This paper presents data on the general properties and complexing ability of cyclodextrins and assessment methods (phase solubility, DSC tests and X-ray diffraction, FTIR spectra, analytical method). ...It focuses on the formation of drug deposits on the surface of a textile underlayer, using a cyclodextrin compound favoring the inclusion of a drug/active principle and its release onto the dermis of patients suffering from skin disorders, or for protection against insects. Moreover, it presents the kinetics, duration, diffusion flow and release media of the cyclodextrin drug for in vitro studies, as well as the release modeling of the active principle. The information focuses on therapies: antibacterial, anti-allergic, antifungal, chronic venous insufficiency, psoriasis and protection against insects. The pharmacodynamic agents/active ingredients used on cotton, woolen and synthetic textile fabrics are presented.
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Smart polymeric micelles (PMs) are of practical interest as nanocarriers for the encapsulation and controlled release of hydrophobic drugs. Two hydrophobic drugs, naturally-based curcumin (Cur) and ...synthetic 5-fluorouracil (5-FU), were loaded into the PMs formed by a well-defined pH-sensitive poly(2-vinyl pyridine)-b-poly(ethylene oxide) (P2VP90-b-PEO398) block copolymer. The influence of the drug loading on the micellar sizes was investigated by dynamic light scattering (DLS) and it appears that the size of the PMs increases from around 60 to 100 nm when Cur is loaded. On the contrary, the loading of the 5-FU has a smaller effect on the micellar sizes. This difference can be attributed to higher molar mass of Cur with respect to 5-FU but also to higher loading efficiency of Cur, 6.4%, compared to that of 5-FU, 5.8%. In vitro drug release was studied at pH 2, 6.8, and 7.4, and it was observed that the pH controls the release of both drugs. At pH 2, where the P2VP sequences from the “frozen-in” micellar core are protonated, the drug release efficiencies exceed 90%. Moreover, it was demonstrated, by in vitro assays, that these PMs are hemocompatible and biocompatible. Furthermore, the PMs protect the Cur against the photo-degradation, whereas the non-ionic PEO corona limits the adsorption of bovine serum albumin (BSA) protein on the surface. This study demonstrates that these pH-sensitive PMs are suitable for practical utilization as human-safe and smart, injectable drug delivery systems.
Two natural polymers, i.e., cellulose and water soluble pullulan, have been selectively oxidized employing the TEMPO-mediated protocol, to allow the introduction of C
-OOH groups. Thereafter, the ...composite hydrogels of poly(vinyl alcohol) (PVA) and different content of the oxidized polysaccharides were prepared by the freezing/thawing method. The Fourier transform infrared spectroscopy (FTIR) has been used to discuss the degree of interaction between the hydrogels constituents into the physical network. The homogeneity of the prepared hydrogels as revealed by the SEM show an excellent distribution of the oxidized polysaccharides inside the PVA matrix. The samples exhibit self-healing features, since they quickly recover the initial structure after being subjected to a large deformation. The cell viability was performed for the selected hydrogels, all of them showing promising results. The samples are able to load L-arginine both by physical phenomena, such as diffusion, and also by chemical phenomena, when imine-type bonds are likely to be formed. The synergism between the two constituents, PVA and oxidized polysaccharides, into the physical network, propose these hydrogels for many other biomedical applications.
spp. extracts are known for their use in traditional Korean, Chinese, and Japanese medicine in the treatment of gastrointestinal disorders, anxiety, and allergies. Among their main components with ...pharmacological activity, the most relevant are magnolol and honokiol, which also show antitumoral activity. The objectives of this work were to study some physicochemical properties of both substances and their stability under different conditions of temperature, pH, and oxidation. Additionally, liposomes of honokiol (the least stable compound) were formulated and characterized. Both compounds showed pH-dependent solubility, with different solubility-pH profiles. Magnolol showed a lower solubility than honokiol at acidic pH values, but a higher solubility at alkaline pH values. The partition coefficients were similar and relatively high for both compounds (log P
≈ 4.5), indicating their lipophilic nature. Honokiol was less stable than magnolol, mainly at neutral and basic pH values. To improve the poor stability of honokiol, it was suitably loaded in liposomes. The obtained liposomes were small in size (175 nm), homogeneous (polydispersity index = 0.17), highly negatively charged (-11 mV), and able to incorporate high amounts of honokiol (entrapment efficiency = 93.4%). The encapsulation of honokiol in liposomes increased its stability only at alkaline pH values.
Drug delivery to the anterior or posterior segments of the eye is a major challenge due to the protection barriers and removal mechanisms associated with the unique anatomical and physiological ...nature of the ocular system. The paper presents the preparation and characterization of drug-loaded polymeric particulated systems based on pre-emulsion coated with biodegradable polymers. Low molecular weight biopolymers (chitosan, sodium hyaluronate and heparin sodium) were selected due to their ability to attach polymer chains to the surface of the growing system. The particulated systems with dimensions of 190–270 nm and a zeta potential varying from −37 mV to +24 mV depending on the biopolymer charges have been obtained. Current studies show that particles release drugs (dexamethasone/pilocarpine/bevacizumab) in a safe and effective manner, maintaining therapeutic concentration for a longer period of time. An extensive modeling study was performed in order to evaluate the drug release profile from the prepared systems. In a multifractal paradigm of motion, nonlinear behaviors of a drug delivery system are analyzed in the fractal theory of motion, in order to correlate the drug structure with polymer. Then, the functionality of a SL(2R) type “hidden symmetry” implies, through a Riccati type gauge, different “synchronization modes” (period doubling, damped oscillations, quasi-periodicity and intermittency) during the drug release process. Among these, a special mode of Kink type, better reflects the empirical data. The fractal study indicated more complex interactions between the angiogenesis inhibitor Bevacizumab and polymeric structure.
Endometriosis is considered a serious public health issue because of the large number of females affected by this illness. Chronic pain management in patients with endometriosis demands new ...strategies to increase the life quality of these patients. The development of drug delivery systems represents a new approach in pain treatment among endometriosis patients. Diclofenac sodium, one of the most utilized nonsteroidal anti-inflammatory drugs (NSAID), has its own limitations when being used in formulas such as oral, parental, or local applications. In this paper, a series of four drug release formulations based on chitosan, 2-hydroxy-5-nitrobenzaldehyde, and diclofenac sodium salt were prepared in view of the investigation of the drug release ability. The formulations were analyzed from a morphological and supramolecular point of view by scanning electron microscopy and polarized light microscopy. The in vitro drug release ability was investigated by mimicking a physiologic environment. A mathematical model, using the fractal paradigm of motion, is utilized to explain the behaviors of the drug delivery system presented in this paper. These results suggest a great potential of the proposed drug delivery system, based on chitosan and 2-hydroxy-5-nitrobenzaldehyde to improve the diclofenac sodium salt bioavailability, and it may represent a future treatment formula for endometriosis pain.
The present paper focuses on solid lipid particles (SLPs), described in the literature as the most effective lipid drug delivery systems that have been introduced in the last decades, as they ...actually combine the advantages of polymeric particles, hydrophilic/lipophilic emulsions and liposomes. In the current study, we present our most recent advances in the preparation of alendronate (AL)-loaded SLPs prepared by hot homogenization and ultrasonication using various ratios of a self-emulsifying lipidic mixture of Compritol 888, Gelucire 44/14, and Cremophor A 25. The prepared AL-loaded SLPs were investigated for their physicochemical, morphological and structural characteristics by dynamic light scattering, differential scanning calorimetry, thermogravimetric and powder X-ray diffraction analysis, infrared spectroscopy, optical and scanning electron microscopy. Entrapment efficacy and actual drug content were assessed by a validated HPLC method. In vitro dissolution tests performed in simulated gastro-intestinal fluids and phosphate buffer solution pH 7.4 revealed a prolonged release of AL of 70 h. Additionally, release kinetics analysis showed that both in simulated gastrointestinal fluids and in phosphate buffer solution, AL is released from SLPs based on equal ratios of lipid excipients following zero-order kinetics, which characterizes prolonged-release drug systems.
The current studies entail quality by design (QbD)-enabled development of a simple, rapid, precise, accurate, and cost-effective high-performance liquid chromatographic method for estimation of ...metformin hydrochloride (M-HCl). Design of experiments (DoE) was applied for multivariate optimization of the experimental conditions of the HPLC method. Risk assessment was performed to identify the critical method parameters (CMPs) using Ishikawa diagram. The factor screening studies were performed using a two-factor three-levels design. Two independent factors, buffer pH and mobile phase composition, were used to design mathematical models. Central composite design (CCD) was used to study the response surface methodology and to study in depth the effects of these independent factors, thus evaluating the critical analytical attributes (CAAs), namely, retention time, peak area, and symmetry factor as the parameters of method robustness. Desirability function was used to simultaneously optimize the CAAs. The optimized and predicted data from contour diagram consisted of 0.02 M acetate buffer pH = 3/methanol in a ratio of 70/30 (v/v) as the mobile phase with a flow rate 1 mL/min. The separation was made on a Thermoscientific ODS HypersylTM chromatographic column (250 × 4.6 mm, 5 μm) with oven temperature 35 °C and UV detection at 235 nm. The optimized assay conditions were validated according to ICH guidelines. Hence, the results clearly showed that QbD approach could be successfully applied to optimize HPLC method for estimation of M-HCl. The method was applied both for the evaluation of M-HCl content in tablets, and for in vitro dissolution studies of M-HCl from conventional and prolonged-release tablets.
Amiodarone low solubility and high permeability is the limiting step for its bioavailability, therefore new formulations are needed to improve the solubility of amiodarone either to increase its oral ...bioavailability or to reduce its toxic effects. Complexation of amiodarone with cyclodextrin results in improved dissolution rate, solubility, and allows for a more controlled drug release. We characterized the acute toxicity of a new amiodarone 2-hydroxypropyl-β-cyclodextrin complex (AMD/HP-β-CD) as powdered form and as a matrix based on Kollidon® and chitosan, administered intraperitoneally in laboratory animals. There were developed two formulations of matrix: one containing only pure AMD as a control sample (Fc) and one containing the inclusion complex with the optimal solubility (F). AMD was equitoxic with HP-β-CD after intraperitoneal administration (289.4 mg/kg for AMD and 298.3 mg/kg for AMD/HP-β-CD), with corresponding histopathological changes. The matrix based formulations presented higher LD50 values for acute toxicity, of 347.5 mg/kg for Fc and 455.6 mg/kg for F10, conducting to the idea of a safer administration because KOL and CHT matrix modified the solubility and controlled the AMD release. The LD50 is 1.5 higher for AMD/HP-β-CD included in a KOL and CHT based matrix compared to the pure AMD, administered intraperitoneally.
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