Design of an Oral Tablet Containing Furosemide Nanoparticles with Elevated Bioavailability.

The solubility and permeability of the Biopharmaceutics Classification System (BCS) class IV drugs, such as furosemide (FUR), are low. Thus, the oral bioavailability of these drugs needs to be augmented. Here, we aimed to design orally disintegrating tablets containing FUR nanoparticles to improve bioavailability after oral administration. The FUR nanoparticles were generated by bead-milling in water containing 0.5% methylcellulose and 0.5% 2-hydroxypropyl-ß-cyclodextrin (w/w%). Particle size was approximately 47-350 nm (mean particle size, 188 nm). An orally disintegrating tablet (FUR-NP tablet) comprising FUR nanoparticles (1%) was successfully produced by employing suspensions outlined above that incorporated additives (4% D-mannitol, 0.4% polyvinylpyrrolidone, and 16% gum Arabic, w/w%), followed by freeze-drying. The FUR-NP tablet disaggregated after only 5 s in water, liberating nano-sized FUR particles (172 nm). Experiments using rats showed the absorption of the FUR-NP tablet was significantly improved by comparison with a FUR tablet containing microparticles. In summary, the orally disintegrating tablet containing FUR nanoparticles markedly enhanced the bioavailability of FUR. We anticipate this formulation will also improve the bioavailability of other BCS class IV drugs.

Piezo1 channel causes lens sclerosis via transglutaminase 2 activation.

Presbyopia is caused by age-related lenticular hardening, resulting in near vision loss, and it occurs in almost every individual aged ≥50 years. The lens experiences mechanical pressure during for focal adjustment to change its thickness. As lenticular stiffening results in incomplete thickness changes, near vision is reduced, which is known as presbyopia. Piezo1 is a mechanosensitive channel that constantly senses pressure changes during the regulation of visual acuity, and changes in Piezo1 channel activity may contribute to presbyopia. However, no studies have reported on Piezo1 activation or the onset of presbyopia. To elucidate the relevance of Piezo1 activation and cross-linking in the development of presbyopia, we analysed the function of Piezo1 in the lens. The addition of Yoda1, a Piezo1 activator, induced an increase in transglutaminase 2 (TGM2) mRNA expression and activity through the extra-cellular signal-regulated kinase (ERK) 1/2 and c-Jun-NH2-terminal kinase1/2 pathways. In ex vivo lenses, Yoda1 treatment induced γ-crystallin cross-linking via TMG2 activation. Furthermore, Yoda1 eye-drops in mice led to lenticular hardening via TGM2 induction and activation in vivo, suggesting that Yoda1-treated animals could serve as a model for presbyopia. Our findings indicate that this presbyopia-animal model could be useful for screening drugs for lens-stiffening inhibition.

Recovery from indomethacin-induced gastrointestinal bleeding by treatment with teprenone.

BACKGROUND: Gastrointestinal injuries caused by nonsteroidal anti-inflammatory drugs (NSAIDs) is a serious side effect in patients with rheumatoid arthritis (RA). However, effective therapeutic strategies have yet to be established. In this study, we investigated the therapeutic effects of teprenone (TEP), a gastric mucosal protective drug, on NSAID-induced gastrointestinal injuries in rats with RA (AA rats). METHODS: Gastrointestinal injury was induced by oral administration of indomethacin (IMC), a typical NSAID. TEP was orally administered after IMC-induced gastrointestinal bleeding, and the stomach, jejunum, and ileum were excised. RESULTS: On day 14 of IMC administration, lesion areas in the stomach, jejunum, and ileum were significantly larger in AA rats than in normal rats. When TEP was orally administered to AA rats, the lesion areas in the stomach, jejunum, and ileum significantly decreased compared with those in control rats (IMC-induced AA rats). Therefore, we measured NOS2 mRNA and NO levels, which were significantly decreased in rats with IMC-induced AA after treatment with TEP. CONCLUSIONS: These results suggest that the oral administration of TEP may be useful for the treatment of NSAID-induced gastrointestinal injuries in patients with RA.

Therapeutic Effects of Hydrogel Formulations Incorporating Troxipide Nanoparticles on Oral Mucositis in Hamsters.

Purpose: Medical therapies, such as the use of anti-inflammatory agents, are commonly used for the treatment of oral mucositis (OM). However, these treatments have limited efficacy in treating severe cases of OM. In this study, we aimed to develop a carbopol gel incorporating troxipide (TRO) nanoparticles and methylcellulose (TRO-NP gel) and demonstrate its efficacy in accelerating wound healing in a hamster model of OM (OM model) induced by acetic acid injection. Methods: TRO nanoparticles were prepared using bead milling. The crystalline form was determined by powder X-ray diffraction, and the particle size was measured using a NanoSight LM10 instrument. The drug release was determined using a Franz diffusion cell, and the hamsters injected with acetic acid were selected to evaluate the therapeutic effect of OM. Results: After preparing TRO nanoparticles, we observed a mixture of crystals and amorphous TRO, and the particle size of TRO in the TRO-NP gel ranged from 50 to 280 nm. The TRO-NP gel exhibited a more uniform TRO distribution and viscosity compared to the Carbopol gel containing TRO microparticles (TRO-MP gel). However, the solubility of TRO was comparable in both TRO-MP and TRO-NP gels. The TRO-NP gel released a higher amount of TRO than that from the TRO-MP gel, with detectable release of TRO nanoparticles. TRO levels in the cheek pouches of hamsters treated with TRO-NP gel were higher than those treated with TRO-MP gel. The increased TRO levels in the cheek pouches of hamsters treated with TRO-NP gel were attenuated by treatment with 40 µM dynasore, an inhibitor of clathrin-dependent endocytosis (CME). Moreover, the therapeutic effect of the TRO-NP gel was superior to that of the TRO-MP gel in the hamster model of OM. Conclusion: We have designed a TRO-NP gel, and this gel showed excellent TRO delivery into the cheek pouch tissue through the CME pathway. Moreover, the TRO-NP gel treatment enhanced wound healing after acetic acid injection.

Oral 5-aminolevulinic acid combined with sodium ferrous citrate prevents blood-aqueous barrier breakdown after anterior chamber paracentesis in healthy beagle dogs.

This study investigated the preventive effect of 5-aminolevulinic acid combined with sodium ferrous citrate (5-ALA/SFC) on blood-aqueous barrier (BAB) breakdown induced after anterior chamber paracentesis (ACP) in beagles. 5-ALA/SFC (1/0.64 mg/kg or 3/1.92 mg/kg) or carprofen (4.0 mg/kg) was orally administered daily for 7 days prior to ACP. Then, a sample of the aqueous humor (AH) was collected from one eye via ACP (first sample) and again 60 min later (second sample). The protein and prostaglandin E2 (PGE2) concentrations in both samples were measured. Compared with the control group, high-dose 5-ALA/SFC and carprofen significantly reduced the AH protein and PGE2 concentrations in the second sample. Our findings suggest that 5-ALA/SFC suppresses BAB breakdown in dogs.

Poly(oxyethylene)/Poly(oxypropylene) butyl ether prolongs the repellent effect of N,N-diethyl-3-toluamide on the skin.

N,N-diethyl-meta-toluamide (DEET) is a widely used insect repellent, with minimal skin permeation and sustained repellent activity in the superficial layers of the skin. In this study, we prepared a 10% DEET formulation consisting of 40% ethanol with or without 2% poly(oxyethylene)/poly(oxypropylene) butyl ether (POE-POP), an amphiphilic random copolymer. Further, we demonstrated the effects of POE-POP on tensile stress (stickiness), hydrophobicity, skin retention, permeation, and repellent activity of DEET. Stickiness was measured in male ICR mice (7-week old), and skin retention and permeation were evaluated in male Wistar rats (7-week old). In addition, female Aedes albopictus were used to measure the repellent action of DEET. The addition of POE-POP did not affect stickiness, volatility, and degradability but decreased logP and increased viscosity of DEET. Next, we demonstrated the behavior of DEET formulations in the rat skin. POE-POP prolonged the retention of DEET in the superficial layers of the rat skin (skin surface and stratum corneum) and decreased the penetration of DEET into rat skin tissues (epithelium and dermis). The repellent effect of DEET was also enhanced by the addition of POE-POP. However, severe skin damage was not observed after repetitive treatment with DEET formulations containing POE-POP for one month (twice a day). In conclusion, we demonstrated that a 10% DEET formulation consisting of 40% ethanol and 2% POE-POP attenuated the skin penetration and prolonged the repellent action of DEET without causing stickiness and skin damage. We conclude that the combination of ethanol and POE-POP is useful as a safe and effective delivery system for the development of insect repellent formulations containing DEET.

Nasal Absorption Enhancement of Mometasone Furoate Nanocrystal Dispersions.

Purpose: We designed a 0.05% mometasone furoate (MF) nanocrystal dispersion and investigated whether the application of MF nanocrystals in nasal formulations enhanced local absorption compared to traditional nasal MF formulations (CA-MF). Methods: MF nanocrystal dispersions (MF-NPs) were prepared by bead milling MF microcrystal dispersions (MF-MPs) consisting of MF, 2-hydroxypropyl-ß-cyclodextrin, methylcellulose, and purified water. Pluronic F-127 combined with methylcellulose, Pluronic F-68, or carbopol was used as a base for in situ gelation (thickener). MF concentrations were measured using high-performance liquid chromatography, and nasal absorption of MF was evaluated in 6 week-old male Institute of Cancer Research (ICR) mice. Results: The particle size range of MF prepared with the bead mill treatment was 80-200 nm, and the nanoparticles increased the local absorption of MF, which was higher than that of CA-MF and MF-MPs. In addition, unlike the results obtained in the small intestine and corneal tissue, the high absorption of nanocrystalline MF in the nasal mucosa was related to a pathway that was not derived from energy-dependent endocytosis. Moreover, the application of the in situ gelling system attenuated the local absorption of MF-NPs, owing to a decrease in drug diffusion in the dispersions. Conclusion: We found that nanoparticulation of MF enhances local intranasal absorption, and nasal bioavailability is higher than that of CA-MF. In addition, we demonstrate that viscosity regulation is an important factor in the design of nasal formulations based on MF nanocrystals. These findings provide insights for the design of novel nanomedicines with enhanced nasal bioavailability.

Sodium Ferrous Citrate and 5-Aminolevulinic Acid Exert a Therapeutic Effect on Endotoxin-Induced Uveitis in Rats.

The metabolism of 5-aminolevulinic acid (ALA) is more efficient when combined with sodium ferrous citrate (SFC). Our previous study revealed that oral administration of ALA, which has anti-inflammatory properties, and SFC (ALA/SFC) immediately before lipopolysaccharide (LPS) inoculation suppressed endotoxin-induced uveitis (EIU) in rats. However, the therapeutic effect of ALA/SFC post-administration remains unexplored. Hence, this study aimed to evaluate the therapeutic efficacy of ALA/SFC on EIU in rats, which were administered with a gastric gavage of ALA/SFC (100/157 mg/kg) or prednisolone (Pred, 10 mg/kg) after 4 h of LPS inoculation. The treatment groups showed ameliorated clinical scores, inflammatory cells, protein levels in the aqueous humor (AqH), and histopathologic evaluation 24 h after LPS inoculation. Furthermore, the treatment groups had reduced tumor necrosis factor-α, nitric oxide, prostaglandin E2, and interleukin-6 levels in the AqH. ALA/SFC demonstrated an anti-inflammatory effect equivalent to that demonstrated by Pred. These findings indicate that ALA/SFC exerts a therapeutic effect on EIU in rats, indicating its clinical usefulness in uveitis treatment.

Application of Granulated Nickel-Aluminum-Zirconium Complex Hydroxide in the Flow Method for Recovery of Chromium(VI) Ions.

A colloidal silicate granulated nickel-aluminum-zirconium (CSG-NAZ) was prepared, and the chromium(VI) (Cr(VI)) ions recovery capacity was evaluated using a sodium sulfate solution in a column experiment. The amount adsorbed and breakthrough time were enhanced by decreasing the flow rate (flow rate is in the order of 3.0 > 2.0 > 0.5 mL). The breakthrough curves and model parameters were estimated using the Thomas and Yoon-Nelson models. The obtained data confirmed to fit both the Yoon-Nelson model (0.858-0.906) and the Thomas model (0.813-0.906). Additionally, Cr(VI) ions that adsorbed onto CSG-NAZ could be desorbed using a sodium sulfate solution in a column experiment. The total recovery percentage of Cr(VI) ions was 80.9% after six repetitions of adsorption/desorption. Finally, the obtained results revealed that CSG-NAZ was a candidate adsorbent for the recovery of Cr(VI) ions owing to its applicability toward a continuous system.

Aquaporins contribute to vacuoles formation in Nile grass type II diabetic rats.

Regulation of ion and water microcirculation within the lens is tightly controlled through aquaporin channels and connexin junctions. However, cataracts can occur when the lens becomes cloudy. Various factors can induce cataracts, including diabetes which is a well-known cause. The most common phenotype of diabetic cataracts is a cortical and/or posterior subcapsular opacity. In addition to the three main types and two subtypes of cataracts, a vacuole formation is frequently observed; however, their origin remains unclear. In this study, we focused on the aquaporins and connexins involved in diabetes-induced cataracts and vacuoles in Nile grass type II diabetes. The results showed that the expression of aquaporin 0 and aquaporin 5 increased, and that of connexin 43 decreased in diabetic rat lenses. Additionally, aquaporin 0 and 5 were strongly localized in peripheral of vacuoles, suggesting that aquaporins are involved in vacuoles formation. Transillumination photography revealed large vacuoles at the tip of the Y-suture in the anterior capsule of the diabetic lens, and several small vacuoles were observed in the posterior capsule. Within the vacuoles, cytoplasmic degradation and aggregation of fibrous material were observed. Our findings suggest that aquaporins are potential candidate proteins for preventing vacuole formation.

Skin absorption of felbinac solid nanoparticles in gel formulation containing l-menthol and carboxypolymethylene.

BACKGROUND: It is important to design an effective formulation to enhance the skin penetration, and nanotechnologies have been used in dermal and transdermal drug delivery. In this study, we prepared formulations (gels) containing l-menthol and felbinac (FEL) solid nanoparticles (FEL-NP gel) for topical application, and investigated the local and systemic absorption of the prepared FEL-NP gel. METHODS: FEL solid nanoparticles were obtained by bead milling of FEL powder (microparticles), and a topical formulation (FEL-NP gel) consisting of 1.5% FEL solid nanoparticles), 2% carboxypolymethylene, 2% l-menthol, 0.5% methylcellulose, and 5% 2-hydroxypropyl-ß-cyclodextrin (w/w %) were prepared. RESULTS: The particle size of FEL nanoparticles was 20-200 nm. The released FEL concentration from FEL-NP gel was significantly higher than that from FEL gel without bead mill treatment (carboxypolymethylene gel in which FEL microparticles (MPs) instead of FEL nanoparticles were incorporated, FEL-MP gel), and FEL was released as nanoparticles from the gel. Moreover, both transdermal penetration and percutaneous absorption of FEL-NP gel were significantly increased compared with those of FEL-MP gel, and the area under the FEL concentration-time curve (AUC) of FEL-NP gels was 1.52- and 1.38-fold of commercially available FEL ointment and FEL-MP gel, respectively. In addition, after 24 h of treatment, the FEL content in rat skin treated with FEL-NP gels was 1.38- and 2.54-fold higher than that when treated with commercially available FEL ointment and FEL-MP gel, respectively. Moreover, the enhanced skin penetration of FEL-NP gels was significantly attenuated by inhibition of energy-dependent endocytosis, such as clathrin-mediated endocytosis. CONCLUSIONS: We successfully prepared a topically applied carboxypolymethylene gel containing FEL nanoparticles. In addition, we observed that the endocytosis pathway was mainly related to the high skin penetration of FEL nanoparticles, and FEL-NP gel application resulted in high local tissue concentration and systemic absorption of FEL. These findings provide useful information for the design of topically applied nanoformulations against inflammation by providing local and systemic effects.

5-ALA/SFC Ameliorates Endotoxin-Induced Ocular Inflammation in Rats by Inhibiting the NF-κB Signaling Pathway and Activating the HO-1/Nrf2 Signaling Pathway.

Sodium ferrous citrate (SFC) is involved in the metabolism of 5-aminolevulinic acid (5-ALA) and enhances its anti-inflammatory effects. The effects of 5-ALA/SFC on inflammation in rats with endotoxin-induced uveitis (EIU) have yet to be elucidated. In this study, during lipopolysaccharide injection, 5-ALA/SFC (10 mg/kg 5-ALA plus 15.7 mg/kg SFC) or 5-ALA (10 or 100 mg/kg) was administered via gastric gavage, wherein we saw that 5-ALA/SFC ameliorated ocular inflammation in EIU rats by suppressing clinical scores; by infiltrating cell counts, aqueous humor protein, and inflammatory cytokine levels; and by improving histopathological scores to the same extent as 100 mg/kg 5-ALA. Immunohistochemistry showed that 5-ALA/SFC suppressed iNOS and COX-2 expression, NF-κB activation, IκB-α degradation, and p-IKKα/ß expression, and activated HO-1 and Nrf2 expression. Therefore, this study has investigated how 5-ALA/SFC reduces inflammation and revealed the pathways involved in EIU rats. 5-ALA/SFC is shown to inhibit ocular inflammation in EIU rats by inhibiting NF-κB and activating the HO-1/Nrf2 pathways.

Effect of Ointment Base on the Skin Wound-Healing Deficits in Streptozotocin-Induced Diabetic Rat.

Wound-healing deficits of the skin, one of the most common complications in patients with diabetes, delay wound healing, significantly reducing the patient's QOL. Therefore, the topical treatment of wound areas with drug-containing ointments and dressings is important. In this study, we investigated the effect of various ointment bases on skin wound healing in normal and streptozotocin-induced diabetic rats (STZ rats). Three ointment bases were used: white ointment (oil-based), absorbent cream (emulsion-based, w/o), and macrogol ointment (water-based). Skin wound healing in STZ rats was delayed compared with that in normal rats. Each of the three ointment bases was applied to the skin wound area in normal rats, and there was no difference in the therapeutic effect. The therapeutic effect of both white ointment and absorbent cream was higher in the STZ rats group than that in the non-treated group, and delayed wound healing was observed in STZ rats treated with macrogol ointment. In conclusion, skin wound healing in STZ rats is affected by the properties of the ointment base, and it is important to use an ointment base that controls the drying of the wound area in STZ rats. These findings provide information for the selection of ointment bases useful for application to skin wounds in patients with diabetes.

Hesperetin treatment attenuates glycation of lens proteins and advanced­glycation end products generation.

Advanced glycation end products (AGEs) in lens proteins increase with aging, thus inducing cataracts and/or presbyopia. Hesperetin (Hst), which is an abundant plant flavanone largely derived from citrus species, and its derivatives attenuate cataracts and presbyopia in vivo and in vitro; however, no reports have described its effects on AGE formation in lens proteins. The present study demonstrated that AGEs in lens proteins increase with age in mice. Additionally, it showed that Hst can prevent AGEs and N(ε)­carboxymethyl­lysine generation and modification of lens proteins using in vitro in human lens epithelial cell lines and ex vivo in mouse lens organ cultures. Furthermore, treatment with Hst prevented lens hardening and decreased chaperone activity in lens proteins. These results suggested that Hst and its derivatives are good candidates for the prevention of presbyopia and cataracts.

Potential of waste mangosteen shell in the removal of cadmium ions: Effects of pH, contact time, and temperature.

In this study, waste biomass adsorbents produced from mangosteen shells (MGS) were prepared (denoted as MGS500 and MGS1000). The physical and chemical characteristics, such as scanning electron microscopy, thermogravimetric-differential thermal analysis, specific surface area, pore volumes, surface functional groups, and point of zero charge of the prepared MGS samples were determined, and the adsorption capacity of cadmium ions from aqueous media was assessed. The effects of pH, adsorption time, temperature, and coexistence on adsorption were carefully assessed using an inductively coupled plasma optical emission spectrometer under several experimental conditions. The adsorption capacity decreased in the order, MGS < MGS500 < MGS1000. The optimal pH for cadmium ion removal was 5.0. The amount of cadmium ions adsorbed gradually increased with time, and adsorption equilibrium was achieved within 24 h after adsorption. Additionally, the amount of adsorbed cadmium ions increased with increasing adsorption temperature. To elucidate the adsorption mechanism in detail, the elemental distribution and X-ray photoelectron spectra of the prepared adsorbents were analyzed. Finally, desorption solutions such as HNO3, H2O, and NaOH were used to desorb the absorbed cadmium ions from MGS1000. Under our experimental conditions, the desorption percentage of cadmium ions was approximately 98.8% using HNO3. In conclusion, MGS1000 exhibited a good adsorption capacity of 12.0 mg/g for adsorbing cadmium ions from aqueous media and desorption capacity with HNO3 at 1000 mmol/L.

Orally disintegrating tablets containing famotidine nanoparticles provide high intestinal absorbability via the energy-dependent endocytosis pathway.

The permeability of the Biopharmaceutics Classification System (BCS) class III drugs are low, and their oral bioavailability needs to be improved. In this study, we attempted to design oral formulations containing famotidine (FAM) nanoparticles to overcome the limitations of BCS class III drugs. Dispersions containing FAM nanoparticles with a particle size of approximately 50-220 nm were produced by the bead-milling treatment. Moreover, we succeeded in preparing an orally disintegrating tablet containing FAM nanoparticles using the dispersions described above, additives (D-mannitol, polyvinylpyrrolidone, and gum arabic), and freeze-dry treatment (FAM-NP tablet). The FAM-NP tablet was disaggregated 3.5 s after addition to purified water, and the FAM particles in the redispersion of the FAM-NP tablet stored for 3 months were nano-sized (141 ± 6.6 nm). The ex-vivo intestinal penetration and in vivo absorption of FAM in rats applied with the FAM-NP tablet were significantly higher than those in rats applied with the FAM tablet containing microparticles. In addition, enhanced intestinal penetration of the FAM-NP tablet was attenuated by an inhibitor of clathrin-mediated endocytosis. In conclusion, the orally disintegrating tablet containing FAM nanoparticles improved low mucosal permeability and low oral bioavailability and overcame these issues of BCS class III drugs as oral formulations.

Effects of Oral 5-Aminolevulinic Acid on Lipopolysaccharide-Induced Ocular Inflammation in Rats.

This study aimed to investigate the anti-inflammatory effect of 5-aminolevulinic acid (5-ALA) on endotoxin-induced uveitis (EIU) in rats. EIU was induced in male Sprague Dawley rats by the subcutaneous injection of lipopolysaccharide (LPS). During LPS injection, 5-ALA diluted with saline was administered via gastric gavage. After 24 h, clinical scores were assessed after which aqueous humor (AqH) samples were obtained. The number of infiltrating cells, protein concentration, and levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nitric oxide (NO), and prostaglandin E2 (PGE2) in AqH were measured. For histological examination, both eyes of some rats were enucleated. In vitro, a mouse macrophage cell line (RAW264.7 cells) was stimulated by LPS with or without 5-ALA. Western blot was used to analyze the expression of inducible NO synthase (iNOS) and cyclooxygenase-2. 5-ALA suppressed the EIU clinical scores, infiltrating cell number, and protein concentration while improving the histopathologic scores. In particular, 100 mg/kg 5-ALA reduced the concentrations of NO, PGE2, TNF-α, and IL-6 in AqH, similar to 1 mg/kg prednisolone. In addition, 5-ALA suppressed iNOS upregulation in LPS-stimulated RAW264.7 cells. Therefore, 5-ALA has an anti-inflammatory effect on EIU through the inhibition of the upregulation of inflammatory mediators.

Role of mucoadhesive agent in ocular delivery of ganciclovir microemulsion: cytotoxicity evaluation in vitro and ex vivo.

PURPOSE: The aim of the present study was to investigate increase in delivery of drug upon formulation as mucoadhesive microemulsion system and further to investigate possibility of any cytotoxic effects using such formulation. MATERIAL AND METHODS: Considering hydrophilic and small molecular nature of the drug, it was attempted to be formulated as microemulsion, by using pseudo ternary phase diagram method. Thus, three types of microemulsions were prepared; oil in water, water in oil type and chitosan-coated microemulsion. These microemulsions were characterized for several physicochemical properties like size, zeta potential, Polydispersity index, and compared for in vitro cell viability and ex vivo corneal irritation study. RESULTS: All three microemulsions were quite stable, transparent and homogenous systems. They showed similar drug release pattern, but highest ex vivo goat corneal permeation was observed with Chitosan coated microemulsion when compared with ganciclovir solution. CONCLUSION: All microemulsions were found to be non-irritant in in vitro cell viability assay and ex vivo corneal irritation study, indicating the potential of using such systems for delivery of drug to eye.

Function of mitochondrial cytochrome c oxidase is enhanced in human lens epithelial cells at high temperatures.

Enhancement of density via human lens epithelium (HLE) cell proliferation is the underlying cause of nuclear cataracts. Moreover, our previous epidemiological study demonstrated that the risk of nuclear cataract development is significantly higher under elevated environmental temperatures compared with under lower temperatures. The present study investigated the relationship between temperature and cell proliferation in terms of mitochondrial function, which is a nuclear cataract­inducing risk factor, using two different HLE cell lines, SRA01/04 and immortalized human lens epithelial cells NY2 (iHLEC­NY2). Cell proliferation was significantly enhanced under the high­temperature condition (37.5˚C) in both cell lines. The cell growth levels of SRA01/04 and iHLEC­NY2 cells cultured at 37.5˚C were 1.20­ and 1.16­fold those in the low­temperature cultures (35.0˚C), respectively. Moreover, the levels of cytochrome c oxidase mRNA (mitochondrial genome, cytochrome c oxidase­1­3) and its activity in SRA01/04 and iHLEC­NY2 cells cultured at 37.5˚C were higher compared with those in cells cultured at 35.0˚C. In addition, adenosine­5'­triphosphate (ATP) levels in SRA01/04 and iHLEC­NY2 cells were also significantly higher at 37.5˚C compared with those at 35.0˚C. By contrast, no significant differences in Na+/K+­ATPase or Ca2+­ATPase activities were observed between HLE cells cultured at 35.0 and 37.5˚C. These results suggested that expression of the mitochondrial genome was enhanced in high­temperature culture, resulting in a sufficient ATP content and cell proliferation for lens opacity. Therefore, elevated environmental temperatures may increase the risk of nuclear cataracts caused by HLE cell proliferation via mitochondrial activation.

Design of a Transdermal Sustained Release Formulation Based on Water-Soluble Ointment Incorporating Tulobuterol Nanoparticles.

We aimed to investigate which base was suitable for preparing transdermal formulations incorporating tulobuterol (TUL) nanoparticles (30-180 nm) in this study. Three bases (water-soluble, absorptive, and aqueous ionic cream) were selected to prepare the transdermal formulations, and TUL nanoparticles were prepared with a bead-milling treatment. In the drug release study, the TUL release from the water-soluble ointment was higher than that from the other two ointments. Moreover, the addition of l-menthol enhanced TUL nanoparticle release from the ointment, and the rat skin penetration of the TUL water-soluble ointment was also significantly higher than that of the other two ointments. In addition, the drug penetration of the TUL water-soluble ointment with l-menthol sustained zero-order release over 24 h, and the skin permeability of TUL increased with TUL content in the ointment. On the other hand, this penetration was significantly inhibited by treatment with a caveolae-mediated endocytosis inhibitor (nystatin). In conclusion, we found that the water-soluble base incorporating TUL nanoparticles and l-menthol was the best among those assessed in this study. Furthermore, the pathway using caveolae-mediated endocytosis was related to the skin penetration of TUL nanoparticles in the TUL water-soluble ointment with l-menthol. These findings are useful for the design of a transdermal sustained-release formulation based on TUL nanoparticles.