Dissolution Percentage Research Articles

Characterization of matrix embedded formulations for combination spray-dried particles comprising pyrazinamide and rifampicin

Dry powder inhalers (DPIs) are becoming increasingly popular in the treatment of both systemic and pulmonary diseases. In an effort to enhance the DPIs, we developed spray-dried particles (SDP) using highly branched cyclic dextrin (HBCD) as an excipient. Pyrazinamide (PZA) and rifampicin (RFP) were employed in the present study. The cytotoxicity of HBCD for an excipient of inhalable formulations was evaluated using A549 cell lines as a model of alveoli cells. No cytotoxic effect was observed. Moreover, unlike the formulation prepared with PZA only, combination SDPs achieved a fair fine particle fraction of both model drugs, especially the formulation prepared with 40% ethanol concentration ratio which obtained fine particle fraction (FPF) of 48.7% ± 6.9% and 51.2% ± 6.5% of PZA and RFP, respectively. The dissolution profile of the hydrophobic model drug, RFP was highly enhanced after being included in composite spray-dried powders. In a 60 min dissolution test, untreated hydrophobic RFP can only obtain a dissolution percentage of 9.7% ± 2.5%, while a dissolution percentage near 100% was obtained when it had been prepared into composite powder form, the improvement may be contributed by the acquired amorphous characteristics which were revealed in PXRD analysis. The deeper understanding on HBCD that was acquired through this study shows a great potential of HBCD to be applied as an additive in preparing DPIs.

Toxic effect of triphenyltin in the presence of nano zinc oxide to marine copepod Tigriopus japonicus

Marine organisms are naturally exposed to different environmental pollutants including organic pollutants and nanoparticles. The interactive effects between nanoparticles and other chemicals on aquatic organisms have raised concerns regarding the potential of nanomaterials as the vector for other chemicals. In the present study, the effect of nano zinc oxide (nZnO) on the bioavailability of triphenyltin chloride (TPTCl) was studied, and their combined acute and reproductive toxicity to the marine copepod Tigriopus japonicus were evaluated. At experimental concentration ranges of nZnO in this study, the percentage of dissolution of Zn2+ was relative stable (from 62% to 66%), and nZnO did not affect the bioavailability of TPTCl to the copepods. The acute toxicity of binary mixtures of nZnO/TPT was equivalent to that of the mixture of Zn2+/TPT. In agreement with the decrease in TPTCl's LC50 values at the presence of nZnO, their interacting effect was synergistic based on response addition response surface model, and the interacting parameter was modelled to be −1.43. In addition to acute toxicity test, reproductive toxicity tests revealed that exposure to nZnO and TPTCl didn't affect the successful mating rate and the number of nauplii in the 1st brood, but they extended the time for the eggs to hatch from 2.53 days to 3.94 and 3.64 days, respectively. The exposure to nZnO/TPTCl mixture delayed the time to hatch to 5.78 days.

Fabrication and evaluation of self-nanoemulsifying oil formulations (SNEOFs) of Efavirenz

The current work designed to fabricate and evaluate self-nanoemulsfying oil formulations (SNEOFs) of Efavirenz (Efz) a BCS class II drug with the objective of increasing its solubility as well as in vitro dissolution rate for improvisation of bioavailability. Preliminary screening of drug which includes solubility, emulsifying ability and ternary phase diagrams was carried out to fabricate SNEOFs. Various thermodynamic stability studies were exercised to find out the stable SNEOFs. Robustness to dilution, % transmittance and turbidity, droplet size analysis, TEM study, cloud point measurement, viscosity and refractive index were executed on the stable SNEOFs to characterize the delivery system. FTIR study was adopted for the compatibility of the additives with the drug. In vitro release profiles of SNEOFs compared with Efz, percent dissolution efficiency (DE) and dissolution half-life (t50) were evaluated. A low percent DE (30.12%) and high t50 was obtained for Efz whereas all SNEOFs showed a DE of greater than 78.48% and less than 9 min t50. The optimized SNEOFs (F8) demonstrated a significant (p < 0.05) increase in bioavailability over Efz. Thus the designed optimized delivery system could be instrumental in increasing aqueous solubility of Efz, improving its release performance and enhancement of oral absorption.

Solid Form of Lipid-Based Self-Nanoemulsifying Drug Delivery Systems for Minimization of Diacerein Adverse Effects: Development and Bioequivalence Evaluation in Albino Rabbits.

This work aimed to enhance the oral bioavailability of diacerein. The drug was incorporated in self-nanoemulsifying drug delivery system. Ternary phase diagrams were constructed using Capryol™90, Miglyol®812 and isopropyl myristate as oils, Tween®80 and Tween®20 as surfactants and PEG 200 and PEG 300 as co-surfactants. Among a total of 432 formulae, 17 formulae were clear. They were assessed for mean droplet size, polydispersity index (PDI), saturation solubility and transmission electron microscopy. Solid granules were obtained by adsorption on Aeroperl®300. Results for DSC, PXRD, and SEM of prepared granules revealed that diacerein was molecularly dispersed within the formula. Desirability factor was adopted to find the granules with maximum solubility, maximum dissolution efficiency, maximum dissolution rate and percentage of drug dissolved at 5min and minimum dissolution time and Carr's index. The optimized formula consisted of 10% Miglyol®812, 70% Tween®80 and 20% PEG 200 adsorbed to Aeroperl® 300 with a ratio of 2:1 preconcentrate:carrier. It recorded a 3.77-fold increase in bioavailability, compared to the marketed product. Such enhancement means lower doses and less gastrointestinal side effects.

High dispersed phyto-phospholipid complex/TPGS 1000 with mesoporous silica to enhance oral bioavailability of tanshinol.

Phenolic acids are widely distributed in the plant kingdom and possess a broad spectrum of pharmacological activity. However, low oral bioavailability restricts their application. In this study, a high dispersed phyto- phospholipid complex with mesoporous silica containing TPGS 1000 (TPC-SD) was fabricated using Tanshinol (Tan) as model drug. Phospholipid complex (PC) was employed to improve the n-octanol/water partition coefficient (log P) and apparent permeability coefficients (Papp) of Tan. Mesoporous silica was used to compensate for the negative effects of phospholipid on drug's dispersion and dissolution owing to its viscosity and poor water-solubility. TPGS 1000, a P-gp inhibitor, was used to block the efflux of Tan. Log P tests showed that the lipophilicity of Tan was significantly enhanced by Tanshinol phospholipid complex (TPC) formation. In vitro dissolution results showed that the cumulative dissolution percentage of Tan from TPC-SD was 4.33- fold of that from TPC in 120 min A Caco-2 permeability test confirmed that Papp (AP-BL) of TPC and TPC-SD increased approximately 2.22- and 3.53- fold compared to those of unformulated Tan, respectively (p < 0.01, p < 0.01). Pharmacokinetic studies demonstrated that the AUC0-∞ of TPC-SD was 2.23- and 1.47- fold compared with those of unformulated Tan and TPC, respectively (p < 0.01, p < 0.01). These results indicated that the high dispersed phyto- phospholipid complex/TPGS 1000 by mesoporous silica can be a promising drug delivery system to improve the oral bioavailability of free phenolic acids.

BIOEQUIVALENCE STUDIES OF MARKETED CLOZAPINE TABLETS BY USING OPTIMIZED VALIDATED LIQUID CHROMATOGRAPHIC METHOD

Objective: A simple, selective, precise and accurate method was developed for the estimation of Clozapine by RP-HPLC technique.Methods: Chromatographic conditions used are stationary phase, Phenomenex BDS (150 mm x 4.6 mm, 5µ), Mobile phase was methanol and water in (80:20) ratio and flow rate was maintained at 1.0 ml/min, column temperature was set at 25 °C, detection wavelength was 240 nm, and diluent was mobile phase. These conditions were finalized for the optimized method.Results: Linearity study was carried out between 10-60 µg/ml, the R2 value was found to be as 0.995. Precision was found to be as follows for system precision 1.052, method precision 1.662, and intraday precision 1.02 and for interday precision 0.93. The % Recovery was found to be 98.60%. LOD and LOQ were found to be 2.7 µg/ml and 8.4 µg/ml respectively. By using the above method assay of the marketed formulation was carried out and the % purity was found to be 99.28 %. Stability studies of Clozapine were done, in all conditions degradation was found to be within the acceptable range.Conclusion: The current validated method was finally applied in bioequivalence studies of four different brands of Clozapine by using dissolution apparatus and percentage drug release was found to be 99.48%, it was within the acceptable limit (NLT 85 %) as per USP.

IMPROVED DISSOLUTION CHARACTERISTICS AND SOLUBILITY ENHANCEMENT OF POORLY WATER SOLUBLE DRUG BY NOVEL METHOD USING NATURAL GUM AND WATER SOLUBLE POLYMER

The main objective of the present study is too prepared, characterized and evaluate and surfactant used as a carrier in solid dispersions for enhancing the dissolution rate of simvastatin. The feasibility of formulating solid dispersions of pure drug with gum and surfactant combination that enhanced dissolution rate was also investigated. Solid dispersions of simvastatin in gum: surfactant different polymer ratios were prepared by kneading method and evaluated for dissolution rate and efficiency. All the solid dispersions prepared gave rapid and higher dissolution of simvastatin when compared with pure drug. The DE60 was also increased from many folds in the case of pure drug and solid dispersions. Experimental design was applied systematically and determine the influence of the individual and combined effect on independent variables (X1) ratio and (X2) concentration of surfactants on the dependent variables percent dissolution efficiency at 60 min (%DE 60) and yield percent and optimized formulation selected and characterised by its UV, Differential scanning caloriemetery, Scanning electron microscopy and X- Diffraction studies and formulated into capsule dosage form. In conclusion, the result of this work to suggest that solid dispersion is a useful technique for enhancing the solubility and dissolution study of water insoluble drug. Keywords: Solubility enhancement, Poorly water soluble drug, Simvastatin, Solid dispersions

Controlling the Optical and Magnetic Properties of Nanostructured Cuprous Oxide Synthesized from Waste Electric Cables

Cuprous oxide Cu2O nanopowders were purposefully synthesised from waste electric cables (WECs) via a simple precipitation route at room temperature using lactose as a reducing agent. In this regard, dimethyl sulfoxide (DMSO) was first applied as an organic solvent for the dissolution of the cable insulating materials. Several parameters were investigated during dissolution of WECs such as dissolution temperature, time and solid/liquid ratio to determine the dissolution percentage of the insulating materials in DMSO. The morphology and the optical properties of the formed Cu2O particles were investigated using X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy and UV–visible–near IR spectrophotometer. XRD data confirmed the presence of single crystalline phase of Cu2O nanoparticles. FE-SEM and TEM images revealed spherical, cubic and octahedral shapes with the various particle sizes ranged from 16 to 57 nm depending on the synthesis conditions. A possible mechanism explaining the Cu2O nanostructures formation was proposed. The band gap energies of the Cu2O nanostructures were estimated and the values were located between 1.5 and 2.08 eV. Photoluminescence spectroscopy analysis clearly showed a noticeably blue-shifted emission for the synthesized samples compared to spectrum of the bulk. Eventually, magnetic properties of the synthesized nanoparticles have been measured by vibrating sample magnetometer and the attained results implied that the synthesized particles are weakly ferromagnetic in nature at normal temperature.

STUDY OF IN VITRO ANTI-LITHIATIC EFFECT OF IPOMOEA BATATAS (L) LEAVES AND TUBEROUS ROOTS

Objective: The present study was to demonstrate the in vitro anti-lithiatic effect of Ipomoea batatas (Convolvulaceae) leaves and tuberous roots.Methods: The obtained ethanolic extract of I. batatas leaves and tuberous roots (EIBL and EIBR) and aqueous extract of I. batatas leaves and roots (AIBL and AIBR) were used for this in vitro study. The dissolution method of calcium oxalate by titrimetry method and calcium phosphate by colorimetric method was studied. Nucleation and aggregation of calcium oxalate crystals were determined by a spectrophotometric assay.Results: In the estimation of calcium oxalate by titrimetry method, the I. batatas leaves and roots have very significant (p&lt;0.01) capability to dissolve calcium oxalate. Percentage dissolution of calcium oxalate crystals was found to be 37.53%, 22.74%, 39.74%, and 24.28% for EIBL, AIBL, EIBR, and AIBR, respectively. In the estimation of calcium phosphate by colorimetric method, the percentage dissolution of calcium phosphate crystals by EIBL, AIBL, EIBR, and AIBR was found to be 67.15%, 43.17%, 76.74%, and 47.96%, respectively. The I. batatas leaves and roots were significantly (p&lt;0.01) dissolved calcium phosphate also. The results were clearly shown that I. batatas extracts significantly (p&lt;0.01) inhibited both nucleation and aggregation of calcium oxalate crystals by concentration-dependent manner. The maximum percent inhibition of calcium oxalate nucleation by EIBL, AIBL, EIBR, and AIBR was found to be 59.09%, 50.0%, 84.09%, and 47.73%, respectively, at 1000 μg/ml. The EIBL, AIBL, EIBR, and AIBR were inhibited calcium oxalate aggregation by 63.46%, 36.54%, 84.61%, and 42.3%, respectively, at 1000 μg/ml.Conclusions: The results clearly indicate that I. batatas leaves and tuberous roots were found to express in vitro anti-lithiatic potential.

IN VITRO ANTI-UROLITHIATIC ACTIVITY OF FRESH JUICE OF CITRUS LIMON (L.)

The study was planned to investigate the anti-urolithiatic activity of fresh juice of Citrus limon L. fruit. The phytochemical screening was also undertaken to reveal the alkaloids, flavonoids, reducing sugar, vitamin C, amino acid and sterols present in the sample. Macromolecule supersaturation of higher molecular weight components of plant extract exerts its action similar to natural urinary inhibitors and inhibits crystal aggregation and growth. Pharmacological evaluation of Citrus limon L. was performed by the percentage dissolution and turbidity method. Calcium oxalate crystals were synthetically prepared and packed in a semi-permeable membrane in both methods. Result was compared statistically and it showed significant P&lt;0.001 anti-urolithiasis activity as compared to control and standard (Cystone).

Effects of various tool pin profiles on mechanical and metallurgical properties of friction stir welded joints of cryorolled AA2219 aluminium alloy

Friction stir welding (FSW) process was conducted on cryorolled (CR) AA2219 plate using different tool pin profiles such as cylindrical pin, threaded cylindrical pin, square pin and hexagonal pin profiles. The FSW was carried out with pairs of 6 mm thick CR aluminium plates with different tool pin profiles. The different tool pin profile weld portions' behaviors like mechanical (tensile strength, impact and hardness) and metallurgical characteristics were analyzed. The results of the mechanical analysis revealed that the joint made by the hexagonal pin tool had good strength compared to other pin profiles. This was due to the pulsating action and material flow of the tool resulting in dynamic recrystallization in the weld zone. This was confirmed by the ultra fine grain structure formation in Weld Nugget (WN) of hexagonal pin tool joint with a higher percentage of precipitate dissolution. The fractograph of the hexagonal tool pin weld portion confirmed the finer dimple structure morphology without having any interior defect compared to other tool pin profiles. The lowest weld joint strength was obtained from cylindrical pin profile weld joint due to insufficient material flow during welding. The Transmission Electron Microscope and EDX analysis showed the dissolution of the metastable θ″, θ′ (Al2Cu) partial precipitates in the WN and proved the influence of metastable precipitates on enhancement of mechanical behavior of weld. The XRD results also confirmed the Al2Cu precipitation dissolution in the weld zone.

Solid dispersion adsorbate technique for improved dissolution and flow properties of lurasidone hydrochloride: characterization using 32 factorial design

The aim of the present study was to improve the dissolution and flow properties of lurasidone hydrochloride (LH) by solid dispersion adsorbate (SDA) technique. Solid dispersions (SDs) of LH were prepared by fusion method using Poloxamer P188. The melt dispersion was adsorbed onto the porous carrier Florite (calcium silicate). A 32 factorial design was employed to quantify the effect of two independent variables, namely ratio of carrier (Poloxamer 188) and LH in SD and ratio of adsorbent (Florite) to SD. SDA granules of LH were studied for flow properties and characterized using differential scanning calorimetry, scanning electron microscopy, and X-ray diffraction. Tablets of optimized composition of SDA granules (equivalent to 20 mg of drug) and plain tablets were prepared by direct compression method. The dissolution studies were carried out in Mcllvaine buffer (pH 3.8) as per USFDA guidelines and characterized for parameters such as percent dissolution efficiency, t50, and Q30. Tablets prepared from SDA granules showed almost four-fold increase in cumulative percentage drug release as compared to tablets prepared from plain LH. The value of dissolution efficiency was enhanced from 49.60% for plain tablets to 94.15% for SDA tablets. SDA granules did not show any change in drug release and X-ray diffraction pattern after storage at 40 °C/75% of RH for 3 months, which confirms that Florite prevented conversion of drug from amorphous form to crystalline form improving physical stability of the amorphous state of LH.

Atmospheric nutrients in seawater under current and high pCO2 conditions after Saharan dust deposition: Results from three minicosm experiments

The Mediterranean basin receives among the highest dust fluxes in the world ocean, and also appears to be one of the regions the most strongly impacted by ocean acidification. The aim of this study was to assess, on a short time scale (one-week), the effect of ocean acidification on the dissolution of nutrients (inorganic nitrogen, phosphate and iron) from Saharan dust. Three experiments were performed in three distinct seasons: in May, after the spring bloom with low autotrophic biomass, in September, at the end of the oligotrophic period, and in January, during the winter bloom. On each occasion, a dust flux of 10 g m−2 was simulated at the surface of two minicosms (tanks of ∼0.3 m3) filled with filtered (<0.2 µm) seawater collected in the Bay of Villefranche (NW Mediterranean Sea). One minicosm served as a control and the other was acidified to reach a partial pressure of CO2 (pCO2) close to that projected for the end of this century (∼1250 μatm). Following a high-resolution sampling protocol, results showed that whatever the season and in situ biogeochemical conditions (1) all nitrogen from dust was soluble in seawater, allowing a large and stable increase in the stock of NOx (nitrate + nitrite) under the two pCO2 conditions (ambient and future), (2) transient increases in dissolved iron and phosphate concentrations were driven by scavenging processes, with a low dissolution percentage averaging 0.14 ± 0.08 and 4.7 ± 1.2%, respectively. While the absence of pCO2 effects on the release of atmospheric nitrogen was confirmed in the present study, no clear conclusion could be drawn for phosphate and dissolved iron as a consequence of very low concentrations and rapid (within less than 1 h) dissolved-particulate exchanges. Nevertheless, as the lifetime of these elements in solution is limited to a few hours, whatever the pH conditions, our results suggest that ocean acidification would have only a minor impact on their bioavailability for surface phytoplankton communities in such Low Nutrient Low Chlorophyll areas.

Kaolin Bleaching by Leaching Using Phosphoric Acid Solutions

&lt;p&gt;This paper presents a study of kaolin ore bleaching from the municipality of Agua Blanca of Iturbide, Hidalgo, México. This process was carried out using solutions of phosphoric acid as the leaching reagent for the iron dissolution process. It is well known that iron oxide is the major contaminant of clay minerals and silicate used in industry. These contents should be decreased, usually by .1%, to achieve a required whiteness index of 90% (ISO) or higher. The whitening improves its economic value, making it possible to use it as a high-quality raw material in industries such as ceramics and paper. For this purpose, we examined the effect of parameters such as the concentration of the leaching reagent (0.10 M,0.50 M,1 M, and3 M), temperature (298–373 K), and pH level (1, 2 and 3). The experimental results showed that the studied variables have a great influence over the ability to obtain an iron dissolution percentage of more than 98% after 2 hours and 373 K.&lt;/p&gt;

Preparation and characterization of solid lipid nanoparticles of furosemide using quality by design

ABSTRACTThe present work aimed to synthesize solid lipid nanoparticles (SLNs) of Furosemide (FRSM). The parameter sensitivity analysis showed a significant effect of particle size and reference solubility on the AUC0–∞, Cmax and tmax. The FRSM-encapsulated SLNs were synthesized by the phase inversion temperature (PIT) technique using 32 factorial design. The optimal level of 221.28 mg of Compritol 888 ATO and 420 mg of Cremophor RH 40 showed a mean hydrodynamic diameter (MHD) of 25.54 ± 0.57 nm, a polydispersity index (PdI) of 0.158 ± 0.01, the % entrapment efficiency of 80.70 ± 4.06%, percent dissolution efficiency of 71.72 ± 1.52% and time elapsed for 50% drug release of 3.67 ± 0.15 h. The PIT was determined using the turbidity method and the values ranged between 75°C and 73°C. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) images represent spherical to sub-spherical and smooth surface of SLN. The Fourier transform-infrared (FTIR), differential scanning calorimetry (DSC) and x-ray diffraction (XRD) depict the drug-excipient compatibility. Korsmeyer–Peppas was found to be the best fit release kinetics model (R2 = 0.973; K-value = 29.96 and release exponent = 0.40), predicting the Fickian diffusion. The results advocate that the optimized formulation (OF) could promote the controlled release, and improve the physicochemical stability of the formulation. Hence, SLN could be a potential drug carrier for the peroral delivery of FRSM.

PREPARATION OF ZEOLITE X COATINGS ON SODA-LIME TYPE GLASS PLATES

Abstract - The dissolution of glass in highly alkaline reaction mixtures and the impact of this phenomenon on zeolite coating formation were investigated. Coating samples were prepared and characterized by X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEGSEM) and thermogravimetry (TG). It was demonstrated that zeolite X coatings might be prepared on soda-lime glass. Glass dissolved to some degree, up to 2% of its original mass, in the reaction mixtures for the conditions investigated. This dissolution affected the zeolite synthesis taking place on the glass surface, resulting in phases different from those obtained on inert metal surfaces in some cases, especially for the use of reaction mixtures with relatively high Si/Al ratios. The percentage of dissolution of glass plates increased with their decreasing thickness, indicating a surface phenomenon for the dissolution. The stabilities of the coatings, which varied with the synthesis conditions, benefited from the addition of extra thin layers of polyacrylic acid.

DESIGN OF DUAL RELEASE DRUG DELIVERY SYSTEM OF ROXYTHROMYCIN AND AMBROXOL HYDROCHLORIDE

Upper respiratory tract infections (URTIs) are illnesses caused by an acute infection which involves the upper respiratory tract: nose, sinuses, pharynx or larynx. Roxithromycin (macrolide antibiotic) and ambroxol HCl (mucolytic) are used for this treatment. The dual release system of roxythromycin and ambroxol HCl was successfully prepared by bi-layer tablet approach for management of URTI. Quick release of roxithromycin was achieved by using disintegrants and slow release of ambroxol HCl was achieved by using matrix formulation of drug with HPMC K4M and ethyl cellulose. The 32 full factorial design was adopted for optimization of polymer concentration to achieve identical drug release with theoretical dissolution profile. The amount of HPMC K4M and ethyl cellulose were selected as independent variable and the similarity factor with theoretical dissolution profile and percentage drug release at 10th hr was selected as dependent variables. The prepared dual release tablets were evaluated for physical parameters, drug content, in vitro drug release study, etc. All the parameters were found to be acceptable in range. As the concentration of HPMC K4M is increased, the drug release decreases and the effect of ethyl cellulose was found to be less compared to HPMC K4M.

Analysis of root canal organic tissue dissolution capacity according to the type of irrigation solution and agitation technique

Aim: To analyze the root canal organic tissue dissolution capacity promoted by irrigating solutions, with or without the use of different agitation techniques. Methods: Bovine pulp tissue fragments were initially weighed. The following irrigating solutions were tested: 2.5% sodium hypochlorite, 2% chlorhexidine digluconate solution, and distilled water. The irrigating protocols were: immersion, mechanical agitation with endodontic files, and ultrasonic or sonic systems (Endoactivactor® and Easy Clean®). At the end of the protocols, the pulps were weighed to determine their final weight. For comparison, the average percentage of tissue dissolution in relation to the groups was analyzed using the Kruskal-Wallis nonparametric test complemented by multiple comparisons test. The significance level was set at 5%. Results: Among the irrigation solutions, 2.5% sodium hypochlorite showed a higher dissolving power than 2% chlorhexidine digluconate and distilled water. Furthermore, ultrasonic and sonic systems were more effective irrigating protocols than immersion and mechanical agitation with endodontic files. Conclusions: The combination of sodium hypochlorite with an agitation system promotes a greater degree of tissue degradation.

Inclusion complex of tamibarotene with hydroxypropyl-β-cyclodextrin: Preparation, characterization, in-vitro and in-vivo evaluation

The goal of this study was to improve the solubility and oral bioavailability of tamibarotene by complexing it with hydroxypropyl-β-cyclodextrin (HP-β-CD). The inclusion complex of tamibarotene with hydroxypropyl-β-cyclodextrin (Am80-HP-β-CD) was prepared through a freeze-drying method at the mole ratio of 1:1 (Am80: HP-β-CD). Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) indicated the formation of Am80-HP-β-CD. In vitro dissolution studies showed that the solubility and dissolution percentage of Am80-HP-β-CD was improved substantially compared to Am80. An improved dissolution with approximately 97% drug release in 3 min was observed, in comparison with Am80 with approximately 60% release in 45 min. In vivo studies indicated that the AUC0-∞ has increased 2.79 times and the Cmax 4.37 times after the formation of inclusion complex. The decrease of tmax indicated the Am80-HP-β-CD inclusion complex can be absorbed into blood faster. In short, the solubility and bio-availability of Am80 has notably increased with the complexation of HP-β-CD. Therefore, using the inclusion technique is a promising method to improve the solubility of insoluble drugs.

Potassium recovery from the fly ash from a grate boiler firing agro‐residues: effects of unburnt carbon and calcination pretreatment

AbstractBACKGROUNDThe biomass‐fired power in China is mainly fueled by agro‐residue, and is suffering the bottlenecks of feedstock supply, super heater corrosion and nutrient cycle. How to recycle the ash nutrient to farmland is crucial for ecological sustainability. This work investigated potassium recovery from the fly ash of a grate boiler firing agro‐residue using leaching methods.RESULTSThe studied ash contains a massive amount of fixed carbon (158.92 mg g−1) and little volatile matter (39.44 mg g−1). The unburnt carbon strongly decreases the concentration (CK) in the leachate and recovery percentage (RPK) of potassium nutrient by 17.6–24.1% and 9.0–18.8%, respectively. Calcination pretreatment in air at 500 °C for 30 min should be employed before leaching to remove the unburnt carbon. Mineralogy analysis shows that low‐temperature pre‐calcination (≤575 °C) does not affect potassium solubility. Under the optimal leaching of calcined ash in water with liquid‐to‐solid ratio 3 for 30 min at room temperature, CK in the leachate, dissolution percentage (DPK) and recovery percentage (RPK) of potassium element reached 17.21 g L−1, 82.0%, and 62.6%, respectively.CONCLUSIONSThe fly ash from grate boilers firing agro‐residue is much better than other marginal potash sources. This work is helpful to improve the technology of agro‐residue fired power. © 2016 Society of Chemical Industry