scholarly journals Polypseudorotaxanes of Pluronic® F127 with Combinations of α- and β-Cyclodextrins for Topical Formulation of Acyclovir

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 613
Author(s):  
Cristina Di Donato ◽  
Rosa Iacovino ◽  
Carla Isernia ◽  
Gaetano Malgieri ◽  
Angela Varela-Garcia ◽  
...  
Keyword(s):  
Water Solubility ◽  
Virus Infections ◽  
X Ray Diffraction ◽  
Topical Formulation ◽  
Gelling Properties ◽  
Hen’S Egg ◽  
Ft Ir ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Simplex Virus

Acyclovir (ACV) is one of the most used antiviral drugs for the treatment of herpes simplex virus infections and other relevant mucosal infections caused by viruses. Nevertheless, the low water solubility of ACV limits both its bioavailability and antiviral performance. The combination of block copolymer micelles and cyclodextrins (CDs) may result in polypseudorotaxanes with tunable drug solubilizing and gelling properties. However, the simultaneous addition of various CDs has barely been investigated yet. The aim of this work was to design and characterize ternary combinations of Pluronic® F127 (PF127), αCD and βCD in terms of polypseudorotaxane formation, rheological behavior, and ACV solubilization ability and controlled release. The formation of polypseudorotaxanes between PF127 and the CDs was confirmed by FT-IR spectroscopy, X-ray diffraction, and NMR spectroscopy. The effects of αCD/βCD concentration range (0–7% w/w) on copolymer (6.5% w/w) gel features were evaluated at 20 and 37 °C by rheological studies, resulting in changes of the copolymer gelling properties. PF127 with αCD/βCD improved the solubilization of ACV, maintaining the biocompatibility (hen’s egg test on the chorio-allantoic membrane). In addition, the gels were able to sustain acyclovir delivery. The formulation prepared with similar proportions of αCD and βCD provided a slower and more constant release. The results obtained suggest that the combination of Pluronic with αCD/βCD mixtures can be a valuable approach to tune the rheological features and drug release profiles from these supramolecular gels.

Study on the Properties of the Gelatin Modified Chitosan Films

2012 ◽  
Vol 482-484 ◽  
pp. 863-867 ◽  
Author(s):  
Wei Dong ◽  
Li Jun Qu ◽  
Xiao Qing Guo
Keyword(s):  
Mechanical Properties ◽  
Water Solubility ◽  
Composite Films ◽  
Chitosan Film ◽  
X Ray Diffraction ◽  
Elongation At Break ◽  
X Ray ◽  
Modified Chitosan ◽  
Ft Ir ◽  
Chitosan Films

Abstract: With the purpose to improve the mechanical properties and cut costs of chitosan films, a series of gelatin-chitosan films were prepared. The effect of gelatin content on the mechanical properites of films was studied. FT-IR spectrum and X-ray diffraction analysis showed good compatibility between gelatin and chitosan. The composite films exhibited a higher TS(tensile strengths) and ES(elongation at break) compared with chitosan film, especially when the content of gelatin in blends was 30%. The TS and ES revealed that the interaction between chitosan and gelatin was the strongest when the content of gelatin in blends was 30%. The results obtained from percent water absorption indicated these two biopolymers were high hydrophilicity polymer. The water solubility of composite films was higher than chitosan films. The results suggest that the interactions between gelatin and chitosan was good for the mechanical properties of composite films.

Production of Micro Crystalline Cellulose from Tapioca Solid Waste: Effect of Acid Concentration on its Physico-chemical Properties

2020 ◽  
Vol 23 (5) ◽  
pp. 147-151
Author(s):  
Ansharullah Ansharullah ◽  
Nur Muhammad Abdillah Saenuddin ◽  
RH Fitri Faradilla ◽  
Asranuddin Asranudin ◽  
Asniar Asniar ◽  
...  
Keyword(s):  
Solid Waste ◽  
Water Solubility ◽  
Chemical Properties ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Crystalline Cellulose ◽  
Cellulose Content ◽  
X Ray Diffraction ◽  
Physico Chemical ◽  
Ft Ir

This study was aimed to examine the production of microcrystalline cellulose (MCC) from tapioca solid waste (TSW), using HCl hydrolysis with various concentrations, i.e., 2 N, 2.5 N, 3 N, and 3.5 N. MCC was produced by delignifying the TSW with NaOH 20%, and bleaching with NaOCl 3.5% to produce α-cellulose, and subsequently hydrolyzing α-cellulose with three different HCl concentrations to produce MCC. The physicochemical properties of MCC were then analyzed, including Scanning Electron Micrograph (SEM), X-ray diffraction (XRD), and FTIR spectra. The results showed that hydrolysis with 2.0 N HCl resulted in a higher yield of 61.28%, α-cellulose content of 56.33%, moisture 6.25%, pH of 6.54; ash 0.23%, and water solubility 0.34%. SEM analysis showed the morphology and size of the MCC produced were like those of a commercial MCC (Avicel PH101), while the XRD analysis showed the higher concentration of HCl gave rise to an increased crystalline index. FT-IR spectrum analysis indicated that TSW, MCC produced, and commercial MCC had similar functional groups.

scholarly journals Paeonol-Loaded Ethosomes as Transdermal Delivery Carriers: Design, Preparation and Evaluation

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1756 ◽  
Author(s):  
Hongdan Ma ◽  
Dongyan Guo ◽  
Yu Fan ◽  
Jing Wang ◽  
Jiangxue Cheng ◽  
...  
Keyword(s):  
Transdermal Delivery ◽  
Water Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Ir Studies ◽  
Transmission Electron ◽  
Wide Range ◽  
Ft Ir ◽  
Poor Stability

Paeonol exhibits a wide range of pharmacological activities, such as anti-inflammatory, antidiabetic as well as pain-relieving activities. However, its intrinsic properties, such as low water solubility, poor stability and low oral bioavailability, restrict its clinical application. The current study aimed to optimize paeonol-loaded ethosomal formulation and characterize it in terms of encapsulation efficiency (EE), vesicle size (VS), zeta potential (ZP) and polydispersity index (PDI), in addition to differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) studies. Here, paeonol-loaded ethosomes were prepared by the injection method and optimized by the single-factor test and central composite design-response surface methodology. The optimized paeonol-loaded ethosomes had an EE of 84.33 ± 1.34%, VS of 120.2 ± 1.3 nm, negative charge of −16.8 ± 0.36 mV, and PDI of 0.131 ± 0.006. Ethosomes showed a spherical morphology under the transmission electron microscope (TEM). DSC, XRD and FT-IR results indicated that paeonol was successfully incorporated into the ethosomes. In-vitro transdermal absorption and skin retention of paeonol from paeonol-loaded ethosomes were 138.58 ± 9.60 µg/cm2 and 52.60 ± 7.90 µg/cm2, respectively. With reasonable skin tolerance, ethosomes could be a promising vehicle for transdermal delivery of paeonol.

scholarly journals PREPARATION OF ACYCLOVIR-ISONICOTINAMIDE COCRYSTAL BY SOLVENT EVAPORATION METHOD WITH METHANOL AND ISOPROPANOL

2020 ◽  
Vol 21 (3) ◽  
pp. 109
Author(s):  
Agnes Nuniek Winantari ◽  
Roisah Nawatila ◽  
Cecilia Jocelyn
Keyword(s):  
Herpes Simplex ◽  
Water Solubility ◽  
Parent Drug ◽  
Solvent Evaporation ◽  
Synthetic Analog ◽  
Solvent Evaporation Method ◽  
Evaporation Method ◽  
Varicella Zoster ◽  
Ft Ir ◽  
Simplex Virus

PREPARATION OF ACYCLOVIR-ISONICOTINAMIDE COCRYSTAL BY SOLVENT EVAPORATION METHOD WITH METHANOL AND ISOPROPANOL. Acyclovir is a nucleoside synthetic analog antiviral group used in the treatment of Herpes simplex virus (HSV-1 & HSV-2) and Varicella zoster virus (VZV). Acyclovir has low water solubility, so it needs to be modified in the form of cocrystal with isonicotinamide. This study aims to obtain the physical characteristics produced by acyclovir-isonicotinamide cocrystal (1:1) made through the solvent evaporation method with methanol and isopropanol. The crystalline formed is characterized by DSC, PXRD, FT-IR and SEM. The characterization results showed the presence of new crystals that formed between acyclovir-isonicotinamide in methanol and isopropanol solvents. Thermograms showed sharp exothermic peaks at 183.31°C and 186.24°C. The diffractogram showed a new peak at 2θ = 5.19 and 5.82. The spectrum showed a shift in wavelength in the cocrystal formed. The cocrystal has a different morphology compared with parent drug and coformer on analysis using SEM. This research shows that acyclovir can form cocrystal with isonicotinamide by solvent evaporation method with methanol and isopropanol.

scholarly journals Mechanochemical Synthesis and Physicochemical Characterization of Previously Unreported Praziquantel Solvates with 2-Pyrrolidone and Acetic Acid

Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1606
Author(s):  
Debora Zanolla ◽  
Lara Gigli ◽  
Dritan Hasa ◽  
Michele R. Chierotti ◽  
Mihails Arhangelskis ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Pxrd Pattern ◽  
Intrinsic Dissolution ◽  
Ft Ir ◽  
Biopharmaceutical Properties

Two new solvates of the widely used anthelminthic Praziquantel (PZQ) were obtained through mechanochemical screening with different liquid additives. Specifically, 2-pyrrolidone and acetic acid gave solvates with 1:1 stoichiometry (PZQ-AA and PZQ-2P, respectively). A wide-ranging characterization of the new solid forms was carried out by means of powder X-ray diffraction, differential scanning calorimetry, FT-IR, solid-state NMR and biopharmaceutical analyses (solubility and intrinsic dissolution studies). Besides, the crystal structures of the two new solvates were solved from their Synchrotron-PXRD pattern: the solvates are isostructural, with equivalent triclinic packing. In both structures acetic acid and 2-pyrrolidone showed a strong interaction with the PZQ molecule via hydrogen bond. Even though previous studies have shown that PZQ is conformationally flexible, the same syn conformation as the PZQ Form A of the C=O groups of the piperazinone-cyclohexylcarbonyl segment is involved in these two new solid forms. In terms of biopharmaceutical properties, PZQ-AA and PZQ-2P exhibited water solubility and intrinsic dissolution rate much greater than those of anhydrous Form A.

β-lactam Functionalized Poly(isoprene-b-ethylene oxide) Amphiphilic Block Copolymer Micelles as a New Nanocarrier System for Curcumin

2010 ◽  
Vol 6 (3) ◽  
pp. 277-284 ◽  
Author(s):  
Konstantinos Gardikis ◽  
Konstantinos Dimas ◽  
Aristidis Georgopoulos ◽  
Eleni Kaditi ◽  
Stergios Pispas ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Ethylene Oxide ◽  
Amphiphilic Block Copolymer ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

Donnan Equilibria in Polymeric Micellar Systems with Weak Polyelectrolyte Shells: The Lowering of the pH Value

1997 ◽  
Vol 62 (11) ◽  
pp. 1730-1736 ◽  
Author(s):  
Petr Munk ◽  
Zdeněk Tuzar ◽  
Karel Procházka
Keyword(s):  
Ionic Strength ◽  
Block Copolymer ◽  
Ph Value ◽  
Electrolyte Solutions ◽  
Hydrogen Ions ◽  
Micellar Systems ◽  
Weak Electrolytes ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Polyelectrolyte Solutions

When two electrolyte solutions are separated and only some of the ions can cross the boundary, the concentrations of these ions are different on both sides of the boundary. This is the well-known Donnan effect. When weak electrolytes are involved, the imbalance includes also hydrogen ions: there is a difference of pH across the boundary and the dissociation of nondiffusible weak electrolytes is suppressed. The effect is very pronounced when the concentration of the weak electrolyte is high and ionic strength is low. The significance of this phenomenon is discussed for polyelectrolyte solutions, and particularly for block copolymer micelles with weak polyelectrolyte shells. The effect is quite dramatic in the latter case.

A Monte Carlo Study of Flexible Polymer Chain Conformations in Restricted Volumes. I. A Model for Insoluble Blocks Conformations in Swollen Cores of Multimolecular Spherical Block Copolymer Micelles

1993 ◽  
Vol 58 (10) ◽  
pp. 2290-2304 ◽  
Author(s):  
Zuzana Limpouchová ◽  
Karel Procházka
Keyword(s):  
Monte Carlo ◽  
Block Copolymer ◽  
Monte Carlo Study ◽  
Volume Effect ◽  
Micellar Systems ◽  
Flexible Polymer ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Chain Conformations ◽  
Chain Lengths

Monte Carlo simulations of chain conformations in a restricted spherical volume at relatively high densities of segments were performed for various numbers of chains, N, and chain lengths (number of segments), L, on a tetrahedral lattice. All chains are randomly end-tethered to the surface of the sphere. A relatively uniform surface density of the tethered ends is guaranteed in our simulations. A simultaneous self-avoiding walk of all chains creates starting conformations for a subsequent equilibration. A modified algorithm similar to that of Siepmann and Frenkel is used for the equilibration of the chain conformations. In this paper, only a geometrical excluded volume effect of segments is considered. Various structural and conformational characteristics, e.g. segment densities gS(r), free end densities gF(r) as functions of the position in the sphere (a distance from the center), distributions of the tethered-to-free end distances, ρTF(rTF), etc. are calculated and their physical meaning is discussed. The model is suitable for studies of chain conformations is swollen cores of multimolecular block copolymer micelles and for interpretation of non-radiative excitation energy migration in polymeric micellar systems.

Study of Sedimentation Velocity of Block Copolymer Micelles

1993 ◽  
Vol 58 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Minmin Tian ◽  
C. Ramireddy ◽  
Stephen E. Webber ◽  
Petr Munk
Keyword(s):  
Block Copolymer ◽  
Methacrylic Acid ◽  
Mixed Solvent ◽  
Hard Spheres ◽  
Sedimentation Velocity ◽  
Hydrodynamic Coefficient ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Size Heterogeneity ◽  
Good Agreement

No anomalies were observed during the measurement of sedimentation coefficients of block copolymer micelles formed by copolymers of styrene and methacrylic acid in a mixed solvent; 80 vol.% of dioxane and 20 vol.% of water. The shapes of the sedimenting boundaries suggest that the size heterogeneity of the micelles is small. Linear relations between 1/s and c were obtained. The value of the hydrodynamic coefficient κ was between 2 and 4 in a good agreement with the value 2.75 or 2.86 that was obtained by combining Burgers' or Fixman's values of the coefficient of the concentration dependence kvs for hard spheres with Einstein's value of [η] for spheres.

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