Solvent Evaporation Technique Research Articles

Study of crystalline growth, structural characteristics, optical behavior, thermo and dielectric properties of isoniazid single crystal

In this study, isoniazid single crystals were synthesized using solvent mediated followed by slow solvent evaporation techniques for testing the electro-optics application. Powder XRD analysis was used to record several scattering peaks for the obtained grown material, and the presence of scattering peak positions results correlated to the reported scattering peak position of the above title compound’s orthorhombic crystal structure. Further, the single crystal XRD analysis confirmed the orthorhombic crystal system based on the obtained lattice parameters of synthesized crystal. The grown crystal was scanned using an FT-IR analysis, and its chemically attached functional groups were detected in the spectrum. According to UV–visible studies, isoniazid has a transmittance value of more than 90 %. In addition, the transmittance behavior of the grown compound changed significantly depending on its wavelength. The nonlinear optical property study of the grown crystal was characterized, and the results of the second harmonic generation efficiency values correlate with those of standard reference crystal. Thermal stability and melting temperature of the grown crystal were investigated using TG/DTA studies. The temperature vs weight loss plot revealed weight loss in the temperature range of 225 °C to 400 °C for the grown crystal. Using differential thermo gravimetric analysis (DTA), the melting temperature of the synthesized crystal was determined to be 170 °C. The dielectric constant and dielectric loss responses of grown isoniazid crystals are found to be less at high frequencies and increase exponentially at low frequencies due to the presence of polarization effects.

Design and Development of Pharmacosome Loaded with Piroxicam to Improve Oral Bioavailability

The design of the present investigation was to prepare Piroxicam bounded pharmacosomes to improve the water solubility, bioavailability and to minimize the gastrointestinal toxicity of Piroxicam. Pharmacosome is a potential approach in vesicular drug delivery systems which exhibits several advantages over conventional vesicular drug delivery systems. Pharmacosomes are phospholipid complexes with a potential to improve bioavailability of poorly water soluble as well as poorly lipophilic drugs. Piroxicam was complexed with soya phosphatidylcholine in various ratios using conventional solvent evaporation technique. In our study, Pharmacosomes thus prepared were subjected to drug solubility, drug content evaluation, surface morphology (by scanning electron microscopy), crystallinity (by X- ray powder diffraction), quality control tests for capsules and in-vitro dissolution study. Solubility profile of the prepared complexes was found to be much better than Piroxicam pure drug. This improvement in solubility of the prepared pharmacosomes may result in improved dissolution and lower gastrointestinal toxicity. Drug content was found to be 96.84%w /W for the optimized Piroxicam phospholipid complex, F1 (Piroxicam: lecithin ratio of 1:1). The pharmacosomes were found to be disc shaped in scanning electron microscopy. X-ray powder diffraction data confirmed the formation of phospholipid complexes. The formulation F1 showed 94.69% drug release while the free Piroxicam showed a total of only 60.42% at the end of 10-hour dissolution study. Thus the solubility and hence the bioavailability of Piroxicam can be increased to a greater extent by complexing it with soya phosphatidylcholine.

Transdermal therapeutic system: Study of cellulose nanocrystals influenced methylcellulose-chitosan bionanocomposites

Over the past few years, there is a drive toward the fabrication and application of bio-based non-cytotoxic drug carriers. Cellulose nanocrystals (CNCs) have gotten immense research attention as a promising bioderived material in the biomedical field due to its remarkable properties. The delivery of analgesic and anti-inflammatory drug, ketorolac tromethamine (KT) by transdermal route is stipulated herewith to fabricate suitable transdermal therapeutic systems. We have synthesized CNCs from jute fibers and aim to develop a non-cytotoxic polymer-based bionanocomposites (BNCs) transdermal patch, formulated with methylcellulose (MC), chitosan (CH), along with exploration of CNCs for sustained delivery of KT, where CNCs act as nanofiller and elegant nanocarrier. CNCs reinforced MCCH blends were prepared via the solvent evaporation technique. The chemical structure, morphology, and thermal stability of the prepared bionanocomposites formulations were studied by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), TGA, DSC, DMA, and SEM. The In vitro drug release studies were executed using Franz diffusion cells. The BNC patches showed in-vitro cytocompatibility and the drug release study revealed that BNC containing 1 wt% CNCs presented the best-sustained drug release profile. The bioderived CNCs appear to enhance the BNCs drug's bioavailability, which could have a broad prospect for TDD applications.

Study an effect of various orgainic solvents for preparation of glipizide mucoadhesive microspheres

Glipizide is a potent, rapid-acting with short duration of action and well tolerated second-generation sulfonylureas effective in reducing postprandial glucose level. However, if a dosage is missed before a meal, the risk of postprandial hypoglycemia and post-meal glucose excursions is always linked with the use of glipizide for the treatment of type 2 diabetes mellitus. Type 2 diabetes mellitus is a polygenic illness that includes both insulin secretion dysfunction and peripheral insulin resistance. (1)The study an effect of organic solvents preparation of glipizide controlled released mucoadhesive microspheres. (2)The microspheres were formulated conventional tremendous technique by emulsion solvent evaporation technique. (3) Mucoadhesive microspheres were evaluation parameters Examine by their impact on mucoadhesion, drug encapsulation efficacy (EE%), and in-vitro drug release. The produced microspheres were subjected to physical characterizations such as FTIR, DSC, particle analyzer, and SEM. Using cock stomach tissue, the ex-vivo mucoadhesive properties of the various orgainic solvents microspheres were studied. When compared to the other solvents microspheres employing, such as ethanol, methanol, acetone, glipizide loaded ethanol mucoadhesive microspheres had a higher EE percent (83.63±0.17%), a more sustained release profile over 10 hours, and superior adherence to cock stomach mucosa.

Defect-induced measurements of semi-organic ammonium hydrogen oxalate oxalic acid dihydrate single crystals using gamma irradiation

The structural, optical, mechanical and electrical properties of pure and 5—20-kGy gamma-irradiated semi-organic single crystals of ammonium hydrogen oxalate oxalic acid dihydrate (NH4H3(C4O8).2H2O) are presented. The crystals were synthesized at room temperature using facile solvent evaporation technique. Powder XRD measurements indicate gradual enhancement in crystallinity and lattice defect annihilation for low radiation dosage. Radiation-induced increase in optical band gap (4.01–4.16 eV) indicates high damage threshold of the crystals. Quenching of photoluminescence is attributed to the lowering of surface defect density with radiation. The influence of gamma radiation on the functional vibrations of the crystals is studied using FTIR-Raman spectroscopy. Vickers microhardness measurements show gradual enhancement in crystal hardness with the increase in radiation. An increase in forward resistance with irradiation is observed from I–V measurements and is attributed to high transparency of the crystals. These results indicate the viability of NH4H3(C4O8) 2H2O crystals in potential space optoelectronic applications.

Formulation and optimization of Paliperidone palmitate biodegradable injectable microspheres using Box-Behnken design

The objective of study was to formulate and optimize poly lactic-co-glycolic acid based long-acting injectable microspheres of Paliperidone palmitate (PP) using Box- Behnken design for treatment of schizophrenia. The oral bioavailability of PP is 28%, it necessitates the formulation of PP in injectable dosage form. In this study, PP microspheres were manufactured using oil in water (O/W) emulsion solvent evaporation technique. Box-Behnken design was selected to study effect of independent variables (X) on dependent variables (Y). Independent variables in this study were drug: polymer ratio (X1), homogenization speed (X2), rate of addition (X3). While mean particle size (Y1), drug loading (Y2), entrapment efficiency (Y3), burst release (Y4) and drug release on day 21 (Y5) were considered as dependent variables. The statistical evaluation of data was performed by using Design Expert software. Size of formulated microspheres was studied using laser diffraction technique. The shape of particles was determined using digital microscope and scanning electron microscopy (SEM). Drug release was studied using controlled temperature shaking water bath apparatus. Fourier transforms infrared spectroscopy (FTIR) and differential scanning calorimetric (DSC) study was carried out to detect any incompatibility. Nuclear magnetic resonance (NMR) techniques were used to characterize end cap and monomer ratio in developed microspheres. The prepared PP microspheres exhibited smooth surface and spherical shape. Box-Behnken design was employed for optimization of microspheres. Mean particle size of prepared PP microspheres was found to be in between 12 ± 3.7 μm and 152 ± 3.4 μm. Drug loading in prepared microspheres was found in between 19.4 ± 0.2% to 46.5 ± 0.7%. Entrapment efficiency of prepared microspheres was obtained between 58.6 ± 0.8% and 96.8 ± 1.4%. Drug release from PP microspheres was observed as near zero order. The observed and predicted values of all responses were in close agreement with each other. End cap analysis and molar ratio of Lactic acid: Glycolic acid for formulated microspheres was found to be ester end cap and ∼75:25 respectively. The optimized PP microspheres were capable of releasing drug in vitro up to 28 days. The optimized novel PP injectable microspheres are having profound advantages over conventional oral drug delivery systems in treatment of schizophrenia.

Formulation and evaluation of polymeric microspheres of a poorly soluble drug celecoxib

The aim of this present work was to formulate microspheres of BCS Class II drug Celecoxib. The drug was identified by melting point study and FT-IR spectroscopy. Therapeutic success of a drug is greatly depended on its bioavailability. Majority of the recently discovered drugs shows poor solubility (BCS Class II) which decreases the bioavailability upon oral administration. Microspheres are a novel technique to circumvent this obstacle, which can increase bioavailability of drugs significantly. Polymeric microspheres with Polyvinylpyrrolidone and Eudragit L-100, prepared by Emulsion Solvent Diffusion and Evaporation technique, showed a range of drug release profile at intestinal pH 6.8. Different batches of microspheres were prepared by varying the drug-polymer ratio. Microparticulate systems like microspheres improve absorption which increases the bioavailability, ultimately leading to more efficient drug therapy. The microsphere system also provides protection to the gastric mucosa from GIT-irritant drugs thus decreasing toxic effects and sustained releases allows lower dosage frequency. Prepared microspheres were evaluated on various parameters like entrapment efficiency, %yield, particle size, scanning electron microscope analysis, and in-vitro drug release profile. Solid spherical microspheres were produced which showed good entrapment efficiency (43%-91%) and released 70-90% of the drug content in 10hrs.

Synergetic effect of bismuth vanadate over copolymerized carbon nitride composites for highly efficient photocatalytic H2 and O2 generation

The development of copolymerized carbon nitride (CN)-based photocatalysts may support advances in photocatalytic overall water splitting. However, the recombination of charge carriers is the main bottleneck that reduces its overall photocatalytic activity. To overcome this problem, the construction of heterojunction technology has emerged as an effective approach to reduce the charge carrier recombination, thereby improving charge separation and transport efficiency. In this work, an innovative heterojunction was prepared between Quinolinic acid (QA) modified CN (CN-QAx) and novel nanorod-shaped bismuth vanadate (BiVO4) (BiVO4/CN-QAx) for overall water splitting through a simple in-situ solvent evaporation technique. The obtained results show that the synthesized samples have efficient and improved activities for releasing H2 (862.1 μmol/h) and O2 (31.58 μmol/h) under visible light irradiation. Furthermore, an exceptional apparent quantum yield (AQY) of 64.52 % has been recorded for BiVO4/CN-QA7.0 at 420 nm, which might be due to the substantial isolation of photoinducedcharge carriers. Therefore, this work opens up a new channel toward efficient CN-based photocatalysts in the sustainable energy production processes.

Evaluation of PLGA nanoparticles containing outer membrane proteins of Acinetobacter baumannii bacterium in stimulating the immune system in mice.

Background and purpose:Acinetobacter baumannii (A. baumannii) is known as a pathogen with antibiotic resistance, causing respiratory infections. PLGA has been approved for use in vaccines as well as drug delivery. This study was performed to evaluate PLGA nanoparticles containing the outer membrane proteins (OMPs) of A. baumannii in stimulating the mice’s immune system and improving pneumonia.Experimental approach:Double emulsion solvent evaporation technique was used. The properties of the obtained nanospheres were determined using a zetasizer, FTIR, and AFM devices. Nanoparticles were administered to mice BALB/c by applying the intramuscular route. ELISA was used to measure the amounts of immunoglobulins produced; also, an opsonophagocytic killing assay was used to measure the effectiveness of immunoglobulins. Immunized mice were then challenged with live A. baumannii through the lungs; their internal organs were also removed for bacteriological studies.Findings/Results:The prepared particles were 550 nm in diameter with a negative surface charge. The production of the OMPs specific IgG was much higher in the group receiving nanoparticles containing antigen as compared to those getting pure antigen. The immunoglobulins produced against nanoparticles were superior to those developed against pure antigens. Mice that received the new nanovaccine were more resistant to pneumonia caused by this bacterium than those that received pure antigen.Conclusion and implication:Overall, it can be said that PLGA nanoparticles could deliver their internal antigens (OMPs) well to the immune system of mice and stimulate humoral immunity in these animals, thus protecting them against pneumonia caused by A. baumannii.

Alpha Tocopherol Loaded Polymeric Nanoparticles: Preparation, Characterizations, and In Vitro Assessments Against Oxidative Stress in Spinal Cord Injury Treatment.

Spinal cord injury (SCI) is characterized by mechanical injury or trauma to the spinal cord. Currently, SCI treatment requires extremely high doses of neuroprotective agents, which in turn, causes several adverse effects. To overcome these limitations, the present study focuses on delivery of a low but effective dose of a naturally occurring antioxidant, α-tocopherol (α-TP). Calcium alginate nanoparticles (CA-NP) and poly D,L-lactic-co-glycolic acid nanoparticles (PLGA-NP) prepared by ionotropic gelation and solvent evaporation technique had particle size of 21.9 ± 11.19 and 152.4 ± 10.6nm, respectively. Surface morphology, surface charge, as well as particle size distribution of both nanoparticles were evaluated. Entrapment of α-TP into CA-NP and PLGA-NP quantified by UPLC showed entrapment efficiency of 4.00 ± 1.63% and 76.6 ± 11.4%, respectively. In vitro cytotoxicity profiles on human astrocyte-spinal cord (HA-sp) showed that blank CA-NP at high concentrations reduced the cell viability whereas blank PLGA-NP showed relatively safer cytotoxic profiles. In addition, PLGA nanoparticles encapsulated with α-TP (α-TP-PLGA-NP) in comparison to α-TP alone at high concentrations were less toxic. Pretreatment of HA-sp cells with α-TP-PLGA-NP showed two-fold higher anti-oxidative protection as compared to α-TP alone, when oxidative stress was induced by H2O2. In conclusion, CA-NP were found to be unsuitable for treatment of SCI due to their cytotoxicity. Comparatively, α-TP-PLGA-NP were safer and showed high degree of protection against oxidative stress than α-TP alone.

Preparation and preformualation estimation method of floating microsphere of ofloxacin

Floating drug delivery systems are mainly expected to remain buoyant in gastric contents and consequently to enhance the bioavailability of drugs Microsphere is loaded with a drug in their outer polymer shells was prepared by a novel emulsion-solvent diffusion method. It is floated continuously over the surface of acidic dissolution media containing the surfactant for invitro time 12 hours. Floating microspheres of ofloxacin were prepared by novel o/w emulsion solvent evaporation technique using Ethyl cellulose polymers order to retain drug in body for longer period of time. Ofloxacin has short half-life of 9 hrs. So we prepared a microsphere for increasing their activity.

Preparation and Physicochemical Characterizations of p-Methoxycinnamic acid – Succinic Acid Cocrystal by Solvent Evaporation Technique

Background: PMCA (p-Methoxycinnamic acid) is an active pharmaceutical ingredient derived from Kaempheria galanga L (known as kencur in Indonesia), which is poorly soluble in water. It can cause problems in the development of pharmaceutical dosage forms. Several methods have been carried out to increase the solubility of PMCA such as complex formation with β-cyclodextrin, or solid dispersion. The cocrystal formation method is a solubility enhancement method that has been developed recently.
 Aim: The aim of the study was the preparation and physicochemical characterization of PMCA co-crystal with succinic acid (SA) as its conformer by solvent evaporation technique.
 Methods: PMCA-SA cocrystal was made by the solvent evaporation method with a 1:1 molar ratio. Physicochemical characterization of PMCA and SA cocrystal was performed by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and scanning electron microscope (SEM).
 Results: The DSC thermogram showed a decrease in the melting point of cocrystal compared to PMCA (173.55˚C), SA (187.55˚C), and its physical mixture (159.53˚C). The cocrystal thermogram displayed an endothermic peak at 158.46 ° C. Diffractogram of PMCA- SA cocrystal exhibited new diffraction peaks at an angle of 2θ = 21.92; 25.91 and 39.25˚ which was not found in the diffractogram of every single component nor its physical mixture. SEM photomicrograph showed PMCA-SA cocrystal as a rod-shaped crystal that had a different surface morphology and smaller size than the constituent materials.
 Conclusions: Based on the physicochemical characterization data above, it could be ascertained that PMCA-SA cocrystals had formed, these cocrystals were expected to increase the solubility of PMCA in water.

Fire-Extinguishing Microcapsule Composite Separator for Chemical Safety Management in Lithium-Ion Battery System

With recent rapid technological developments, the use of fossil fuels has drastically increased, posing environmental concerns such as global warming and air quality deterioration due to the presence of particulate matter such as fine dust. Renewable energies, such as solar energy and wind energy, have been considered as promising alternatives to reduce the use of fossil fuels. However, the energy generated by renewable energy sources varies significantly and is dispersed because of its strong dependence on environmental conditions. Therefore, energy storage systems (ESSs) should be installed for the stable use of renewable energy systems and stable delivery in response to consumer demand.Among the many batteries used in ESSs, lithium-ion batteries (LIBs) have been used widely as a power source because of their relatively high voltage (~4.7 V vs Li) and high energy density (650 W h kg−1). Long-term reliability is necessary to utilize LIBs in ESSs; however, many drawbacks associated with the long-term use of LIBs have been reported recently in ESSs employing LIBs. Although the performance of LIBs is gradually improving, safety issues such as fire and explosion remain a major issue and disturbed the development of LIBs. In this study, we manufactured Fire-extinguishing Microcapsule (FEMC) containing extinguishing substances for the safety of the battery. Encapsulation of the extinguishing material inside a stable polymer shell prevented the extinguishing material from reacting directly with the electrolyte in the battery. The direct reaction of the extinguishing material with the electrolyte negatively affects the battery performance and causes a short circuit in the battery. When thermal runaway occurs in the battery, the outer shell material melts and the internal fire extinguishing material is released, effectively preventing fire and explosion of the battery.The FEMC was encapsulated by using solvent evaporation technique. To confirm FEMC’s extinguishing effects self-extinguishing time (SET) was measured, and we observed FEMC’s physical properties such as encapsulation, size by using characterization techniques (FE-SEM, TEM, TGA, etc). As a result, the size of the FEMC was evenly distributed about 2 μm to 5 μm, and the surface was generally smooth. In addition, extinguishing material was largely located in the middle of the interior, and the core-shell structure in which stable polymer shell was wrapped around a very thin wall was confirmed. The fire extinguishing effect by FEMC was confirmed in the electrolyte, and as a result, the bare electrolyte without a fire extinguishing additive was extinguished in about 115 sec. On the other hand, when FEMC containing extinguishing material was conducted SET test, it was confirmed that the combustion time decreased by about 12 sec. Compared with bare electrolyte, the combustion time was reduced by about 84.4%. Through this, it was confirmed that the FEMC had an excellent effect in extinguishing the fire in the electrolyte.

DESIGN AND DEVELOPMENT OF SIMVASTATIN-LOADED PHARMACOSOMES TO ENHANCE TRANSDERMAL PERMEATION

Objective: The objective of the selected study was to design and formulate simvastatin-loaded pharmacosomes and then incorporate into a transdermal patch by solvent evaporation technique to enhance the solubility, bioavailability, and half-life of simvastatin. Methods: Simvastatin comes under the BCS-II class, which has low solubility and high permeability. Simvastain loaded pharmacosomes of six different formulations were prepared by taking simvastatin and soya lecithin in varying ratios and dissolved in a high polarity solvent dichloromethane and then subjected to the solvent evaporation method. Results: Formulated simvastatin-loaded pharmacosomes (SLP) were subjected to evaluation; out of six formulations, optimized formulation (F3) shown in vitro drug release of 86.88%; particle size of 151.6 nm with zeta potential of-16.5mV, which indicates good stability. SEM studies confirmed their smooth, porous structure with a number of nano-channels. The FT-IR spectra and DSC showed a stable character of simvastatin in a mixture of lipid and solvent shows compatible and revealed the absence of drug polymer interactions. The SLP was loaded into a transdermal patch by solvent evaporation method and evaluated for physical characteristics and results were found to be patch surface pH 6.15±0.08, thickness 0.146±0.0096 mm, weight uniformity 1.12±1.73, % swell-ability 13.50±0.028 for best patch formulation (F3). Conclusion: This research paper gives an outline on the significance of simvastatin-loaded Pharmacosomes as a transdermal patch for enhancing trans-permeation through the skin and its characterization and results. Through obtained results, it is concluded that pharmacosomes is a promising carrier to enhance the permeation of the selected drug through skin.

Anti-CD44 and EGFR Dual-Targeted Solid Lipid Nanoparticles for Delivery of Doxorubicin to Triple-Negative Breast Cancer Cell Line: Preparation, Statistical Optimization, and In Vitro Characterization.

Background Despite being more aggressive than other types of breast cancer, there is no suitable treatment for triple-negative breast cancer (TNBC). Here, we designed doxorubicin-containing solid lipid nanoparticles (SLNs) decorated with anti-EGFR/CD44 dual-RNA aptamers, which are overexpressed in TNBC. For more efficiency in the nuclear delivery of doxorubicin, dexamethasone (Dexa) was chemically attached to the surface of nanoparticles. Methods To prepare the cationic SLNs, 6-lauroxyhexyl BOC-ornithine (LHON) was synthesized and was chemically attached to dexamethasone to form Dexa-LHON complexes. The doxorubicin-containing SLNs were prepared via double emulsification (w/o/w) and the solvent evaporation technique. The preparation of SLNs was statistically optimized using the central composite response surface methodology. Independent factors were the GMS/lecithin concentration ratio and the amount of Tween 80, while responses considered were particle size, polydispersity index, and entrapment efficiency of the nanoparticles. The optimized nanoparticles were studied morphologically using transmission electron microscopy, and in vitro release of doxorubicin from nanoparticles was studied in phosphate-buffered saline. Then, the designated aptamers were attached to the surface of nanoparticles using electrostatic interactions, and their cytotoxicity was assessed in vitro. Results The size, PDI, zeta potential, EE%, and LE% of the prepared nanoparticles were 101 ± 12.6 nm, 0.341 ± 0.005, +13.6 ± 1.83 mV, 69.98 ± 7.54%, and 10.2 ± 1.06%, respectively. TEM images revealed spherical nanoparticles with no sign of aggregation. In vitro release study exhibited that 96.1 ± 1.97% of doxorubicin was released within 48 h of incubation. The electrostatic attachment of the designated aptamers to the nanoparticles' surface was confirmed by reducing the zeta potential to −15.6 ± 2.07 mV. The in vitro experiments revealed that the SLNs/DOX/Dexa/CD44 or EGFR aptamers were substantially more successful than SLNs/DOX/Dexa at inhibiting cell proliferation. Using the MDA-MB-468 cell line, we discovered that SLN/DOX/Dexa/CD44/EGFR aptamers were more effective than other constructs in inhibiting cell proliferation (p < 0.001). The reduction of cell viability using this construct suggests that targeting numerous proliferation pathways is effective. Conclusion Overall, the finding of this investigation suggested that SLNs/DOX/Dexa/CD44/EGFR could be a promising new enhanced anticancer delivery system and deserved further preclinical consideration.

Comparison of Microemulsion and Solvent Evaporation Technique for Solubility Enhancement of Amlodipine Besylate

Introduction: Amlodipine besylate is a calcium channel blocker indicated for hypertension and angina. It is described as slightly soluble in water and due to its limited solubility, it may result in poor bioavailability. The aim of this study is to enhance the solubility of amlodipine besylate using solvent evaporation method and microemulsion technique and to compare the two methods. Method: Solid dispersions (SD) of amlodipine besylate were developed by employing solvent evaporation method. PEG6000 was the polymer of choice and different drug:polymer ratios were used. Evaluation of the prepared SDs include solubility studies, dissolution studies and scanning electron microscopy (SEM). As for the microemulsion technique, microemulsions were prepared by phase titration method and the optimized microemulsion formulation was then characterized for solubility studies and dissolution studies. Results: SD3 with drug:polymer ratio of 1:4 achieved the highest solubility which was 96.97 mg/ml ± 0.92 whereas the solubility of the optimized microemulsion was found to be 112.54 mg/ml ± 0.92. In solvent evaporation method, as the drug:polymer ratio increases, the solubility and dissolution rate of SDs increases. Conclusion: The two methods had significantly enhance the solubility of amlodipine besylate however the microemulsion technique showed better solubility profile.

Formulation Development and Characterization of pH Responsive Polymeric Nano-Pharmaceuticals for Targeted Delivery of Anti-Cancer Drug (Methotrexate).

Oral administration of pH sensitive/stimuli responsive nanoparticles are gaining importance because of the limited side effects, minimum dose and controlled drug release. The objective of this study was to develop and evaluate pH sensitive polymeric nanoparticles for methotrexate with the aim to maximize the drug release at target site. In the presented study, pH sensitive polymeric nanoparticles of methotrexate were developed through modified solvent evaporation technique using polymer Eudragit S100. Different process parameters like drug to polymer ratio, speed of sonication, concentration of surfactant and time of sonication were optimized by evaluating their effects on particle size, PDI, zeta potential, entrapment/encapsulation efficiency. The developed formulations were evaluated for their size, polydispersity (PDI), zeta potential, encapsulation efficiency, XRD, scanning electron microscopy, in-vitro drug release and stability studies. Best results were obtained with poloxamer-407 and PVA and were selected as surfactants. Physicochemical characterization of the developed formulations showed that the particle size lies in the range 165.7 ± 1.85–330.4 ± 4.19, PDI 0.119 ± 0.02–0.235 ± 0.008, zeta potential −0.163 ± 0.11–−5.64 ± 0.36 mV, and encapsulation efficiency more than 61%. The results of scanning electron microscopy revealed that nanoparticles have regular geometry with spherical shape. Initially the drug release occur through diffusion followed by erosion. The present studies showed that MTX-ES100 nanoparticles prepared during this study have the desired physicochemical properties, surface morphology and release characteristics used to target the desired organs.

Statistically Optimized Repaglinide-loaded Floating Microspheres for the Gastric Sustained Delivery via Central Composite Design

Repaglinide (RPD) is a short-acting insulin secretagogue widely prescribed for the treatment of type 2 diabetes. In this study, RPD loaded ethyl cellulose/hydroxypropylmethylcellulose (EC/HPMC) floating microspheres (FM) have been formulated for gastric sustained release and improved bioavailability of RPD. Floating microspheres were prepared by oil in water emulsion solvent evaporation technique. A three levels Central-composite design (CCD) was applied to investigate the influence of different formulation components and process variables on the formulation responses and indicate the optimum using the numeric approach through the Minitab® software.

Biodegradable porous micro/nanoparticles with thermoresponsive gatekeepers for effective loading and precise delivery of active compounds at the body temperature

Stimuli-responsive controlled delivery systems are of interest for preventing premature leakages and ensuring precise releases of active compounds at target sites. In this study, porous biodegradable micro/nanoparticles embedded with thermoresponsive gatekeepers are designed and developed based on Eudragit RS100 (PNIPAM@RS100) and poly(N-isopropylacrylamide) via a double emulsion solvent evaporation technique. The effect of initiator types on the polymerization of NIPAM monomer/methylene-bis-acrylamide (MBA) crosslinker was investigated at 60 °C for thermal initiators and ambient temperature for redox initiators. The crosslinked PNIPAM plays a key role as thermal-triggered gatekeepers with high loading efficiency and precise release of a model active compound, Nile Blue A (NB). Below the volume phase transition temperature (TVPT), the gatekeepers possess a swollen conformation to block the pores and store NB within the cavities. Above its TVPT, the chains rearrange, allowing gate opening and a rapid and constant release rate of the compound until completion. A precise “on–off” switchable release efficiency of PNIPAM@RS100 was demonstrated by changing the temperatures to 4 and 40 °C. The materials are a promising candidate for controlled drug delivery systems with a precise and easy triggering mechanism at the body temperature for effective treatments.

Polyethylene Glycol Conjugation for Solubility Enhancement of Cefadroxil, a Poorly Soluble Antibiotic

Introduction: Cefadroxil is the most widely used antibiotic for many bacterial infections but has the drawback of poorly solubility. In an attempt to provide an easier technique which can be scaled up on large scale to provide a simple method to enhance its aqueous solubility, this present work has exploited polyethylene glycol conjugation to enhance its aqueous solubility of cefadroxil.&#x0D; Objective: The main aim of the work is preparation of Polyethylene glycol conjugates of cefadroxil by solvent evaporation technique and to evaluate its solubility enhancement by solubility analysis and to assess drug content uniformity, drug - excipient interaction studies by FTIR spectroscopy.&#x0D; Methodology: Polyethylene glycol conjugates of cefadroxil are prepared by solvent evaporation technique using PEG 6000. Five conjugates of Cefadroxil to PEG6000 taken in weight proportions of (1:0.5), (1:1), (1:2) (1:3) and (1:4) were prepared.&#x0D; Results: Reasonable enhancement of solubility of cefadroxil was evidenced from all the prepared polyethylene glycol conjugates of cefadroxil. Among all CFDL: PEG 6000 (1:4) evidenced high percentage solubility of 81±0.61. IR spectrum of CFDL: PEG6000 (1:4) evidenced disappearance of amide group of cefadroxil indicating conjugate formation which is reversible to release cefadroxil to exhibit its therapeutic effect&#x0D; Conclusion: Polyethylene glycol conjugates of cefadroxil can be prepared easily by solvent evaporation and the conjugate made by weight proportion of CFDL: PEG 6000 (1:4) enhances solubility of cefadroxil by 88% and is promising to be used in formulations cefadroxil with enhanced dissolution and bioavailability.