Quercetin, Rutin And Quercetin-Rutin Incorporated Hydroxypropyl ß-Cyclodextrin Inclusion Complexes.

Quercetin (Q) and rutin (R) are well known and most studied flavonoids due to their activities in reduction of inflammation, oxidative damage, platelet aggregation and inhibition of cancer proliferation. Despite their remarkable potentials they have limited oral bioavailability due to the low water solubility. Therefore in this study inclusion complexes of Q and R with hydroxypropyl-ß-cyclodextrin (HP-ß-CD) were formulated to improve the aqueous solubility, antiproliferative efficacy and also antioxidant activity of the flavonoids. According to the analyses results, aqueous solubilities of Q and R were increased up to ∼630 fold and ∼55 fold, respectively. ZP values were ranged between -21.7±0.3 mV and -6.1±0.8 mV showing the anionic structure of the complexes. 1H-NMR analyses revealed the complex formation considering the shifts of the protons of the APIs as well as HP-ß-CD. The in vitro release analyses revealed that the cumulative release of Q was decreased from 22.9 % to 18.1 and 15.2 for T9 and T 24 formulations respectively while the cumulative release of R increased from 26.8 % up to 64.5 % and 75.8 % with T14 and T24 formulations respectively. According MTT analyses results, Q showed higher antiproliferative effect in MDA-MB-231 and A549 cell lines compared to NIH-3T3 cell lines while R showed remarkable effect only on MDA-MB-231 cell lines at the end of 48 h of incubation period. A synergistic effect was observed in the formulation of combined flavonoid (Q/R) inclusion complexes and an antiproliferative effect was ordered as MDA-MB-231 > A549 > NIH-3T3. The selected complexes T9 (Q), T14 (R) and T24 (Q/R) have shown the highest antioxidant activity with 93.8 %, 65.3 % and 93.1 % respectively with DPPH analyses. In conclusion incoporation of Q, R and Q/R to HP-ß-CD based inclusion complexes have great potentials with enhanced in vitro dissolution characteristics and antiproliferative effects on different types of cancer cell lines for efficient treatment of severe disorders.

Formulation and characterization studies of inclusion complexes of voriconazole for possible ocular application.

In our study, Voriconazole (VOR) was selected as an active agent to be used for the treatment of ocular fungal infections. To overcome low aqueous solubility of VOR, inclusion complexes with α-cyclodextrin (α-CD), ß-cyclodextrin (ß-CD), γ-cyclodextrin (γ-CD), hydroxypropyl-cyclodextrin (HP-CD), hydroxypropyl-ß-cyclodextrin (HP-ß-CD) hydroxypropyl-γ-cyclodextrin (HP-γ-CD), methyl-ß-cyclodextrin (M-ß-CD) and sulfabutylether-ß-cyclodextrin (SBE-ß-CD) were formulated. Characterization studies revealed that inclusion complexes were formulated successfully with the lyophilization method. Aqueous solubility of VOR was enhanced up to 86 fold with the formation of the inclusion complexes. MTT analyses results revealed the safety of the complexes on 3T3 mouse fibroblast cell lines while Microbroth Dilution Method revealed the remarkable antifungal activities of the complexes. Analyses results revealed that inclusion complexes will overcome the poor ocular bioavailability of VOR resulting inefficient treatment of severe ocular fungal infections.

Preparation and in vitro characterization of rosuvastatin calcium incorporated methyl beta cyclodextrin and Captisol® inclusion complexes.

Despite being the most effective hypolipidemic agent, poor physicochemical properties of Rosuvastatin calcium (RCa) remain challenging obstacles in the development of pharmaceutical dosage forms. Inclusion complexes (ICs) of RCa with cyclodextrin (CD) derivatives; methyl-beta-cyclodextrin (M-ß-CD) and sulfobutylether-beta-cyclodextrin (SBE-ß-CD; Captisol®) were formulated by kneading and freeze-drying (lyophilization) methods. Pysicochemical properties of ICs were evaluated by SEM, DSC, XRD, FT-IR, 1H-NMR analyses. Entrapment efficiency (EE), water solubility, in vitro release analyses were also performed. Safety and efficacy of the ICs were analyzed by cytotoxicity and permeation studies on Caco-2 cell lines. Both CDs indicated AL type phase solubility diagrams showing that [1:1] molar ratio. Apparent stability constants (K1:1) were found to be 60.93 M-1 for M-ß-CD and 158.07 M-1 for Captisol®. High EE in the range of 93.50-105.40% was achieved. Molar solubility of RCa was increased 3.7- and 4.1-fold with M-ß-CD and Captisol® ICs, respectively. In vitro release analyses have indicated the equivalence of dissolution profiles for M-ß-CD and Captisol® based ICs to that of pure RCa (f2 > 50). Cytotoxicity studies on Caco-2 cell lines have revealed the safety of ICs for oral use. Permeability studies demonstrated that selected lyophilized F6 formulation has shown the best permeation rate with Papp value of 3.08 × 10-7 cm·s-1. Considering greater water solubility, lower toxicity, high efficiency of complexation as well as, RCa-like permeability and in vitro release behavior at pH 6.8; Captisol® based lyophilized F6 formulation was selected as the best IC to be used in oral dosage forms of RCa.

Physicochemical characterization and pharmacokinetic evaluation of rosuvastatin calcium incorporated solid lipid nanoparticles.

Rosuvastatin calcium (RCa) is a very efficient antihyperlipidemic agent, however, being a BCS class II drug, results in poor oral bioavailability. The present study focused on the enhancement of oral bioavailability of RCa with solid lipid nanoparticles (SLNs). Physicochemical properties of the particles were evaluated by particle size (PS), polidispersity index (PDI), zeta potential (ZP), DSC, FT-IR, XRD, 1H NMR analyses. Entrapment efficiency (EE), drug loading capacity (DL), in vitro release and release kinetics were also analyzed. Safety and efficacy of the formulations were analyzed by cytotoxicity, permeability and pharmacokinetic studies. PS values were ranged between ∼134 and 351 nm with homogenous size distribution (PDI ∼ 0.130-0.33) and ZP data were valued within the range of ∼-17 mV to -41 mV. The SLN2 formulation showed the best cytotoxicity test results and had medium permeability (Papp 5.72 × 10-6 cm sec-1) while pure RCa resulted in low permeability (Papp 3.08 × 10-7 cm sec-1). According to the stability analyses (3 months) 5 ±â€¯3 °C and 25 ±â€¯2 °C were found suitable storage temperatures for SLNs. Pharmacokinetic studies confirmed significant improvement in Cmax (1.4 fold) and AUClast (8.5 fold) by SLNs in comparison with the pure drug indicating the enhanced biopharmaceutical performance of the RCa loaded SLNs.

Preparation, characterization and pharmacokinetic evaluation of rosuvastatin calcium incorporated cyclodextrin-polyanhydride nanoparticles.

Objective: The aim of the study was to formulate, cyclodextrin (CD)-polyanhydride (PA) nanoparticles (CPNs) with rosuvastatin calcium (RCa) in order to enhance the poor oral bioavailability. Methods: CPNs containing RCa/CD complexes were prepared by a modified solvent displacement method and morphological analyses, particle size (PS), polydispersity index (PDI), zeta potential (ZP), encapsulation efficiency (EE), DSC, FT-IR, XRD, 1H-NMR analyses were performed. In vitro release properties, release kinetics, cytotoxicity, in vitro permeability and pharmacokinetic studies were also studied. The stability of the formulations were evaluated during the storage period of 3 months. Results: The physicochemical studies showed that the RCa/CD complexes were well incorporated into CPNs resulted in nanosized particles (215.22 and 189.13 nm) with homogenous size distribution (PDI: 0.203 and 0.182) with relatively high incorporation capacity (76.11 and 68.18%) for the CPN1 and CPN2 formulations respectively. Sustained release of RCa from CPNs were achieved. The cytotoxicity values showed that the safety of the formulations. According to permeability studies, pure RCa had lowest permeability data (3.08 × 10-7 cm⋅s-1 Papp value) while CPNs gained higher permeability data (1.36 × 10-5 and 1.12 × 10-5 cm⋅s-1 Papp values) for the CPN1 and CPN2 formulations respectively. CPN2 formulation was selected for pharmacokinetic studies and analyses results demonstrated that approximately 8-fold relative oral bioavailability enhancement compared to the pure RCa was achieved. Conclusion: Considering the analyses results of the study, CPNs can be regarded as suitable, safe, functional oral delivery systems for RCa with enhanced oral bioavailability.

Vincristine and ɛ-viniferine-loaded PLGA-b-PEG nanoparticles: pharmaceutical characteristics, cellular uptake and cytotoxicity.

The objective of this study was to prepare the ɛ-viniferine and vincristine-loaded PLGA-b-PEG nanoparticle and to investigate advantages of these formulations on the cytotoxicity of HepG2 cells. Prepared nanoparticle has shown a homogeneous distribution with 113 ± 0.43 nm particle size and 0.323 ± 0.01 polydispersity index. Zeta potential was determined as -35.03 ± 1.0 mV. The drug-loading percentages were 6.01 ± 0.23 and 2.01 ± 0.07 for ɛ-viniferine and vincristine, respectively. The cellular uptake efficiency of coumarin-6-loaded nanoparticles was increased up to 87.8% after 4 h. Nanoparticles loaded with high concentrations of both drugs showed a cytotoxic effect on HepG2 cells, having the percentage of cell viability of between 43.23% and 47.37%. Unfortunately, the percentage of apoptotic cells after treated with drugs-loaded nanaoparticles (10.93%) was similar to free forms of drugs (12.1%) that might be due to low ɛ-viniferine release in biological pH at 24 h.

Characterization and Antioxidant Activity of Quercetin/Methyl-ß-Cyclodextrin Complexes.

Quercetin (Qu), a polyphenolic flavonoid, is one of the most effective plant originated antioxidants. Despite the potential use of Qu in clinical trials, low water solubility, stability problems and the scarcity of cellular bioavailability limit its applications. The purpose of this study was to enhance aqueous solubility, dissolution rate and antioxidant activity of Qu by complexation with Methyl-ß- cyclodextrin (M-ß-CD). Analyses results showed that the aqueous solubility, dissolution rate and antioxidant activity of the complex were increased 254-fold, ~3-fold and 10% respectively compared to the pure Qu. Complexes were prepared by freeze-drying and evaporation method. The characteristics of the complexes were evaluated by DSC, XRD, (1)H-NMR, FT-IR, SEM, encapsulation efficacy, in-vitro dissolution rate analyses. Antioxidant activity studies on complexes carried out with DPPH tests. Analyses results showed that the formation of the complexes resulted in enhanced solubility with increased its antioxidant activity of Qu.

Polymeric cyclosporine-A nanoparticles for ocular application.

In the present study, cyclosporine A (CsA) was incorporated successfully into cationic Eudragit RS 100 nanoparticles (EPNs) aiming ocular application. Physicochemical characterization of the EPNs prepared was performed during the storage period of 6 months. Following in vitro release tests, sheep were used in in vivo studies where 100 microL of formulation was applied to both eyes (n = 6) under veterinarian supervision. Aqueous and vitreous humour samples were collected at predetermined time intervals and analyzed by enzyme immune assay (EIA). In vitro relase studies showed the extended release of the incorporated drug from the nanoparticles. However in vivo results demonstrated the prolonged residence time of CsA in the deeper layers (vitreous humour) of the eye with positively charged EPNs.

Cyclosporine-A incorporated cationic solid lipid nanoparticles for ocular delivery.

In the present study, Cyclosporine A (CsA) was successfully incorporated into cationic solid lipid nanoparticles (SLN) for ocular application. Physicochemical characterizations of SLNs were analysed in detail during the storage period of 6 months. Due to the better characteristics like smaller particle size (248.00 +/- 0.33 nm) with narrow size distribution (PI = 0.25 +/- 0.00), high zeta potential (50.30 +/- 0.78 mV) and more stable lipid structure, Dynasan 116 structured FD4 (0.1% CsA) formulation was chosen for in vivo studies. Sheep were used in in vivo studies and 200 microL of formulation was applied to sheep' eyes (n = 6) under veterinarian supervision. Samples were collected at pre-determined time intervals and were analysed by enzyme immune assay (EIA). CsA could be detected in both aqueous and vitreous humour samples for 48 h showing the ocular penetration of formulation. Release profiles were not decreased during 48 h indicating controlled and prolonged release of active agent from positively charged SLN formulations due to increased residence time in eyes. Similarities in CsA concentration data showed that inter-individual variance did not influence the ocular penetration of CsA when formulated as SLN.

Preparation of prolonged release clarithromycin microparticles for oral use and their in vitro evaluation.

Prolonged release microparticles of clarithromycin (CL) were prepared using Eudragit RL 100 and RS 100 by spray-drying and casting-drying techniques. For the characterization of those microparticles, preparation yield, particle size distribution, X-ray diffraction, thermal behavior, active agent content and in vitro dissolution from the microparticles were performed. HPLC was used for the assay of clarithromycin and the assay method was validated. All the formulations obtained showed prolonged release when compared to pure clarithromycin. Microparticles prepared by spray-drying method had a slower release compared to those of casting-drying method. Spray-drying method seems to be a more suitable method to prepare microparticles for prolongation in release.

Enhancement in dissolution pattern of piribedil by molecular encapsulation with beta-cyclodextrin.

The aim of this study was to improve the dissolution behavior of piribedil by molecular encapsulation with beta-cyclodextrin (beta-CD). Toward this aim, physical mixing, co-grinding, and spray-drying methods were used to prepare solid binary systems. Differential scanning calorimetry, X-ray diffractometry, and particle size analysis were used to characterize the binary systems obtained. Complexes of piribedil and beta-CD could be prepared using the spray-drying method. Dissolution of piribedil was improved to a great extent by the complex prepared.

Preparation and in vitro evaluation of pyridostigmine bromide microparticles.

Pyridostigmine bromide (PB) is an anticholinesterase agent whose aqueous solubility is high and which has a short elimination half-life. Its dosage rate in the treatment of myastenia gravis is frequent due to the short half-life and it exhibits side effects. Microparticles designed to deliver a pharmaceutical active ingredient efficiently at the minimum dose and also to enhance stability, reduce side effects and modify drug release were prepared in this study using an acrylic polymer (Eudragit) as the vehicle by the spray-drying technique. The drug was either dissolved or dispersed in the polymeric solution and following the preparation of microparticles using different ratios of ingredients, characterization studies including the determination of shape, particle size distribution, amount loaded, release and stability of PB were performed. The results obtained were compared to those of pure PB. Drug release from microparticles could be modified and was found to depend on the shapes of the microparticles. In vitro evaluation results indicate that the frequent dosage and side effects of pure PB may be reduced with the formulation of microparticles.