Preparation and nutrient release kinetics of enriched biochar-based NPK fertilizers and agronomic effectiveness in direct seeded rice

In present study, two enriched biochar-based fertilizers were prepared having fertilizer grade of 6-6-4 N-P2O5-K2O by intercalation of NPK fertilizers mixture solution as EB-1 and additional humic acid and seaweed extract as EB-2. In laboratory, batch experiment were done to compare nutrients (NH4+, NO3−, P and K+) release patterns of developed fertilizers along with conventional fertilizers. Enriched biochar fertilizers (EB) demonstrated much slower release pattern of NH4+, P and K+, however NO3− release was similar over conventional fertilizers. The cumulative release of N in EB fertilizers was similar to conventional fertilizer, however significantly less of P and K were released during the period of 72 hrs. The field response study of enriched fertilizers EB-2 revealed 29.5, 11.5 and 22.9% higher apparent use efficiency than conventional fertilizer. The slow nutrients release behaviour of EB fertilizers implies reduced losses and enhanced NUE as reflected by higher apparent recovery of N, P and K.

Preparation and Characterization of Sodium Alginate/Chitosan Composite Nanoparticles Loaded with Chondroitin Sulfate

The chondroitin sulfate (CS)/sodium alginate (SA)/chitosan nanoparticles were prepared by electrostatic spraying technology. Laser particle size analyzer measurements indicated that the size of the particles is strongly affected by the weight ratio of raw materials, receiver rotation speed, injection rate, and so on. The size increased and size distribution moved towards the direction of large particle size with the decrease of applied voltage and increased with the increase of the flow rate and weight ratio of SA to CS; there is an optimal value for the effect of stirring rate on particle size and particle size distribution. The effect of different weight ratios of raw materials and pH on the sustained release rate of the product was investigated using a UV-visible spectrophotometer. Results showed the cumulative release rate of these particles was weight ratio of SA to CS and pH-dependent. The cumulative release rate of the CS/SA/chitosan composite nanoparticles with a weight ratio of SA to CS of 2 : 1 was higher at pH 6.8 than that at pH 1.2. By optimizing the process parameters, the CS/SA/chitosan composite particles were prepared, in which most of CS could pass through the stomach and release in the intestinal tract.

Preliminary In Vitro Study of Fluoride Release from Selected Ormocer Materials

The purpose of the in vitro study presented in this paper was to determine the long-term release of fluoride ions from selected ormocer materials (Admira (A), Admira Flow (AF), Admira Seal (AS)). The release of fluoride ions from these materials into a saline solution (0.9% NaCl) and deionized water was tested for 14 weeks. In a long-term study the measurements were taken after 1 and 3 h, then 1, 2, and 3 days and then at weekly intervals for 14 weeks. In a short-term study the measurements were made after 3, 24, 48, 72, 69, 168 h, i.e., within 7 days. All materials used in the test showed a constant level of fluoride release. The highest level of cumulative release of fluoride ions into deionized water was found in the AS material (23.95 ± 4.30 μg/mm2), slightly lower in the A material (23.26 ± 4.16 μg/mm2) and the lowest in the AF material (16.79 ± 2.26 μg/mm2). The highest level of cumulative release into saline solution was found in AF (8.08 ± 1.30 μg/mm2), slightly lower in AS (7.36 ± 0.30 μg/mm2) and the lowest in A (6.73 ± 1.10 μg /mm2). After 1 h of immersion of the samples in the saline solution, the highest level of fluoride was released by AF (0.57 ± 0.06 μg/mm2) followed by A (0.20 ± 0.03 μg/mm2) and AS (0.19 ± 0.02 µg/mm2). Moreover, in the 14-week study, the total amount of fluoride release into the saline, which imitates the environment of the oral cavity, was observed as the highest in the AF sample.

PRELIMINARY FORMULATION STUDY OF LYCOPENE SELF-ASSEMBLE NANOPARTICLES VIA BOX-BEHNKEN DESIGN IMPARTING AN EFFICIENT DRUG DELIVERY: STATISTICAL AND ILLUSTRATIVE APPROACH

Lycopene, a structurally polyene conjugated antioxidant,is frequentlyutilized for the treatment of ailments induced by augmentedoxidative stress.Its colossal structure and poor water-solubilityfailed to show the requisite clinical outcomes. To overcome these drawbacks a formulation study introducing Lycopene as Chitosan-phosphatidylserineself-assembled nanoparticles (LNP)to correlatethe dependent and independent variables employing Box-Behnken design has been performed. LNP formulation was achieved byinjection technique, using chitosan’s intrinsic property of towards Phosphatidylserine for self-assembly. Independent variables, i.e., chitosan concentration (X1), Phosphatidylserine (X2), and injecting rate (X3) were correlatedagainst dependent variables (responses) nanoparticle size, cumulative release,and lycopene encapsulation. Prepared nanocrops were stable, under 300 nmparticle size, Zeta potential below +30 mV, close PDI to 0.3, and exhibited invitro 69-76% cumulative release. Overall, the formulation strategy was fruitful to develop a formulation in the future for efficient drug delivery.

Formulation Design and Evaluation of Solid Lipid Micro-particles of Curcumin for the Treatment of Alzheimer’s disease

Solid lipid microparticles reach the site of its action in a controlled rate and do show controlled release for a better therapeutic result. A good drug carrying and release system involve a controlled drug delivery that improves bioavailability, to enrich stability and to minimise the toxic effects followed with a targeted drug at the site of its action. The solid lipid microparticles of curcumin were prepared in a view to achieving high permeability of curcumin in the brain through blood-brain-barrier. The lipid microsphere solids were prepared by hot melts microencapsulation technique to formulate solid lipid microspheres. Twelve lipid formulations were prepared with varying concentration of surfactants (span 40, span 70, span 90 and Tween 100). The developed formulation was subjected to various parameters such as the particle size, % entrapment efficiencies, yield productions, % cumulative release, percentage yield and drug loading, based upon highest entrapment efficiency, drug release and % cumulative release, the F3 formulation was considered as the best formulation. The prepared microsphere was subjected to different evaluation parameters such as thin-layer chromatography, melting point, FTIR, solubility, compatibility study and In-vitro drug release. The developed formulation shows spherical and smooth surface. The percentage release of drug F3 formulation has been found highest of about 86.23% after 12 hr.

Preparation and application of pH-responsive composite hydrogel beads as potential delivery carrier candidates for controlled release of berberine hydrochloride

For improving the effective concentration of berberine hydrochloride (BH) in the gastrointestinal tract, a series of pH-responsive hydrogel beads were prepared based on carboxymethylstarch-g-poly (acrylic acid)/palygorskite/starch/sodium alginate (CMS-g-PAA/PGS/ST/SA) in the present work. The developed hydrogel beads were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TG). Effect of palygorskite (PGS) content on the swelling properties of hydrogel beads and BH cumulative release were discussed. The pH responsiveness of hydrogel beads was also investigated in different media. Results illustrated that swelling of hydrogel beads and BH cumulative release from hydrogel beads were obviously affected by PGS content. The swelling ratio and BH cumulative release of composite hydrogel beads remarkably slowed down with PGS content increasing in the range from 10 to 40 wt%. The composite hydrogel beads were pH-responsive. At pH 7.4, the swelling ratio and BH cumulative release from composite hydrogel beads were the fastest among the dissolution media of pH 1.2, pH 6.8 and pH 7.4. The BH cumulative release from hydrogel beads was related to the swelling and relaxation of composite hydrogel beads and could be fitted better by the Higuchi model. The obtained composite hydrogel beads could be potentially used for the development of BH pharmaceutical dosage forms.

Fabrication of tri-layered electrospun polycaprolactone mats with improved sustained drug release profile

Modulation of initial burst and long term release from electrospun fibrous mats can be achieved by sandwiching the drug loaded mats between hydrophobic layers of fibrous polycaprolactone (PCL). Ibuprofen (IBU) loaded PCL fibrous mats (12% PCL-IBU) were sandwiched between fibrous polycaprolactone layers during the process of electrospinning, by varying the polymer concentrations (10% (w/v), 12% (w/v)) and volume of coat (1 ml, 2 ml) in flanking layers. Consequently, 12% PCL-IBU (without sandwich layer) showed burst release of 66.43% on day 1 and cumulative release (%) of 86.08% at the end of 62 days. Whereas, sandwich groups, especially 12% PCLSW-1 & 2 (sandwich layers—1 ml and 2 ml of 12% PCL) showed controlled initial burst and cumulative (%) release compared to 12% PCL-IBU. Moreover, crystallinity (%) and hydrophobicity of the sandwich models imparted control on ibuprofen release from fibrous mats. Further, assay for cytotoxicity and scanning electron microscopic images of cell seeded mats after 5 days showed the mats were not cytotoxic. Nuclear Magnetic Resonance spectroscopic analysis revealed weak interaction between ibuprofen and PCL in nanofibers which favors the release of ibuprofen. These data imply that concentration and volume of coat in flanking layer imparts tighter control on initial burst and long term release of ibuprofen.

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

In this study, we investigated the host–guest interactions between oroxin A (OA) and cucurbit[8]uril (Q[8]) using 1H NMR, MS, UV–vis and IR spectroscopy. The results showed that OA and Q[8] formed an inclusion compound (OA@Q[8]) with a molar ratio of 1:1 and a binding constant of 1.299 × 107 L·mol−1. In addition, the effect of Q[8] on the properties of OA was investigated through comparative experiments. The solubility of OA in water increased 22.47-fold when the concentration of Q[8] was 1 × 10−4 mol·L−1. Q[8] hardly affected the antioxidant capacity of OA, while the cumulative release of OA in gastric juice increased 2.3-fold after forming the inclusion compound with Q[8].

The Cucurbit[8]uril effect on the properties of Oroxin A

In this study, we investigated host–guest interactions between Oroxin A (OA) and cucurbit[8]uril (Q[8]) using 1H NMR, MS, UV-Vis and IR spectroscopy. The results showed that OA and Q[8] formed an inclusion compound (OA@Q[8]) with a molar ratio of 1:1 and a binding constant of 1.299 × 107 L·mol−1. In addition, the effect of Q[8] on the properties of OA was investigated through comparative experiments. The solubility of OA in water increased 22.47-fold when the concentration of Q[8] was 1 × 10−4 mol·L−1. Q[8] hardly affected the antioxidant capacity of OA, while the cumulative release of OA in gastric juice increased 2.3-fold after forming the inclusion compound with Q[8].

Optimization of Chitosan–Alginate Microparticles for Delivery of Mangostins to the Colon Area Using Box–Behnken Experimental Design

Chitosan-alginate microparticles loaded with hydrophobic mangostins present in the mangosteen rind extract have been formulated and optimized for colon-targeted bioactive drug delivery systems. The chitosan–mangostin microparticles were prepared using the ionotropic gelation method with sodium tripolyphosphate as the cross-linking agent of chitosan. The chitosan–mangostin microparticles were then encapsulated in alginate with calcium chloride as the linking agent. The mangostin release profile was optimized using the Box–Behnken design for response surface methodology with three independent variables: (A) chitosan–mangostin microparticle size, (B) alginate:chitosan mass ratio, and (C) concentration of calcium chloride. The following representative equation was obtained: percent cumulative release of mangostins (10 h) = 59.51 − 5.16A + 20.00B − 1.27C − 1.70AB − 5.43AC − 5.04BC + 0.0579A2 + 10.25B2 + 1.10C2. Cumulative release of 97% was obtained under the following optimum condition for microparticle preparation: chitosan–mangosteen particle size < 100 µm, alginate:chitosan mass ratio of 0.5, and calcium chloride concentration of 4% w/v. The alginate to chitosan mass ratio is the statistically significant variable in the optimization of sequential release profile of mangostins in simulated gastrointestinal fluids. Furthermore, a sufficient amount of alginate is necessary to modify the chitosan microparticles and to achieve a complete release of mangostins. The results of this work indicate that the complete release of mangostins to the colon area can be achieved using the chitosan–alginate microparticles as the bioactive delivery system.