Person: UĞURLU, TİMUÇİN
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UĞURLU
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TİMUÇİN
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Publication Open Access Managing allergic conjunctivitis via ophthalmic microemulsions: Formulation, characterization, in vitro irritation studies based on EpiOcular™ eye irritation assay and in vivo studies in rabbit eye(2023-01-01) UĞURLU, TİMUÇİN; Yozgatlı V., Üstündağ Okur N., Okur M. E., Sipahi H., Charehsaz M., Aydın A., UĞURLU T.The purpose of this work was the development of an alternative ocular tetrahydrozoline hydrochloride (THZ) microemulsion for the management of allergic conjunctivitis. Pseudo-ternary phase diagrams were used to produce the microemulsions. For the formulation of the microemulsions, isopropyl myristate was selected as oil. Furthermore, various surfactants were applied for the determination of their suitability; ME-1 and ME-4 were developed using Sorbitan monolaurate 80 and Polysorbate 80, for ME-2 and ME-5 Sorbitan monolaurate 80 and macrogolglycerol ricinoleate while for ME-3 and ME-6 Sorbitan monolaurate 80 and Polysorbate 20. For ME-1, ME-2, and ME-3 propylene glycol and ethanol, for ME-4, ME-5, and ME-6 ethanol and polyethylene glycol were used as co-surfactants. Various characterization parameters of microemulsions were evaluated such as droplet size, conductivity, zeta potential, viscosity, and pH. In addition, the drug release, stability, sterility, safety, ex vivo, and in vivo experiments were studied. The characterization showed that the formulations can act as suitable carriers for eye application. In addition, it was revealed that microemulsions were found stable and sterile. The formulations released the drug in a sustained manner. Ex vivo diffusion studies exhibited that the microemulsions can be used for topical delivery to the eye. Assessment of in vitro ocular irritation was conducted by an in vivo prediction model, EpiOcular™ eye irritation test. Based on the in vivo studies, the chosen ideal microemulsion showed longer contact time to the cornea than the commercial product. Moreover, the developed ocular carrier was found to be safe from the viewpoint of in vitro ocular irritancy and mutagenicity. In conclusion, according to characterization results, the THZ microemulsions can act as a hopeful approach for topical eye application.Publication Metadata only Preformulation studies of chitosan nanoparticles for intranasal vaccine administration(2023-05-31) ÖZER ÖNDER, SETENAY; UĞURLU, TİMUÇİN; Özer Önder S., Uğurlu T.Publication Metadata only Effects of some lubricants and evaluation of compression parameters on directly compressible powders(TAYLOR & FRANCIS LTD, 2014) UĞURLU, TİMUÇİN; Ugurlu, Timucin; Halacoglu, Mekin DogaThe objective of this study was to investigate the effects of conventional lubricants including a new candidate lubricant Hexagonal boron nitride (HBN) on direct compression powders. Lubricants such as magnesium stearate, glyceryl behenate, stearic acid, talc and polyethylene glycol(6000) were studied in this article. Tablets were manufactured on an instrumented tablet press with various lubricant concentrations. Bulk and tapped densities, and Carr's index parameters were calculated for powders. Tensile strength, cohesion index, lower punch ejection force and lubricant effectiveness values were investigated for tablets. The deformation mechanisms of tablets were studied during compression from the Heckel plots with or without lubricants. Powders formulated with MGST and HBN showed better flow properties based on Carr's index. MGST was found to be the most effective lubricant based on lubricant effectiveness for tablets. HBN was found very close to MGST with the same concentrations. Other lubricants showed less effectiveness than that of MGST and HBN. It is observed that an increase in the concentration of HBN leads to decreased tensile strength and cohesion index values because of its surface-covering property. Despite covering property, HBN had no significant effect on disintegration time. Based on the Heckel plots at the level of 1%, HBN showed the most pronounced plastic character.Publication Metadata only Scintigraphic evaluation of colon targeting pectin-HPMC tablets in healthy volunteers(ELSEVIER SCIENCE BV, 2009) UĞURLU, TİMUÇİN; Hodges, L. A.; Connolly, S. M.; Band, J.; O'Mahony, B.; Ugurlu, T.; Turkoglu, M.; Wilson, C. G.; Stevens, H. N. E.The in vivo evaluation of colon-targeting tablets was conducted in six healthy male volunteers. A pectin-hydroxypropyl methylcellulose coating was compressed onto core tablets labelled with 4 MBq (99m)Tc-DTPA. The tablets released in the colon in all subjects: three in the ascending colon (AC) and three in the transverse colon (TC). Tablets that released in the TC had reached the AC before or just after food (Group A). The other three tablets released immediately upon AC entry at least 1.5 h post-meal (Group 13). Release onset for Group B was earlier than Group A (343 min vs 448 min). Group B tablets exhibited a clear residence period at the ileocaecal junction (ICJ) which was not observed in Group A. Prolonged residence at the ICJ is assumed to have increased hydration of the hydrogel layer surrounding the core tablet. Forces applied as the tablets progressed through the ICJ may have disrupted the hydrogel layer sufficiently to initiate radiolabel release. Conversely, Group A tablets moved rapidly through the AC to the TC, possibly minimising contact times with water pockets. Inadequate prior hydration of the hydrogel layer preventing access of pectinolytic enzymes and reduced fluid availability in the TC may have retarded tablet disintegration and radiolabel diffusion. (C) 2008 Elsevier B.V. All rights reserved.Publication Metadata only Preparation and in vitro evaluation of PVA/chitosan hydrogels and PLGA nanoparticles containing TGF-beta 1 for wound healing(ELSEVIER, 2019) ÇELİK, ALİ ALPARSLAN; Celik, A.; Sezer, A.; Sahbaz, S.; Ugurlu, T.Publication Metadata only Nanocarriers: Novel Approaches to Oral Delivery of Insulin(MARMARA UNIV, INST HEALTH SCIENCES, 2017) KERİMOĞLU, OYA; Ozer, Setenay; Kerimoglu, Oya; Ugurlu, TimucinDiabetes is among the major chronic diseases at present, and no medication has been developed that can replace the roles of endogenous insulin, especially for type 1 diabetes patients. However, insulin can be frequently administered by the subcutaneous route as a protein macromolecule because enzymatic and absorption-associated problems. It leads to immunogenic symptoms, adipose tissue complaints such as lipodystrophy, and hyperinsulinemia risks because of pharmacokinetic properties that do exactly overlap with those of endogenous insulin. In a remarkable number of patients, failure to attain permanent glycemic control by subcutaneous insulin treatment has shown by clinical trials based on noncompliance. Oral drug administration has always been the most preferred administration pathway for drugs with high patient compliance and convenience. Difficulties in the use of subcutaneous insulin have prompted scientists to find solutions for the oral administration of insulin. Similar to many other fields, nanotechnology has recently come to the fore in the pharmaceutical field. Compared with conventional systems, nanopharmaceuticals are drug delivery systems that enable promoted absorption, protection of the active ingredient from the external environment, lower dose applications, higher bioavailability, controlled release, and prolonged residence time. In vitro and in vivo studies have been performed with varied nanopharmaceutical systems in order to administer insulin orally for this purpose.Publication Open Access Synthesis and characterization of chitosan-PVA hydrogel containing PEGylated recombinant epidermal growth factor on cell culture for wound healing substitute(2022-08-01) SEZER, ALİ DEMİR; UĞURLU, TİMUÇİN; ŞAHBAZ, SEVİNÇ; Doğan M., Şahbaz S., Uğurlu T., Sezer A. D.The aim of the current study was to assess the physicochemical characteristics and wound healing activity of chitosan-polyvinyl alcohol (PVA) crosslinked hydrogel containing recombinant human epidermal growth factor (rh-EGF) or recombinant mouse epidermal growth factor (rm-EGF). The hydrogels were prepared and analyses were made of the morphological properties, viscosity, water absorption capacity, mechanical and bio-adhesive properties. The viscosity of the formulations varied between 14.400 - 48.500 cPs, with the greatest viscosity values determined in K2 formulation. F2 formulation showed the highest water absorption capacity. According to the studies of the mechanical properties, H2 formulation (0.153±0.018 N.mm) showed the greatest adhesiveness and E2 (0.245±0.001 mj/cm2 ) formulation, the highest bio-adhesion values. Hydrogels were cytocompatible considering in vitro cell viability values of over 76% on human keratinocyte cells (HaCaT, CVCL-0038) and of over 84% on human fibroblast cells (NIH 3T3, CRL-1658) used as a model cell line. According to the BrdU cell proliferation results, B1 (197.82±2.48%) formulation showed the greatest NIH 3T3 and C1 (167.43±5.89%) formulation exhibited the highest HaCaT cell proliferation ability. In addition, the scratch closure assay was performed to assess the wound healing efficiency of formulation and the results obtained in the study showed that F2 formulation including PEGylated rh-EGF had a highly effective role. Keywords: Chitosan. rh-EGF. Hydrogel. Texture analyzer. Cell culture.Publication Metadata only Development and In Vitro Evaluation of a Novel Pulsatile Drug Delivery System Containing Dexketoprofen Trometamol(SPRINGER, 2021) UĞURLU, TİMUÇİN; Ugurlu, Timucin; Ilhan, EzgiPurpose A pulsatile drug delivery system containing dexketoprofen trometamol was designed by combining immediate release and colon-targeted mini tablets into a capsule. Methods Both immediate release and colon-targeted mini tablets were prepared by wet granulation. Furthermore, colon-targeted mini tablets were coated with Eudragit L 100, Eudragit S 100, Eudragit RS 30D, and ethylcellulose (Surelease (R)) using Wurster and pan coating methods. Results The optimum drug release of the system developed in the study was found to be mini tablets coated with 30% Eudragit S 100 on a 20% Surelease (R) subcoating for the purpose of colon targeting. Conclusion In the finished product, the immediate release part released the drug within the first hour, and less than 5% release was observed from the colon-targeted tablets in a 0.1 N HCl in 2 h. Then, less than 20% release occurred in the colon-targeted tablets up to 6 h in pH 6.8 phosphate buffer solution. The cumulative release rate reached 100% for up to 12 h. To our knowledge, it was the first time dexketoprofen trometamol was designed by combining both immediate release and colon-targeted mini tablets in a one dosage form.Publication Metadata only In vitro evaluation of pectin-HPMC compression coated 5-aminosalicylic acid tablets for colonic delivery(2002) UĞURLU, TİMUÇİN; Turkoglu, Murat; Ugurlu, TimucinIn this study, we report pectin-HPMC compression coated core tablets of 5-aminosalicylic acid (5-ASA) for colonic delivery. Each 100 mg core tablet contained 5-ASA and was compression coated at 20 kN or 30 kN using 100% pectin, 80% pectin-20% HPMC, or 60% pectin-40% HPMC, at two different coat weights as 400 or 500 mg. Drug dissolution/system erosion/degradation studies were carried out in pH 1.2 and 6.8 buffers using a pectinolytic enzyme. The system was designed based on the gastrointestinal transit time concept, under the assumption of colon arrival times of 6 h. It was found that pectin alone was not sufficient to protect the core tablets and HPMC addition was required to control the solubility of pectin. The optimum HPMC concentration was 20% and such system would protect the cores up to 6 h that corresponded to 25-35% erosion and after that under the influence of pectinase the system would degrade faster and delivering 5-ASA to the colon. The pectin-HPMC envelope was found to be a promising drug delivery system for those drugs to be delivered to the colon.Publication Metadata only Multilayered Tablet Technology, Manufacturing Process, Evaluation and its Application Areas(MARMARA UNIV, FAC MEDICINE, 2016) KERİMOĞLU, OYA; Canbagi, Hatice; Ugurlu, Timucin; Kerimoglu, OyaAccording to new developed technologies, drug industry is also trying to refresh and improve itself. With the conception of rational pharmacotherapy, new technologies becomes smarter than finding new active substances. Correspondingly as a new dosage system, multi-layer tablets that improved to serve this purpose, provides ease of use to patients, reduces the side effects and increases of effectiveness of active agent. Therefore multi-layer tablets are developed to improve both the quality of product and life. Conducted work studied for understanding the bi-layer tablet technique, evaluating the assesment parameters and to giving examples to used spaces.
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