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Objective:To investigate the pharmacokinetics of econazole solid lipid nanoparticles (E-SLNs) after administration of one single dose in rabbit eyes.Methods:E-SLNs with 0.2% econazole was prepared by microemulsion method.Its antifungal activity against Fusarium isolated from the eyes of patients with fungal keratitis was evaluated in vitro and was compared with natamycin eye drops.Four healthy New Zealand white rabbits were assigned to the blank control group without any drug interference during the experimental period, and other matched 21 rabbits were randomized into 7 groups according to the specimen-collected time, with 3 rabbits in each group.E-SLNs of 50 μl was singly applied to conjunctival sac in both eyes in the 21 rabbits, and tear was collected using a filter paper at 5, 15, 30, 60, 90, 120 and 180 minutes following administration of the drug.The cornea specimen was collected at above-mentioned time points respectively.The drug levels in each sample were assayed by high performance liquid chromatography.The accuracy, recovery rate, stability and antifungal activity of the drugs in tear fluid and cornea were detected.This study protocol was approved by the Life Science Ethics Review Committee of Henan Eye Hospital (No.HENNCA-2017-22). Results:For the tear samples and corneal tissue samples, the relative standard deviation ( RSD) of the accuracy of the drug was 2.34%-4.04%; the stability analysis result showed that the RSD of the drugs was less than 10%.The 50% minimum inhibitory concentration (MIC 50) and 90% minimum inhibit concentration (MIC 90) of E-SLNs were 0.37 μg/ml and 0.89 μg/ml, respectively.The MIC 50 and MIC 90 of natamycin were 1.15 μg/ml and 1.70 μg/ml, respectively.After one single dose application of E-SLNs eye drops, the peak time of the drug in tears fluids and cornea of rabbits were 5 minutes and maximum concentrations in tears and cornea were 597.64 μg/g and 33.15 μg/g, respectively. Conclusions:The drug levels in tears and cornea achieved are higher than MIC against Fusarium.
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Objective:To study the pharmacokinetics of the broad-spectrum antifungal drug butenafine nanomicelles (BTF-NM) after topical instillation.Methods:The self-assembly method was used to prepare BTF-NM.The particle size, Zeta potential, and polydispersity index (PDI) of BTF-NM were measured by a nano-particle size-Zeta potential analyzer, and the encapsulation efficiency was determined by high-performance liquid chromatography (HPLC). Forty-two healthy New Zealand white rabbits without eye disease were randomly divided into the BTF-NM group and the BTF suspension (BTF-S) group.The corresponding drugs were instilled in the conjunctival sac with a single instillation of 50 μl.The 7.5 mm filter paper was placed in the conjunctival sac of rabbit eye for 1 minute at 5, 15, 30, 60, 120, 180, 240 minutes after the administration.Then the rabbits were sacrificed by intravenous injection of 4% sodium pentobarbital solution through the ears of the rabbits.The aqueous humor was extracted and the corneal tissue was dissected.The drug concentration of BTF in different tissues was measured by HPLC.The study was approved by the Life Science Ethics Review Committee of Henan Eye Hospital (No.HNEECA-2019-01).Results:The particle size and PDI of BTF-NM were (15.65±0.04)nm and 0.11±0.01, respectively, the Zeta potential was (-0.29±0.36)mV, the encapsulation rate was (98.38±0.29)%.The peak time of the drug both in tears and corneal tissues after BTF-NM application was 5 minutes.The peak concentrations of the drug in tears and corneas of the BTF-NM group were (485.21±66.29) μg/g and (12.53±2.32) μg/g, which were 5.6 and 78 times than that of the BTF-S group, respectively.Within the observation time, the mass fractions of the drug in tears and corneas of the BTF-NM group at each time point were significantly higher than those of BTF-S group at corresponding time points (all at P<0.01), respectively.The area under the concentration-time curve (AUC) 0-240 minutes in tears and corneas of the BTF-NM group was 7 488.90 (μg/g)·minute and 829.01 (μg/g)·minute, which was 7.2 and 52 times than that of the BTF-S group, respectively.No drugs were detected in the aqueous humor of the BTF-NM group and the BTF-S group. Conclusions:BTF-NM is an ideal agent with a simple preparing process, high drug encapsulation efficiency and small particle size.Compared with BTF suspension, BTF-NM can significantly improve the bioavailability of BTF in rabbit corneas.
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Objective To investigate the corneal permeability of cyclosprin A (CsA) loaded on polymeric vector after topical application.Methods The grafted copolymer chitosan-graft-cyclodextrin (CS-g-CD) was synthesized,and the physicochemical structures of the polymer were investigated using nuclear magnetic resonance spectroscopy (NMR) and fourier transform infrared spectroscopy (FT-IR).A novel CsA eye drop was prepared using the grafted copolymer as carrier material.The physicochemical properties of eye drop,including drug-loading content,osmotic pressure and viscosity were investigated by high performance liquid chromatography-mass spectrometry (HPLC-MS),osmotic pressure gauge and viscometer,respectively.New Zealand albino rabbits were randomly divided into intact cornea CsA group,epithelium debrided CsA group and epithelium debrided control group.The corneal epithelia of the left eyes was debrided in the cornea epithelium debrided group.Cornea irritation test was performed on New Zealand albino rabbits.The aqueous humor was taken and the corneas were collected at 0.5 hour and 1 hour after instilled.The concentration of CsA was measured by HPLC-MS.Cy5 labeled vector loaded with Coumarin 6 served as model copolymers system,the penetration capabilities of the double fluorescent labeling copolymers system were monitored in vivo using two-photon scanning fluorescence microscopy on murine corneas after topical application.The use and care of the animals complied with Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results The polymer of CS-g-CD was successfully synthesized and confirmed using NMR and FT-IR.The drug loading of CsA in eye drop solution was 0.06 ％;the osmotic pressure was 305 mOsmol/kg and the viscosity was 36.5 cP.The CsA drug delivery system had a reversible temperature-sensitive drug release behavior and had no obvious irritation on the eyes of New Zealand rabbits.One hour after treatment,the concentration of CsA in the cornea and aqueous humor of epithelium debrided CsA group was (5.88 ± 1.46) μg/g and (149.19 ± 3.93) ng/ml,respectively,which was significantly higher than (3.98 ±0.95) μg/g and (30.25± 11.43) ng/ml in epithelium debrided control group (both at P＜0.05);the concentration of CsA in the aqueous humor of intact cornea CsA group was (7.23 ± 1.31)ng/ml,which was significantly lower than that in epithelium debrided CsA group (P＜0.05).Polymer vectors were mainly retained in the corneal epithelium,and coumarin 6 gradually diffused into the deep corneal stroma with time.Conclusions The grafted copolymer can load CsA,and the eye drop can effectively overcome the corneal barrier and increase the corneal permeability of CsA.
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Objective To investigate the corneal permeability of cyclosprin A (CsA) loaded on polymeric vector after topical application. Methods The grafted copolymer chitosan.graft.cyclodextrin ( CS.g.CD ) was synthesized, and the physicochemical structures of the polymer were investigated using nuclear magnetic resonance spectroscopy ( NMR) and fourier transform infrared spectroscopy ( FT.IR) . A novel CsA eye drop was prepared using the grafted copolymer as carrier material. The physicochemical properties of eye drop,including drug.loading content, osmotic pressure and viscosity were investigated by high performance liquid chromatography.mass spectrometry ( HPLC.MS) ,osmotic pressure gauge and viscometer,respectively. New Zealand albino rabbits were randomly divided into intact cornea CsA group, epithelium debrided CsA group and epithelium debrided control group. The corneal epithelia of the left eyes was debrided in the cornea epithelium debrided group. Cornea irritation test was performed on New Zealand albino rabbits. The aqueous humor was taken and the corneas were collected at 0. 5 hour and 1 hour after instilled. The concentration of CsA was measured by HPLC.MS. Cy5 labeled vector loaded with Coumarin 6 served as model copolymers system, the penetration capabilities of the double fluorescent labeling copolymers system were monitored in vivo using two.photon scanning fluorescence microscopy on murine corneas after topical application. The use and care of the animals complied with Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission. Results The polymer of CS.g.CD was successfully synthesized and confirmed using NMR and FT.IR. The drug loading of CsA in eye drop solution was 0. 06 ％;the osmotic pressure was 305 mOsmol/kg and the viscosity was 36. 5 cP. The CsA drug delivery system had a reversible temperature.sensitive drug release behavior and had no obvious irritation on the eyes of New Zealand rabbits. One hour after treatment,the concentration of CsA in the cornea and aqueous humor of epithelium debrided CsA group was (5. 88±1. 46)μg/g and (149. 19±3. 93)ng/ml,respectively,which was significantly higher than (3. 98±0. 95)μg/g and (30. 25±11. 43)ng/ml in epithelium debrided control group (both at P<0. 05);the concentration of CsA in the aqueous humor of intact cornea CsA group was ( 7. 23 ± 1. 31 ) ng/ml, which was significantly lower than that in epithelium debrided CsA group ( P<0. 05 ) . Polymer vectors were mainly retained in the corneal epithelium, and coumarin 6 gradually diffused into the deep corneal stroma with time. Conclusions The grafted copolymer can load CsA,and the eye drop can effectively overcome the corneal barrier and increase the corneal permeability of CsA.
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OBJECTIVE:To establish a method for the concentration determination of isavuconazole in rabbit cornea. METH-ODS:HPLC was performed on column of Waters X-Bridge C18 with mobile phase of 0.2% glacial acetic acid-acetonitrile(49:51, V/V)at flow rate of 0.7 mL/min,column temperature was 40 ℃,detection wavelength was 284 nm,and injection volume was 10μL. Fifteen Japanese white rabbits with big ears were selected,50 μL of 0.2% isavuconazole suspension was dropped into eyes, then every 3 rabbits were executed after 5,15,30,60,90 min of administration and cornea samples were taken respectively. The determination of isavuconazole were determined after treating. RESULTS:The isavuconazole in leaching solution showed good lin-ear range in 0.0312-2.24μg/mL(r2=0.9999);oethod recovery rate was 91.7%-105.6%(RSD≤6.88%,n=5);extraction recov-ery rate was 100.50%-106.10%(RSD≤2.16%,n=3);and RSDs of inter-day(n=3)and intra-day(n=3)precision and stabili-ty(n=5)tests were lower than 10%. CONCLUSIONS:The method shows strong specificity,high accuracy,good reproducibili-ty,and can rapidly and accurately determine the concentration of isavuconazole in rabbit cornea.
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Background Macrogol 15 hydroxystearate (HS15) is a novel soft non-ionic surfactant and is widely used to solubilize the poorly soluble drugs due to high drug loading and enhancing permeability ability to hydrophobic drug.However,the delivering effects to cornea of HS15 on terbinafine hydrochloride (TH),a insoluble antifungal agents,is unclear.Objective This study was to investigate the promoting corneal absorption effects of HS15 micelles (HNMs) on TH.Methods TH-HNMs was prepared by a co-solvent method.The hydrodynamic droplet size,polydispersity index,and Zeta potential of TH-HNMs were measured by using a Zetasizer.The shape of the micelles was observed under the transmission electron microscope.The high performance liquid chromatography (HPLC) was employed to detect the in vitro cumulative releasing level of TH in the TH-HNMs and drug entrapment efficiency.TH-HNMs was topically adninistered in eyes of 5 healthy male New Zealand rabbits to evaluate the ocular irritation response.Ninety rabbits were randomized into experimental group and control group,and 50 μl of 0.5％ TH-HNMs and 0.5％ oily TH were topically administered in the right eyes of the animals in the experimental group and contral group,respectively.The animals were sacrificed 5,15,30,60,90,120,180,240,360 minutes after eye dropping by over anesthetization way and the corneas were harvested,and the TH content in the cornea was detected using HPLC.The study protocal was approved by Life Science Ethic Committee of Henen Eye Hospital.Results The average size and polyolis persital index of TH-HNMs were 13.32 nm and 0.046,respectively,and its average Zeta potential was-0.133 mV.The drug entrapment efficiency was 100％.The release level of TH from the micelles presented a pH-dependent manner.The release level of TH was (95.20±3.20)％ in the phosphate buffer with pH 5.0 and (0.17± 0.01)％ in the phosphate buffer with pH 7.4.The ocular irritation score was 2,and no visible damage was found around experimental eyes after instillation of TH-HNMs.The peak content of TH in the rabbit cornea 5 minutes was (20.26±2.26)pg/g in the experimental group,which was significantly higher than (1.40± 0.44)μg/g in the control group (t =18.926,P=0.000).The area under the curve (AUC)0.360min of drug concentration-time curve in the experimental group was 1 292.25 μg/(g · min),which was 15.6 times more than the control group.Conclusions TH-HNMs is an ideal agent with a simple preparing process,high drug entrapment efficiency,small size and low ocular irritation.Compared with oily TH,TH-HNMs can effectively enhance the corneal absorption of TH.
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Background Nanoemulsions (NEs) is one of the most popular ophthalmic colloidal drug delivery system due to its long-term stability, low toxicity and irritancy, considerable capacity for solubilization of lipophilic drug molecules and great potential in bioavailability improvement.The cornea pathway is the main route of intraocular absorption after topical use of NEs.Though NEs possess numerous physiological and physicochemical advantages,the use of NEs cannot always obtain satisfactory results.Objective This study was to investigate the impacts of epithelium and stroma on the corneal permeation of topical ophthalmic terbinafine hydrochloride nanoemulsions (TH-NEs).Methods TH-NEs was prepared by the self-emulsification method.The size and Zeta potential of the oil droplets in the formulation were analyzed using a dynamic light-scattering particle size analyzer.The high performance liquid chromatography (HPLC) was used for the in vitro release study.Sixty New Zealand albino rabbits were randomly divided into intact cornea group and cornea epithelium debrided group.The cornea epithelium of the left eyes was debrided in the cornea epithelium debrided group.The TH-NEs were instilled into the lower conjunctival sac of left eyes.Six rabbits were executed from each group 15,30,60,120 and 240 minutes after dosing,respectively.The corneas were collected and analyzed by HPLC.The fluorescein diacetate (FDA) was used to label the TH-NEs.Two C57BL/6 mice with left cornea epithelium debrided and 2 normal mice were used for the fluorescence tracing study.The fluorescence distribution of FDA labeled TH-NEs was observed by a two-photon laser confocal scanning microscope 30 minutes and 60 minutes after single instillation.Results The average size and Zeta potential of the oil droplets were 51.37 nm and-0.232 7 mV respectively,and 0.482％ of encapsulated drugs was released from the TH-NEs after 12 hours.The peak concentrations of TH in the intact cornea and epithelium debrided cornea were (17.85 ± 2.79) μg/g and (4.40± 1.75) μg/g respectively, which occurred 15 minutes postdose.The drug concentrations in the intact cornea were significantly higher than that in the debrided cornea 15,30,60 and 120 minutes after dosing, with significant differences between them (t =9.998,8.658,6.903,7.576;all at P=0.000).The fluorescence was observed in the cornea epithelium when the cornea was intact.The fluorescence intensity in the superior layer of corneal epithelium was obviously higher than that in the deep layers of corneal epithelium 30 minutes and 60 minutes after dosing.No fluorescence was observed in the cornea stroma of both eyes.Conclusions The cornea epithelium is the main of absorption and distribution position of TH-NEs.The cornea stroma is the dominating permeation barrier for the intraocular transportation of the TH-NEs.The cornea stroma may stop the permeation of TH-NEs by molecular exclusion mechanism.