Solubility In Distilled Water Research Articles

The effects of ascorbic acid and tartaric acid on pioglitazone hydrochloride solubility

ABSTRACT Application of two coformers, l-tartaric acid (TA) and ascorbic acid (AA) was evaluated on the solubility of pioglitazone hydrochloride (PGZ.HCl). Solid dispersions were prepared using the solvent evaporation method. Drug solubility was evaluated in bio-relevant media and the results were compared to the physical mixtures (PM) of the drug + coformer, and the pure drug. Physicochemical characterisation of the developed products was characterised using Fourier transformation-infrared spectroscopy (FT-IR), Differential scanning calorimeter (DSC), and X-ray powder diffractometry (XPRD). Physical mixtures of PGZ-AA (PM) were able to enhance drug solubility to the same extent as the solvent evaporation method (PGZ-AA). This indicates that the preparation process has little effect on drug solubility. Up to 7-fold enhancement was observed for drug solubility in distilled water and buffer pH 1.2. Physical mixtures seem more feasible method to significantly enhance drug solubility without the need to use toxic solvents and time-consuming evaporation methods.

ZnO and Fe2TiO5 nanoparticles obtained by green synthesis as active components of alginate food packaging films

The aim of this study was to develop an active alginate packaging film incorporating antioxidant Fe2TiO5 and antibacterial ZnO nanoparticles, obtained by green synthesis utilizing citrus peel waste. The average particle size was estimated as 10 nm for ZnO and 50 nm for Fe2TiO5. Films were prepared using 2.33% (w/v) sodium alginate with 0.11% (w/v) Fe2TiO5 and/or ZnO nanoparticles. The inclusion of nanoparticles resulted in a noticeable colour difference, reduced the transparency, increased UV light protection and improved thermal stability of the film. The dry matter content of the films was around 83%. Film solubility in distilled water was low (< 8%) mainly reflecting crosslinking of the alginate polymer and Ca2+-ions. The lowest swelling degree was obtained for the ZnO/Fe2TiO5 –alginate film (178%). The efficiency of these packaging films was demonstrated through preservation of strawberry freshness. Alginate packaging film with a mixture of metal oxide nanoparticles can facilitate food safety and increase food shelf life.

Effect of Dextrose Cross-Linked Glutaraldehyde Hydrogel on Wound Healing Activity

ABSTRACT Dextrose cross-linked glutaraldehyde hydrogels are effective and promising drug delivery candidates. The addition of chitosan with dextrose resulted in the polymerization of material which resulted in the production of a gel-like structure that was highly viscous and had gelling properties. A swelling and absorption assay was conducted on the hydrogel. The dextrose cross-linked hydrogel has a higher absorption potential for distilled water followed by PBS and the least absorption was observed in the ethanol. Dextrose cross-linked hydrogel favors solubility in distilled water as compared to other solvents. The amoxicillin release by the dextrose cross-linked hydrogel was then tested. The result from drug release demonstrates that the dextrose cross-linked hydrogel released more than 55% of the amoxicillin in 2 hours and the remaining portion of the drug remaining. Therefore, it has a slow drug-release property, and it can be used for further wound-healing studies.

Structure and properties of sulfopropyl chitins prepared in NaOH/urea aqueous solutions

A series of sulfopropyl chitins (SCs) with the degree of substitution (DS) ranging from 0.11 to 0.40 and high degree of acetylation (DA ≥ 0.82) were homogeneously synthesized by reacting chitin with sodium 3-chloro-2-hydroxypropanesulfonate (SCHPS) in NaOH/urea aqueous solutions under mild conditions. The structure and properties of SCs were characterized with 1H NMR, CP/MAS 13C NMR, FT-IR, XPS, XRD, elemental analysis, GPC, AFM, ζ-potential and rheological measurements. The mild reaction conditions resulted in less N-deacetylation and uniform structures with substitution occurring predominantly at the hydroxyl groups at C6 of the chitin backbone. The DS value for SC soluble in dilute alkali solution is as low as 0.16. SC exhibited good solubility in distilled water when its DS value reached 0.28. Water-soluble SCs self-assembled in water into micelles by the attractive hydrophobic and hydrogen-bonding interactions between polymer chains. The water-insoluble SC-2 with lower DS could thermally form smart hydrogels at body temperature (37 °C) in physiological condition. Moreover, the SCs exhibited good biocompatibility, making them suitable for biomedical applications.

Effect of Three Different Liquid Medias in the Sorption and Solubility of Luting Cements: An In Vitro Study.

Background Among the various mechanical and biological properties of luting cement, the most important are its resistance to disintegration, degradation, and stability in the oral cavity. The sorption and solubility of cement alter the mechanical properties by impeding the half-life of the filling. It also leads to variations in dimensions, discoloration, and margin breakage. It is, therefore, essential to choose a low-solubility cement since there is always an interaction between teeth and restorative margins. The aim of this study is to assess and compare the solubility and sorption values of three different luting cements in three liquid media. Materials and methods Three luting cements were used for the investigation. Disc-shaped specimens of the cement, which were of 10 mm diameter and 2 mm height, were prepared. The sample included a total of 126 disc-shaped specimens made up of three materials,glass ionomer cement (GIC), resin cement, and resin-modified GIC, which were used in three liquid media (14 of each material in each medium). Fourteen specimens of each material were placed in glass vials containing 20 ml of each medium: distilled water, artificial saliva, and carbonated water. The samples were then put in an incubator at 37 °C. The measurements and masses of the samples were documented on days one, three, seven, 14, 21, 28, and 35. The samples were taken out of the solution after five weeks and stored in a desiccator with calcium sulphate for another five weeks. The weight and dimensional changes were estimated on days one, three, seven, 14, 21, 28, and 35. The values of water sorption (WSO) and solubility (WSL) were estimated. To determine the mean and standard deviation of each cohort, descriptive statistics were employed. Utilizing the Shapiro-Wilkinson test, the normality was determined. An independent test was used to determine the difference between all pairs of groups, while one-way ANOVA, Dunn test, and post hoc analysis were used to establish the distinction between the three groups. Results One-way ANOVA showed that significant differences existed among the groups: resin cement showed the least sorption and solubility, resin-modified GIC showed the highest solubility in distilled water (0.40 ± 0.03), and GIC showed the highest solubility in both artificial saliva (0.36 ± 0.03) and carbonated water (0.04 ± 0.05). Conclusion Considering the experimental outcomes and the limitations of an in vitro investigation, it was concluded that in the complex setting of the oral environment, this selection procedure is crucial for maintaining mechanical strength and for the long lifespan of dental restorations.

DOUBLE SOLUBILITY OF KEROGEN AND CARBONATES FROM TARFAYA OIL SHALE (MOROCCO) BY POTABLE WATER, DISTILLED WATER OR SEAWATER FROM THE ATLANTIC OCEAN

The solubility of the materials contained in oil shale has often been questioned. Ordinary water coming directly from purification stations or partially distilled water are of primary interest in the energy industry for exploitation or research. Similarly, given that a large proportion of the Tarfaya oil shale is immersed in the Atlantic Ocean, we thought it would be interesting to study the effect of these types of water on the solubility of kerogen under physical conditions of moderate temperature. Ultra-violet and infra-red spectroscopy was used in this work. As the identification energy of the ultraviolet is fairly high compared with the infrared and visible. We were able to follow the evolution of heavy matter from kerogen. The effect of temperature was also highlighted. Spectroscopic identification uses radiation of varying energies depending on the compounds to be detected. For example, for infrared, the energy used to identify substituted unsaturated aliphatic is higher than that used to identify substituted unsaturated monocyclic. As far as our work is concerned, the energy used for identification by UV is sufficiently higher than that for infrared, which means that the compounds to be detected from oil shale can only be heavy hydrocarbons (branched and multisubstituted unsaturated aliphatic chains). Similarly, supercritical fluid extraction using water and other solvents such as toluene is often used to determine the different fractions of organic compounds in oil shale. We are going to use three analytical methods to highlight this solubility in seawater (subsequently the solubility in distilled water), which are ultra-violet spectroscopy, infra-red spectroscopy and the determination of carbonates (mineral matter) by complexometry.

4-methyl-4-[2-(naphthalene)-2-oxoethyl] morpholin-4-ium iodide as a water soluble photoinitiator

Quaternary ammonium salt namely 4-methyl-4-[2-(naphthalen-2-yl)-2-oxoethyl] morpholin-4-ium iodide (WSMPM) was synthesized and characterized. High molar absorptivity at 347 nm (1910 L･mol-1･cm-1) and good solubility in distilled water (10-2 M) allows WSMPM to be used as an effective photoinitiator also in water-soluble systems. Photopolymerization of acrylamide monomer with WSMPM (10-3 M) and a tertiary amine (N-methyldiethanolamine), resulted in 84.4% monomer to polymer conversion. Based on laser photolysis and electron spin resonance, a photoinitiator mechanism was proposed.

Factorial Design for the Optimization of Clindamycin HCl-Loaded Ethosome with various concentrations of Phospholipon 90g and Ethanol

Clindamycin HCl is a drug for the treatment of acne. Clindamycin can act as an anti-acne by interfering with bacterial protein synthesis. The concentration of clindamycin used in the treatment of acne is 1%. Still, the bioavailability of the drug in the serum only reaches 0.7 – 12.4% of the total active substance in the preparation, so it is necessary to develop preparations that can increase the bioavailability of the drug Clindamycin HCl, one of which is in the form of ethosomes. This study aimed to optimize the clindamycin HCl loaded ethosomes formula with variations in the concentration of Phospholipon 90G and ethanol using the 22 factorial design method to obtain four formulas. The concentrations of phospholipon 90G used were 2% and 4%, while ethanol was 20% and 40%, respectively. Ethosomes were prepared using the thin layer hydration method and characterized by percent entrapment efficiency (%EE), particle size, and polydispersity index to determine the optimum formula. Based on the factorial design analysis results, the concentration of Phosholipon 90G, ethanol, and their two interactions significantly affected the value of entrapment efficiency, particle size, and polydispersity index with p&lt;0.05. The optimum formula was obtained using 2% phospolipon 90G and 40% ethanol with an entrapment efficiency of 98.31±0.06, a particle size of 179.6±8.6nm, and a polydispersity index of 0.361±0.015. The optimum formula also showed good solubility in distilled water and acid solvents and good physical stability.

Chemical and Structural Assessment of New Dental Composites with Graphene Exposed to Staining Agents.

Among the newest trends in dental composites is the use of graphene oxide (GO) nanoparticles to assure better cohesion of the composite and superior properties. Our research used GO to enhance several hydroxyapatite (HA) nanofiller distribution and cohesion in three experimental composites CC, GS, GZ exposed to coffee and red wine staining environments. The presence of silane A-174 on the filler surface was evidenced by FT-IR spectroscopy. Experimental composites were characterized through color stability after 30 days of staining in red wine and coffee, sorption and solubility in distilled water and artificial saliva. Surface properties were measured by optical profilometry and scanning electron microscopy, respectively, and antibacterial properties wer e assessed against Staphylococcus aureus and Escherichia coli. A colour stability test revealed the best results for GS, followed by GZ, with less stability for CC. Topographical and morphological aspects revealed a synergism between GZ sample nanofiller components that conducted to the lower surface roughness, with less in the GS sample. However, surface roughness variation due to the stain was affected less than colour stability at the macroscopic level. Antibacterial testing revealed good effect against Staphylococcus aureus and a moderate effect against Escherichia coli.

Effects of pH and Ionic Salts on the Emulsifying and Rheological Properties of Acorn Protein Isolate.

This study was designed to evaluate the emulsifying and rheological properties of acorn protein isolate (API) in different pH mediums (pH 3, 7 and 9) and in the presence of ionic salts (1 M NaCl and 1 M CaCl2). API shows higher solubility in distilled water at pH 7, while at the same pH, a decrease in solubility was observed for API in the presence of CaCl2 (61.30%). A lower emulsifying activity index (EAI), lower stability index (ESI), larger droplet sizes and slight flocculation were observed for API in the presence of salts at different pHs. Importantly, CaCl2 treated samples showed relevantly higher EAI (252.67 m2/g) and ESI (152.67 min) values at all pH as compared to NaCl (221.76 m2/g), (111.82 min), respectively. A significant increase in interfacial protein concentration (4.61 mg/m2) was observed for emulsion at pH 9 with CaCl2, while the major fractions of API were observed in an interfacial layer after SDS-PAGE analysis. All of the emulsion shows shear thinning behavior (τc > 0 and n < 1), while the highest viscosity was observed for emulsion prepared with CaCl2 at pH 3 (11.03 ± 1.62). In conclusion, API, in the presence of ionic salts at acidic, neutral and basic pH, can produce natural emulsions, which could be substitutes for synthetic surfactants for such formulations.

Physico Chemical Analysis of Shilajatu (Shodhita, Marita and Satwapathita)

Shilajatu analysis is conducted as it is rare, controversial and herbo mineral drug. Conventional literature reveals that only Shodana is sufficient enough and no need to go for further processes like Marana and Satwapatana. Unlike Rasaratna samuchhaya, the need for research on physical and chemical properties of Shilajatu is essential and unavoidable. Shilajatu is mineral pitch found in Himalaya rocks as exudations in the form of resin, hence the name Shilajatu. The works focuses on physical and chemical components present in four different forms of Shilajatu in the form of Raw, Shodhita, Marita, Satwapatita. The study is undertaken to assess organoleptic characters, pH, specific gravity, ash value, percentage of acid insoluble ash value and % of water soluble ash, moisture content, solubility in distilled water, and % of solubility. Now a day’s stressful lifestyle, unhealthy diet, polluted environment, extremely pressurized work culture have created havoc among people affecting their physical and mental health leading to Medho vridhi vikaras (Hyperlipidemia). Shilajatu when used with proper Anupana can cure many diseases as said in Charaka chikitsa stana. Analytical study reveals presence of Elements like K, Ca, O, Cl, S, Na, Mg, Si, Al, Pb and oxides like K2O, CaO, SO3, MgO, Na2O, Al2O3, SiO3, P2O5, PbO, CuO, Cl in all the samples. Phytochemicals flavonoids, tannins, steroids triterpenoids, saponin, proteins were present in raw and Shodhita shilajatu.

Chemical and enzymatic destruction of chondroitin sulfate from Arctic skate

Due to its biocompatibility with human and animal tissues, low toxicity, and biodegradability, chondroitin sulfate (CS) is of great interest for medicine. Since CS is used as a pharmaceutical preparation, its molecular weight and solubility determine the possibilities of its use. This work presents the results of studying the chemical and enzymatic destruction of CS macromolecules and its effect on the molecular weight, solubility and crystallinity degree of the polysaccharide. CS was obtained from the cartilaginous tissue of the Arctic skate ( Amblyraja hyperborea ). At the stage of cartilage tissue fermentolysis, the enzymes pancreatin, hepatopancreatin and protosubtil were used. The obtained CS samples were identified by IR spectroscopy. Enzymatic destruction of glycosidic bonds in cholesterol macromolecules was carried out with a 1 % solution of the enzyme hepatopancreatin, chemical destruction with hydrogen peroxide and hydrochloric acid. The CS content in the samples was determined by the Dische method. The chemical composition of CS samples was evaluated by standard methods. The average molecular weight (MW) was determined using high performance liquid chromatography and the nephelometric method. The crystallinity degree (CD) was determined by graphical processing of diffraction patterns obtained by X-ray phase analysis of CS samples. It was found that under the action of hepatopancreatin and hydrogen peroxide, deep destruction of chondroitin sulfate occurs, to the formation of low molecular weight and oligomeric fragments. Under conditions of acid destruction in 0.5 N HCl for 20 min the MW of chondroitin sulfate is reduced by 10 % compared to the initial one. Acid destruction causes a significant decrease in the CD of the CS samples. For CS samples not degraded in acid, the solubility in distilled water increases with decreasing MW and CD. The solubility of CS after acid destruction in the range of pH = 5-9 units is 99.0 ± 0.5 %. This high solubility is most likely explained by the significant content of the amorphous phase in the samples.

FORMULATION OPTIMIZATION AND CHARACTERIZATION OF AQUEOUS INJECTION CONTAINING POORLY SOLUBLE DRUG USING MIXED HYDROTROPIC SOLUBILIZATION

Objective: Mefenamic acid (MFA) is an NSAID that exhibits anti-inflammatory analgesic and antipyretic activity. Peak plasma levels are attained in 2-4 h and the elimination half-life approximates 2 h, repetitive administration of tablets for 3-5 times a day is desired. It is supplied only in the form of tablets for oral administration. In acute conditions drug administered parenterally could give rapid relief from severe symptoms like pain. Thus, formulation of injectable formulation of MFA could be better alternative compared to conventional tablet dosage form. The low aqueous solubility of MFA precludes its use in parenteral formulation development.&#x0D; Methods: In this work attempt were made to enhance the aqueous solubility of mefenamic acid using mixed solvency technique. For that different hydrotropic agents such as Urea, Sodium acetate, sodium benzoate, sodium citrate and their blends were evaluated. Optimal concentration of hydrotropic agent in blend was determined using D-optimal mixture experimental design. The optimized bled was used to develop the aqueous injection of mefenamic acid. The developed injection was subjected for various quality control tests and stability of developed formulation was also evaluated.&#x0D; Results: The aqueous solubility in optimized blend of hydrotropic agent batches (U: SA: SB: SC, 4:4:23:9 %w/v) showed 835.71-fold compared to MFA solubility in distilled water. The quality control tests for parenteral formulation and accelerated stability study were found to be within prescribed limits and stable.&#x0D; Conclusion: The inadequate solubility of MFA was overcome, and aqueous injection was successfully developed which can be serve as cost effective treatment in various indications.

Assessment of Physicochemical Properties and Mineral Compositions of Almond (Prunus amygdalus) Gum of Libyan Origin

Twenty-five authentic samples of Prunus amygdalus gum samples were collected from five different locations in northwest of Libya. Different physicochemical methods were used to characterize this type of gum samples. The mean values of the moisture ranged from 12.55 to 14.93%, ash mean values 4.03 to 4.62%, pH 3.89 to 4.40, W.H.C 52.85 to 60.0%, and O.H.C 136.2 to 156.3%. Solubility of Prunus amygdalus gum showed that it had low solubility in distilled water with the mean values ranged from 20.01 to 35.40%, but it dissolved perfectly in alkali media where solubility increased to 96.3% in 0.05 M Na2CO3. The study exhibited that the mean values of cationic concentration in %(w/w) such as calcium was ranged from 0.552 to 0.585, potassium 0.402 to 0.505, iron 0.0975 to 0.1125, and sodium 0.064 to 0.079, which indicates that Ca has the highest concentration of metallic ions present. Atomic absorption method indicate that all samples contain traces of elements, Li, Cr, Mn, Ni, Zn, Pb, Hg, and Cd. The main functional groups recorded from FTIR spectrum included bands at 3293 cm-1 (O-H in carboxylic group), 1601.77 cm-1 (C=O, amide N-H bend, and C=C), 1357.53 cm-1 (CH3-, and C-O-H in- plane bending vibration), and 1025.74 cm-1 (C-O stretching).

Synthesis, Structural Elucidation and Antimicrobial Activity of Metal (II) Polypyridyl Complexes of 2-Amino-4-(Methylthio) Butanoic Acid

The interaction of selected biometals with dinitrogen donor ligand, 1,10-phennathroline (phen) and amino acid, 2-amino-4-(methylthio)butanoic acid (methionine; met) resulted in isolation of three mononuclear complexes. The prepared complexes were characterized by diverse techniques including elemental and spectroscopic analysis. From the analytical and spectral data, octahedral geometry was proposed to the synthesized metal (II) complexes. Bonding of the metal ion through N- and O- donor atoms of the ligands is revealed by infrared studies. The compounds showed moderate solubility in distilled water and in some common organic solvents. In vivo evaluation of the antimicrobial activities of the metal complexes showed improved inhibitory activity against some micro-organisms as compared to the ligands, with Co(II) and Cu(II) complexes showing the highest activities against the fungi.

Characterization of Bio-active Compounds Essential for Blood Coagulation in the Crude Extracts of Tradescantia zebrina, Tagetes minuta and Codiaeum variegatum Leaves

Aims: Many commercial drugs used for blood clotting are expensive and have associated side-effects. The extracts of Tagetes minuta, Codieum variegatum and Tradescantia zebrine are used for blood clotting. These extracts are highly efficient and have no known side-effects. This study aimed at characterizing crude extracts of these plant species used to accelerate blood clotting.&#x0D; Study Design: An independent measures experimental design was used in the study.&#x0D; Place and duration of study: The research was conducted between 21st September, 2018 and 21st May, 2019. The study was conducted in Maasai mara university, Kenya and Multimedia university of Kenya.&#x0D; Methodology: Extracts of these herbs were obtained and analyzed for absorption bands, functional groups, bio-metal concentrations, physical-chemical parameters, phytochemicals and antimicrobial activity. Test for blood clotting factors (calcium and vitamin K) was also conducted.&#x0D; Results: All extracts had common functional group peaks at 2800-3500 cm-1 (carboxylic OH), 1680 cm-1 (carbonyl), and 1035cm-1 (C-Ostretch). The extracts had an average pH of 6.59 0.702 and conductivity of 0.58 0.079mS. The average solubility in distilled water was 16.67 1.534 g/100 ml water at 37°C. The extracts were found to be abundant in iron, copper and phytochemicals. All extracts portrayed moderate inhibition to E. coli bacteria and C. albicans fungi but mild inhibition towards S. aureus bacteria. The extracts had trace amounts of Vitamin K and moderate amounts of calcium.

In Ukrainian

The aim of the research is the development of compositions and technology for obtaining bioactive glass-ceramic calcium phosphate-silicate coatings on titanium for dental prosthetics, to find the relationship between the structural parameters of the calcium phosphate-silicate coatings surface on titanium with their bioactivity. The structure of the material was studied by means of petrographic analysis (microscope Mi-2e) and X-ray phase analysis (DRON-3M). Solubility and bioactivity of coatings were evaluated in solutions: distilled water (GOST R 31576-2012), SBF (ISO 23317:2012), 10 % albumin solution. The surface free energy was determined by the Owens-Wendet-Rebel-Kaebel method. The surface microrelief of the coatings was assessed by the mean arithmetic deviation of the profile Ra (Surtronic 3+ profilometer). The surface layer structure was investigated by X-ray fluorescence (SPRUT spectrometer-analyzer) and X-ray spectral (PEM Tesla 3 LMU + oxygen spectrometer Oxford X-max 80 mm) methods. The behavior of stem cells on the coatings surface was investigated by fluorescence microscopy (Carl Zeiss Axio Observer Z1). Criteria were selected of model glass synthesis and the model glasses were melted. Glass-ceramic coatings for titanium were applied by slip technology and synthesized under conditions of short-term low-temperature heat treatment. It has been found that the model glasses, after heat treatment, are characterized by behaviour of a volumetric fine-disperced (crystals ≤ 1 μm) crystallization of calcium phosphate - HAP and FAP (Σ ≈ 24÷44 % by volume). The possibility of spontaneous adsorption of proteins on the coatings surface has been confirmed due to the provision of coating parameters: SEM ≈ 65 mJ/m 2 , R a ≈ 3.5 μm and the presence of through pores with a diameter of 10÷100 μm. The changes in the structure and composition of the coatings surface after ageing in SBF have been studied for 1 month period. It has been found that the provision for these model glasses of a set of indicators, namely: solubility in distilled water (30 days) - 0.89 wt. %; ion yield of Ca 2+ is 0.26 wt. % and groups [PO 4 ] 3 – -0.162 wt. %, pH ~ 7.3, is sufficient for the formation of precursors of hydroxyapatite on the coatings surface in vitro. Gradual displacement (build-up) of the coatings surface layers (due to the dissolution of the coating and deposition of the SBF components) was found within the boundaries up to 6.7 μm and the apatite-like layer was formed in 28 days of soaking. These structural and chemical transformations of the surface of glass-ceramic coating form a durable apatite-like layer for 35 days period under in vitro conditions. The formation of this layer creates conditions for increasing the area of mesenchymal stem cell spacing on the coatings surface and allows their use in the creation of bioengineering design with stem cells (in vivo).

EVALUATING THE BEST POLYETHYLENE GLYCOL AS SOLID DISPERSION CARRIER BY TAKING ETORICOXIB AS A MODEL DRUG

Objective: The main objective of the current research is focused in discovering the best polyethylene glycol (PEG) as solid dispersion carrier using etoricoxib (ECB) as a model drug.&#x0D; Methods: Varieties of PEG, namely PEG - 3350, PEG - 4000, PEG - 6000, PEG - 8000, and PEG - 20000, were evaluated as a carrier for making ECB solid dispersions. ECB:PEG was taken in the ratios of 1:1, 1:2, 1:4, and 1:6. The solid dispersions were prepared by microwave fusion method and compressed using 8 station tablet compression machine. The fabricated solid dispersion tablets were tested for physicochemical characteristics and drug release rates. The release of ECB from the prepared solid dispersions was further analyzed kinetically using the first order and Hixson-Crowell’s plots.&#x0D; Results: All the solid dispersion batches were shown satisfactory physicochemical characteristics. ECB solid dispersion batches with PEG - 6000 showed good solubility in distilled water (up to 2.29±0.01 μg/ml) and in 0.1 N HCl (up to 2.18±0.01 μg/ml) when compared with ECB alone (0.21±0.01 μg/ml and 0.32±0.01 μg/ml). The prepared solid dispersions with PEG 6000 are shown good ECB release.&#x0D; Conclusion: Among PEG carriers, PEG - 6000 was found to be the best carrier for increasing the solubility and release rate of ECB form the solid dispersions compared to PEG - 3350, PEG - 4000, PEG - 8000, and PEG - 20000.

A comparative study of the physicochemical properties of hesperidin, MTA-Angelus and calcium hydroxide as pulp capping materials

AimThis study compared the setting time, radiopacity, solubility and pH changes between Hisperidin cement, MTA-Angelus and Calcium hydroxide cements. MethodsThe study was conducted on 3 equal groups of samples of the evaluated capping materials including; Hisperidin (group I, N = 24), MTA-Angelus (group II, N = 24) and Dycal (group III, N = 24). According to the assessed property, these groups were further subdivided into three equal subgroups (8 samples each) including; subgroup A for assessment of the setting time, subgroup B for assessment of radiopacity and subgroup C for assessment of the solubility of the material and evaluation of pH. All recorded data were tabulated and statistically analyzed. ResultsThe highest mean value of setting time was for the MTA-Angelus followed by Hesperidin and Calcium hydroxide with 72.83, 48.26 and 1.58 min, respectively. MTA-Angelus had the highest radiopacity value and followed by Calcium hydroxide then Hesperidin. Hesperidin showed the solubility in distilled water (≈45% mass loss) in relation to Calcium hydroxide (≈19% mass loss). On the other hand, MTA-Angelus showed 9% increase in weight. On contrast to MTA and Calcium hydroxide, Hesperidin showed decrease in pH value throughout the evaluation periods. Higher pH values in MTA-Angelus and Calcium hydroxide were reported in comparison with Hesperidin. ConclusionDespite its slight acidic nature, lower radiopacity and longer initial setting time, Hesperidin, as a natural product, is a promising pulp capping material. Further research on Hesperidin powder is recommended to improve its physicochemical properties and to assess its biological actions.

Calcium phosphates recovery from digester supernatant by fast precipitation and recrystallization

Conditional solubility of dicalcium phosphate dihydrate (DCPD) and hydroxyapatite (HAp) in digester supernatant was determined as a function of pH and was compared to its conditional solubility in distilled water. Conditional solubility of both substances in digester supernatant at pH >5–6 was higher than their conditional solubility in pure water due to the presence of impurities, and this influence is more significant for HAp. Amorphous CaP was precipitated through a fast precipitation process from digester supernatant with initial total phosphate concentration 0.008 mol/L and 0.015 mol/L and Ca/P ratios 2 and 5. The amorphous CaP can be subsequently recrystallized into crystalline CaP. Obtained amorphous products have Ca/P ratio > 1, which allow performing the recrystallization process without further Ca dosing into the system. Batch recrystallization of the amorphous products resulted in crystallization of HAp, DCPD or their mixture depending on the conditions of the process. Maximum achieved P-recovery was 69.5%. The increase of phosphate concentration and the addition of seeding decreased the yield of the process but promoted crystallization of DCPD. The increase of Ca/P ratio had a positive effect on the total P-recovery. Compared with the direct batch crystallization of CaP from digester supernatant, the two-step process with fast precipitation and recrystallization significantly improved the color of the obtained products.