esra baloglu | Ege University (original) (raw)

Papers by esra baloglu

Journal of Drug Delivery Science and Technology

Cal% mada a6%z ici nemlendirici ozelli6i olan iki farkl% jelin viskozite ozelliklerinin belirlenm... more Cal% mada a6%z ici nemlendirici ozelli6i olan iki farkl% jelin viskozite ozelliklerinin belirlenmesi ve do6al tukurukle kar %la t%r%lmas% amaclanm% t%r.Jellerin ve do6al tukuru6un viskozite olcumleri Brookfield dijital viskozimetre cihaz% (Model DV-III) kullan%larak oda s%cakl%6%nda ve vucut %s%s%nda (37oC’ de) gercekle tirilmi tir. Sa6l%kl% 5 ki iden toplanan tukuruk orneklerinin viskozite olcumleri de yapay tukuruk preparatlar%yla ayn% artlarda gercekle tirilmive her bir ornekten 10 olcum yap%larak ortalama viskozite de6erleri elde edilmi tir. Oda s%cakl%6%nda yap%lan olcumlerde jellerin viskozite ozelliklerinin birbirine benzedi6i, ancak 37oC’de BioXtra®’n%n istatistiksel olarak daha du uk viskoziteye sahip oldu6u gozlenmi tir (p

Drug design, development and therapy, 2018

Bladder cancer is responsible for more than 130,000 deaths annually worldwide. Intravesical deliv... more Bladder cancer is responsible for more than 130,000 deaths annually worldwide. Intravesical delivery of chemotherapeutic agents provides effective drug localization to the target area to reduce toxicity and increase efficacy. This study aimed to develop an intravesical delivery system of gemcitabine HCl (Gem-HCl) to provide a sustained-release profile, to prolong residence time, and to enhance its efficiency in the treatment of bladder cancer. For this purpose, bioadhesive microspheres were successfully prepared with average particle size, encapsulation efficiency, and loading capacity of 98.4 µm, 82.657%±5.817%, and 12.501±0.881 mg, respectively. For intravesical administration, bioadhesive microspheres were dispersed in mucoadhesive chitosan or in situ poloxamer gels and characterized in terms of gelation temperature, viscosity, mechanical, syringeability, and bioadhesive and rheological properties. The cytotoxic effects of Gem-HCl solution, Gem-HCl microspheres, and Gem-HCl micro...

###EgeUn###The objective of the study is to develop and evaluate a generic topical formulation co... more ###EgeUn###The objective of the study is to develop and evaluate a generic topical formulation containing isotretinoin and to compare with a brand name product. A gel formulation was developed with hydroxypropylcellulose and characterized by means of appearance, drug content, pH, rheological properties and in vitro drug release profiles. All result was evaluated depending on the requirements of national and international authorities and also literature based knowledge. For this aim, Q1 (qualitative), Q2 (quantitative) and Q3 (microstructure) similarity to the brand name product should be achieved. As a result, a generic gel formulation which can be an alternative for markets was developed and found similar to the brand name product. A generic topical gel formulation of isotretinoin with hydroxypropylcellulose was successfully produced for drug markets. This study revealed all stages and important parameters of a semi-solid generic product development

Journal of Drug Delivery and Therapeutics, 2012

To treat allergic disorders on long term therapy needs plasma concentration of drug in better man... more To treat allergic disorders on long term therapy needs plasma concentration of drug in better manner. This was achieved by formulating the drug in controlled release pattern. Fexofenadine hydrochloride is almost completely absorbed from the gastrointestinal tract following oral administration,but bioavailability is reported to be only about 45% due to hepatic first-pass metabolism. The present study aims to prepare Transdermal patch of Fexofenadine hydrochloride. Preparation of transdermal patches of Fexofenadine hydrochloride using polymers: Hydroxypropyl methyl cellulose, Ethyl cellulose plasticized with Glycerol. The patches were evaluated for various parameters like Thickness, Water-Vapor Permeability, Tensile Strength, Drug Content,Diffusion and Dissolution studies. Prepared patches exhibited Zero Order Kinetics and the permeation profile was matrix diffusion type.In-vitrorelease study of Fexofenadine hydrochloride transdermal patch shown release of drug 79 % at 24 h and also follows zero order kinetics release pattern.

Pharmaceutical Development and Technology, 2006

Background and Objectives: Ornidazole is widely used as an antiprotozoal and antiamoebic drug and... more Background and Objectives: Ornidazole is widely used as an antiprotozoal and antiamoebic drug and its onset of action is within 2 h. The major extent of the drug is metabolized in the liver and excreted in the urine and faeces. Hence, the present study of suppository formulation for sustained systemic delivery of ornidazole is significant which could minimize abdominal disturbances and nausea and delayed onset of action particularly after oral administration. Methods: Bioadhesive suppository formulations were prepared for systemic delivery of ornidazole via rectal and vaginal route. Results: The physical drug-excipient-interaction was confirmed by in-silico docking study. The affinity between drug-HPMC and drug-PEG was found to be-2 and-0.9 k cal/mol respectively. In vitro drug release of the suppositories varied depending on the viscosity grade of HPMC used and all have followed mostly diffusion controlled mechanism. The formulation containing HPMC K100 showed the most sustained release of ornidazole in both the dissolution fluid of pH 7.4 and 4.5 (54.53 and 41.89 % respectively after 360 min). Conclusion: In conclusion, present bio adhesive suppositories could be utilized for sustained systemic delivery of ornidazole via rectal and vaginal route. The findings of this work will contribute to the current knowledge and encourage future pre-clinical research.

Journal of Natural Products, 1999

Bioorganic & Medicinal Chemistry Letters, 2001

The preparation of two new fluorescent derivatives of paclitaxel in which the fluorophore is bond... more The preparation of two new fluorescent derivatives of paclitaxel in which the fluorophore is bonded to paclitaxel at the C-10 position is reported. Both analogues, 10-deacetyl-10-(m-aminobenzoyl)paclitaxel (1, BTax) and 10-deacetyl-10-[7-(diethylamino) coumarin-3-carbonyl]paclitaxel (2, CTax) retain good activity as promoters of in vitro tubulin assembly. Microtubule binding enhances the emission intensity of both probes.

… of Pharmacy and …, 2011

Objectives This study describes the in-situ gelling of econazole nitrate containing thermosensiti... more Objectives This study describes the in-situ gelling of econazole nitrate containing thermosensitive polymers composed of poloxamer 407 and 188 as a novel treatment platform for vaginal candidiasis. Methods Aqueous thermosensitive formulations containing 1% of econazole nitrate and poloxamer 407 and/or 188 were prepared and their rheological, mechanical and drug-release properties determined at 20 ± 0.1°C and/or 37 ± 0.1°C. Based on their biologically suitable thermorheological properties, formulations containing the mixtures of poloxamer 407 and 188 in ratios of 15:15 (F1), 15:20 (F2) and 20:10 (F3) were chosen for comprehensive analysis. Key findings Formulations based on F3 exhibited typical gel-type mechanical spectra (G′ &gt; G″) at 37°C whereas formulations based on F1 and F2 exhibited properties akin to weakly cross-linked gels. Texture profile analysis demonstrated that F3 showed the highest cohesiveness, adhesiveness, hardness and compressibility. No statistically significant differences (P &gt; 0.5) were observed in the release of econazole nitrate from the formulations at pH 4.5, which in all cases followed anomalous diffusion kinetics. Formulations based on 20% poloxamer 407:10% poloxamer 188 were chosen for in-vivo studies and were shown to be effective for the treatment of the vaginal candidiasis. Histopathologic evaluation also supported the effectiveness of the thermosensitive formulation administered intravaginally. Conclusion By careful engineering of the rheological properties, in-situ thermosensitive gel formulations of econazole nitrate were prepared and were shown to be efficacious in the treatment of vaginal candidiasis.

Pharmaceutical Development and Technology, 2016

The purpose of this study was to develop a suitable mucoadhesive in situ gel formulation of clotr... more The purpose of this study was to develop a suitable mucoadhesive in situ gel formulation of clotrimazole (CLO) for the treatment of vaginal candidiasis. For this aim, the mixture of poloxamer (PLX) 407 and 188 were used to prepare in situ gels. Hydroxypropyl methylcellulose (HPMC) K100M or E50 was added to in situ gels in 0.5% ratio to improve the mucoadhesive and mechanical properties of formulations and to prolong the residence time in vaginal cavity. After the preparation of mucoadhesive in situ gels; gelation temperature/time, viscosity, mechanical, mucoadhesive, syringeability, spreadibility and rheological properties, in vitro release behavior, and anticandidal activities were determined. Moreover vaginal retention of mucoadhesive in situ gels was investigated with in vivo distribution studies in rats. Based on the obtained results, it was found that gels prepared with 20% PLX 407, 10% PLX 188 and 0.5% HPMC K100M/E50 might be suitable for vaginal administration of CLO. In addition, the results of in vivo distribution studies showed that gel formulations remained on the vaginal mucosa even 24 h after application. In conclusion, the mucoadhesive in situ gels of CLO would be alternative candidate for treatment of vaginal candidiasis since it has suitable gel properties with good vaginal retention.

Journal of Clinical Pharmacy and Therapeutics, Apr 1, 2003

To compare the efficacy of 500 mg ornidazole vaginal ovules (VO) and vaginal tablets (VT) in the ... more To compare the efficacy of 500 mg ornidazole vaginal ovules (VO) and vaginal tablets (VT) in the treatment of bacterial vaginosis. Patients were allocated at random to one group of 50 subjects to be treated with a VO (500 mg) prepared in our laboratory and to a second group of 50 subjects to be treated with a VT of ornidazole (500 mg). Therapeutic efficacy was assessed by Nugent's scoring system and clinical criteria (Amsel's criteria) before and 1 week after treatment. At the first follow-up visit, complete disappearance of the signs and symptoms or highly significant reduction in intensity of symptoms was observed in both treatment groups. No significant difference was evident between the two ornidazole formulations.

International Journal of Nanomedicine, 2015

This study aimed to develop an intravesical delivery system of gemcitabine HCl for superficial bl... more This study aimed to develop an intravesical delivery system of gemcitabine HCl for superficial bladder cancer in order to provide a controlled release profile, to prolong the residence time, and to avoid drug elimination via urination. For this aim, bioadhesive nanoparticles were prepared with thiolated chitosan (chitosan-thioglycolic acid conjugate) and were dispersed in bioadhesive chitosan gel or in an in situ gelling poloxamer formulation in order to improve intravesical residence time. In addition, nanoparticle-loaded gels were diluted with artificial urine to mimic in vivo conditions in the bladder and were characterized regarding changes in gel structure. The obtained results showed that chitosan-thioglycolic acid nanoparticles with a mean diameter of 174.5±3.762 nm and zeta potential of 32.100±0.575 mV were successfully developed via ionotropic gelation and that the encapsulation efficiency of gemcitabine HCl was nearly 20%. In vitro/ex vivo characterization studies demonstrated that both nanoparticles and nanoparticle-loaded chitosan and poloxamer gels might be alternative carriers for intravesical administration of gemcitabine HCl, prolonging its residence time in the bladder and hence improving treatment efficacy. However, when the gel formulations were diluted with artificial urine, poloxamer gels lost their in situ gelling properties at body temperature, which is in conflict with the aimed formulation property. Therefore, 2% chitosan gel formulation was found to be a more promising carrier system for intravesical administration of nanoparticles.

End-stage liver disease accounts for over 30,000 deaths annually in the United States. Orthotopic... more End-stage liver disease accounts for over 30,000 deaths annually in the United States. Orthotopic liver transplantation is the only clinically proven treatment for patients with end-stage liver failure. A limitation of this therapy is a shortage of donor ...

In this study, the degradation of nitrendipine in acidic (pH 1) and alkaline (pH9) solutions at 1... more In this study, the degradation of nitrendipine in acidic (pH 1) and alkaline (pH9) solutions at 100°C was investigated spectrophotometrically.The decomposition of nitrendipine was faster in the acidic medium than in the alkaline medium. It was found that the degradation of nitrendipine solution at 100°C obeyed first-order kinetics. The reaction rate constants (kobs) and chemical half-lives (t1/2) were calculated. The major degradation product was identified as dehydronitrendipine by the use of relevant UV, IR, 1H NMR and mass spectrometry.

International Journal of Cosmetic Science, 2000

Stable multiple emulsions that contain different lipophilic surfactants in the internal aqueous p... more Stable multiple emulsions that contain different lipophilic surfactants in the internal aqueous phase have been formulated. The multiple systems were assessed by evaluating several parameters such as macroscopic aspect, droplet size, percent release and accelerated stability under centrifugation or elevated temperature. The effect of polymeric and monomeric surfactants on the release mechanism and stability was examined. An excess of monomeric surfactant in the oil phase enhances the release rate and decreases stability. The release rate can be decreased by an increase of the lipophilic surfactant concentration. It appears that the more the oil globule swells, the less hydrosoluble drug is released. As a result a high swelling capacity is associated with better stability.

Pharmaceutical Development and Technology, 2005

A new and alternative evaluation method is preferred for swelling studies of bioadhesive tablet f... more A new and alternative evaluation method is preferred for swelling studies of bioadhesive tablet formulations. CIELAB color coordinates, related to visual color response, are used for the first time to follow the swelling state and to calculate the swelling volume. The results are evaluated statistically. A simple equation is given to explain the relation between the swelling volume change % and color difference for three different bioadhesive formulations. It was found that the estimated equation is in good agreement with observed swelling volume results.

Journal of Microencapsulation, 1997

In this work, nitrofurantoin and amoxicillin trihydrate microcapsules were prepared by complex co... more In this work, nitrofurantoin and amoxicillin trihydrate microcapsules were prepared by complex coacervation at pH 3.5 using carboxymethylcellulose-gelatin at a weight ratio of 3:7. Release rates were studied as a function of core:wall ratios of microcapsules. Dissolution tests of microcapsules and their tabletted microcapsules were studied in artificial gastric and intestinal media without enzyme using the USP XXII basket method. Release rates were examined kinetically and the ideal kinetic models were estimated for drug release. In addition, the micromeritics of these microcapsules were investigated. In order to standardize the drug powder and the microcapsule product for industrial application, the micromeritic properties of microcapsules were studied by determining their bulk volume and weight, tapping volume and weight, fluidity, angle of repose, weight deviation, particle size distribution, density and porosity. Hausner ratio and consolidation index were also calculated to understand flowability rates of microcapsules when tableting or filling into gelatin capsules. The results indicated that the nitrofurantoin microcapsules need appropriate glidant but the amoxicillin trihydrate microcapsules did not. Moreover, it was observed that the microencapsulation changed the micromeritic properties of the drugs significantly.

Journal of Dispersion Science and Technology, 2011

Functional materials with antimicrobial properties are being investigated in order to provide sho... more Functional materials with antimicrobial properties are being investigated in order to provide shoes with new properties and added value by incorporating natural antimicrobial agents to conventional materials (leather, fabrics, foams, etc). Microencapsulation is an effective method to protect these functional natural biocides from reactions with moisture, light, and oxygen. If a footwear material is treated with microencapsulated biocide agents, higher