Hatice Yesim Karasulu

Doxorubicin (Dox) is a widely used chemotherapeutic agent, but its clinical application is limited by severe dose-dependent toxicities, particularly cardiotoxicity. To overcome these challenges, two novel formulations—liposomal doxorubicin (Dox-Lip) and proliposomal doxorubicin (Dox-P-Lip) —were developed and systematically compared with the reference listed drug (RLD), focusing on physicochemical comparability and in vitro bioequivalence in accordance with FDA guidance. Dox-Lip was prepared using alternative lipid compositions and a modified pH gradient–based active loading method, while Dox-P-Lip was obtained by lyophilization of the liposomal formulation. Characterization studies included encapsulation efficiency (EE%), lipid content, drug-to-lipid ratio, internal pH, morphology, bilayer phase behavior, PEG surface density, particle size, zeta potential, and PEG layer thickness determined using the Fixed Aqueous Layer Thickness (FALT) model. In vitro drug release was evaluated under simulated plasma, variable pH and temperature, and ultrasound exposure. Both formulations exhibited high encapsulation efficiencies (EE%) exceeding 90%, comparable to those of the RLD. Moreover, these formulations demonstrated approximately 2.1-fold thicker PEG layers, indicating improved steric stabilization. Although these formulations exhibited slightly higher leakage under stress conditions, the encapsulation efficiency (EE%) consistently remained above 90%, confirming their structural integrity. Overall, the novel formulations demonstrated physicochemical similarity and stability relative to the RLD, supporting their potential as bioequivalent and clinically viable liposomal Dox alternatives. Graphical Abstract

We developed a novel, rapid and efficient high performance liquid chromatography (HPLC) method and validated to analyse the quantification of Lamivudine (LAM) in different pharmaceutical formulations, including pure form, commercial tablet, and nanostructured lipid carrier (NLC), a novel drug carrier system. Accurate analysis of the amount of active ingredient in pharmaceutical formulations is very important for assessment of the quality and therapeutic efficacy of formulations. In method, we used distilled water: methanol (MeOH) (60:40 v/v) as mobile phase and analysed on C18 column. To analyse the eluent, the method was performed at 270 nm, with a flow rate of 1 mL/min, in 10 min. The calibration curve obtained showed linearity in the concentration range 2-60 ppm. The average recovery of pharmaceutical preparations (Zeffix, GlaxoSmithKline tablets and NLC formulation) was 99.552%. Our method’s limit of detection (LOD) was 1.494 μg/mL. Our method’s limit of quantification (LOQ) was 0.514 μg/mL. The method also allowed the determination of the amount of LAM contained in the existing commercial formulation and the newly developed NLC formulation and the verification of the homogeneity of the pharmaceutical formulations. The results obtained show that the developed HPLC method can be used reliably in both formulation development and stability studies in NLC drug carrier systems.

The objective of this study develop a novel proliposome formulation containing Doxorubicin (Dox) and was to validate sensitive and selective reversed-phase high-performance liquid chromatographic (HPLC) method for the evaluation of Dox concentrations of proliposome formulation. The samples were chromatographed on C18 column (Zorbax Eclipse Plus 5µm 4.6 x 250 mm) using a mobile phase with Sodium Lauryl Sulphate solution:Acetonitrile (%50:%50) and detected 254 nm. Linearity was confirmed in the concentration range 10.0–75.0 µg/mL. Specificity, linearity, working range, LOD, LOQ, accuracy, precision, robustness and system suitability studies were done from HPLC validation parameters. Liposome formulation containing Dox was developed by pH gradient method then proliposome formulation was developed with lyophilisation technique. The developed HPLC method, the encapsulation capacity (EE%) was found to be 90%±0.5 and the drug loading capacity (DL%) was found to be 100.0%±0.3. In addition, in vitro release studies and stability study results were evaluated with validated HPLC method. It was observed that developed Dox-proliposome formulation increased Dox release at pH 5.5, pH 6.5 and pH 7.5 by 23.9%, 30.2% and 14.8%, respectively, compared to commercial product. The result of F2 test performed in pH 7.5 media was 51.4%. According to the results of the physicochemical tests performed within the stability studies, it was observed that there was no significant change at the end of 12 months. These results show that the HPLC method developed, and validation study performed are important and applicable in the development, characterization, in vitro release and stability studies of the novel proliposome formulation.

Objective: Valsartan (VST) is a Biopharmaceutical classification system (BSC) class II active ingredient with a bioavailability of approximately 25% and is utilized to treat high blood pressure (hypertension). This study aimed was to showcase the stability and increase the permeability of VST by developing self-emulsifying drug delivery systems (SEDDS) and solidified SEDDS (S-SEDDS) formulations. Material and Method: The ratios of the components were determined by the pseudo-ternary phase diagram, and the characterization studies were conducted in the previous study. Stability was performed in long-term (25±2˚C, 60±5% relative humidity) and accelerated (40±2˚C, 75±5% relative humidity) conditions. The intestinal permeability of SEDDS formulations was evaluated by Caco-2 cells. Result and Discussion: Formulations for 12 month, droplet sizes were found to be 67.52 ± 5.26 nm and 176.93 ± 17.34 nm for SEDDS of VST (VST-SEDDS) and S-SEDDS of VST (VST-S-SEDDS), respectively. During this period, polydispersity indexes were: VST-SEDDS, 0.56±0.1; VST-S-SEDDS, 0.58±0.05. Both formulations increased VST permeability across Caco-2 cells: VST-SEDDS by 2.32x (powder) and 2.18x (commercial); VST-S-SEDDS by 1.38x (powder) and 1.30x (commercial). The formulation components did not have cytotoxic effects. These results demonstrated that newly developed VST-SEDDS and VST-S-SEDDS formulations with high permeability may be a desirable approach for antihypertensive therapy.

Hipertansiyon, kardiyovasküler hastalık için ana risk faktörüdür. Valsartan, anjiyotensin II'nin anjiyotensin Tip 1 reseptörü üzerindeki etkisini spesifik olarak bloke ederek yaygın olarak kullanılan, etkili ve iyi tolere edilen antihipertansif ajandır. Ancak gastrointestinal sistemin üst kısmından emilir ve buranın asidik ortamı nedeniyle bu bölgede az çözünür ve oral biyoyararlanımı sadece %25'tir. Bu çalışmanın amacı, Valsartan'ın (VST) ticari formülasyonuna alternatif olarak yeni bir dozaj formu geliştirmektir. Bu amaçla, VST’ın çözünürlüğünü artırmak ve pH'tan bağımsız bir çözünürlüğe sahip olan katı kendiliğinden emülsifiye olabilen ilaç taşıyıcı sistem (S-SEDDS) formülasyonu geliştirmek hedeflenmiştir. VST'ın en yüksek çözünürlük gösterdiği SEDDS bileşenlerini belirlemek için çözünürlük çalışmaları yapılmıştır. Çözünürlük çalışmalarına göre; yağ fazı olarak izopropil miristat (3.5 mg/mL), yüzey etkin maddeler olarak Capyrol 90 (19.8 mg/mL) ve Tween 20 (32.5 mg/mL), yardımcı yüzey etkin madde olarak ise Transcutol HP (168.9 mg/mL) kullanılmıştır. Çözünürlük çalışmaları ile belirlenen yardımcı maddeler ile üçgen faz diyagramları çizilmiştir. VST içeren SEDDS formülasyonları Avicel pH101 ve Hidroksipropil metil selüloz’a (HPMC) ayrı ayrı yaş granülasyon tekniği ile adsorbe edilmiş ve karakterizasyon çalışmaları yapılmıştır. Geliştirilen VST-SEDDS, VST-SEDDS-Avicel ve VST-SEDDS-HPMC formülasyonları pH 1.2 ortamında ticari ürüne göre VST salınımı arttırmıştır. Ayrıca VST-SEDDS-Avicel formülasyonunun açlık, tokluk durumlarından ve pH değişiminden etkilenmediği gözlenmiştir. Bu nedenle VST-SEDDS-Avicel formülasyonunun, pH'tan bağımsız çözünürlüğü arttırdığı ve antihipertansif tedavi için potansiyel bir formülasyon adayı olabileceği söylenebilmektedir.

Hepatocellular carcinoma (HCC), more than 800 000 cases reported annually, is the most common primary liver cancer globally. Doxorubicin hydrochloride (Dox-HCl) is a widely used chemotherapy drug for HCC, but efficacy and tolerability are limited, thus critical to develop delivery systems that can target Dox-HCl to the tumour site. In this study, liver-targeting ligand glycyrrhetinic acid (Gly) was conjugated to polyethylene glycol (PEG) via Steglich reaction and incorporated in liposomes, which were then loaded with Dox-HCl by pH gradient method. The optimal formulation Gly-Peg-Dox-ProLP-F6 showed high Dox-HCl encapsulation capacity (90.0%+/- 1.85%), low particle size (120 +/- 3.2 nm). Gly-Peg-Dox-ProLP-F6 formulation demonstrated substantially greater toxicity against HCC cells than commercial Dox-HCl formulation (greater against 1.14, 1.5, 1.24 fold against Hep G2, Mahlavu and Huh-7 cells, respectively), but was 1.86-fold less cytotoxic against non-cancerous cell line AML-12. It increased permeability from apical to basolateral (A-B) approximately 2-fold. Gly-Peg-Dox-ProLP-F6 demonstrated superior antitumor efficacy in mouse liver cancer model as evaluated by IVIS. Isolated mouse liver tissue contained 2.48-fold Dox more than Dox-HCl after administration of Gly-Peg-Dox-ProLP-F6, while accumulation in heart tissue was substantially lower. This Gly-Peg-Dox-ProLP-F6 formulation may improve HCC outcomes through superior liver targeting for enhanced tumour toxicity with lower systemic toxicity.