Spray-drying Technique Research Articles

Inhalable dry powder containing remdesivir and disulfiram: Preparation and in vitro characterization

The respiratory tract, as the first and most afflicted target of many viruses such as SARS-CoV-2, seems to be the logical choice for delivering antiviral agents against this and other respiratory viruses. A combination of remdesivir and disulfiram, targeting two different steps in the viral replication cycle, has showed synergistic activity against SARS-CoV-2 in-vitro. In this study, we have developed an inhalable dry powder containing a combination of remdesivir and disulfiram utilizing the spray-drying technique, with the final goal of delivering this drug combination to the respiratory tract. The prepared dry powders were spherical, and crystalline. The particle size was between 1 and 5 μm indicating their suitability for inhalation. The spray-dried combinational dry powder containing remdesivir and disulfiram (RDSD) showed a higher emitted dose (ED) of >88% than single dry powder of remdesivir (RSD) (∼72%) and disulfiram (DSD) (∼84%), with a fine particle fraction (FPF) of ∼55%. Addition of L-leucine to RDSD showed >60% FPF with a similar ED. The in vitro aerosolization was not significantly affected after the stability study conducted at different humidity conditions. Interestingly, the single (RSD and DSD) and combined (RDSD) spray-dried powders showed limited cellular toxicity (CC50 values from 39.4 to >100 µM), while maintaining their anti-SARS-CoV-2 in vitro (EC50 values from 4.43 to 6.63 µM). In a summary, a combinational dry powder formulation containing remdesivir and disulfiram suitable for inhalation was developed by spray-drying technique which showed high cell viability in the respiratory cell line (Calu-3 cells) retaining their anti-SARS-CoV-2 property. In the future, in vivo studies will test the ability of these formulations to inhibit SARS-CoV-2 which is essential for clinical translation.

PLA stereocomplex-chitosan nanoparticles loaded with tenofovir alafenamide as a long-acting antiretrovirals

Antiretroviral therapy (ART) is a major method of HIV and AIDS treatment; however, it has several limitations, such as poor drug availability, cytotoxicity or renal clearance of the drug molecules. The drugs can be encapsulated in biocompatible polymeric nanocarriers to overcome these limitations. Therefore, the NPs composed of different ratios of poly(l-lactide) PLLA, poly(d-lactide) PDLA, and chitosan (CHI) were prepared by spray-drying technique. Subsequently, the NPs were loaded with the antiretroviral drug - tenofovir alafenamide (TAF). The influence of process variables and nanoparticles (NPs) composition on particle size, drug encapsulation and release was investigated. Finally, it was proved that obtained formulations are non-toxic, and their antiviral efficiency was quantified by JurkatE6 cells infected with HIV. Our findings ascertain that PLLA/PDLA/CHI nanocarriers have great potential for delivering anti-HIV therapeutics.

Novel rivaroxaban-loaded microsphere systems with different surface microstructure for enhanced oral bioavailability.

This study compares rivaroxaban-loaded polymeric microsphere systems with three types of surface microstructure. Three types of polymeric microspheres loaded with rivaroxaban were fabricated using a spray-drying technique: solvent-evaporated, surface-attached, and solvent-wet microspheres, depending on whether the drug and additives used are soluble in the solvent. The solvent-evaporated and surface-attached microspheres had a rivaroxaban/polyvinylpyrrolidone/sodium lauryl sulfate (SLS) weight ratio of 1/0.25/2.2, and the solvent-wetted microspheres contained rivaroxaban/polyvinyl alcohol/SLS in equal weight ratio (1/0.25/2). The physicochemical properties of the microspheres were evaluated using scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and particle size distribution analysis. The aqueous solubility and dissolution rate of rivaroxaban in the three types of microspheres were compared to those of the drug powder. The solvent-evaporated, surface-attached, and solvent-wetted microspheres were approximately 208, 140, and 172 times as soluble as the drug powder, and the final dissolution rate (120min) was approximately 5, 2, and 4 times that of the drug powder, respectively. In addition, the oral bioavailability increased by approximately 2, 1.3, and 1.6 times compared to that of the drug powder (area under drug concentration-time curve: 2101.3 ± 314.8, 1325.2 ± 333.3, and 1664.0 ± 102.6h·ng/mL, respectively). Finally, the solvent-evaporated microspheres showed the greatest improvement (solvent evaporating microspheres > solvent wetted microspheres > surface-attached microspheres ≥ drug powder). Therefore, the solvent-evaporated microspheres may represent a novel oral dosage form that improves the oral bioavailability of rivaroxaban, a poorly soluble drug.

Spray-Dried Inhalable Microparticles Combining Remdesivir and Ebselen against SARS-CoV-2 Infection.

There is a continuous effort to develop efficient treatments for coronavirus disease 2019 (COVID-19) and other viral respiratory diseases. Among the different strategies, inhaled treatment is considered one of the most logical and efficient approaches to treating COVID-19, as the causative "SARS-CoV-2 virus RNA" predominantly infects the respiratory tract. COVID-19 treatments initially relied on repurposed drugs, with a few additional strategies developed during the last two years, and all of them are based on monotherapy. However, drug combinations have been found to be more effective than monotherapy in other viral diseases such as HIV, influenza, and hepatitis C virus. In the case of SARS-CoV-2 infection, in vitro studies have shown synergistic antiviral activity combining remdesivir with ebselen, an organoselenium compound. Therefore, these drug combinations could ensure better therapeutic outcomes than the individual agents. In this study, we developed a dry powder formulation containing remdesivir and ebselen using a spray-drying technique and used L-leucine as an aerosolization enhancer. The prepared dry powders were spherical and crystalline, with a mean particle size between 1 and 3 µm, indicating their suitability for inhalation. The emitted dose (ED) and fine particle fraction (FPF) of remdesivir- and ebselen-containing dry powders were ~80% and ~57% when prepared without L-leucine. The ED as well as the FPF significantly increased with values of >86% and >67%, respectively, when L-leucine was incorporated. More importantly, the single and combinational dry powder of remdesivir and ebselen showed minimal cytotoxicity (CC50 > 100 μM) in Calu-3 cells, retaining their anti-SARS-CoV-2 properties (EC50 2.77 to 18.64 μM). In summary, we developed an inhalable dry powder combination of remdesivir and ebselen using a spray-drying technique. The spray-dried inhalable microparticles retained their limited cytotoxicity and specific antiviral properties. Future in vivo studies are needed to verify the potential use of these remdesivir/ebselen combinational spray-dried inhalable microparticles to block the SARS-CoV-2 replication in the respiratory tract.

Development, Physicochemical Properties, and Antibacterial Activity of Propolis Microcapsules.

Propolis is a well-known natural antibacterial substance with various biological activities, such as anti-inflammatory and antioxidant activity. However, applications of propolis are limited due to its low water solubility. In this study, propolis microcapsules were developed with a core material of ethanol extract of propolis and shell materials of gum arabic and β-cyclodextrin using a spray-drying technique. The optional processing formula, particle size distribution, morphology, dissolution property, and antibacterial activity of propolis microcapsules were determined. The results showed that the optional processing obtained an embedding rate of 90.99% propolis microcapsules with an average particle size of 445.66 ± 16.96 nm. The infrared spectrogram and thermogravimetric analyses showed that propolis was embedded in the shell materials. The propolis microcapsules were continuously released in water and fully released on the eighth day, and compared to propolis, the microcapsules exhibited weaker antibacterial activity. The minimum inhibitory concentrations (MICs) of propolis microcapsules against Escherichia coli and Staphylococcus aureus were 0.15 and 1.25 mg/mL, and their minimum bactericidal concentrations (MBCs) were 0.3 and 1.25 mg/mL, respectively. This water-soluble propolis microcapsule shows the potential for use as a sustained-release food additive, preservative, or drug.

Enhanced Thermal Decomposition and Safety of Spherical CL-20@MOF-199 Composites via Micro-Nanostructured Self-Assembly Regulation.

The characteristics of high burning rate, high energy output, and low pressure exponent have always been the focus of development in the field of composite solid rocket propellants. In this paper, a metal-organic framework (MOF-199) compound is introduced to prepare micro-nanospherical CL-20@MOF-199 composites via the spray-drying self-assembly technique to reach the above goals. MOF-199, which acts as an attractive combustion catalyst and a safety regulator, is uniformly coated on the surface of CL-20 with close interface contact between particles, effectively accelerating the thermal decomposition of CL-20 and ensuring safety performance. The average noncovalent interaction (aNCI) analysis illustrates that there are strong C-H···O hydrogen bonds and van der Waals interaction between CL-20 and MOF-199 molecules, greatly enhancing the effect of interparticle assembly. The effects of different contents of MOF-199 on the thermal, safety, and energy properties of CL-20 were discussed. The thermal analysis demonstrates that MOF-199 has a significant thermal catalytic effect on CL-20, with an advanced peak temperature of thermal decomposition of 14.2 °C and a reduced activation energy barrier of 34.2 kJ·mol-1, mainly benefitting from more exposed catalytic active sites and close interface contact. In addition, CL-20@MOF-199 composites exhibit decreased mechanical sensitivity (IS: 21-40 cm, FS: 80-240 N) and excellent energy performance. This work clearly demonstrates that MOF-199 is both a superior combustion catalyst and a good safety buffer for CL-20, and it opens new potential for further applications of CL-20 in composite solid propellants.

Effect of Microencapsulation on Functional Properties of Sugarcane Juice Acidified with Orthophosphoric Acid by Using Spray Drying Technique

Effect of Microencapsulation on Functional Properties of Sugarcane Juice Acidified with Orthophosphoric Acid by Using Spray Drying Technique

Human lactoferrin-clay mineral nanohybrids as emerging green biomaterials: A physicochemical characterization

Herein montmorillonite and halloysite have been exploited to prepare advanced lactoferrin-loaded nanohybrid biomaterials for potential biomedical applications. Nanohybrids were prepared following two methodologies: a traditional procedure which induces spontaneous drug-clay interactions to take place in aqueous environment and by spray drying, as alternative and preferred industrial technique for protein processing. Structural assembly of the obtained nanohybrids was assessed by solid state characterization techniques and determination of their surface charge properties. Full microscopy studies, including scanning electron microscopy and ultra-high resolution transmission electron microscopy coupled with EDS were also carried out. Cytotoxicity assays were performed to assess biocompatibility of nanohybrids towards human fibroblast cell cultures. Results showed that both intercalation-solution and spray drying procedures led to the effective formation of nanohybrids structures, with greater extent of peptide-clay mineral interactions in those obtained by spray drying. All the samples exhibited cell viability % higher than 80%, with best results for halloysite coupled with spray drying technique.

Formulation of Papaya Fruit Powder Incorporated Instant Drink Mix

Papaya (Carica papaya L.) is a tropical fruit with excellent health benefits. However, papaya fruit with soft flesh is easily damaged and susceptible to oxidative degradation, which is not favourable for extended storage and transportation. One way of preserving papaya fruit is by drying into powdered form using spray-drying or freeze-drying techniques. The papaya fruit powder can then be transformed into various products such as instant drink mix and health supplements. This study aims to develop a suitable formulation of papaya fruit powder incorporated instant drink mix with high nutritional content and good sensory properties. Six different combinations were tried with different amount of papaya powder and other ingredients and evaluated for their physical and sensory properties. According to the results, the most liked Sample 3 has the greatest acceptability score due to its optimal flavour, aroma, and taste. Proximate analysis of Sample 3 revealed moisture content (5.3%), total carbohydrate (77.7%), total fat (0.3%), ash content (4.1%), total dietary fibre (0.2%) and protein (12.6%) which was comparable to available commercial product. Furthermore, the microbial activity test showed that the total plate count of microbes is 7.3×103 CFU/gm which is categorized as accepted and satisfied. This study demonstrates a practical use of powdered papaya fruit incorporated into instant drink mix that can be nutritional and convenient with good sensory properties.

Evaluation of the Survival of Lactobacillus fermentum K73 during the Production of High-Oleic Palm Oil Macroemulsion Powders Using Rotor-Stator Homogenizer and Spray-Drying Technique.

This study aimed to evaluate the survival of the probiotic Lactobacillus fermentum when it is encapsulated in powdered macroemulsions to develop a probiotic product with low water activity. For this purpose, the effect of the rotational speed of the rotor-stator and the spray-drying process was assessed on the microorganism survival and physical properties of probiotic high-oleic palm oil (HOPO) emulsions and powders. Two Box-Behnken experimental designs were carried out: in the first one, for the effect of the macro emulsification process, the numerical factors were the amount of HOPO, the velocity of the rotor-stator, and time, while the factors for the second one, the drying process, were the amount of HOPO, inoculum, and the inlet temperature. It was found that the droplet size (ADS) and polydispersity index (PdI) were influenced by HOPO concentration and time, ζ-potential by HOPO concentration and velocity, and creaming index (CI) by speed and time of homogenization. Additionally, HOPO concentration affected bacterial survival; the viability was between 78-99% after emulsion preparation and 83-107% after seven days. The spray-drying process showed a similar viable cell count before and after the drying process, a reduction between 0.04 and 0.8 Log10 CFUg-1; the moisture varied between 2.4% and 3.7%, values highly acceptable for probiotic products. We concluded that encapsulation of L. fermentum in powdered macroemulsions at the conditions studied is effective in obtaining a functional food from HOPO with optimal physical and probiotic properties according to national legislation (>106 CFU mL-1 or g-1).

Microencapsulation of Bacillus subtilis and oat β-glucan and their application as a synbiotic in fish feed

To improve survival during storage and exposure to adverse conditions, Bacillus subtilis was microencapsulated with oat β-glucan by spray-drying technology. The characterisation of the microcapsules was designed to compare free and microencapsulated cells through exposure to simulated gastric fluids (SGF) throughout storage for 90 days at different temperatures. The characterisation included analysis of efficiency, morphology, moisture, water activity, hygroscopicity, particle size, and zeta potential. The microcapsules presented a particle size of 1.5 ± 0.34 μm and an encapsulation efficiency of 77.9 ± 3.06%. After SGF, the survival of microencapsulated cells was 8.4 ± 0.07 log CFU mL−1 while that of free cells was 7.6 ± 0.06 log CFU mL−1. After 90 days of storage, only microencapsulated cells remained above 6 log-unit of viability. In conclusion, spray-drying technique combined with the addition of oat β-glucan proved to be an efficient method to protect B. subtilis under storage and SGF with potential application in fish feed.

Preparation and molecular interaction of organic solvent-free piperine pro-liposome from soy lecithin

Pro-liposome is a type of drug delivery system (DDS) with numerous advantages as a stable material with various applicability for several pharmaceutical dosage forms, to effectively deliver the material to reach its target in the human body. Nevertheless, it is mostly designed by employing an organic solvent hence giving rise to safety issues. We have developed a method for the preparation of organic solvent-free liposomes composed of soy lecithin and cholesterol by highlighting the importance of temperature during the initial mixing process, a self-hydration of a thin layer spread film, and a spray-drying technique with a suitable excipient as the carrier. The method was successfully applied to prepare a stable pro-liposome containing 0.17% (w/w) of piperine with an encapsulation efficiency of 95.58 ± 2.91%. Moreover, the study revealed that a piperine molecule forms hydrophobic interaction with six of the adjacent phospholipids in the liposome structure, this information can be useful for researchers designing similar studies. In conclusion, organic solvent-free pro-liposome can be an alternative method in the development of DDS, and several factors could be continuously improved to fulfill the intended pro-liposome characteristic.

Stabilization of AlH3 Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate.

Aluminum hydride (AlH3) is a promising fuel component of solid propellant, but its stabilization is still challenging. Herein, surface functionalization of hydrophobic perfluoropolyether (PFPE) followed by ammonium perchlorate (AP) coating has been implemented. In particular, AlH3@PFPE@xAP (x = 10, 30, 50, or 64.21%) composites (AHFPs) were prepared by a spray-drying technique. The PFPE-functionalized AlH3 with a hydrophobic surface shows an increased water contact angle (WCA) from 51.87° to 113.54°. Compared with pure AlH3, the initial decomposition temperatures of AHFPs were increased by 17 °C, and the decomposition properties of AP in the AHFPs were also enhanced with significantly decreased peak temperature and fairly increased energy output. Moreover, the decomposition induction time of AHFPs-30% was improved by almost 1.82 times that of raw AlH3, which indicates that the coatings of PFPE and AP could improve the stability of AlH3. The maximum flame radiation intensity of AHFPs-30% was 21.6 × 103, which is almost 7.71 times that of pure AlH3 (2.8 × 103).

Evaluation of Lactic Acid Bacteria Isolated from Piglets Tract and Encapsulation of Selected Probiotic Cells

Fourteen lactic acid bacteria (LAB) strains were isolated from the intestinal tract and feces of piglets. Among these isolates, only twelve were biochemically (API 50 CHL and ABIS online for bacterial identification) and genetically (16S rRNA sequencing) confirmed as Limosilactobacillus fermentum, Lactobacillus acidophilus, and Lactiplantibacillus plantarum. Experiments to evaluate the probiotic potential of the isolates including pH tolerance (pH 2.0 and 3.0), bile salts (0.3% ox gall) resistance, hemolysis activity, antibiotic susceptibility, and high-temperature resistance were tested. Only two isolates from identified strains exhibited high survival rates when exposed to low pH and bile salts, these were L. acidophilus IBNA 76 and L. plantarum IBNA 84. The antibiotic test presented 100% resistance of both strains to gentamicin, kanamycin, lincomycin, colistin sulfate, erythromycin, amikacin, oxytetracycline, enrofloxacin, streptomycin, and tilmicosin, lower than the 0.6 mm inhibition zone diameter. Promising isolates (L. acidophilus IBNA 76 and L. plantarum IBNA 84) were exposed to the spray-drying technique based on visible probiotic potential and survival rates. Carrier matrix material was used as a maltodextrin-glucose solution. The encapsulation probiotic isolated survived both over 67% and 77%, corresponding to a decrease in strain viability from 109 to 107 CFU/g. After further in vitro evaluations, the findings of this study showed that, from all LAB strains, L. acidophilus IBNA 76 and L. plantarum IBNA 84 may be considered probiotic candidates for animal nutrition and may have promising performance in piglet feed due to their origin of isolation.

Pharmaceutical characterization of probucol bile acid-lithocholic acid nanoparticles to prevent chronic hearing related and similarcellular oxidative stress pathologies.

Background: Sensorineural hearing loss has been associated with oxidative stress. However, an antioxidant that passes effectively through the ear remains elusive. Method: Probucol (PB)-based nanoparticles were formed using a spray-drying encapsulation technique, characterized and tested in vitro. Results: Uniform, spherical nanoparticles were produced. The addition of lithocholic acid to PB formulations did not affect drug content or production yield, but it did modify capsule size, surface tension, electrokinetic stability and drug release. Cell viability, bioenergetics and inflammatory profiles were improved when auditory cells were exposed to PB-based nanoparticles, which showed antioxidant properties (p<0.05). Conclusion: PB-based nanoparticles can potentially protect the auditory cell line from oxidative stress and could be used in future in vivo studies as a potential new therapeutic agent for sensorineural hearing loss.

Microencapsulates of Blue Maize Polyphenolics as a Promising Ingredient in the Food and Pharmaceutical Industry: Characterization, Antioxidant Properties, and In Vitro-Simulated Digestion.

An anthocyanin-rich blue maize waste product was used for anthocyanin extraction. To preserve bioactive phenolic compounds, a spray-drying technique was employed using conventional wall material maltodextrin (MD), with novel one, hydroxypropyl-β-cyclodextrin (HPBCD). The obtained spray-dried maize extract (SME) and microencapsulates were analyzed based on physicochemical powder properties, chemical analysis, antioxidant activity, and digestibility. The examined microencapsulates demonstrated good powder properties, exhibited a high powder yield (up to 83%), and had a low moisture content (less than 5%). HPBCD and MD + HPBCD combinations demonstrated superior powder properties in the terms of decreasing the time necessary for rehydration (133.25 and 153.8 s, respectively). The mean average particle diameter ranged from 4.72 to 21.33 µm. DSC analyses signified high powder thermal stability, around 200 °C, related to the increasing preservation with biopolymer addition. The total phenolic and anthocyanin compounds ranged from 30,622 to 32,211 mg CE/kg (CE-catechin equivalents) and from 9642 to 12,182 mg CGE/kg (CGE-cyanidin 3-glucoside equivalents), respectively, associated with good bioactive compound protection. Microencapsulates with both carriers (15% MD and 15% HPBCD) had the highest digestibility (73.63%). Our results indicated that the microencapsulates created with the active ingredient and the wall materials (MD and HPBCD) could protect phenolic compounds/anthocyanins against ABTS radicals (63.53 and 62.47 mmol Trolox Eq/kg, respectively).

Development of Persian gum-based microcapsules to speed up the release of cinnamon essential oil in the simulated saliva conditions

In this study, spray-drying technique was used to develop Persian gum-based microcapsules having cinnamon essential oil (CEO) where, using a simple centroid mixture design, the proportion of maltodextrin to Persian gum was optimized. The response factors which were optimized included powder recovery, encapsulation efficiency, and the release of CEO. Based on the formulation optimization, 8.25% maltodextrin and 1.74% Persian gum were required to achieve the optimum microcapsules having the highest powder recovery, encapsulation efficiency and CEO release. The evaluation of the optimum microcapsules was carried out based on particle size, moisture content, solubility, in vitro release, antioxidant activity, Fourier transform infrared spectra (FTIR), differential scanning calorimetry (DSC), and chemical compositions through Gas Chromatography-Mass Spectrometry (GC-MS). Physical interaction between CEO and the wall materials was proved by the results of FTIR. Enhanced water solubility of the CEO and guarding impact on antioxidant activity were observed in the optimum microcapsules. The pattern of the release of encapsulated CEO from simulated saliva is best described as the Fickian diffusion mechanism where immediate release (80%) of the encapsulated CEO was observed. Based on the findings of this study, efficient and novel carriers for the encapsulation of essential oils could be developed through Persian gum microcapsules.

Enhancing the reaction efficiency and ignition performance of core-shell Al@HMX composites by precise catalysis of graphene-based carbohydrazide complexes

The incomplete combustion of aluminum in solid propellants leads to a low-level energy release. As a promising strategy, fuel/oxidizer interfacial control is proved to be effective for enhancing their reaction efficiency and less environmental dependence. In this paper, in order to investigate the effect of interfacial control on the reaction efficiency of Al and HMX, spherical Al@HMX composites with polydopamine as interfacial layer were prepared via spray-drying technique. The morphology, structure, heat of reaction, thermal stability, condensed/gaseous products, decomposition kinetics as well as the ignition performance of the composites under the catalytic effects of graphene-based carbohydrazide complexes (GO-CHZ-M, M = Co2+ or Ni2+) were comprehensively investigated. Results showed that the heat of reaction of Al@HMX increased by 220 J g−1 compared to corresponding physical mixture (5655 J g−1), which was further increased to 6210 J g−1 in presence of minor GO-CHZ-Co (1 wt%) as a catalyst. Moreover, the thermal decomposition temperature of HMX was slightly increased in Al@HMX composites. Under the synergy of interfacial control and GO-based catalysts, the enhanced reaction efficiency of Al with HMX was observed and verified by a shorter ignition delay time (reduced from 126 to 71 ms) and the condensed products analysis, with decreasing unreacted Al content and increasing content of submicron-sized particles. Gaseous products investigation illustrated that there were two main decomposition pathways for Al@HMX composites: the CN scission (dominant) and NN scission, where the latter could be enhanced by GO-CHZ-M catalysts.

Optimization, Fabrication and Characterization of Novel Meloxicam-Loaded Surface Attached Solid Dispersions to Ameliorate its Aqueous Solubility and Dissolution Employing Spray-Drying Technique

Objective: To formulate unmodified crystalline meloxicam solid dispersions by the use of surfactants and polymer. This polymeric particulate system is named as meloxicam-loaded surface attached solid dispersion (MSDs). Methodology: This experimental study was conducted at Lab of Physical and Industrial Pharmacy, Hanyang University, South Korea. The duration of this study was around seven months. The first phase of this study (optimization and fabrication) was completed within 3 months, while, solubility, dissolution and physicochemical characterization was completed in next 4 months. These surfaces attached solid dispersions were prepared by using spray drying technology. Moreover, HPMC and SLS were used as hydrophilic carriers. Various MSDs were prepared using carriers/drug, and were evaluated for aqueous solubility and dissolution studies. Results: Amongst different formulation prepared, MSDs3 having Meloxicam/HPMC/SLS in a (1:0.5:0.5) gave the highest solubility and dissolution (i.e. from 0.25 ±0.17ug/ml of meloxicam to 153 ±5.3ug/ml). Moreover, dissolution was enhanced from 2.96 ±0.55% to 47 ±1.07% at 15 minutes. Furthermore, physicochemical characterization was performed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). Conclusion: In conclusion we can predict a better solubility and dissolution of meloxicam in surface attached solid dispersion. Keywords: Meloxicam, solubility enhancement, spray drying, surface attached, solid dispersion

Characterization and Molecular Modelling of Non-Antibiotic Nanohybrids for Wound Healing Purposes.

The healing process of chronic wounds continues to be a current clinical challenge, worsened by the risk of microbial infections and bacterial resistance to the most frequent antibiotics. In this work, non-antibiotic nanohybrids based on chlorhexidine dihydrochloride and clay minerals have been developed in order to design advanced therapeutic systems aimed to enhance wound healing in chronic lesions. To prepare the nanohybrids, two methodologies have been compared: the intercalation solution procedure and the spray-drying technique, the latter as a one-step process able to reduce preparation times. Nanohybrids were then fully studied by solid state characterization techniques. Computational calculations were also performed to assess the interactions between the drug and the clays at the molecular level. In vitro human fibroblast biocompatibility and antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa were assessed to check biocompatibility and potential microbicidal effects of the obtained nanomaterials. The results demonstrated the effective organic/inorganic character of the nanohybrids with homogeneous drug distribution into the clayey structures, which had been confirmed by classical mechanics calculations. Good biocompatibility and microbicidal effects were also observed, especially for the spray-dried nanohybrids. It was suggested that it could be due to a greater contact area with target cells and bacterial suspensions.