Effect of Polymers nature and Stirring Speeds on Physicochemical Properties and the Controlled Release of Allopurinol-loaded Microspheres

Allopurinol is an antigout drug therapy, commonly used in the treatment of chronic gout or hyperuricaemia associated with treatment of diuretic conditions. In the present study, new formulations based on Allopurinol, have been prepared with the microencapsulation by solvent evaporation process. Microspheres were prepared using pure Allopurinol and polymeric matrices (ethylcellulose EC, poly (ε-caprolactone) PCL, β-cyclodextrin CD and hydroxypropylmethylcellulose HPMC) at different compositions and stirring speeds to investigate the effect of these parameters on loading efficiency and drug release kinetics. The formulations produced were characterized by various methods : Fourier transforms infrared spectroscopy (FTIR), X-ray powder diffractometry, optical microscopy, surface morphology by scanning electron microscopy (SEM) and drug loading, as well as in vitro release studies in the simulated stomach tract. Depending on the stirring speed and the composition of the microparticles, the active ingredient loading is in a range from 10.46 ± 1.45 to 46.40 ± 0.5%. The microspheres are spherical and the mean Sauter diameter (d32) of the microparticles obtained is smaller and is in the range of 47.71 to 151.01 µm. Different release profiles were obtained and show that the release rate is strongly influenced by the characteristics of the microparticles ; namely, the stirring rates and the composition of the microparticles. The release mechanism was identified by modelling using Higuchi and Korsmeyer-Peppas models. Resumen. Alopurinol es una droga terapéutica para tratar la gota, y se utiliza en el tratamiento de gota crónica o hiperuricemia asociada con el tratamiento de condiciones diuréticas. En este estudio, nuevas formulaciones basadas en Alopurinol se prepararon mediante microencapsulación por el proceso de evaporación de disolvente. Microesferas se prepararon usando Alopurinol puro y diferentes matrices poliméricas (etil-celulosa EC, poli(-caprolactona) PCL, β-cyclodextrina CD e hidroxipropil-metil-celulose HPMC) en diferentes composiciones y velocidades de agitación, para investigar el efecto de estos parámetros en la eficiencia de carga y en la cinética de liberación del fármaco. Las formulaciones obtenidas fueron caracterizadas por diferentes técnicas : Espectroscopía infrarroja de transformadas de Fourier (FTIR), difractometría de rayos X de polvos, microscopía óptica, morfología de superficies mediante microscopía electrónica de barrido electrónico, y la eficiencia de carga del fármaco, así como estudios de liberación in vitro en tracto estomacal simulado. Dependiendo de la velocidad de agitación y la composición de las micropartículas, la carga del ingrediente activo se encuentra en el rango de 10.46 ± 1.45 a 46.40 ± 0.5%. Las microesferas son esféricas y el diámetro medio de Sauter (d32) de las micropartículas obtenidas es menor, y se encuentra en el rango de 47.71 a 151.01 µm. Se obtuvieron diferentes perfiles de liberación y se observa que la velocidad de liberación está influenciada principalmente por las características propias de la producción de las micropartículas ; en particualr, las velocidades de agitación y las composición de las micropartículas. El mecanismo de liberación se ajusta mejor a los modelos matemáticos de Higuchi and Korsmeyer-Peppas.

Solubility enhancement of glipizide and development of its fast-dissolving oral film

Background: Difficulty in swallowing tablet dosage form is common among all ages people, especially old and pediatrics. Fast dissolving oral films (FDOFs) may represent an innovative dosage type that settles the issue of gulping and supply fast onset of action. Objective: The objective of the present investigation was to increase the solubility of poorly soluble Glipizide (BCS Class II) by solid dispersion technique and develop its FDOFs. Methods: A solvent evaporation process was used to make a solid dispersion of the Glipizide. The saturation solubility of glipizide and its solid dispersion was determined in a different solvent. For the film preparation, solvent casting method was chosen. The excipients were selected based on pre-formulation data. The composition of the film was optimized based on a trial-and-error basis using different concentrations of plasticizer. The average weight, thickness, disintegration time, tensile strength, surface pH, folding endurance, drug content, and in-vitro dissolution analysis of the films were all taken into consideration. Results: There was no incompatibility between drug / solid dispersion and the excipients. The solid dispersion of the glipizide showed improved solubility by almost 10 folds. Many of the formulated films disintegrated in less than 30 seconds. At the end of 5 minutes, the optimized film had released more than 90% of the compound. The prepared films were found to be stable at room temperature. Conclusion: The solubility of Glipizide was improved successfully by solubilization technique using soluplus. The FDOFs of the glipizide were successfully formulated using pullulan as polymer.

Multilayer Methylcellulose Substrate-Based Wearable Touch Sensor and Display for Communication

In recent years, flexible printed circuit boards (FPCBs) that have polyimide substrates have been widely used in electronic devices for industrial and academic research owing to their light weight, high dielectric constant, and flexibility. However, these FPCBs have a critical limitation of recycling, as polyimide is not degradable or eco-friendly. To overcome this issue, we fabricated cellulose-based FPCBs. Transparent and flexible methyl cellulose-based substrate was produced through a simple solvent evaporation process. The circuit layer was patterned of an Ag/carbon-nanotube composite fabricated using a stencil mask. The methyl cellulose-based FPCBs were evaluated for diverse mechanical stresses such as bending, torsional, and tensile stresses. In addition, their surface morphology was analyzed using optical microscopy and scanning electron microscopy. For the electrical properties, in addition to the current–voltage curves, their dielectric properties were analyzed. Finally, we reported the successful wearable communication device of the cellulose-based FPCBs in a 5 × 5 touch panel and a 5 × 5 light-emitting diode display.

Facile Fabrication and Characterization of Sb(III)- Impregnated Magnetic Carbon Nitride Nanosheets: Evaluation of Its Catalytic Activity for Greener Synthesis of Biologically Relevant Imidazo[1,2-a]pyridines

The magnetic nanoparticle (Fe3O4) and catalytic antimony trichloride (SbCl3) were co-immobilized in the graphitic carbon nitride nanosheets (SbCl3@Fe3O4/g‑C3N4) using a straightforward solvent evaporation process. The designed catalysts showed excellent catalytic activity for the Groebke–Blackburn–Bienaymé multicomponent reaction for the preparation of substituted imidazo[1, 2-a]pyridines at room temperature. This convergent synthetic protocol enabled molecular diversity synthesis under appealingly mild conditions with operational simplicity in a selective, time, and cost‐effective manner. X-ray diffraction (XRD), infrared spectroscopies (FTIR), thermogravimetry (TG), Scanning electron microscopy (SEM), indicate the structural integrity of all components. The combination of environmentally benign reaction conditions, effortless composite recyclability offers magnetic carbon nitride economically viable for industrial processes.

The Effect of Stirring Speeds to the Entrapment Efficiency in a Nanoparticles Formulation of Java Plum’s seed Ethanol Extract (Syzygium cumini)

Java Plum’s (Syzygium cumini) seed contains flavonoids in the form of quercetin. Quercetin plays an essential role in stimulating insulin production from pancreatic beta cells. However, it could be easily degraded by gastric acid or the digestive system. Thus, in this research, a good delivery system for quercetin will be established, namely nanoparticles. The study objectives are determining the entrapment efficiency’s percentage of nanoparticle preparations from ethanol extracts of Java Plum’s seeds as well as observing the effect of stirring speed on the percentage of entrapment efficiency. Java Plum’s seed extract was obtained by maceration method using ethanol 70% with the ratio between the simplicial powder and solvent is 1 : 4 respectively. Meanwhile, the solvent evaporation process was undergone by using a water bath with temperature not exceeding 70°C. The nanoparticle formulation of Java Plum’s seed extract was made by adding polymers in the form of chitosan and sodium tripolyphosphate cross-linker with three variations of stirring speed (500, 1000, and 1500 rpm) using a magnetic stirrer. The percentage of entrapment efficiency was obtained by subtracting the flavonoids levels of Java Plum’s seeds extract and flavonoids levels of Java Plum’s seeds extract in nanoparticles. Then, the value was divided by flavonoids levels of Java Plum’s seeds extract and multiplied by 100%. Quercetin levels obtained by absorbance readings using spectrophotometry UV-Visible, then absorbance value added into variable X on equation quercetin’s standard curve y = 0,0229x + 0,0644. The results show that the percentage of entrapment efficiency at speed variations of 500, 1000, and 1500 rpm are 48.8459%, 49.1064%, and 56.0413% respectively. According to the t-test two independent samples statistical test, the data has a 0.961 probability value (500 rpm vs 1000 rpm), 0.324 probability value (1000 rpm vs 1500 rpm), 0.25 (500 rpm vs 1500 rpm). Probability value > 0.05, which means the stirring speed does not significantly influence the percentage of entrapment efficiency.

The Effect of Poly (Ethylene Glycol) Emulation on the Degradation of PLA/Starch Composites

As a hydrophilic renewable polymer, starch has been widely used in biocompatible plastics as a filler for more than two decades. The present study aimed at investigating the effects of polyethylene glycol (PEG), as a plasticizer, on the physicochemical properties of a hybrid composite—polylactic acid (PLA) and thermoplastic starch (TPS). A solvent evaporation process was adopted to gelatinize the starch and disparate PEG contents ranging from 3 to 15 wt.% (with respect to the sample weight) were examined. It was revealed that the increase in the PEG content was accompanied by an increment in the starch gelatinization degree. Referring to the microstructural analyses, the TPS/PLA mixture yielded a ductile hybrid composite with a fine morphology and a uniform phase. Nevertheless, two different solvents, including acetone and ethanol, were used to assess if they had any effect on the hybrid’s morphology, tensile strength and thermal properties. It was found that ethanol culminated in a porous hybrid composite with a finer morphology and better starch distribution in the PLA structure than acetone. As the result of PEG addition to the composite, the crystallinity and tensile strength were decreased, whereas the elongation increased. The hydrolytic degradation of samples was assessed under different pH and thermal conditions. Moreover, the microbial degradation of the PLA/TPS hybrid composite containing different PEG molar fractions was investigated in the soil for 45 days. The rate of degradation in both hydrolytic and biodegradation increased in the samples with a higher amount of PEG with ethanol solvent.

Biodegradable, bile salt microparticles for localized fat dissolution

Bile acids are proposed as therapeutic agents for various diseases, including liver diseases and obesity. However, oral or subcutaneous administration of a solubilized version of these drugs has limited efficacy and imposes unwanted side effects. Here, we describe a gold-templating method for fabricating stable, bile salt—cholate or deoxycholate—microparticles. The gold ions’ reduction at the oil-water interface in a double emulsion solvent evaporation process enables a gold–bile salt interaction and the formation of bile salt particles. We demonstrate that composite microparticles release cholate/deoxycholate into solution via a surface erosion process. We illustrate these particles’ capability to lyse adipocytes, both in vitro and in vivo, with minimal side effects, contrary to the Food and Drug Administration–approved salt solution that leads to severe inflammation and ulceration. Overall, particle-based cholate/deoxycholate opens opportunities for localized delivery of these salts, improving efficacy while minimizing side effects associated with oral and subcutaneous use.

Nanosuspension as an Efficient Carrier for Improved Ocular Permeation of Voriconazole

Background: The present limitations related to the ocular administration of antifungal drugs for the treatment of fungal keratitis include poor ocular bioavailability, limited retention time, and low ocular tissues penetration. Methods: This study aimed to prepare a novel ophthalmic voriconazole-loaded nanosuspension based on Eudragit RS 100. Pharmasolve® was explored as a corneal permeation enhancer in voriconazole ophthalmic formulation using in vitro and in vivo experiments. Briefly, 1% voriconazole-loaded nanosuspension was prepared using the quasi-emulsion solvent evaporation process. Results: Characterizations of the voriconazole-loaded nanosuspension by Zetasizer Nano ZS and transmission electron microscope (TEM) showed a uniform spherical shape without any agglomeration. The well-discreted nanoparticle with size of 138 ± 1.3 nm was achieved with high entrapment efficiency (98.6 ± 2.5 %) and a positive zeta potential in the range of 22.5 - 31.2 mV, indicating excellent physical stability. Discussion: Voriconazole-loaded nanosuspension containing the penetration enhancer displayed good permeability both in vitro and in vivocompared with the commercial voriconazole injection. The voriconazole-loaded nanosuspension exhibited good antifungal activity, significantly inhibiting the growth of Candida albicans at a lower concentrations of voriconazole (2.5 μg/mL, p < 0.05). Conclusion: In conclusion, the voriconazole-loaded nanosuspension containing Pharmasolve® can be used as an effective ophthalmic formu-lation for the topical ocular delivery of voriconazole.

Elaboration of Charged Poly(Lactic-co-Glycolic Acid) Microparticles for Effective Release of Tranexamic Acid

In this study, tranexamic acid (TA) was used as a model compound to study the charge effect on the physicochemical properties of poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs). Charged PLGA MPs were elaborated by the incorporation of a quaternary ammonium, cetyltrimethylammonium bromide (CTAB), during the double emulsion solvent evaporation process. Three TA-CTAB-carrying modes of PLGA MPs were designed in the CTAB-free (TA-MP), adsorption (TA-CTABAD), or encapsulation (TA-CTABEN) form. The obtained MPs were characterized by morphology and TA-MP affinity. The experiment revealed that the three prepared MPs were spherical and smooth, with pores on their surfaces. TA-CTABAD had a relatively narrow size distribution, compared with that of TA-MP and TA-CTABEN. The particle sizes of TA-MP, TA-CTABEN, TA-CTABAD were measured as 59 ± 17, 54 ± 20, and 19 ± 8 μm, respectively. The zeta potential of the three MPs was found to be in the order: TA-CTABAD > TA-CTABEN > TA-MP. Differential scanning calorimetry (DSC) indicated that the manufacturing process had no influence on the glass transition temperature of the MPs, which was close to 48 °C. Thermogravimetric analysis illustrated that the presence of CTAB slightly changed the thermal stability of PLGA MPs. In vitro release showed that TA-CTABAD exhibited faster TA release than TA-MP and TA-CTABEN in a basic environment (pH of 13), probably because of electrostatic attraction. At pH = 1, the release of TA from TA-CTABEN was faster than those from TA-MP and TA-CTABAD, probably because of electrostatic repulsion. However, the effect of electrostatic interaction was not significant at pH = 7.4.

Uji Anti Bakteri Ekstrak Daun Sawo Manila (Manilkara zapota) Terhadap Escherichia coli

Manilkara zapota L was included plant which the most popular in South East of Asian. The society also used young fruit, bark, and Sapilla Manila Leaf as tradisional medicine diaerrhea resistant, because substance of tanin was contained in it could hampered and killed the number of bacterias such as Shigella, Salmonella thypii, Escherichia coli. This research purposed for knowing ability of blocked energy from exstract Sapilla Manila Leaf towards Escherichia coli. This research experimentalsm with used qualitatif methode and diffusion methode. Concentration extract of Sapilla Manila Leaf which was used namely 5%, 10%, 15%, 20% with 5 times,. The result of research showed that extract Sapilla Manila Leaf with each that concentrat have not hampered growth of Escherichia coli. The possibility was caused by several factors such as the concentration level of the extract, the nature of the bacteria used and the tools used in the solvent evaporation process.