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Öğe Characterization of dexamethasone containing lipid-based self nano emulsified drug release system(2023) Komesli, Yelda; Dinç, Bircan; Ege, Mehmet AliLipid-based drug delivery systems are promising systems for hydrophobic drug delivery. A lipid-based self-nano-emulsified ocular drug release system has been synthesized for improving the topical ocular delivery of hydrophobic drugs. The aim is to develop preformulation that reaches the vitreal fluid, bypassing the ocular barriers, without requiring intravitreal injection. To eliminate the complications, dexamethasone (Dex) is applied in the lipid-based system called the self-nano-emulsified drug release system (DexSNEDDS). DexSNEDDS was synthesized via different oils, surfactants, and cosurfactants suitable for ophthalmic use. The resulting system was characterized by Raman, UV, FTIR Spectra, DSC, and SEM. Dex was loaded into lipids in ratios of 31.35% Labrasol/Span 80 (1:1), 31.35% transcutol, and 17.64% oleic acid. DexSNEDDS was applied to HUVEC cells, and MTT cell viability experiments were performed to determine the cytotoxicity. The size of the prepared lipid spheres was approximately 50-200 nm according to SEM images. Zeta sizer results confirm the SEM image evaluations. Differential scanning calorimeter measurements of Dex and DexSNEDDS show characteristic peaks between 221 and 261 celcius. The fingerprint region of Dex is seen in peaks between 1700 and 1600 cm(-1) in Raman spectra and at 1740, 1640, 1350, 1070, and 887 cm(-1) in FTIR spectra, and the regions emerged in the spectra of DexSNEDDS. The viability results revealed that the difference between DexSNEDDs in treated and untreated cells was not statistically significant, and DexSNEDDS is safe for in vivo testing.Öğe LC-MS/MS of Dexamethasone in Rabbit Vitreous Liquid Delivered through Novel Self-nanoemulsifying Drug Delivery Systems(BENTHAM SCIENCE, 2024) Komesli, Yelda; Gözet, Fatma Tuba; Öztürk Şen, BehiyeBackground: Dexamethasone (DEX), delivered through newly developed self-nanoemulsifying drug delivery systems, which is administered to rabbit eyes, has been presented. The instrumental parameters of the multiple LC-MS/MS methods in the literature are modified according to rabbit vitreous liquid and current laboratory conditions. Methods: Quick optimization of the chromatographic and mass spectrometric parameters was done by inspecting the available literature for the analysis of DEX by LC-MS/MS from biological matrices. Chromatographic separation was achieved in the reverse mode using C18 (50x2.1 mm, 5 mu m) as a stationary phase and acetonitrile and water with ammonium acetate as a mobile phase in gradient elution. Quantitation was done in multiple reaction monitoring (MRM) mode by following the transition of m/z 393 > m/z 373 in positive ion mode. The method was also validated in terms of selectivity, within-day accuracy and precision, linearity, and limit of detection (LOD). The extraction of DEX from rabbit vitreous liquid samples was carried out by protein precipitation using acetonitrile: water (70:30, v/v). Results: DEX and beclomethasone (IS) were successfully separated and detected under optimized experimental settings. The method was selective for DEX and linear in the range of 0.5 and 250 ng/ml. The lower limit of quantification (LLOQ) was determined to be 0.238 ng/ml. The percent relative standard deviation (RSD) and recovery (%) of the low, medium, and high calibration levels were below 10% and within the range of 111%-114%, respectively. RSD (%) and recovery (%) of the LLOQ were below 17% and 82%, respectively. The validated method was successfully applied for the determination of pharmacokinetic properties of newly formulated dexamethasone self-nanoemulsifying drug delivery systems (DEXSNEDDS) used to administer DEX intravitreally to the rabbit. Conclusion: LC-MS/MS conditions for the analysis of LC-MS/MS were determined by examining relevant literature for accomplishing simple and practical optimization of the experimental parameters, followed by method validation and analysis of rabbit vitreous liqiud. As conclusion, pharmacokinetic data of DEXSNEDDS has been obtained in the most accurate, sensitive, economical and rational way possible.Öğe Nano formulations as drug delivery systems(Altınbaş Üniversitesi, 2022) Yılmaz Kayan, Sema; Komesli, YeldaClassical drug forms are used frequently and in repeated doses. Undesirable situations may occur when the dose used for the concentration of the active substance released into the system falls below the sufficient amount or rises above the toxic level. As a result of the developments achieved in nanotechnological research, nanoparticles, which have many applications in the clinic, have made a significant impact in the pharmaceutical industry. The practical use of nanoparticles in applications such as direct binding to the active substance, entrapment and targeting in the pharmaceutical industry has made nanoparticles a preferred position. When implanted systems with nanocarriers reach the target area, uptake in organs, tissues and cells increases. These structures use active and passive targeting strategies to deliver the active substance to the targeted cells. The use of nanocarriers in drug delivery systems provides many advantages. The results obtained from the studies carried out so far are that, thanks to the targeting of cancer drug-loaded nanocarriers, treatment alternatives with higher selectivity have emerged. In this study, nanoparticles as drug delivery are discussed and how to increase bioavailability with nanoparticles is discussed with their advantages.Öğe Permeability of olmesartan medoxomil from lipid based and suspension formulations using an optimized HDM-PAMPA model(2022) Komesli, Yelda; Karasulu, ErcümentHexadecane membrane-parallel artificial membrane permeability assay (HDM-PAMPA) is based on an artificial hexadecane membrane that separates the two compartments (donor and acceptor compartment). This model is used to predict the permeability of drugs in gastrointestinal tract and to simulate the passive absorption. In vivo behaviour of the drugs can be estimated with these systems in drug development studies. In our study we optimized HDM-PAMPA model to determine permeability of olmesartan medoxomil (OM) lipid based drug delivery system (OM-LBDDS). In order to prove that LBDDS formulation facilitates the weak permeability of OM, permeation rates were compared with the OM suspension formula (containing 0.25% v/w CMC). The experiment was performed on a 96-well MultiScreen® PAMPA filter plate (MAIPN4510). The permeability of olmesartan formulations from the donor to acceptor compartment separated by a HDM membrane were determined by the previous validated HPLC method. We created positive control series without coating hexadecane membrane to present the LBDDS and suspension formulation permeability from uncoated plates. The effective permeability constant (Pe) was calculated by the formula and improvement of permeability of OM-LBDDS formulation from hexadecane membrane was confirmed. On the contrary there was no permeation of OM-Suspension in the hexadecane coated plates. As a result, the intestinal permeability of OM-LBDDS was calculated to be at least 100 times more than the suspension. OM-Suspension permeation was only observed in the hexadecane uncoated positive control plates. This was also manifestation of HDM-PAMPA mimicking permeability of intestines because of its lipidic construction.
