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Karakucuk A, Canpinar H, Celebi N. Ritonavir nanosuspensions prepared by microfluidization with enhanced solubility and desirable immunological properties. Pharm Dev Technol 2022; 27:1027-1037. [PMID: 36343117 DOI: 10.1080/10837450.2022.2145309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The objective of this study was to develop ritonavir (RTV) nanosuspensions (NSs) by microfluidization method. Particle size (PS) measurements were performed by photon correlation spectroscopy. Amorphous properties of the particles were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The dissolution studies were conducted in fed state simulated intestinal fluid (FeSSIF) medium. The flow cytometry was utilized to determine the lymphocyte sub-groups and immune response of NSs. RTV NSs were obtained with 400-500 nm PS. The crystal properties of RTV remain unchanged. The solubility of NS was enhanced five times. 57% and 18% of RTV were dissolved in FeSSIF medium for NSs and coarse powder. According to immunological studies, the prepared NSs did not significantly alter the ratio of CD4+/CD8+. Therefore, NSs may be a beneficial approach for the oral administration of RTV.
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Affiliation(s)
- Alptug Karakucuk
- Department of Pharmaceutical Technology, Ankara Medipol University Faculty of Pharmacy, Ankara, Turkey.,Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, Ankara, Turkey
| | - Hande Canpinar
- Department of Basic Oncology, School of Medicine, Institute of Oncology, Hacettepe University, Ankara, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, Ankara, Turkey.,Department of Pharmaceutical Technology, Baskent University Faculty of Pharmacy, Ankara, Turkey
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Oktay AN, Celebi N, Ilbasmis-Tamer S, Kaplanoğlu GT. Cyclodextrin-based nanogel of flurbiprofen for dermal application: In vitro studies and in vivo skin irritation evaluation. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.104012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Oktay AN, Ilbasmis-Tamer S, Uludag O, Celebi N. Enhanced Dermal Delivery of Flurbiprofen Nanosuspension Based Gel: Development and Ex Vivo Permeation, Pharmacokinetic Evaluations. Pharm Res 2021; 38:991-1009. [PMID: 34086139 DOI: 10.1007/s11095-021-03060-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/11/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE The objective of this study was to optimize the Flurbiprofen (FB) nanosuspension (NS) based gel and to investigate the in vitro release, ex vivo permeation, the plasma concentration-time profile and pharmacokinetic parameters. METHODS FB-NSs were developed using the wet milling process with the Design of Experiment (DoE) approach. The optimum FB-NS was characterized on the basis of SEM, DSC, XRPD, solubility and permeation studies. The dermal gel was prepared by incorporating FB-NS into HPMC gel. Then the in-vitro release, ex vivo permeation studies were performed, and pharmacokinetic studies were evaluated on rats. RESULTS The particle size, polydispersity index and zeta potential values of optimum NS were determined as 237.7 ± 6.8 nm, 0.133 ± 0.030 and - 30.4 ± 0.7 mV, respectively. By means of the surfactant content and nanosized particles of the nanosuspension, the solubility of FB was increased about 7-fold. The percentage permeated amount of FB from FB-NS gel (8.40%) was also found to be higher than the physical mixture (5.25%) and coarse suspension (reference) (2.08%) gels. The pharmacokinetic studies showed that the Cmax of FB-NS gel was 2.5 times higher than the reference gel, while AUC0-24 was 2.96 times higher. CONCLUSION FB-NSs were successfully prepared with a wet milling method and optimized with the DoE approach. The optimized FB nanosuspension gel provided better permeation and pharmacokinetic performance compared to FB coarse suspension gel.
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Affiliation(s)
- Ayse Nur Oktay
- Department of Pharmaceutical Technology, Gazi University-Faculty of Pharmacy, Ankara, Turkey.,Department of Pharmaceutical Technology, University of Health Sciences- Gulhane Faculty of Pharmacy, Ankara, Turkey
| | - Sibel Ilbasmis-Tamer
- Department of Pharmaceutical Technology, Gazi University-Faculty of Pharmacy, Ankara, Turkey
| | - Orhan Uludag
- Department of Pharmacology, Gazi University-Faculty of Pharmacy, Ankara, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Gazi University-Faculty of Pharmacy, Ankara, Turkey. .,Department of Pharmaceutical Technology, Başkent University-Faculty of Pharmacy, Ankara, Turkey.
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Karakucuk A, Tort S, Han S, Oktay AN, Celebi N. Etodolac nanosuspension based gel for enhanced dermal delivery: in vitro and in vivo evaluation. J Microencapsul 2021; 38:218-232. [PMID: 33752553 DOI: 10.1080/02652048.2021.1895344] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AIM The objective of this study was to develop dermal nanosuspension (NS) based gel formulation of etodolac (ETD). METHODS Etodolac nanosuspension (ETD-NS) was prepared by wet milling method and dispersed in hydroxypropyl methylcellulose (NS-HPMC) or hydroxyethyl cellulose (NS-HEC) gels. Rheologic and mechanical properties were investigated. In vitro and ex vivo permeability studies were performed. Topical anti-inflammatory and analgesic activity were evaluated in regard to carrageenan-induced inflammatory paw oedema and radiant heat tail-flick method, respectively. RESULTS The ETD-NS with approximately 190 nm particle size (PS), 0.16 polydispersity index (PDI), and -15 mV zeta potential (ZP) values were obtained. The work of bioadhesion values of NS-HEC and NS-HPMC gels were 0.229 mJ/cm2 for both gels. Dermal permeation of ETD from NS-HEC gel (7.18%) was found significantly higher than the NS-HPMC gel (4.56%). Enhanced anti-inflammatory and analgesic activity of NS-HEC gels were observed in comparison with micronised ETD. CONCLUSIONS ETD-NS based gel formulation is promising for topical delivery of ETD.
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Affiliation(s)
- Alptug Karakucuk
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Ankara, Turkey
| | - Serdar Tort
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Ankara, Turkey
| | - Sevtap Han
- Department of Pharmacology, Faculty of Pharmacy, Gazi University, Ankara, Turkey
| | - Ayse Nur Oktay
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.,Department of Pharmaceutical Technology, Gulhane Faculty of Pharmacy, University of Health Sciences, Ankara, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.,Department of Pharmaceutical Technology, Faculty of Pharmacy, Baskent University, Ankara, Turkey
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Celik-Tekeli M, Celebi N, Tekeli MY, Aktas Y. Evaluation of the hypoglycemic effect of exendin-4's new oral self-nanoemulsifying system in rats. Eur J Pharm Sci 2020; 158:105644. [PMID: 33197556 DOI: 10.1016/j.ejps.2020.105644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/27/2020] [Accepted: 11/06/2020] [Indexed: 01/24/2023]
Abstract
The objective of this study is to develop a new self-nanoemulsifying system containing exendin-4 with or without enzyme inhibitor chymostatin and to evaluate the effects of oral administration of exendin-4 and exendin-4/chymostatin loaded self nanoemulsifying system on plasma exendin-4, plasma insulin, blood glucose levels and to compare with the oral and subcutaneous administration of exendin-4 in non-diabetic and streptozotocin-induced type 2 diabetic rats. Exendin-4 and exendin-4/chymostatin loaded self-nanoemulsifying system containing ethyl oleate as the oil phase, Cremophor EL®/Labrasol® as the surfactants and propylene glycol as the co-solvent were prepared. The mean droplet size, polydispersity index, zeta potential and viscosity of exendin-4 loaded self-nanoemulsifying system were found as 24.28 ± 0.43 nm, 0.17 ± 0.01, -1.28 ± 3.61 mV, 79.60 ± 3.30 m.Pas, respectively. The mean droplet size, polydispersity index, zeta potential and viscosity of exendin-4/chymostatin loaded self-nanoemulsifying system were found as 20.25 ± 0.35 nm, 0.11 ± 0.02, -1.85 ± 2.49 mV, 100.02 ± 7.65 m.Pas, respectively according to our previous study. In the present study, we focused on long-term physical stability studies, pharmacokinetic studies and pharmacodynamic studies of prepared self-nanoemulsifying systems. According to the long- term physical stability data, exendin-4 and exendin-4/chymostatin loaded self-nanoemulsifying systems were found stable both at 5°C ± 3°C and at 25°C ± 60% RH for 12 months. Exendin-4 and exendin-4/chymostatin loaded self-nanoemulsifying systems increased AUC and Cmax values in non-diabetic rats compared to the oral exendin-4 solution. In diabetic rats, exendin-4/chymostatin loaded self nanoemulsifying systems increased Cmax values compared to the exendin-4 solution. Exendin-4/chymostatin loaded self-nanoemulsifying system decreased inter-subject variability compared to commercial Byetta®. At 30th minute after administration of exendin-4 loaded self-nanoemulsifying system, exendin-4/chymostatin loaded self nanoemulsifying system and Byetta®, blood glucose levels decreased to 23%, 25%, 29%, respectively. It has been shown that pharmacodynamic response is close to Byetta® with exendin-4/chymostatin self-nanoemulsifying system oral administration. In conclusion, a self nanoemulsifying system was found to be a suitable carrier system, and the combination with enzyme inhibitor chymostatin is thought to be promising for oral delivery of exendin-4.
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Affiliation(s)
- Merve Celik-Tekeli
- Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, 06330 Ankara, Turkey; Department of Pharmaceutical Technology, Erciyes University Faculty of Pharmacy, 38238 Kayseri, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, 06330 Ankara, Turkey; Department of Pharmaceutical Technology, Baskent University Faculty of Pharmacy, 06790 Ankara, Turkey
| | - M Yasin Tekeli
- Department of Pharmacology and Toxicology, Erciyes University Faculty of Veterinary Medicine, 38238 Kayseri, Turkey
| | - Yesim Aktas
- Department of Pharmaceutical Technology, Erciyes University Faculty of Pharmacy, 38238 Kayseri, Turkey.
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Oktay AN, Ilbasmis-Tamer S, Han S, Uludag O, Celebi N. Preparation and in vitro / in vivo evaluation of flurbiprofen nanosuspension-based gel for dermal application. Eur J Pharm Sci 2020; 155:105548. [PMID: 32937211 DOI: 10.1016/j.ejps.2020.105548] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/18/2020] [Accepted: 09/10/2020] [Indexed: 11/28/2022]
Abstract
Flurbiprofen (FB) is an analgesic and anti-inflammatory drug, but its low water solubility (BCS Class II) limits its dermal bioavailability. The aim of this study is to develop a FB nanosuspension (NS) based gel and to evaluate its analgesic and anti-inflammatory activities in rats. FB-NS was produced by the wet milling method with Plantacare 2000Ⓡ, as stabilizer. The FB-NS was then incorporated in different carrier gels such as hydroxypropyl methyl cellulose (HPMC), polycarbophil, oleogel, and chitosan. To select the optimum gel type, visual examinations, pH and rheological property measurements, texture profile analysis, in vitro release and ex vivo permeation studies were performed. Following these tests, the analgesic and anti-inflammatory activities of the optimum NS based gel were evaluated using the tail flick and carrageenan-induced paw edema methods consecutively. The NS was successfully prepared with the wet milling method, and the PS, PDI and ZP values were found to be 237.7 ± 6.8 nm, 0.133±0.030, and -30.4 ± 0.7 mV; respectively. Among the NS-based gels, HPMC gel showed more suitable rheological and mechanical properties, also the percentage of permeated FB and the flux value observed for HPMC gel were higher for HPMC than for the other gels. Thus, HPMC gel was selected as a carrier gel for in vivo pharmacodynamics studies. The anti-inflammatory activity of FB-NS HPMC gel was higher than that of the physical mixture gel and that of the coarse suspension gel. Results of our analgesic activity studies showed that, in the 180th min of FB nanosuspension treatment, the latency time was significantly prolonged compared to that of the control group (p<0.05). As a conclusion, while nanosuspensions increased the in vivo pharmacodynamics effect of FB by means of nanosized particles and a large surface area, the HPMC gel as a carrier prolonged the contact time of NSs with skin and eased the dermal application.
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Affiliation(s)
- Ayse Nur Oktay
- Department of Pharmaceutical Technology, Gazi University-Faculty of Pharmacy, Ankara, Turkey
| | - Sibel Ilbasmis-Tamer
- Department of Pharmaceutical Technology, Gazi University-Faculty of Pharmacy, Ankara, Turkey
| | - Sevtap Han
- Department of Pharmacology, Gazi University-Faculty of Pharmacy, Ankara, Turkey
| | - Orhan Uludag
- Department of Pharmacology, Gazi University-Faculty of Pharmacy, Ankara, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Gazi University-Faculty of Pharmacy, Ankara, Turkey; Department of Pharmaceutical Technology, Başkent University-Faculty of Pharmacy, Ankara, Turkey.
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Aktas Y, Celik Tekeli M, Celebi N. Development and characterization of exendin-4 loaded self-nanoemulsifying system and in vitro evaluation on Caco-2 cell line. J Microencapsul 2020; 37:41-51. [PMID: 31714163 DOI: 10.1080/02652048.2019.1692945] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Aim: Aim of this study was to develop exendin-4 and exendin-4/chymostatin loaded self-nanoemulsifying drug delivery system (SNEDDS).Methods: Surfactants and co-surfactants were mixed, oil phase containing exendin-4 or exendin-4/chymostatin was added dropwise for SNEDDS. Short term physical stability test was performed prior to the release, lipolysis and permeability studies.Results: SNEDDS containing ethyl oleate: Cremophor EL®: Labrasol®: propylene glycole (15:42.5:21.25: 21.25) were selected for in vitro release and intestinal permeability studies for suitable parameters and physical stability test results. SNEDDS were obtained which yielded Grade B nanoemulsions having droplet size below 25 nm. In vitro release studies showed that 73.79% of the peptide was released for 2 h at pH 6.8. Both exendin-4 and exendin-4/chymostatin loaded SNEDDS were non-toxic to Caco-2 cells. Permeability coefficients of both exendin-4 loaded SNEDDS and exendin-4/chymostatin loaded SNEDDS were higher than exendin-4 solution.Conclusions: Intestinal permeability of exendin-4 has been improved by SNEDDS formulations.
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Affiliation(s)
- Yesim Aktas
- Department of Pharmaceutical Technology, Erciyes University Faculty of Pharmacy, Kayseri, Turkey
| | - Merve Celik Tekeli
- Department of Pharmaceutical Technology, Erciyes University Faculty of Pharmacy, Kayseri, Turkey.,Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, Ankara, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, Ankara, Turkey
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Karakucuk A, Celebi N. Investigation of Formulation and Process Parameters of Wet Media Milling to Develop Etodolac Nanosuspensions. Pharm Res 2020; 37:111. [PMID: 32476048 DOI: 10.1007/s11095-020-02815-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/02/2020] [Indexed: 12/19/2022]
Abstract
PURPOSE Etodolac (ETD) is one of the non-steroidal anti-inflammatory drugs which has low aqueous solubility issues. The objective of this study was to develop ETD nanosuspensions to improve its poor aqueous solubility properties while investigating formulation and process parameters of wet media milling method via design of experiment (DoE) approach. METHODS The critical formulation parameters (CFP) were selected as ETD amount, stabilizer type and ratio as well as critical process parameters (CPP) which were bead size, milling time and milling speed. The two-factorial-23 and The Box-Benkhen Designs were generated to evaluate CFP and CPP, respectively. Particle size (PS), polydispersity index (PDI) and zeta potential (ZP) were analyzed as dependent variables. Characterization, physical stability and solubility studies were performed. RESULTS Optimum nanosuspensions stabilized by PVP K30 and Poloxamer 188 showed 188.5 ± 1.6 and 279.3 ± 6.1 nm of PS, 0.161 ± 0.049 and 0.345 ± 0.007 PDI, 14.8 ± 0.3 and 16.5 ± 0.4 mV of ZP values, respectively. The thermal properties of ETD did not change after milling and lyophilization process regarding to DSC analysis. Also, the crystalline state of ETD was preserved. The morphology of particle was smooth and spherical on SEM. The dry-nanosuspensions stayed physically stable for six months at room temperature. The solubility of nanosuspensions increased up to 13.0-fold in comparison with micronized ETD. CONCLUSIONS In conclusion, it is found that the poor solubility issue of ETD can be solved by nanosuspension. DoE approach provided benefits such as reducing number of experiments, saving time and improving final product quality by using wet media milling.
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Affiliation(s)
- Alptug Karakucuk
- Faculty of Pharmacy, Department of Pharmaceutical Technology, Gazi University, Etiler-Yenimahalle, Ankara, Turkey.
| | - Nevin Celebi
- Faculty of Pharmacy, Department of Pharmaceutical Technology, Gazi University, Etiler-Yenimahalle, Ankara, Turkey
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Mutlu-Agardan NB, Yilmaz S, Kaynak Onurdag F, Celebi N. Development of effective AmB/AmB-αCD complex double loaded liposomes using a factorial design for systemic fungal infection treatment. J Liposome Res 2020; 31:177-188. [PMID: 32290745 DOI: 10.1080/08982104.2020.1755980] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Amphotericin B (AmB) is a very potent antibiotic which still remains as the gold standard for the treatment of systemic fungal infections. AmB is a member of Biopharmaceutical Classification System Class IV, mainly characterized by its poor solubility and low permeability. In this study, AmB/AmB-α cyclodextrin complex double loaded liposomes (DLLs) were developed using the design of experiments (DoE®) approach to optimize/determine the effects of lipid composition and other parameters on final product properties such as encapsulation efficacy, particle size, polydispersity index, and zeta potential. Experimental design 24 was used for optimization of these properties in which four factors were studied in two levels. DLLs showed much higher physical stability than liposomes loaded only with free AmB by the means of particle size, zeta potential and encapsulation efficiency, in addition exhibited sustained release of AmB over 72 h (26.7%) with faster onset time. On the other hand, fourfold improved antimicrobial efficiency, minimum inhibitory concentration (0.125 µg/ml), and minimum fungicidal concentration (0.5 µg/ml) was determined by DLLs against C. albicans compared to Ambisome®. Dose dependent effects of the DLLs were investigated by cytotoxicity studies on Vero and L-929 cells. No significant cytotoxicity observed for AmB/AmB-αCD complex DLLs and Ambisome at tested concentrations while free AmB caused severe cytotoxicity. Lastly the developed DLLs did not cause an increase in NGAL (an early biomarker for acute kidney toxicity) levels for both Vero and HK-2 cell lines compared to free AmB.
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Affiliation(s)
- N Basaran Mutlu-Agardan
- Faculty of Pharmacy, Department of Pharmaceutical Technology, Gazi University, Ankara, Turkey
| | | | - Fatma Kaynak Onurdag
- Faculty of Pharmacy, Department of Pharmaceutical Microbiology, Trakya University, Edirne, Turkey
| | - Nevin Celebi
- Faculty of Pharmacy, Department of Pharmaceutical Technology, Gazi University, Ankara, Turkey
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Tashan E, Karakucuk A, Celebi N. Correction to: Development of Nanocrystal Ziprasidone Orally Disintegrating Tablets: Optimization by Using Design of Experiment and In Vitro Evaluation. AAPS PharmSciTech 2020; 21:144. [PMID: 32430673 DOI: 10.1208/s12249-020-01703-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Several typos occurred during the production process and captions were misplaced. The corrected captions for Picture 1, Fig. 6-9 are below.
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Affiliation(s)
- Emine Tashan
- Department of Pharmaceutical Technology, Faculty of Pharmacy Gazi University, Ankara, Turkey.,Zoleant Pharmaceuticals International, Istanbul, Turkey
| | - Alptug Karakucuk
- Department of Pharmaceutical Technology, Faculty of Pharmacy Gazi University, Ankara, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Faculty of Pharmacy Gazi University, Ankara, Turkey.
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Tashan E, Karakucuk A, Celebi N. Development of Nanocrystal Ziprasidone Orally Disintegrating Tablets: Optimization by Using Design of Experiment and In Vitro Evaluation. AAPS PharmSciTech 2020; 21:115. [PMID: 32296987 DOI: 10.1208/s12249-020-01653-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/07/2020] [Indexed: 12/17/2022] Open
Abstract
The objective of the current study was to develop ziprasidone hydrochloride monohydrate (ZHM) nanocrystal-based orally dispersible tablet (ODT) formulations. Design of experiment approach was used to develop ODTs. The tablets were compressed using direct compression method and characterized with quality control tests. In vitro dissolution studies and Caco-2 cell permeability tests were executed. The hardness and friability values of nanocrystal-based ODTs were found 31.2 N and 1.05%, respectively. The disintegration time was below 10 s. Dissolution profile in pH 7.4 phosphate buffer showed that nanocrystal-based ODTs and commercial product were dissolved in 120 min 58.98% and 16%, respectively. In pH 7.4 phosphate buffer with SLS, sample groups dissolved above 85% at the end of the study. Permeability value and cumulative ZHM amount on the cells were improved with nanocrystals. In conclusion, the novel formulation of ZHM nanocrystal-based ODTs was successfully developed for alternative dosage form.
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Oktay AN, Ilbasmis-Tamer S, Celebi N. The effect of critical process parameters of the high pressure homogenization technique on the critical quality attributes of flurbiprofen nanosuspensions. Pharm Dev Technol 2020; 24:1278-1286. [PMID: 31535942 DOI: 10.1080/10837450.2019.1667384] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Flurbiprofen (FB) is an effective nonsteroidal anti-inflammatory and BCS class II drug and its poor solubility plays a critical role in limiting its bioavailability. Nanosuspensions can be defined as nanosized colloidal dispersions of drug particles stabilized with stabilizers. The solubility of poor soluble drugs can be increased thanks to their small size and large surface area. The aim of this study is to optimize FB nanosuspensions. The formulations were stabilized with Plantacare 2000® as a surfactant using a combination of High Speed Homogenization (HSH) and High Pressure Homogenization techniques (HPH). We also investigated the effects of the critical process parameters (CPPs) of these techniques (homogenization speed & time for HSH and homogenization pressure & cycle for HPH) on three critical quality attributes of nanosuspensions, being the particle size (PS), polydispersity index (PDI) and zeta potential (ZP). After the optimization of HSH, the macrosuspension was transferred to a high pressure homogenizer. After producing FB nanosuspensions by the HPH technique, seven processes which comprise different homogenization pressures, or combinations and different cycles, were applied. Due to the combination of HSH and HPH techniques and the optimization of CPPs, an optimum formulation for a dermal application was found using a 33 full factorial design with these process parameters, and characterization studies were also performed.
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Affiliation(s)
- Ayse Nur Oktay
- Department of Pharmaceutical Technology, Gazi University , Ankara , Turkey
| | | | - Nevin Celebi
- Department of Pharmaceutical Technology, Gazi University , Ankara , Turkey
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Karakucuk A, Teksin ZS, Eroglu H, Celebi N. Evaluation of improved oral bioavailability of ritonavir nanosuspension. Eur J Pharm Sci 2019; 131:153-158. [PMID: 30790704 DOI: 10.1016/j.ejps.2019.02.028] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 02/12/2019] [Accepted: 02/17/2019] [Indexed: 01/02/2023]
Abstract
The main objective of this study was to evaluate the pharmacokinetics of ritonavir (RTV) nanosuspension in rats in both fed and fasted state in comparison with coarse powder, physical mixture and commercial product (Norvir®). The point to point relation model was generated between the results of in vitro dissolution and in vivo pharmacokinetic studies. The oral RTV nanosuspension was prepared with microfluidization method. Nanosuspension was obtained with 540-550 nm of particle size, 0.1-0.4 of particle size distribution and about -20 mV of zeta potential values. According to in vivo pharmacokinetic studies in rats, Cmax and AUC0-t values in nanosuspension displayed an 8.9- and 12.5-fold increase compared to the coarse powder, and a 1.9- and 2.1-fold increase compared to the commercial product, respectively in the fed group. The point to point relation model showed that the correlation model was significant. It is concluded that nanosuspension is a promising drug delivery system to enhance oral bioavailability of ritonavir.
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Affiliation(s)
- Alptug Karakucuk
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Ankara, Turkey
| | - Zeynep S Teksin
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Ankara, Turkey
| | - Hakan Eroglu
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
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Akpolat C, Murat M, Celebi N. Evaluation of choroidal changes in patients with ocular toxoplasmosis using spectral domain optical coherence tomography. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Karakucuk A, Celebi N, Teksin ZS. Preparation of ritonavir nanosuspensions by microfluidization using polymeric stabilizers: I. A Design of Experiment approach. Eur J Pharm Sci 2016; 95:111-121. [PMID: 27181836 DOI: 10.1016/j.ejps.2016.05.010] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/06/2016] [Accepted: 05/10/2016] [Indexed: 11/26/2022]
Abstract
The objective of this study was to prepare ritonavir (RTV) nanosuspensions, an anti-HIV protease inhibitor, to solve its poor water solubility issues. The microfluidization method with a pre-treatment step was used to obtain the nanosuspensions. Design of Experiment (DoE) approach was performed in order to understand the effect of the critical formulation parameters which were selected as polymer type (HPMC or PVP), RTV to polymer ratio, and number of passes. Interactions between the formulation variables were evaluated according to Univariate ANOVA. Particle size, particle size distribution and zeta potential were selected as dependent variables. Scanning electron microscopy, X-ray powder diffraction, and differential scanning calorimetry were performed for the in vitro characterization after lyophilization of the optimum nanosuspension formulation. The saturation solubility was examined in comparison with coarse powder, physical mixture and nanosuspension. In vitro dissolution studies were conducted using polyoxyethylene 10 lauryl ether (POE10LE) and biorelevant media (FaSSIF and FeSSIF). The results showed nanosuspensions were partially amorphous and spherically shaped with particle sizes ranging from 400 to 600nm. Moreover, 0.1-0.4 particle size distribution and about -20mV zeta potential values were obtained. The nanosuspension showed a significantly increased solubility when compared to coarse powder (3.5 fold). Coarse powder, physical mixture, nanosuspension and commercial product dissolved completely in POE10LE; however, cumulative dissolved values reached ~20% in FaSSIF for the commercial product and nanosuspension. The nanosuspension showed more than 90% drug dissolved in FeSSIF compared to the commercial product which showed ~50% in the same medium. It was determined that RTV dissolution was increased by nanosuspension formulation. We concluded that DoE approach is useful to develop nanosuspension formulation to improve solubility and dissolution rate of RTV.
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Affiliation(s)
- Alptug Karakucuk
- Gazi University, Faculty of Pharmacy, Department of Pharmaceutical Technology, Etiler 06330 Yenimahalle, Ankara, Turkey
| | - Nevin Celebi
- Gazi University, Faculty of Pharmacy, Department of Pharmaceutical Technology, Etiler 06330 Yenimahalle, Ankara, Turkey.
| | - Zeynep Safak Teksin
- Gazi University, Faculty of Pharmacy, Department of Pharmaceutical Technology, Etiler 06330 Yenimahalle, Ankara, Turkey
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Celebi N, Ataksor B, Taskın H, Bingoldag NA. Indoor radon measurements in Turkey dwellings. Radiat Prot Dosimetry 2015; 167:626-632. [PMID: 25389360 DOI: 10.1093/rpd/ncu329] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 10/03/2014] [Indexed: 06/04/2023]
Abstract
In this work, indoor radon radioactivity concentration levels have been measured in dwellings of Turkey within the frame of the National Radon Monitoring Programme. The (222)Rn concentrations were measured with time-integrating passive nuclear etched track detectors in 7293 dwellings in 153 residential units of 81 provinces, and the radon map of Turkey was prepared. Indoor radon concentrations were distributed in the range of 1-1400 Bq m(-3). The arithmetic mean of the radon gas concentration was found to be 81 Bq m(-3); the geometric mean was 57 Bq m(-3) with a geometric standard deviation of 2.3.
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Affiliation(s)
- N Celebi
- Cekmece Nuclear Research and Training Centre, Yarımburgaz Mah. Nükleer Araştırma Merkezi Yolu No: 10, Istanbul 34303, Turkey
| | - B Ataksor
- Cekmece Nuclear Research and Training Centre, Yarımburgaz Mah. Nükleer Araştırma Merkezi Yolu No: 10, Istanbul 34303, Turkey
| | - H Taskın
- Cekmece Nuclear Research and Training Centre, Yarımburgaz Mah. Nükleer Araştırma Merkezi Yolu No: 10, Istanbul 34303, Turkey
| | - N Albayrak Bingoldag
- Cekmece Nuclear Research and Training Centre, Yarımburgaz Mah. Nükleer Araştırma Merkezi Yolu No: 10, Istanbul 34303, Turkey
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Cakirtekin V, Yildirim A, Bakan N, Celebi N, Bozkurt O. Comparison of the Effects of Thiopental Sodium and Propofol on Haemodynamics, Awareness and Newborns During Caesarean Section Under General Anaesthesia. Turk J Anaesthesiol Reanim 2015. [DOI: 10.5152/tjar.2015.75547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Artunc F, Brechtel K, Kattner B, Celebi N, Bunz H, Jorbenadze R, Lutz S, Weyrich P, Haap M. Nierenversagen und wiederholte Episoden eines blitzartig auftretenden Lungenödems bei einer 70-jährigen Patientin - Fall 5/2013. Dtsch Med Wochenschr 2013; 138:1410. [DOI: 10.1055/s-0033-1343266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- F. Artunc
- Medizinische Klinik, Universitätsklinikum Tübingen
| | - K. Brechtel
- Radiologische Klinik, Universitätsklinikum Tübingen
| | - B. Kattner
- Medizinische Klinik, Universitätsklinikum Tübingen
| | - N. Celebi
- Medizinische Klinik, Universitätsklinikum Tübingen
| | - H. Bunz
- Medizinische Klinik, Universitätsklinikum Tübingen
| | | | - S. Lutz
- Medizinische Klinik, Universitätsklinikum Tübingen
| | - P. Weyrich
- Medizinische Klinik, Universitätsklinikum Tübingen
| | - M. Haap
- Medizinische Klinik, Universitätsklinikum Tübingen
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Kaltalioglu K, Coskun-Cevher S, Tugcu-Demiroz F, Celebi N. PDGF supplementation alters oxidative events in wound healing process: a time course study. Arch Dermatol Res 2013; 305:415-22. [DOI: 10.1007/s00403-013-1326-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 02/04/2013] [Accepted: 02/08/2013] [Indexed: 12/19/2022]
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Kucukomeroglu B, Maksutoglu F, Damla N, Cevik U, Celebi N. A study of environmental radioactivity measurements in the Samsun province, Turkey. Radiat Prot Dosimetry 2012; 152:369-375. [PMID: 22619352 DOI: 10.1093/rpd/ncs071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This study was concerned with the measurement of natural and artificial radionuclides in soil samples and indoor radon concentrations in the Samsun province, Turkey. In soil samples, the values of individual mean activity of (226)Ra, (232)Th, (40)K and (137)Cs radionuclides were found to be 31, 22, 341 and 16 Bq kg(-1), respectively. The radiological parameters, such as the absorbed dose rate in air, the annual effective dose (AED) and excess lifetime cancer risk, were calculated. Indoor radon measurements were carried out with CR-39-based radon dosemeters at 127 dwellings in the Samsun province. The mean annual (222)Rn activity was found to be 106 Bq m(-3) (equivalent to an AED of 1.88 mSv). The seasonal variation of (222)Rn activity shows that maximum levels are observed in the winter, while minimum levels are observed in the summer. The mean lifetime fatality risk for the studied area was estimated at 1.45×10(-4). The results obtained did not significantly differ from those obtained in other parts of the country.
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Affiliation(s)
- B Kucukomeroglu
- Department of Physics, Karadeniz Technical University, 61080 Trabzon, Turkey
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Celebi N, Weyrich P, Bunz H, Velden J, Artunc F. Akutes Nierenversagen nach gastrointestinaler Blutung – Fall 10/2012. Dtsch Med Wochenschr 2012; 137:2447. [DOI: 10.1055/s-0032-1327279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- N. Celebi
- Medizinische Klinik, Universitätsklinikum Tübingen
| | - P. Weyrich
- Medizinische Klinik, Universitätsklinikum Tübingen
| | - H. Bunz
- Medizinische Klinik, Universitätsklinikum Tübingen
| | - J. Velden
- Nephropathologische Abteilung, Pathologisches Institut, Universitätsklinikum Erlangen
| | - F. Artunc
- Medizinische Klinik, Universitätsklinikum Tübingen
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Celebi N, Georges G, Machicao F, Artunc F, Rettig I. Zwei Patientinnen mit echoreichen Markpyramiden - Fall 7/2012. Dtsch Med Wochenschr 2012; 137:1510. [DOI: 10.1055/s-0032-1305087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- N. Celebi
- Abteilung für Endokrinologie, Diabetologie, Nephrologie, Angiologie und Klinische Chemie, Medizinische Universitätsklinik Tübingen
| | - G. Georges
- Abteilung für Endokrinologie, Diabetologie, Nephrologie, Angiologie und Klinische Chemie, Medizinische Universitätsklinik Tübingen
| | - F. Machicao
- Abteilung für Endokrinologie, Diabetologie, Nephrologie, Angiologie und Klinische Chemie, Medizinische Universitätsklinik Tübingen
| | - F. Artunc
- Abteilung für Endokrinologie, Diabetologie, Nephrologie, Angiologie und Klinische Chemie, Medizinische Universitätsklinik Tübingen
| | - I. Rettig
- Abteilung für Endokrinologie, Diabetologie, Nephrologie, Angiologie und Klinische Chemie, Medizinische Universitätsklinik Tübingen
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Celebi N, Zwirner K, Lischner U, Bauder M, Ditthard K, Schürger S, Riessen R, Engel C, Balletshofer B, Weyrich P. Student tutors are able to teach basic sonographic anatomy effectively - a prospective randomized controlled trial. Ultraschall Med 2012; 33:141-5. [PMID: 21104601 DOI: 10.1055/s-0029-1245837] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
PURPOSE Ultrasound is a widely used diagnostic tool. In medical education, it can be used to teach sonographic anatomy as well as the basics of ultrasound diagnostics. Some medical schools have begun implementing student tutor-led teaching sessions in sonographic abdominal anatomy in order to meet the growing demand in ultrasound teaching. However, while this teaching concept has proven to be feasible and well accepted, there is limited data regarding its effectiveness. We investigated whether student tutors teach sonographic anatomy as effectively as faculty staff sonographers. MATERIALS AND METHODS 50 medical students were randomly assigned to one of two groups. 46 of these could be included in the analysis. One group was taught by student tutors (ST) and the other by a faculty staff sonographer (FS). Using a pre/post-test design, students were required to locate and label 15 different abdominal structures. They printed out three pictures in three minutes and subsequently labeled the structures they were able to identify. The pictures were then rated by two blinded faculty staff sonographers. A mean difference of one point in the improvement of correctly identified abdominal structures between the pre-test and post-test among the two groups was regarded as equivalent. RESULTS In the pre-test, the ST (FS) correctly identified 1.6 ± 1.0 (2.0 ± 1.1) structures. Both the ST and FS group showed improvement in the post-test, correctly identifying 7.8 ± 2.8 vs. 8.9 ± 2.9 structures, respectively (p < .0001 each). Comparing the improvement of the ST (6.2 ± 2.8 structures) versus the FS (6.9 ± 3.2) showed equivalent results between the two groups (p < .05 testing for equivalence). CONCLUSION Basic abdominal sonographic anatomy can be taught effectively by student tutors.
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Affiliation(s)
- N Celebi
- University of Tuebingen, Department Internal Medicine IV.
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Weyrich P, Christ M, Celebi N, Riessen R. Triagesysteme in der Notaufnahme. Med Klin Intensivmed Notfmed 2012; 107:67-78; quiz 79. [DOI: 10.1007/s00063-011-0075-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Accepted: 01/09/2012] [Indexed: 11/28/2022]
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Ozer C, Gonul B, Celebi N, Yetkin G, Elmas C, Erdogan D. Effect of Oral TGF-Α Formulations on ASA Induced Duadenal Ulcer and The Role of Lipid Peroxidation in The Healing Process. Turk J Bioch 2012. [DOI: 10.5505/tjb.2012.53215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Kucukomeroglu B, Yesilbag YO, Kurnaz A, Celik N, Cevik U, Celebi N. Radiological characterisation of Artvin and Ardahan provinces of Turkey. Radiat Prot Dosimetry 2011; 145:389-394. [PMID: 21131329 DOI: 10.1093/rpd/ncq442] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Indoor radon concentration measurements were carried out and corresponding annual effective doses due to exposure to indoor radon were determined in Artvin and Ardahan provinces located in the eastern part of Turkey. The measurements were performed for four seasons in order to determine the seasonal fluctuations mostly observed in indoor environments. Indoor radon concentration values were observed to range from 21 to 321 Bq m⁻³ for the Artvin province and from 53 to 736 Bq m⁻³ for the Ardahan province. It was observed that minimum indoor radon concentration values were obtained in summer, while the highest ones were observed in winter. Indoor radon concentration values of the current study were compared with those of other provinces in Turkey. As elevated indoor radon concentrations are mostly correlated with high ²³⁸U activity concentrations in soil, a total of 57 and 33 soil samples were collected from the Artvin and Ardahan provinces, respectively, to determine ²³⁸U activity concentration as well as the concentration of ²³²Th and ⁴⁰K--naturally occurring radionuclides. It was also observed that soil samples collected from the study areas contained ¹³⁷Cs as an artificial radionuclide.
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Affiliation(s)
- B Kucukomeroglu
- Department of Physics, Karadeniz Technical University, 61080 Trabzon, Turkey
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Celebi N. Poster Board Number: 02: Comparison of Lidocaine Methabolism for Different Anesthesia Techniques in Rabbits With Liver Disease. J Oral Maxillofac Surg 2010. [DOI: 10.1016/j.joms.2010.06.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Celebi N, Kirchhoff K, Lammerding-Köppel M, Riessen R, Weyrich P. Medical clerkships do not reduce common prescription errors among medical students. Naunyn Schmiedebergs Arch Pharmacol 2010; 382:171-6. [PMID: 20535451 DOI: 10.1007/s00210-010-0530-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 05/21/2010] [Indexed: 10/19/2022]
Abstract
Prescribing correctly represents one of the most essential skills of a doctor when it comes to patient safety. Unfortunately, prescribing errors still account for a large proportion of avoidable drug-related problems (DRP). Despite this shortcoming, many medical schools do not provide specific prescribing training and assume that students acquire sufficient prescribing skills during regular medical clerkships. We therefore investigated whether there is an association between the individual time spent by students in internal-medicine clerkships and the number of prescription errors committed in a standardized prescribing test for common drug-related problems in a medical inpatient setting. Seventy-four fifth-year medical students (25 +/- 3 yrs, 24 m, 50 f) who had completed their formal pharmacology training filled in prescription charts for two standardized patient paper cases. The charts were rated by two blinded consultants from the field of internal medicine using a checklist for common prescription errors. Students were divided into three groups according to the number of weeks previously spent in internal-medicine clerkships. Group differences in the number of prescription errors made were subsequently examined. Students committed 69% +/- 12% of all possible prescription mistakes. There was no significant difference between the group without clerkships in internal medicine (G1) (71 +/- 9%), the group with one to four weeks (G2) (67 +/- 15%), and the group with more than five weeks of clerkships (G3) (71 +/- 10%), p = .76. Medical students do not seem to acquire the necessary skills to avoid common prescription errors during regular clerkships in internal medicine. This study provides evidence to suggest that specific prescription training within medical education is warranted in order to prevent DRP.
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Affiliation(s)
- N Celebi
- Department of Internal Medicine, Division of Diabetes, Endocrinology, Angiology, Nephrology and Clinical Chemistry, University Hospital of Tübingen, Otfried-Mueller-Str. 10, 72076, Tübingen, Germany
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Bas B, Ozan B, Muglali M, Celebi N. Treatment of masseteric hypertrophy with botulinum toxin: A report of two cases. Med Oral Patol Oral Cir Bucal 2010. [DOI: 10.4317/medoral.15.e649] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Abstract
Monitoring of radon in underground mines is important in order to assess the radiological hazards to occupational workers. Radon concentration levels in three underground lignite mines (Tunçbilek, Omerler and Eynez) of Turkey were obtained in this study. For this reason, atmospheric radon level measurements were carried out in mines using CR-39 track detectors. Chemical etching of the detector tracks and subsequent counting were performed at Cekmece Nuclear Research and Training Center. The obtained results were evaluated according to the International Commission of Radiation Protection and the Turkish Atomic Energy Authority whose radon action levels for workplaces are 500-1500 and 1000 Bq(-3), respectively. The radon gas concentrations in the lignite mines were determined to be between 50 +/- 7 and 587 +/- 16 Bq m(-3). The results obtained in these experiments are far under the action levels. The computed radon doses for the mine workers of Tunçbilek, Omerler and Eynez lignite mines are 1.23, 2.44 and 1.47 mSv y(-1), respectively.
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Affiliation(s)
- S Cile
- Institute of Energy, Istanbul Technical University (ITU), Ayazaga Kampusu, 34469-Istanbul, Turkey
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Kucukomeroglu B, Kurnaz A, Damla N, Cevik U, Celebi N, Ataksor B, Taskin H. Environmental radioactivity assessment for Bayburt, Turkey. J Radiol Prot 2009; 29:417-428. [PMID: 19690358 DOI: 10.1088/0952-4746/29/3/006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This study assesses the results of environmental radioactivity measurements for Bayburt Province in the Eastern Black Sea area of Turkey. Using gamma-ray spectrometry, activity concentrations of the natural radionuclides (226)Ra, (232)Th and (40)K and a fission product (137)Cs were investigated in soil samples. The activity concentrations of (226)Ra, (232)Th and (40)K in various building materials such as sand, cement and marble and in drinking waters were determined. The activity concentrations vary from 16 to 54 Bq kg(-1) for (226)Ra, from 10 to 21 Bq kg(-1) for (232)Th and from 113 to 542 Bq kg(-1) for (40)K in building materials. The mean specific activity concentrations of (226)Ra, (232)Th and (40)K in drinking waters were 93, 30 and 504 mBq l(-1), respectively. The concentrations of gross alpha and beta radioactivity in drinking water samples collected from four different sampling stations have been determined. The results show that the gross alpha and beta activities are lower than the screening levels given by the World Health Organization (WHO), which are a maximum contaminant level of 0.5 Bq l(-1) and 1.0 Bq l(-1) gross alpha and beta radioactivity, respectively, in drinking water. Indoor radon measurements were made in 44 dwellings in Bayburt by using Cr-39 detectors. Radon concentrations in dwellings in Bayburt varied from 17 to 125 Bq m(-3) and the average value was 56 Bq m(-3). The results obtained in this study indicate that the region has a background radiation level that is within the typical natural range and shows no significant departures from other parts of the country.
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Affiliation(s)
- B Kucukomeroglu
- Department of Physics, Karadeniz Technical University, Trabzon, Turkey
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Karamustafa F, Celebi N, Değim Z, Unal N. Transport evaluation of alendronate across Caco-2 cell monolayers. Pharmazie 2009; 64:98-103. [PMID: 19320282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The transport of alendronate through Caco-2 monolayers in the absence and presence of absorption enhancers (sodium taurocholate-STC and dimethyl-beta-cyclodextrin-DM-beta-CD) was studied. The viability of Caco-2 cells was determined by MTT assay. The effects of the experiment period and serum existence in Dubelco's Modified Eagle's Medium (DMEM) on cell viability were examined. The least toxic concentrations of alendronate, STC and DM-beta-CD were found as 0.2% (w/v), 5 mM and 0.3% (w/v), respectively. Transport experiments were performed with these concentrations in DMEM supplemented with serum for an 8 h period. DM-beta-CD increased the transport of alendronate through Caco-2 monolayers significantly. No significance was observed with STC. Cell integrity was determined by measuring the electrical resistance values at the end of the transport experiments and found to be decreased to a greater extent with DM-beta-CD. These results indicate that DM-beta-CD is a promising agent for improving the transport of alendronate.
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Affiliation(s)
- F Karamustafa
- Department of Pharmaceutical Technology, Gazi University, Faculty of Pharmacy, Etiler, Ankara, Turkey
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Orgün Y, Altinsoy N, Sahin SY, Ataksor B, Celebi N. A study of indoor radon levels in rural dwellings of Ezine (Canakkale, Turkey) using solid-state nuclear track detectors. Radiat Prot Dosimetry 2008; 131:379-384. [PMID: 18621916 DOI: 10.1093/rpd/ncn190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Indoor radon activity level and radon effective dose (ED) rate have been carried out in the rural dwellings of Ezine (Canakkale) during the summer season using Radosys-2000, a complete set suitable to radon concentration measurements with CR-39 plastic alpha track detectors. The range of radon concentration varied between 9 and 300 Bq m(-3), with an average of 67.9 (39.9 SD) Bq m(-3). Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, it has been found that the 222Rn ED rate in the dwellings studied ranges from 0.4 to 5.2 mSv y(-1), with an average value of 1.7 (1.0) mSv y(-1). There is a possibility that low radon concentrations exist indoors during the summer season in the study area because of relatively high ventilation rates in the dwellings. A winter survey will be needed for future estimation of the annual ED.
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Affiliation(s)
- Y Orgün
- Faculty of Mines, Istanbul Technical University (ITU), Ayazaga Kampusu, 34469 Istanbul, Turkey
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Abstract
The indoor radon concentration in Adana, Turkey was measured in living rooms of 52 houses during winter 2005 and 57 houses during summer 2005. Forty-four houses were selected for both winter and summer researches for estimating seasonal variations. Indoor radon concentrations were measured seasonally over hotter and colder 2 months over the whole year, using CR-39 passive nuclear track radon detectors. The radon concentrations were ranged from 15 to 97 Bq m(-3) on January-February 2005 for 60 d and from 5 to 70 Bq m(-3) on June-July 2005 for 60 d. The average summer concentration measured was 25.8 Bq m(-3) and the average winter concentration was 48.9 Bq m(-3) in 44 houses that observed seasonal variations. The differences between winter and summer periods were ranged from 1 to 77 Bq m(-3). The average value in both winter and summer periods is 37 Bq m(-3) in 44 houses that observed seasonal variations. This value is below the worldwide indoor radon concentration distribution of 46 Bq m(-3). The annual effective dose equivalent from (222)Rn was 0.9 mSv y(-1).
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Affiliation(s)
- M Degerlier
- University of Cukurova Science and Art Faculty Physics Department, Balcali, Adana, Turkey.
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Canbay O, Celebi N, Sahin A, Celiker V, Ozgen S, Aypar U. Ketamine gargle for attenuating postoperative sore throat. Br J Anaesth 2008; 100:490-493. [DOI: 10.1093/bja/aen023] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Canbay O, Celebi N, Arun O, Karagöz A, Sarıcaoğlu F, Özgen S. Efficacy of intravenous acetaminophen and lidocaine on propofol injection pain. Br J Anaesth 2008; 100:95-98. [DOI: 10.1093/bja/aem301] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Aytekin H, Bayata S, Baldik R, Celebi N. Radon measurements in the Catalagzi Thermal Power Plant, Turkey. Radiat Prot Dosimetry 2008; 128:251-3. [PMID: 17616544 DOI: 10.1093/rpd/ncm332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The Catalağzi Thermal Power Plant (CTPP) (41(0)30'48.4('')N and 0.31(0)53'41.5('')E) is located at nearly 13 km North-east of Zonguldak city, which is located at the West Black Sea coast in Turkey. The middling products with high ash content of bituminous coals are used in this plant. Seasonal radon concentration measurements have been carried out by using CR-39 plastic track detectors in and around the CTPP. The annual average radon concentration has been found to vary from a minimum of 39.8 +/- 28.9 Bq m(-3) in the ash area to a maximum of approximately 75.0 +/- 15.7 Bq m(-3) in the service building of the power plant. The annual average radon concentration in the dwellings of the thermal power plant colony of the plant is 71.0 +/- 33.4 Bq m(-3). The effective dose has been found to vary from 0.38 to 0.71 mSv y(-1) with a mean value of 0.56 mSv y(-1), which is lower than the effective dose values 3-10 mSv given as the range of action levels recommended by International Commission on Radiological Protection: Protection against radon-222 at home and at work, ICRP Publication 65 (1993).
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Affiliation(s)
- H Aytekin
- Department of Physics, Zonguldak Karaelmas University, 67100 Zonguldak, Turkey.
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Alemdaroğlu C, Degim Z, Celebi N, Şengezer M, Alömeroglu M, Nacar A. Investigation of epidermal growth factor containing liposome formulation effects on burn wound healing. J Biomed Mater Res A 2008; 85:271-83. [DOI: 10.1002/jbm.a.31588] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Tarhan O, Canbay O, Celebi N, Uzun S, Sahin A, Coşkun F, Aypar U. Subhypnotic doses of midazolam prevent nausea and vomiting during spinal anesthesia for cesarean section. Minerva Anestesiol 2007; 73:629-633. [PMID: 18046293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
BACKGROUND We aimed to evaluate the efficacy of subhypnotic doses of midazolam and propofol for peripartum nausea and vomiting during regional anesthesia for elective cesarean section in order to prevent emesis in at least 50% of patients. METHODS A prospective, double blind, placebo-controlled study was carried out. Patients were randomly allocated to one of three groups to receive placebo (saline, N=28), propofol (20 mg bolus and 1.0 mg x kg(-1) x h(-1) infusion, N=30), and midazolam (1 mg bolus and 1.0 mg x h(-1) infusion, N=30) at subhypnotic doses intravenously (i.v.) immediately after the umbilical cord was clamped. Bupivacaine hydrochloride (8-10 mg) and fentanyl (10 microg) were injected into the intervertebral space for spinal anesthesia. Blood pressure was monitored at 2 min intervals and intraoperative postdelivery emetic episodes and ephedrine consumption were recorded. The study was carried out at the Anesthesiology Department, Hacettepe University, Turkey, hospitalized care. We included 90 parturients with ASA physical status I and II between the ages of 20 and 38 years undergoing spinal anesthesia for elective cesarean delivery to evaluate the efficacy of subhypnotic doses of propofol and midazolam and, in particular, the incidence of nausea, retching, and vomiting intraoperatively. RESULTS The incidence of nausea, retching, and vomiting was significantly higher in the control group, compared to the propofol and midazolam groups. Total ephedrine consumption was significantly higher in the control group compared to the propofol and midazolam groups. CONCLUSION A subhypnotic dose of midazolam (1 mg x h(-1)) was as effective as the subhypnotic dose of propofol (1 mg x kg(-1) x h(-1)) for the prevention of nausea and vomiting in parturients undergoing cesarean section under spinal anesthesia.
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Affiliation(s)
- O Tarhan
- Department of Anesthesiology, Faculty of Medicine, Hacettepe University of Ankara, Turkey
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Alkan A, Ozer M, Baş B, Bayram M, Celebi N, Inal S, Ozden B. Mandibular symphyseal distraction osteogenesis: review of three techniques. Int J Oral Maxillofac Surg 2007; 36:111-7. [PMID: 17223309 DOI: 10.1016/j.ijom.2006.11.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2006] [Revised: 10/24/2006] [Accepted: 11/20/2006] [Indexed: 11/18/2022]
Abstract
Mandibular symphyseal distraction osteogenesis (MSDO) is an alternative strategy to correct mandibular transverse deficiencies and dental crowding. Only a limited number of practitioners have reported their clinical experience and potential complications of this procedure to widen the mandible in a large case series. This study involved retrospective analysis of 40 patients who underwent mandibular symphyseal distraction osteogenesis. Three different types of distractor were used to widen the mandible: tooth-borne in 21 patients, bone-borne in 5 patients and hybrid (both bone and tooth-borne) in 14 patients. The distraction amount ranged from 7 to 11 mm (mean 7.31 mm). While 39 patients underwent successful mandibular symphyseal distraction, there was one failure. Most of the complications were experienced in bone-borne distractors, such as breakage of the distractor rod, gingival recession, secondary infection and ptosis of the chin. In the light of these findings, it is suggested that a lingually placed tooth-borne hyrax appliance is more suitable and reliable than the other distraction devices. Further larger studies are needed in order to better evaluate the effectiveness of bone-borne or hybrid devices.
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Affiliation(s)
- A Alkan
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
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Abstract
The final aim/target of Pharmaceutical Sciences is to design successful dosage forms for effective therapy, considering individual patient needs and compliance. Development of new drug entities, particularly using peptides and proteins, is growing in importance and attracting increased interest, as they are specifically effective at a comparably low dose. These very potent and specific peptides and proteins can now be produced in large quantities due to increased knowledge and advancements in biotechnological and pharmaceutical applications. A number of peptide and protein products are now available on the market, and numerous studies investigating them have been published in the literature. Although many peptide/protein like products are generally designed for parenteral administration, some other noninvasive routes have also been used. For example, desmopressin is delivered nasally and deoxyribonuclease by inhalation. Although peptides and proteins are generally orally inactive, cyclosporine is an exception. In order to design and develop long-acting, more effective peptide/protein drugs, the controlled release mechanisms and effective parameters need to be understood and clarified. Therefore, we review herein various peptide/protein delivery systems, including biodegradable and nondegradable microspheres, microcapsules, nanocapsules, injectable implants, diffusion-controlled hydrogels and other hydrophilic systems, microemulsions and multiple emulsions, and the use of iontophoresis or electroporation, and discuss the results of recent researches.
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Affiliation(s)
- I Tuncer Degim
- Gazi University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 06330- Etiler, Ankara, Turkey
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Karakas O, Canbay O, Celebi N, Sahin A, Karagoz A, Iskit A, Aypar U. 317 THE EFFECTS OF LORNOXICAM AND KETAMINE ON INFLAMMATION AND MECHANICAL HYPERALGESIA MODELS IN RATS. Eur J Pain 2006. [DOI: 10.1016/s1090-3801(06)60320-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Honca M, Karagoz A, Deniz M, Celebi N, Canbay O, Ozgen S. 484 COMPARISON OF CAUDAL PRILOCAINE, BUPIVACAINE AND ROPIVACAINE FOR POSTOPERATIVE ANALGESIA IN CHILDREN. Eur J Pain 2006. [DOI: 10.1016/s1090-3801(06)60487-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Bal N, Saricaoglu F, Uzun S, Dal D, Celebi N, Celiker V, Aypar U. Perioperative anxiety and postoperative behavioural disturbances in children. Eur J Anaesthesiol 2006; 23:470-5. [PMID: 16507189 DOI: 10.1017/s0265021506000408] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2006] [Indexed: 11/05/2022]
Abstract
BACKGROUND AND OBJECTIVE This study was designed to determine if subhypnotic propofol reduces postoperative behavioural disturbances in children undergoing sevoflurane induction compared with intravenous propofol induction for elective adenoidectomy and tonsillectomy. METHODS Following Ethics Committee approval and parental informed consent, ASA I-II, 120 children (2-10 yr) were recruited. Parents were not allowed to accompany their child. Unpremedicated children were randomly allocated to groups receiving inhalation induction with sevoflurane, 2-2.5 mg kg-1 intravenous propofol induction or inhalation induction with sevoflurane followed by subhypnotic dose of propofol (1 mg kg-1). Anaesthesia was maintained with 2-4% sevoflurane, O2 and N2O. Anxiety on arrival to operating theatre, at anaesthesia induction and 30 min after emergence was assessed. Parents completed a state-trait anxiety inventory test preoperatively and a post hospitalization behaviour questionnaire a week later to assess children's postoperative behavioural disturbances. Kruskal-Wallis test, Wilcoxon signed rank sum test, Bonferroni's test, Paired t-test, t-test, Pearson and Spearman's rank correlation test, chi2-test were used for statistical analysis. RESULTS The anxiety level at induction was high in all groups (P < 0.05). There was no difference between groups in respect to anxiety at other measurement times. A relation between preoperative anxiety level and postoperative behavioural disturbances was determined (P < 0.05). Some behavioural disturbances as nightmare/night fear and desire of sleeping with parents were rarely seen in intravenous propofol induction group (P < 0.05). CONCLUSION Addition of subhypnotic dose of propofol to sevoflurane induction did not reduce the incidence of postoperative behavioural disturbances.
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Affiliation(s)
- N Bal
- Department of Anaesthesiology and Reanimation, Hacettepe University Faculty of Medicine, Ankara, Turkey
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Alemdaroğlu C, Değim Z, Celebi N, Zor F, Oztürk S, Erdoğan D. An investigation on burn wound healing in rats with chitosan gel formulation containing epidermal growth factor. Burns 2006; 32:319-27. [PMID: 16527411 DOI: 10.1016/j.burns.2005.10.015] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Indexed: 11/26/2022]
Abstract
Various studies have shown that chitosan is effective in promoting wound healing. In this study, we aimed to develop an effective chitosan gel formulation containing epidermal growth factor (EGF), and to determine the effect on healing of second-degree burn wounds in rats. Ten micrograms per millilitre EGF in 2% chitosan gel was prepared. In an in vitro study to investigate release of EGF from the formulations, the release rate was 97.3% after 24 h. In in vivo studies, animals were divided into six groups as follows: silver sulfadiazine [Silverdin cream (SIL)], chitosan gel with and without EGF (EJ, J), EGF solution (ES) and untreated control groups [unburned (S) and untreated (Y) rats] applied groups, respectively. A uniform deep second-degree burn of the backskin was performed with water heated to 94+/-1 degrees C during a 15-s exposure. The EGF formulations were repeatedly applied on the burned areas with a dose of 0.160 microg/cm2 for 14 days (one application per day). Healing of the wounds was evaluated immunohistochemically, histochemically and histologically on the tissue samples. When the results were evaluated immunohistochemically, there were significant increases in cell proliferation observed in the EGF containing gel applied group (p<0.001). The histochemical results showed that the epithelization rate in the EJ group was the highest compared to the ES group results (p<0.001). The histological results indicated and supported these findings. It can be concluded that a better and faster epithelization was observed in the EJ group compared to the other groups.
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Affiliation(s)
- Ceren Alemdaroğlu
- Department of Pharmaceutical Technology, Gazi University, Faculty of Pharmacy, 06330 Etiler, Ankara, Turkey
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Cilek A, Celebi N, Tirnaksiz F. Lecithin-based microemulsion of a peptide for oral administration: preparation, characterization, and physical stability of the formulation. Drug Deliv 2006; 13:19-24. [PMID: 16401589 DOI: 10.1080/10717540500313109] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The objective of our study was to prepare and characterize a stable microemulsion formulation for oral administration of a peptide, e.g., rh-insulin. The microemulsions were prepared using Labrafil M 1944 CS, Phospholipon 90G (lecithin), absolute alcohol, and bidistilled water. Commercially available soybean lecithins (namely, Phospholipon 80, phosphatidylcholine purity 76 +/- 3%, and Phospholipon 90G, phosphatidylcholine purity 93 +/- 3%) were used in the study. The results showed that the phase diagram obtained using a low purity lecithin was not similar to that obtained with a high purity lecithin. We observed that the microemulsion area was wider at the phase diagram obtained with the higher purity lecithin. We found that the extent of the microemulsion region depended upon both the purity of the lecithin and the surfactant/co-surfactant (s/co-s) mixing ratios (K(m)). The rheological studies showed that microemulsions followed a Newtonian behavior. Such physical characteristics as viscosity, turbidity, density, conductivity, refractive index, droplet size, physical appearance, and phase separation of the microemulsion were measured at different temperatures (4 degrees C, 25 degrees C, and 40 degrees C) during 6 months. The results indicated that the physical characteristics of the developed microemulsions did not change under different storage temperatures (p > 0.05).
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Affiliation(s)
- Ayşe Cilek
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Ankara, Turkey
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Baldik R, Aytekin H, Celebi N, Ataksor B, Taşdelen M. Radon concentration measurements in the Amasra coal mine, Turkey. Radiat Prot Dosimetry 2006; 118:122-5. [PMID: 16357025 DOI: 10.1093/rpd/nci374] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In this study, the results of atmospheric radon measurements that were performed for the Amasra underground coal mine in Zonguldak bituminous coal basin (Turkey) are presented. The radon measurements were performed for 40 days between November 2004 and December 2004 using passive nuclear etched track detectors. The radon concentrations vary from a minimum value 49 Bq m(-3) in a site located at +40 m to a maximum value 223 Bq m(-3) in a site located at -100 m. Mean concentration is 117 (Bq m(-3)). This value is well below the action level of 500-1,500 Bq m(-3) recommended by the International Commission on Radiological Protection (ICRP) (1993). The mean effective dose value for workers of this mine of 3.4 microSv per day was obtained. This result shows that protection against radiological hazards would not be necessary for workers of this mine((2)).
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Affiliation(s)
- R Baldik
- Zonguldak Karaelmas University, Department of Physics, 67100, Zonguldak, Turkey
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