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The study aimed to enhance the solubility of the poorly water-soluble drug, fenofibrate, by loading it onto mesoporous silica, forming amorphous solid dispersions. Solid dispersions with 30% fenofibrate were prepared using the solvent evaporation method with three solvents (ethyl acetate, acetone, and isopropanol) at different temperatures (40 °C, boiling point temperature). Various characteristics, including solid-state properties, particle morphology, and drug release, were evaluated by different methods and compared to a pure drug and a physical mixture of fenofibrate and silica. Results revealed that higher solvent temperatures facilitated complete amorphization and rapid drug release, with solvent choice having a lesser impact. The optimal conditions for preparation were identified as ethyl acetate at boiling point temperature. Solid dispersions with different fenofibrate amounts (20%, 25%, 35%) were prepared under these conditions. All formulations were fully amorphous, and their dissolution profiles were comparable to the formulation with 30% fenofibrate. Stability assessments after 8 weeks at 40 °C and 75% relative humidity indicated that formulations prepared with ethyl acetate and at 40 °C were physically stable. Interestingly, some formulations showed improved dissolution profiles compared to initial tests. In conclusion, mesoporous silica-based solid dispersions effectively improved fenofibrate dissolution and demonstrated good physical stability if prepared under appropriate conditions.

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Phytoconstituents have been widely used since ancient times to form a complex with phospholipids due to their various therapeutic actions. Despite having strong pharmacodynamic efficiency, numerous phytoconstituents have shown lower in vivo bioavailability and few adverse effects. Phytochemicals soluble in water exhibit poor absorption, leading to a limited therapeutic impact. Phytosome nanotechnology overcomes this limitation by creating a bound of phytochemicals with phospholipids. This method exhibits improved absorption because phytosomes inhibit significant herbal extract components from being degraded by gastric juices and gut flora. This improves bioavailability, increases clinical benefit, and ensures delivery to tissues without compromising nutritional stability. This review also aims to highlight those vesicular systems that could be used in phytosome technology. Additionally, this review highlights the preparation, advantage, characterization, applications, and recent development of phytosome and ethosome with a list of recent patents and marketed formulations and their uses.

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OBJECTIVES: To prepare 7-hydroxyethyl chrysin (7-HEC) loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles and to detect the in vitro release. METHODS: The 7-HEC/PLGA nanoparticles were prepared by emulsification solvent volatilization method. The particle size, polydispersity index (PDI), encapsulation rate, drug loading and zeta potential were measured. The prescription was optimized by single factor investigation combined with Box-Behnken response surface method. Mannitol was used as protectant to prepare lyophilized powder, and the optimal formulation was characterized and studied for the in vitro release. RESULTS: The optimal formulation of 7-HEC/PLGA nanoparticles was as follows: drug loading ratio of 2.12∶20, oil-water volume ratio of 1∶14.7, and 2.72% soybean phospholipid as emulsifier. With the optimal formulation, the average particle size of 7-HEC/PLGA nanoparticles was (240.28±0.96) nm, the PDI was 0.25±0.69, the encapsulation rate was (75.74±0.80)%, the drug loading capacity was (6.98±0.83)%, and the potentiostatic potential was (－18.17±0.17) mV. The cumulative in vitro release reached more than 50% within 48 h. CONCLUSIONS: The optimized formulation is stable and easy to operate. The prepared 7-HEC/PLGA nanoparticles have uniform particle size, high encapsulation rate and significantly higher dissolution rate than 7-HEC.

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Protein/peptide drugs are extensively used to treat various chronic and serious diseases. The short half-life in vivo of protein and peptide as therapeutics drug limit the realization of complete effects. Encapsulating drugs in microspheres can slow the speed of drug release and prolong the efficacy of drugs. The solvent evaporation method is widely used to prepare protein/ peptide microspheres because of its facile operation and minimal equipment requirements. This method has several challenges in the lower encapsulation efficiency, fluctuant release profiles and the stabilization of protein/peptides, which researchers believe may be solved by adjusting the preparation parameter or formulation of microspheres. The article discusses the formulation parameters that govern the preparation of protein/peptide-loaded microspheres by the solvent evaporation method, which provides an overview of the current promising strategies for solvent evaporation for protein/peptide microspheres. The article takes parameter evaluation as the framework, facilitating subsequent researchers to quickly find possible solutions when encountering problems.

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Poly lactic-co-glycolic acid (PLGA) is an ideal polymer for the delivery of small and macromolecule drugs. Conventional preparation methods of PLGA nanoparticles (NPs) result in poor control over NPs properties. In this research, a microfluidic mixer was designed to produce insulin-loaded PLGA NPs with tuned properties. Importantly; aggregation of the NPs through the mixer was diminished due to the coaxial mixing of the precursors. The micromixer allowed for the production of NPs with small size and narrow size distribution compared to the double emulsion solvent evaporation (DESE) method. Furthermore, encapsulation efficiency and loading capacity indicated a significant increase in optimized NPs produced through the microfluidic method in comparison to DESE method. NPs prepared by the microfluidic method were able to achieve a more reduction of trans-epithelial electrical resistance values in the Caco-2 cells compared to those developed by the DESE technique that leads to greater paracellular permeation. Compatibility and interaction between components were evaluated by differential scanning calorimetry and fourier transform infrared analysis. Also, the effect of NPs on cell toxicity was investigated using MTT test. Numerical simulations were conducted to analyze the effect of mixing patterns on the properties of the NPs. It was revealed that by decreasing flow rate ratio, i.e. flow rate of the organic phase to the flow rate of the aqueous phase, mixing of the two streams increases. As an alternative to the DESE method, high flexibility in modulating hydrodynamic conditions of the microfluidic mixer allowed for nanoassembly of NPs with superior insulin encapsulation at smaller particle sizes.

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The objective of this study was to prepare poly(lactide-co-glycolide) (PLGA) microparticles loaded with nanosized drug by combining non-aqueous wet bead milling and microencapsulation. 200-300 nm dexamethasone, hydrocortisone and dexamethasone sodium phosphate nanosuspensions were successfully prepared by wet bead milling the drug in dichloromethane using PLGA as a stabilizer. PLGA microparticles loaded with nanosized drugs were then prepared by a solid-in-oil-in-water (S/O/W) solvent evaporation method or solid-in-oil-in-oil (S/O/O) organic phase separation method. The microparticles were characterized by laser diffraction (LD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and in vitro drug release. The nanosized drugs were homogeneously distributed within the microparticle matrix and remained crystalline, however, with a decrease in crystallinity. High drug encapsulation efficiencies >80 % were achieved at theoretical drug loadings between 5 and 30 %. Drug release profiles could be controlled by varying PLGA grades/blends, microparticle size and drug loadings. Quasi-linear release profiles without the PLGA-typical slow release phase were achieved with PLGA encapsulated nanosized drug.

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Background: Solid dispersion (SD) has been used conventionally as a successful technique for improving the dissolution profile and bioavailability of poorly water-soluble drugs. The aim of this study was to progress the dissolution rate and bioavailability of naproxen (BCS class II) by SD technique. Materials & methods: In this study, hydrophilic carriers are used for preparing solid dispersion of naproxen by evaporation method. The prepared optimized SDNs were evaluated by in-vitro drug dissolution test, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The in-vivo analgesic effects tests of the optimized SDNs (SDN-2 and SDN-5) were performed by tail immersion method and writhing method. Results: All the prepared SDNs exhibited a significant increase in the dissolution of naproxen compared to that of the pure drug. Among them, SDN-2 (the dispersion with sodium starch glycolate at 1:2 ratio of naproxen and sodium starch glycolate) and SDN-5 (using the combination of PEG-8000 and sodium starch glycolate with naproxen at 1:1:1 ratio) showed faster dissolution rate as compared to other solid dispersions (SDNs) and pure naproxen. SDN-2 showed 5.4 times better dissolution rate and SDN-5 depicted 6.5-fold increment of dissolution rate compared to pure naproxen drug. DSC, PXRD and SEM microscopy showed that the drugs crystallinity was decreased during the preparation process. FTIR study revealed that naproxen was stable in polymeric dispersions and there was no interaction among the drug and polymers. In writhing method, the percentage inhibition of the number of writhes showed significantly greater (p < 0.01), (p < 0.0001) analgesic activity for the higher dose treatment groups SDN-2(H), and SDN-5(H), respectively, when contrasted to the pure drug naproxen. For tail immersion test, there is increase in latency time at 90 min which is significantly greater (P < 0.01), (P < 0.05), (P < 0.01) for treatment groups SDN-2(H), SDN-5(L), and SDN-5(H), respectively that ultimately authenticates that the optimized SDNs (SDN-2, SDN-5) showed better analgesic activity in mice in comparison with the pure drug. Conclusion: It can be concluded that dissolution of the naproxen could be improved by the making solid dispersion using sodium starch glycolate and/or combination of sodium starch glycolate and PEG 8000 due to the complete transformation of drug into amorphous form with the entire loss of crystallinity, as evidenced by DSC, PXRD, and SEM and also consequences the enhanced analgesic activity in mice.

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Nanoparticles can be used as drug carriers in various applications (e.g., in pulmonary drug delivery and mucosal vaccination). For further investigations, such as drug release studies, as well as for cell and tissue targeting, particles with defined properties are needed. The purpose of the study was to show a multi-step systematic method utilising quality by design to ensure the quality of ovalbumin loaded polylactic-co-glycolic acid nanoparticles (OVA-PLGA-NP), which can be delivered to the lung, and to gain knowledge of the preparation method (double-emulsion solvent evaporation method) in an early development process. Within a definitive screening design, several process parameters (OVA, PLGA and stabiliser concentrations, stirring time and stirring speed of inner emulsion and stirring time and stirring speed of double emulsion) were varied to analyse their impact on resulting properties (z-average, PDI, loading efficiency and loading capacity). The results showed that the preparation of the inner emulsion mainly influenced the drug loading, while the parameters of the second emulsifying step controlled the size. Then a central composite response surface design was used to achieve a predictable OVA-PLGA-NP with an average particle size of 700 nm and high drug-loading. This also enabled the demonstration of curvature and interaction of the stabiliser and the PLGA concentration.

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The current study aimed to improve the poor solubility of albendazole (ABZ) by means of phospholipid complexation, hence to improve its oral bioavailability. The solvent-evaporation method for ABZ-phospholipid complex (ABZ-PC) preparation was established for the first time. And a systematic optimization of preparation conditions of ABZ-PC was performed. Physicochemical studies of ABZ-PC were performed with FTIR, DSC, and XRD measurements to confirm the formation of the ABZ-PC and reveal the interaction mechanism between ABZ and phospholipid molecules. Solubility determination and morphological characterization were applied to verify the solubility improvement of prepared ABZ-PC. Moreover, the pharmacokinetic performance of ABZ-PC was further evaluated in vivo compared with raw materials of ABZ. Under optimal preparation conditions, the AE of ABZ-PC could be approximately 100%. Physicochemical studies indicated that the P = O group in the phospholipid molecule would interact with the N-H group in the ABZ molecule through hydrogen bonds and ABZ was dispersed in an amorphous state after being prepared into ABZ-PC. The aqueous solubility of ABZ-PC in deionized water (pH7.0) improved by 30-folds than free ABZ, and the AUC0-t of ABZ-PC was significantly increased by 2.32 times in comparison with raw materials of ABZ through oral administration. The current study developed an effective method for the phospholipid complexation of ABZ. With significantly improved solubility in an aqueous environment, the prepared ABZ-PC exhibited improved oral bioavailability and pharmacokinetic characteristics indicating it could be potentially applied in the oral drug delivery of ABZ.

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The improvement in the stability of solid-in-oil-in-water (S/O/W) emulsions, which are used as carriers for protein delivery, was investigated. For this purpose, emulsions were prepared using trimyristin, a solid fat, as the oil phase, and using the membrane emulsification and solvent evaporation methods. The samples were made into stable fine emulsions using polyvinyl alcohol, a hydrophilic polymer, as an emulsifier, and by controlling the particle size uniformly. The S/O/W emulsions prepared by this method showed almost no leakage of encapsulated proteins and exhibited controlled release in an intestinal environment.

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AIM: This study aimed to investigate the effect of polymer type on solidification rate of PLGA polymeric microparticles and particle size/distribution of the emulsion droplets/hardened PLGA polymeric microparticles during solvent evaporation process using FBRM (Focussed Beam Reflectance Measurement). METHODS: PLGA polymeric microparticles were prepared by an O/W solvent evaporation method using various PLGA polymers, including PLGA Resomer® RG503H, RG502H and RG752H. The particle size mean, chord length distribution (CLD), and chord count of the emulsion droplets/hardened microparticles were monitored by FBRM. The morphology of polymeric microparticles were characterised by optical microscopy and scanning electron microscopy (SEM). RESULTS: The transformation of the emulsion droplets into solid microparticles occurred within the first 30 (± 1.04), 34 (± 1.15) and 37 (± 0.82) min and square weighted mean chord lengths are 64.08 (± 3.18), 52.36 (± 5.27) and 42.18 (± 4.61) µm when PLGA Resomer® RG503H, RG502H and RG752H were used respectively. Larger square weighted mean chord length of PLGA polymeric microparticles gave lower chord counts. PLGA RG752H microparticles gave smallest square weighted mean chord length and the chord counts was the highest. The CLDs measured by FBRM showed that a larger particle size mean gave longer CLD and a lower peak of particle number. SEM data revealed that the morphology of microparticles was influenced by type and physical properties of polymer. CONCLUSIONS: FBRM can be employed for online monitoring of the shift in the microparticle CLD and detect transformation of the emulsion droplets into solid microparticles during the solvent evaporation process. The microparticle CLD and transformation process were strongly influenced by polymer type.

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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.

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Sandostatin long-acting release (SLAR) depot for 1-month controlled release of octreotide is a somatostatin analogue product that has been used extensively in the pharmacological treatment of acromegaly. The complexities in the SLAR coacervation manufacturing processes and the use of a unique glucose-starpoly(lactic-co-glycolic acid) (PLGA-glu) may have contributed to the lack of US FDA-approved generic products referencing SLAR in the USA. To address this challenge, we encapsulated octreotide acetate by the commonly used solvent evaporation method in microspheres of a similar composition to SLAR, including the use of a comparable PLGA-glu. Based on our previous study that identified key formulation variables to prepare octreotide acetate/PLGA-glu microspheres, including lowering initial peptide pH and introducing an annealing step post loading, here we added NaCl to the external water phase to further improve the formulation. The resulting microspheres exhibited highly similar release and stability performance in vitro to SLAR, including an exceptionally low initial burst. The very low initial burst was also confirmed by pharmacokinetics in rats. Full erosion behavior analysis (polymer MW, water uptake and mass loss) revealed a slightly faster degradation of SLAR than the solvent evaporation formulations. Analysis of kinetics of dry Tg of the formulations reflected (a) the elevated residual solvent in SLAR and was not duplicated in the solvent evaporation formulations, and (b) the slightly higher Tg of peptide loaded formulations relative to than blank microspheres, consistent with the interaction of the acetate salt of octreotide with linear PLGA chains in the PLGA-glu. These data indicate that it is possible to prepare peptide loaded microspheres by the solvent evaporation method with extraordinarily similar performance to microspheres, such as those in SLAR, that are prepared by the low-burst release coacervation method.

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Nanostructured lipid carriers (NLC) are novel lipidic nanosystems that provide significant improvements in terms of high drug loading capacity and controlled drug release. The purpose of the present work was based on the design, development, and physicochemical characterization of lactoferrin-loaded NLCs as a new therapeutic alternative for the keratoconus treatment. Lactoferrin-loaded NLCs were successfully prepared by a double emulsion/solvent evaporation method. The resultant NLC were assessed in terms of particle size, size distribution, surface charge, morphology, encapsulation efficiency (EE), loading capacity (LC), stability, cytotoxicity, in vitro release, and ocular surface retention. Resulting data showed a size of 119.45 ± 11.44 nm, a 0.151 ± 0.045 PDI value and a surface charge of -17.50 ± 2.53 mV. Besides, high EE and LC values were obtained (up to 75%). The in vitro release study demonstrated a lactoferrin controlled release pattern. NLCs were also stable, non-toxic and show mucoadhesive properties. Thus, a consistent preclinical base was obtained, where NLC may be considered as a potential controlled release novel drug delivery system of lactoferrin for the keratoconus treatment.

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Nanoparticle shape has been acknowledged as an important design parameter due to its influence on nanoparticle interaction with biological systems. However, there is lacking of simple and scalable preparation technique for drug loaded non-spherical polymeric nanoparticles for a long time, thus hindering the potential applications. Although our previous research has modified the traditional emulsion solvent evaporation technique by adding guest molecules to prepare non-spherical poly (lactic-co-glycolic acid) (PLGA) particles, it is difficult to obtain nano-sized rods with minor axis less than 200 nm, which may have great potential in cancer therapy. Herein, in present research, the two-step ESE method was used and optimized to prepare poly (lactic-co-glycolic acid) nanorods for paclitaxel delivery. Firstly, the single-factor experiment was used to screen the influence of multi-factors including type of guest molecules, concentration of guest molecules, emulsification method, surfactant concentration, oil volume, poly (lactic-co-glycolic acid) concentration on the size and shape to determine the range of variables; based on the above range, a multi-factor and multi-level orthogonal experiment was designed. The formula is evaluated by the rod fabrication yield and the aspect ratio of major axis to minor axis. The results showed that the yield of nanorods in the optimal formula was 99% and the aspect ratio was 5.35 ± 2.05 with the minor axis of 135.49 ± 72.66 nm, and major axis of 657.77 ± 307.63 nm. In addition, the anti-cancer drug paclitaxel was successfully encapsulated in PLGA nanorods by the same technique. Our results not only enrich the ESE technique for preparing small sized poly (lactic-co-glycolic acid) nanorods, but also envision the potential application of nanorods for targeted cancer therapy with the delivery of paclitaxel.

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@#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.

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Core-shell microspheres hold great promise as a drug delivery system because they offer several benefits over monolithic microspheres in terms of release kinetics, for instance a reduced initial burst release, the possibility of delayed (pulsatile) release, and the possibility of dual-drug release. Also, the encapsulation efficiency can significantly be improved. Various methods have proven to be successful in producing these core-shell microspheres, both the conventional bulk emulsion solvent evaporation method and methods in which the microspheres are produced drop by drop. The latter have become increasingly popular because they provide improved control over the particle characteristics. This review assesses various production methods for core-shell microspheres and summarizes the characteristics of formulations prepared by the different methods, with a focus on their release kinetics.

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To overcome the problems of frequent leakage accidents during oil exploitation, a superhydrophobic and superoleophilic porous MS/PDA/DT sponge was successfully prepared via mild solvent evaporation method, and a polydopamine assisted surface coating of 1-dodecanethiol (DT) on a melamine sponge (MS) substrate. Surface structure and performance of the MS/PDA/DT sponge were characterized by Scanning Electron Microscope (SEM), Fourier transform infrared spectrometer (FTIR), and Video Optical Contact Angle (CA) metre. The results showed that the as-prepared MS/PDA/DT sponge has a high-water contact angle (WCA) of 147.2°, which is probably attributed to both the rough surface derived from in situ growth and the low surface energy due to grafting of hydrophobic 1-dodecanethiol. The durability of the as-constructed MS/PDA/DT sponge was studied by repeated abrasion tests. After 50 abrasion cycles, the superhydrophobicity of the MS/PDA/DT sponge good mechanical durability. The MS/PDA/DT sponge can effectively absorb oil with an absorption capacity of up to 24 times its weight. The superhydrophobic and superoleophilic MS/PDA/DT sponge has the potential as a promising adsorbent for oil/water separation.Highlights The MS/PDA/DT sponge was prepared via the mild solvent evaporation method.The contact angle of the MS/PDA/DT sponge was 147.2o.The adsorption capacity of the MS/PDA/DT sponge was 24 times their weight.The cost-efficient, environmentally friendly porous materials show high oil/water separation efficiency.

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Microparticles are widely used in myriad fields such as pharmaceuticals, foods, cosmetics, and other industrial fields. Compared with traditional methods for synthesizing microparticles, microfluidic techniques provide very powerful platforms for creating highly controllable emulsion droplets as templates for fabricating uniform microparticles with advanced structures and functions. Microfluidic techniques can generate emulsion droplets with precisely controlled size, shape, and composition. A more precise preparation process brings an effective tool to control the release profile of the drug and introduces an easily accessible reproducibility. The paper gives information about basic droplet-based set-ups and examples of attainable microparticle types preparable by this method.

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Targeting the deficiencies of Lingzhu Powder, this study introduced the particle design technology to improve its quality. Based on the mechanism of particle design for powder and the characteristics of solvent evaporation method, composite particles consisting of Succinum, Cinnabaris, and artificial Bovis Calculus were prepared. And the powder properties of composite particles and physical mixtures as well as the content uniformity of toxic components were investigated for exploring the technological advantages of particle design in improving the quality of Lingzhu Powder. The results showed that the composite particles prepared using solvent evaporation method and particle design technology were micro-particles, and the stable agglomerate structure could be observed under SEM. Composite particles exhibited better fluidity and compliance in oral intake than physical mixtures. The differences in chromatism, bulk density, and content uniformity of the composite particles were smaller than those of physical mixtures, and the corresponding RSD values \[4.8%, 1.8%, 3.4%(bilirubin), and 0.63%(HgS), respectively\] were smaller. The solvent evaporation combined with particle design technology can be utilized to significantly improve the quality of Lingzhu Powder, which has provided new ideas for the optimization of the quality of traditional Chinese medicinal powder.

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