivery system: the thin drug-lipid film method to incorporate the drug into a liposomal membrane, and a remote-loading method to load the drug into the interior of a cationic liposome. The membranes accordingly comprised PEGylated neutral or cationic liposomes. PtCQ was efficiently loaded into PEGylated neutral and cationic liposomes using the thin drug-lipid film method (encapsulation efficiency, EE: 76.1±6.7% for neutral liposomes, 1 : 14 drug-to-lipid weight ratio; 70.4±9.8% for cationic liposomes, 1 : 14 drug-to-lipid weight ratio). More PtCQ was loaded into PEGylated neutral liposomes using the remote-loading method than by the thin drug-lipid film method and the EE was maximum (96.1±4.5% for neutral liposomes, 1 : 7 (w/w)). PtCQ was encapsulated in PEGylated cationic liposomes comprising various amounts of cationic lipids (0-20 mol%; EE: 96.9-92.3%) using the remote-loading method. PEGylated neutral liposomes and cationic liposomes exhibited minimum leakage of PtCQ after two months' storage at 4°C, and further exhibited little release under in vitro culture conditions at 37°C for 72 h. These results provide a useful framework for the design of future liposome-based in vivo drug delivery systems targeting the malaria parasite.

The development of taste-masking technologies for foods and drugs is essential because it would enable people to consume and receive healthy and therapeutic effect without distress.In the current study, in order to develop a novel method to prepare nanocomposite particles (microparticles containing bitter nanoparticles) in only one step, by using spray drying, a two-solution mixing nozzle-equipped spray dryer that we previously reported was used. The nanocomposite particles with or without poorly water-soluble polymers prepared using our spray-drying technique were characterized.(1) The organic solution containing quinine, a model of bitter compound and poorly water-soluble polymers and (2) sugar alcohol (mannitol) aqueous solution were separately flown in tubes and two solutions were spray dried through two-solution type spray nozzle to prepare polymer-blended quinine nanocomposite particles. Mean diameters of nanoparticles, taste-masking effect and dissolution rate of quinine were evaluated.The results of taste masking by taste sensor suggested that the polymer (Eudragit EPO, Eudragit S100 or Ethyl cellulose)-blended quinine nanocomposite particles exhibited marked masking of instrumental quinine bitterness compared with the quinine nanocomposite particles alone. Quinine nanocomposite formulations altered the quinine dissolution rate, indicating that they can control intestinal absorption of quinine.These results suggest that polymer-blended quinine composite particles prepared using our spray-drying technique are useful for masking bitter tastes in the field of food and pharmaceutical industry.

Simvastatin is a cholesterol-lowering drug known to affect bone formation in vivo and its sustainable administration into localized areas is of particular interest in the dental field. Two simvastatin-loaded poly(lactic-co-glycolic acid) (PLGA) formulations (PLGA microspheres and PLGA nanospheres) were compared to investigate whether a sustainable supply of simvastatin from a PLGA-based carrier is effective for bone regeneration. PLGA microspheres successfully presented sustained release of simvastatin for one month, whereas simvastatin was continuously released from PLGA nanospheres for one week. The difference of drug release pattern between two PLGA particles was confirmed by Korsmeyer–Peppas mathematical model. PLGA microspheres and simvastatin alone (no carrier) induced the proliferation MC3T3-E1 cells and increased alkaline phosphatase (ALP) activity, a differentiation marker of MC3T3-E1 cells, whereas PLGA nanospheres did not. These results suggested that PLGA nanospheres had an adverse effect on bone generation in vitro due to the production of PLGA metabolized products. Both PLGA microspheres and PLGA nanospheres provided a bone formation effect in an in vivo rat calvaria bone defect model and PLGA microspheres were superior to PLGA nanospheres. Our data suggest that simvastatin-loaded PLGA microspheres can release simvastatin sustainably and induce bone formation more efficiently than PLGA nanospheres, thus promoting bone regeneration.

Taste-masking granules were prepared by coating granules with a taste-masking layer prepared by combining the water-insoluble and -soluble polymers, ethylcellulose and hypromellose, respectively. These granules showed an immediate drug release property after a suitable lag time. We confirmed that the dissolution behavior depended on the polymer ratio in the taste-masking layer. The result showed that the dissolution lag time and rate of the taste-masking granules were shortened and enhanced, respectively by increasing the hypromellose content. Films with the same polymer ratio as the taste-masking layer were prepared, and their physical properties were measured to evaluate the relationship between the dissolution behavior and the film properties. The tensile strength of the films decreased with an increasing concentration of hypromellose. Furthermore, there was a relationship between the tensile strength of the films and dissolution rate of the taste-masking granules. The lag time was significantly shortened when the hypromellose blending ratio exceeded 20%, and this change was suggested to be associated with the water permeability of the film. These results indicate that the tensile strength and water permeability of the films were influenced by the polymer ratio, which also influenced the dissolution behavior of the taste-masking granule.

In the development of drugs for intra-articular administration, sustained-release formulations are desirable because it is difficult to maintain the effect of conventional injections due to immediate drug leakage from the joint cavity. In this study, a sustained-release poly(lactic-co-glycolic acid) (PLGA) microsphere formulation for intra-articular administration containing indocyanine green (ICG) as a model drug was prepared to follow its fate after intra-articular administration in rats with a real-time in-vivo imaging system. ICG administered as an aqueous solution leaked from the joint cavity in a short time and was excreted outside the body within 1-3 d. However, ICG in the sustained-release formulation was retained in the joint cavity and released for 2 weeks. Next, a sustained-release formulation containing PLGA microspheres in a hyaluronic acid (HA) gel formulation was prepared. After gradual release in two stages, we could achieve sustained release for a longer period. It is considered that a combination formulation of PLGA microspheres and HA gel can significantly improve the sustained release of a drug administered into the knee joint.

The production of three-dimensional (3D)-printed drugs holds promise for future personalized medicine. Here, we prepared tablets containing naftopidil as a model drug using a semisolid extrusion-type 3D bioprinter applicable for tissue engineering. A hydrogel is typically used as the printer ink for 3D bioprinters, and we incorporated various amounts of hydroxypropyl methylcellulose hydrogel (30%, 40%, and 50% gel) into the printer ink. The resulting 3D-printed gel product was dried to obtain tablets. The rheological properties of the printer ink changed as its composition was changed, and tablets were prepared successfully from several formulations. Increasing the amount of hydroxypropyl methylcellulose hydrogel in the printer ink led to delayed drug dissolution, decreased weight, and decreased hardness of the tablets. Delayed drug dissolution was also observed when the amount of disintegrating agent typically used in powder compression tablets was increased in the ink, and increasing the incorporated amount of the disintegrating agent crospovidone increased the hardness of the tablets. Our results will provide useful information for the preparation of tablets using semisolid extrusion-type 3D printers.

Functional liposome administration via the pulmonary route is of interest to treat pulmonary diseases, including cancer. Here, a block copolymer used as a medical additive, Poloxamer 188 (P188), was incorporated into liposome membranes, and the thermosensitive characteristics of the DPPC/P188 hybrid liposomes were assessed. An increase in P188 incorporation in DPPC liposomes enhanced the release of calcein, a fluorescence marker, from liposomes at 42°C in vitro; calcein release was significantly slower at 37°C. The lipid composition was optimal at a DPPC/P188 ratio of 3:0.4 (molar ratio). DPPC/P188 liposomes did not exhibit in vitro cytotoxicity against A549 cells and Raw 264.7 cells used as models of pulmonary cells or trigger in vivo acute inflammation as determined by the secretion of tumor necrosis factor alpha. Next, an anticancer drug, doxorubicin (DOX), was loaded with approximately 90% efficiency into DPPC/P188 liposomes using a remote-loading method and a DOX–phospholipid ratio of 1:20 (w/w). The interior buffer of liposome has remarkably changed DOX release at 42°C. DOX released from DPPC/P188 liposomes at 42°C exhibited cytotoxic effects toward A549 cells comparable with free DOX solution. These results suggest that a DOX-loaded DPPC/P188 liposome formulation administered via the pulmonary route may be useful for treating lung cancer. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3824–3832, 2015

Efonidipine hydrochloride ethanolate (NZ-105) is a novel 1,4-dihydropyridine derivative and Ca antagonist. Its chemical structure is distinctive, being a solvate composed of an equimolar adduct of ethanol and efonidipine hydrochloride, and it represents one of a few cases of solvates marketed as a pharmaceutical drug. The research presented in this paper used methods to assess its solid-state properties and included thermal analysis (thermogravimetry-differential thermal analysis, TG-DTA), Fourier transform infrared spectroscopy (FT/IR), evolved gas analysis-mass spectrometry (EGA-MS), environmental (low-vacuum) scanning electron microscopy (E-SEM), variable temperature powder X-ray diffraction, and single-crystal X-ray structure analysis, in order to clarify the thermal behavior of the hydrogen chloride and ethanol adducts of efonidipine in the study of the thermal stability of efonidipine hydrochloride ethanolate. Upon heating, efonidipine hydrochloride ethanolate first released ethanol and subsequently formed a decomposition product with the elimination of chloride ions. X-ray diffraction patterns and particulate forms were markedly altered after the release of ethanol, which suggested the interaction of ethanol molecules with chloride ions and efonidipine molecules within the crystal structure. Vastly different from efonidipine, the crystal structure of efonidipine hydrochloride ethanolate arranges the chloride ion within a basket-type conformation formed by the bulky diphenyl and phosphate groups. This distinctive crystal structure was thought to suppress the elimination of chloride ions and contribute significantly to the improved thermal stability of the compound.

Lung cancer is the major cause of cancer-related death worldwide. Curcumin attracted attention due to its promising anti-cancer properties, however its poor aqueous solubility and bioavailability have to be overcome. In the current study curcumin is encapsulated in krill lipids-based liposomes (marinosomes) to develop a potential anticancer therapy from low-cost and readily available nutraceuticals. Reflux followed by thin drug-lipid film method is used successfully to incorporate the drug into the liposomal membrane at high encapsulation efficiency (EE). The curcumin-loaded marinosomes (CURMs) showed a powerful antioxidant activity (EC50 ≒ 4 μg/mL). Additionally, CURMs exhibited good physicochemical and oxidative stability after eight weeks’ storage at 4 °C. Furthermore, CURMs exhibited sustained release of about 30% of their curcumin content under in vitro culture conditions at 37 °C after 72 h. Consequently, CURMs showed its maximum cytotoxic effect (IC50; 11.7 ± 0.24 μg/ml) after incubation for 72 h against A549 lung cancer cells. Additionally, CURMs inhibited the proliferation of HUVECs in a dose-dependent manner with IC50 of 2.64 ± 0.21 μg/ml after incubation for 24 h. The current study presents the CURM as a favorable in vitro drug delivery system to target cancer disease.

Ranibizumab is a humanized monoclonal antibody fragment against vascular endothelial growth factor (VEGF)-A and is widely used to treat age-related macular degeneration (AMD) caused by angiogenesis. Ranibizumab has a short half-life in the eye due to its low molecular weight and susceptibility to proteolysis. Monthly intravitreal injection of a large amount of ranibizumab formulation is a burden for both patients and medical staff. We therefore sought to develop a sustainable release system for treating the eye with ranibizumab using a drug carrier. A ranibizumab biosimilar (RB) was incorporated into microparticles of poly(lactic-co-glycolic acid) (PLGA) biodegradable polymer. Ranibizumab was sustainably released from PLGA microparticles (80+% after 3 weeks). Assay of tube formation by endothelial cells indicated that RB released from PLGA microparticles inhibited VEGF-induced tube formation and this tendency was confirmed by a cell proliferation assay. These results indicate that RB-loaded PLGA microparticles are useful for sustainable RB release and suggest the utility of intraocular sustainable release systems for delivering RB site-specifically to AMD patients.

The pulverization of poorly water-soluble drugs and drug candidates into nanoscale particles is a simple and effective means of increasing their pharmacological effect. Consequently, efficient methods for pulverizing compounds are being developed. Femtosecond lasers, which emit ultrashort laser pulses, can be used to generate nanoscale particles without heating and are finding in various fields, including pharmaceutical science. Laser ablation holds promise as a novel top-down pulverization method for obtaining drug nanoparticles. We used a poorly water-soluble compound, curcumin (diferuloyl methane), to understand the characteristics of femtosecond laser pulverization. Various factors such as laser strength, laser scan speed, and the buffer solution affected the size of the curcumin particles. The minimum curcumin particle size was approximately 500 nm; the particle size was stable after 30 days. In vitro studies suggested that curcumin nanoparticles exhibited a cytotoxic effect on C6 rat glioma cells, and remarkable intracellular uptake of the curcumin nanoparticles was observed. The results suggest that femtosecond laser ablation is a useful approach for preparing curcumin nanoparticles that exhibit remarkable therapeutic effects.

X-ray inspection equipment is widely used to detect missing materials and defective goods in opaque containers. Its application has been expanded to the pharmaceutical industry to detect the presence of drug tablets in aluminum foil press-through packaging. However, the effect of X-rays on the pharmaceutical quality of drug tablets is not well known.In this study, the effect of X-rays on the pharmaceutical quality of drug tablets was investigated.Exposure of acetaminophen, loxoprofen and mefenamic acid tablets to X-ray doses of 0.34 mGy (thrice the dose by X-ray scanning) to 300 Gy (maximum dose from our X-ray equipment) was demonstrated, and the samples were evaluated by formulation tests.Exposure to X-rays did not affect the pharmaceutical quality of the drug content. The samples exposed to X-rays exhibited almost the same profile in formulation tests (dissolution test, disintegrating test and hardness test) as control samples (0 Gy). The combination of X-ray exposure with accelerated temperature and humidity tests (six months) also did not affect the pharmaceutical quality. The color change of light-sensitive drugs (nifedipine and furosemide tablets) after X-ray exposure was negligible ( 1.0). In contrast, tablet color was remarkably changed by light from a D65 lamp.The X-ray scanning and X-ray exposure under our experimental conditions did not affect the pharmaceutical quality of drug tablets.

Nanocomposite particles are microparticles containing nanoparticles and are a promising approach for the effective handling and preservation of drug nanoparticles. Nanocomposite particles have several advantages such as improving the dissolution rate and oral bioavailability of poorly-water-soluble drugs. Nanocomposite particles of a poorly-water-soluble drug, simvastatin (SMV), were generated using a spray dryer equipped with a two-solution mixing-type nozzle developed to produce nanocomposite particles in one step. Attempts were initially made to prepare SMV nanoparticles by a typical nanoprecipitation method using just the anti-solvent effect without spray drying, but needle-type drug crystals were obtained and it was difficult to prepare SMV nanoparticles. In contrast, SMV nanocomposite particles containing 200–300 nm diameter SMV nanoparticles were obtained by spray drying through a two-solution mixing-type nozzle. The SMV nanocomposite particles exhibited remarkably enhanced dissolution rates compared with the original SMV powder. We therefore succeeded in preparing SMV nanocomposite particles by spray drying and prevented drug crystal growth using the anti-solvent effect. This spray drying technique is useful for preparing drug nanoparticles for pharmaceutical applications.