Freeze-drying Technique Research Articles

Formulation and Characterization of Itraconazole as Nanosuspension Dosage Form for Enhancement of Solubility

Abstract
 Itraconazole is a triazole antifungal given orally for the treatment of oropharyngeal and vulvovaginal candidiasis, for systemic infections including aspergillosis, candidiasis, and for the prophylaxis of fungal infections in immunocompromised patients.
 The study aimed to formulate a practical water-insoluble Itraconazole, with insufficient bioavailability as nanosuspension to increase aqueous solubility and improve its dissolution and oral bioavailability.
 Itraconazole nanosuspension was produced by a solvent-antisolvent nanoprecipitation method in the presence of different stabilisers (Poloxamer-188, HPMCE5) at different ratios with the drug alone or combination with surfactant(tween 80, SLS).
 The results exhibit that the particle sizes of all prepared itraconazole formulations were in the nano size. The best formula (F6) has a particle size. ( 42 ) nm and Zeta potential of (- 21.86 ) mV. In vitro cumulative release from the nanosuspension was (88 %) at (30) min when compared to the pure drug (13%) and lyophilized nanoparticles (98.2%) at (30)min. Effect of different parameters was investigated.
 Fourier transforms infrared spectroscopy(FTIR), Differential scanning calorimetry (DSC) and X-ray diffraction (XRD), Scanning electron microscope( SEM) was done for the optimized nanoparticles prepared by lyophilization technique
 Thus, Nanosuspension appears to be an encouraging approach to formulate Itraconazole nanosuspension with high solubility and dissolution rate.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Keywords: Itraconazole, Nanoprecipitation method, Nanosuspension

Effect of microencapsulation using soy protein isolate and gum arabic as wall material on red raspberry anthocyanin stability, characterization, and simulated gastrointestinal conditions.

This study involves microencapsulation of anthocyanin extract (AC) from red raspberry using a freeze drying technique involving ultrasonication of soy protein isolate (SPI), gum arabic (AG), and their combination. Analyses included microcapsule properties, encapsulation efficiency, antioxidant capacity using the DPPH assay, Fourier-transform infrared spectroscopy (FTIR), color, thermal stability, stability during storage, morphology, and simulated gastrointestinal conditions. Encapsulation efficiency (EE) ranged from 93.05% to 98.87% for all microcapsules. The morphology of microcapsules by scanning electron microscopy (SEM) indicated a broken glass shape, with mean size of microcapsules ranging from 21.07±2.71μm to 48.19±2.33μm using Mastersizer analyzer. A good relationship obtained between zeta potential (ZP) and FTIR spectrum indicated that there is a chemical cross linking interaction between wall material and core material. All microcapsules enhanced the thermal stability of AC in the temperature range 80-114°C. Furthermore, AC retention (up to 48%) during storage at 37°C for 60days revealed that treatment H combination of SPI and AG was best. In addition, SPI and AG combination presented good release behavior under simulated gastrointestinal conditions compared with unencapsulated anthocyanin.

40 Comparison of slow and rapid freezing in freeze-dried ram spermatozoa

Semen lyophilisation is an interesting technique that might be a cheap alternative to long-term storage in liquid nitrogen. The first significant result of this method was achieved by Wakayama and Yanagimachi in the 1998 and demonstrated, for the first time, the birth of healthy mouse pups from epididymal freeze-dried (mouse) spermatozoa. The authors follow the lyophilisation technique, commonly used in the pharmaceutical and food industries, namely, deep freezing, which requires direct immersion of the semen sample into liquid nitrogen before vacuum drying. In this work, we focused on the freezing phase to improve and make the technique more reliable. We compared two protocols: 1) rapid freezing, where the semen is plunged directly into liquid nitrogen (LN group), and 2) slow freezing, where the sample is frozen with a freezing rate of 1°C min−1 until −50°C (SL group). Then, both frozen samples were lyophilized. Subsequently, after an interval ranging between 1 and 3 months, dry spermatozoa from LN and SL groups were used for intracytoplasmic sperm injection (ICSI), and the embryo development was evaluated at 24h (2-cell stage) and 7 days (expanded blastocyst) post-ICSI. Moreover, acrosome integrity was evaluated with Pisum sativum agglutinin (PSA) staining on part of the semen, immediately after freezing. The LN-group semen showed the acrosome completely melted, whereas the SL group showed better integrity of the acrosome, which was comparable to that of the normal frozen (vital) spermatozoa. At 24h post-ICSI the number of cleaved embryos in the SL group was higher than in the LN group (42/100 (42%) vs. 19/75 (25.3%), SL and LN, respectively; P=0.0253). The blastocyst rate 7 days after ICSI in the SL group was higher (7/100 (7%) than that in the LN group (2/75 (2.7%); P=0.0238). Our data show that lyophilisation can be conveniently achieved in ram spermatozoa without liquid nitrogen, thus simplifying the procedure. These data support the idea that lyophilisation might be a valuable and cheaper alternative to liquid nitrogen for long-term storage of ram semen.

Preparation and characterization of glass–ceramic reinforced alginate scaffolds for bone tissue engineering

Abstract

Effects of salt concentration on the structure and properties of composite fiber of carboxymethyl cellulose/N-2-hydroxylpropyl trimethyl ammonium chloride chitosan prepared by polyelectoyte complexation-freeze drying

The conventional electrospinning process for the preparation of fibers usually require complex equipment and complicated preparation processes, as well as chemical crosslinkers and organic solvents, which limits its application in the preparation of biomedical materials. In the current study, carboxymethyl cellulose/N-2-hydroxylpropyl trimethyl ammonium chloride chitosan (CMC/HACC) composite fibers were fabricated by polyelectrolyte complexation (PEC) and freeze drying coupled method in both pure water and NaCl solution. The structures of the as-prepared fibers and the effects of NaCl concentration on the structures of fibers were studied by FTIR, solid 13C NMR, XRD, XPS and SEM. The formation mechanism of the composite fiber and the effects of NaCl concentration on structure and properties of the composite fiber were simulated in the Materials Studio software and discussed. The swelling properties and the thermal decomposition kinetics of the composite fiber were studied. The results suggest that the addition of NaCl electrolyte to the complexing system significantly affects the structure and properties of the PEC fiber. Our work has provided a new preparation route to the composite fibers of natural polymers with controllable structures and properties by the combination of PEC and freeze drying techniques using NaCl with desired concentration as the electrolyte.

Effects of the high-pulsed electric field pretreatment on the mechanical properties of fruits and vegetables

A high-pulsed electric field (HPEF) technique show potentials to reduce the drying time and energy consumption of a vacuum freeze-drying technique, which can maintain the nutritional and sensory properties of the foods. It is important to understand effects of the HPEF treatment and the optimized operation parameters on changing the mechanical properties of fruits and vegetables for improvement of the vacuum freeze-drying process. The viscoelastic properties of four types of fruits and vegetables with and without the HPEF pretreatment were studied using experimental measurements of the stress relaxation and creep of the fruits and vegetables. The stress relaxation parameters of the fruits and vegetables were estimated according to the Generalized Maxwell model. The values of the equilibrium elastic modulus (Ee) decreased more than 92%, and relaxation time (T) values decreased more than 17%, after HPEF pretreatment. The creep parameters of the fruits and vegetables were estimated according to the Burger four-parameter model. The values of the instantaneous elastic modulus (E0) decreased more than 70%, the retarded elastic modulus (Er) decreased more than 92%, and the viscosity coefficient (ηr) decreased more than 94% after the HPEF pretreatment. The results showed that the HPEF pretreatment improved the vacuum freeze-drying process.

The effect of biomimetic coating and cuttlebone microparticle reinforcement on the osteoconductive properties of cellulose-based scaffolds

Polymer-based scaffolds have already gained popularity in many biomedical applications due to convenient routes for fabrication and favourable structural, physicochemical and functional characteristics. However, polymeric scaffolds lack osteoconductivity and some synthetic polymers carry the risk of inflammatory response caused by degradation by-products. Those facts limit their practical use in bone tissue engineering. In this study, three-dimensional (3D) porous scaffolds from naturally derived polymer, namely regenerated cellulose, were prepared using a non-hydrolytic sol-gel and lyophilization techniques. To induce osteoconductive properties of the polymeric scaffolds, cuttlebone microparticles were immobilized and the surface coating was achieved via in vitro mineralization using 10-fold concentrated simulated body fluid (10x SBF). Biogenic activity of cuttlebone is explained by its chemical composition, which includes polysaccharide β-chitin and macro-, micro- and trace elements favourable for mineralization. Parallel the scaffolds were examined during long-term (24 weeks) in vitro mineralization in 1x SBF for the purpose to investigate apatite-forming ability of the scaffolds. A nice cauliflower-like structures and needle-like dents of the spherical aggregates, which are characteristic to hydroxyapatite precursors, were observed on the surface of cellulose/cuttlebone scaffolds by SEM. 10x SBF coating enhanced cell attachment to the scaffolds because SBF elements are known to increase bioactivity by inducing re-deposition of carbonate apatite crystallites on scaffold surface. Additionally, calcium and phosphate depositions were clearly observed on the developed scaffolds using von Kossa and Alizarin Red S staining. Proliferative and osteoconductive effects on the osteoblast-like MG-63 cells demonstrate the cellulose/cuttlebone scaffolds soaked in 10x SBF as a favourable material for bone tissue engineering.

Freeze-drying enables homogeneous and stable sample preparation for determination of fecal short-chain fatty acids

BackgroundThe analysis methods for fecal short-chain fatty acids (SCFAs) have evolved considerably. Recently, the role of SCFAs in gastrointestinal physiology and their association with intestinal microbiota and disease were reported. However, the intra-fecal variability and storage stability of SCFAs have not been extensively investigated. The aim of this study was to understand the limitations of the measurement of SCFAs in crude feces and develop a useful pre-examination procedure using the freeze-drying technique. MethodsSCFAs in crude feces, obtained from healthy volunteers, and freeze-dried feces were determined by derivatization with isobutyl chloroformate, followed by liquid–liquid extraction with hexane, and separation and analysis using gas chromatography–mass spectrometry. ResultsAmong the SCFAS, the maximum intra-fecal variability was observed for iso-butyrate (coefficient of variation of 37.7%), but the freeze-drying procedure reduced this variability (coefficient of variation of 7.9%). Similar improvements were also observed for other SCFAs. Furthermore, significant decreases in the SCFA amounts were observed with storage at 4 °C for 24 h. ConclusionsThe freeze-drying procedure affords fecal SCFA stability, even with storage at room temperature for 3 d. The freeze-drying procedure allows reliable SCFA measurements without labour-intensive processes. Therefore, the freeze-drying procedure can be applied in basic, clinical, and epidemiological studies.

Optimal Use of Thai Sinlek Rice (IR) Provides the Nutraceutical Effect on Erythropoiesis in Rats

Iron-deficiency anemia (IDA) is the major cause of anemia in developing countries commonly associated with poor nutrition, pregnancy, celiac disease, hook-worm infestation and aging process. Iron fortification in staple food is recommended to help preventing IDA; however, the iron dosing may cause adverse effects and oxidative damage to the gut lumen resulting in gastrointestinal irritation and poor absorption. The Thai Sinlek rice (Oryza sativaL.) (IR) was developed as a new crossbreed of Jasmine (Hom nin) rice and white (Hom Mali 105) rice (WR) and is abundant with iron, phenolic compounds, tocopherols and tocotrienols. Previously, the consumption of IR drink (14.7 mg/100-mL serving/d) for 1 month significantly increased levels of hemoglobin (Hb) and tended to increase levels of serum iron (SI) and transferrin saturation (TS) in anemic elderly subjects. However, the nutraceutical effect of IR from iron fortification together with potential oxidative effects have not been properly tested in an animal model. To prepare the functional IR, we digested IR grains with a-amylase and dried the hydrolysate by using lyophilization technique. Iron content of the hydrolysate was determined using ferrozine colorimetric and inductively coupled plasma-mass spectrometry (ICP-MS) methods. IR hydrolysate was found to contain 13.9 mg iron/g dry weight compared with 1.94 mg iron/g in white rice (WR). Antioxidant activity was assayed using 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid radical (ABTS*) decolorizing method,and anti-hemolysis activity was determined using 2,2-azobis(2-amidinopropane) dihydrochloride radical (AAPH*) induced red blood cells (RBC) method as shown in Figure 1. The IR hydrolysate has higher antioxidant and anti-hemolysis activities in a dose dependent manner compared to the WR hydrolysate and controls (PBS). HPLC analysis also showed some amounts of phenolic compounds, g-oryzanol, tocopherols and tocotrienols in the IR hydrolysate (data not shown). To assess luminal absorptivity of iron, two Wistar rats were fed once with the IR hydrolysate (500 mg/kg body weight) and collected blood samples at different time points for 24 h. The finding reveals an increment of serum iron (SI) and transferrin saturation (TS) levels at 5 h and the maximum levels at 15 h (Figure 2). Finally, to study nutraceutical effects of the IR hydrolysate, Wistar rats (5 males, 5 females) were fed with the IR (50, 100 and 200 mg/kg) for 3 months and sacrificed for blood collection and analysis. Hematological parameters were determined using an automated Coulter cell counter (Table 1). The treatment with the IR at 50 mg/kg was found to increase significantly levels of RBC parameters e.g., Hb, hematocrit (Hct), red blood cell counts (RBC) and mean corpuscular volume (MCV) and total white blood count compared to higher dosing of the IR and control with deionized water (DI). In the highest IR dose (200 mg/kg), Hb, Hct and RBC were lowest suggesting a potential iron related toxicity probably on chronic intestinal inflammation. Our finding highlights that the optimal use of the IR should balance between the benefit from iron fortification to enhance hematopoiesis by preventing IDA against the risk of iron toxicity from dosing due to excessive free iron species and redox activity generation. Disclosures No relevant conflicts of interest to declare.

Development and mechanical characterization of bilayer tubular scaffolds for vascular tissue engineering applications

Poly(l-lactide-co-e-caprolactone) (PLCL) is a potential material to fabricate scaffolds for vascular tissue engineering. In this work, scaffolds with a multilayered structure comprising a combination of porous and fibrous structures were developed. PLCL was used to fabricate the inner layer of the tubular scaffolds using the freeze-drying technique. The inner layer was then covered by an outer layer fabricated by the melt-spinning technique. The morphology and physical structure of the scaffolds were evaluated through SEM micrographs. The freeze-drying technique formed a porous structure, while the melt-spinning method formed a fibrous structure for the bilayer scaffolds. Physicochemical properties were also investigated by DSC and FTIR measurements; no new functional groups were found to have formed during the freeze-drying or melt-spinning processes. Mechanical properties and fracture mechanism under a tensile loading condition were carefully analyzed to characterize the deformation and fracture behaviors. It was found that the bilayer scaffolds exhibited better mechanical properties than single-layer scaffolds with higher maximum stress at 675.41 kPa, strain at maximum stress at 69.42%, fracture energy at 412.45 kJ/m3 and burst pressure at 147.93 kPa. Porosity, swelling ratio and in vitro biodegradation were measured to ensure its suitability for vascular tissue applications. The bilayer scaffolds with both porous and fibrous structures meet the requirements for vascular tissue engineering.

Effect of phosphate glass reinforcement on the mechanical and biological properties of freeze-dried gelatin composite scaffolds for bone tissue engineering applications

Development of three-dimensional scaffolds is an important step in tissue engineering to repair, rebuild and regenerate damaged tissues. In this study, three dimensional porous gelatin (G) and phosphate glass (PG, 1 and 2 wt%) reinforced gelatin composite (GPG1 and GPG2) scaffolds were developed by freeze drying technique and their suitability as tissue engineering scaffolds was evaluated. FESEM images revealed the formation of an interconnected porous network with porosity above 70% and pore size around 100−500 μm. The developed scaffolds showed swelling, biodegradation and apatite formation on the surface of the scaffolds. Four fold enhancement in compressive modulus was observed with the introduction of PG content in the gelatin matrix which increased further with increase in PG content. Cytotoxicity and cell attachment of the scaffolds were evaluated with MG-63 cells, which revealed non-toxic nature of the scaffold leading to attachment of cells. Cell proliferation of MG-63 on the scaffolds was examined by DNA quantification assay, which showed increased proliferation with PG content and further increase with increase in PG content. In order to evaluate the drug delivery performance of the PG reinforced gelatin composite, ciprofloxacin loaded gelatin and composite (GPG1 and GPG2) samples were prepared and release study was carried out. Prolonged and sustained release behaviour was observed for the PG reinforced gelatin scaffolds which were due to the strong interaction between the PG-ciprofloxacin-gelatin and Fickian diffusion mechanism was observed for GPG2 scaffold. The present study showed that the PG reinforced gelatin scaffold is a potential candidate for bone tissue engineering applications and also serve as drug delivery system.

Chitosan-Hydroxyapatite Scaffold for Tissue Engineering in Experimental Lumbar Laminectomy and Posterolateral Spinal Fusion in Wistar Rats.

Study DesignExperimental study with an animal model.PurposeTo evaluate the role of a chitosan and hydroxyapatite composite for spinal fusion in a lumbar experimental model based on regenerative tissue engineering principles.Overview of LiteratureChitosan and hydroxyapatite represent an alternative biodegradable implant material for tissue engineering and regeneration. The combination of chitosan and hydroxyapatite in a 20:80 ratio could potentiate their individual properties as an implantable composite for experimental laminectomy.MethodsPhase I: design and synthesis of a porous composite scaffold composed of chitosan-hydroxyapatite using a freeze drying technique. Phase II: experimental microsurgical lumbar laminectomy at L5. A total of 35 Wistar rats were categorized into three experimental groups: control (laminectomy alone), experimental (laminectomy with implant), and reference (intact spine) (n=5 per group). Postoperative structural and functional evaluations were performed using computed tomography scans. In addition, radiologic, clinical, histological, and immunohistochemical microstructures were evaluated.ResultsAt the laminectomy site, the composite implant induced bone regeneration, which was observed in the axial reconstruction of the rat lumbar spine in all cases. Biomechanical changes in the lumbar spine were observed by radiology in both groups after the surgery. The posterolateral space was covered by a bone structure in the treated spine, a condition not seen in the control group. The range of motion was 7.662°±0.81° in the scaffold group versus 20.72°±3.47° in the control group. Histological findings revealed qualitatively more bone tissue formation in the implant group.ConclusionsA composite of chitosan-hydroxyapatite at a 20:80 ratio induced bone formation after experimental laminectomy in rats and led to spinal fusion, which was assessed by radiology and biomechanical tests. No functional complications in posture or walking were observed at 90 days post-surgery, despite biomechanical changes in the spine.

Synergy between surfactants and mucoadhesive polymers enhances the transbuccal permeation of local anesthetics from freeze-dried tablets.

We report on the advance of freeze-dried mucoadhesive orodispersible tablets (ODTs) loaded with prilocaine (PRC) and lidocaine (LDC) hydrochlorides, aiming to promote noninvasive buccal anesthesia. The influences of combining biocompatible polymers (pullulan and HPMC K100 LV) and a blend of surfactants (oleic acid, polysorbate 80 and propylene glycol) acting as chemical enhancers on the permeation of such drugs through the esophageal porcine epithelium and in vitro mucoadhesion were investigated. The ODTs were also characterized in terms of average weight, thickness, pH, drug content, in vitro release, thermal behavior and scanning electronic microscopy. A dissolution test showed fast drug release within one hour. The drug release data for all ODTs fitted first order. No significant influence of the type of mucoadhesive polymer on release was observed, while the drug release from ODTs decreased in the presence of chemical enhancers. For the ODT containing pullulan the drug release mechanism was anomalous transport, whist for all others it was case-II transport. A remarkable synergic effect between pullulan and chemical enhancers on the permeation flux, lag time, and permeability coefficient of both drugs, but mainly for PRC was observed. Pullulan together with permeation enhancers also substantially improved the work of mucoadhesion as compared to HPMC. In contrast, HPMC improved drug retention in the epithelium. The novel drug delivery platform achieved by combining a freeze-drying technique, mucoadhesive biocompatible polymers, and chemical permeation enhancers displayed an effective strategy for the transbuccal delivery of PRC and LDC that can be used to improve needle-free buccal anesthesia.

Microcapsule efficiency of ethanol extract of rosella petal flower (hibiscus sabdariffa linn) coated crude carrageenan (Eucheuma cottony)

The research of microcapsule efficiency of ethanol extract of sepal flower (Hibiscus sabdariffa Linn) coated crude carrageenan has been done. The aim of research is to determine the highest efficiency microencapsulation based on the ratio of ethanol extract of the sepal flower toward seaweed crude carrageenan (Eucheuma cottony ) as coating substance. The microencapsulation was carried out by using freeze drying technique. This encapsulation may preserve the active compound of ethanol extract. Ratio of ethanol extract of the sepal flower toward seaweed crude carrageenan were set at 1:3; 1:4; 1:5; 1:6 and 1:7 (w/w). The result of research obtained that the highest efficiency ratio is at 1:7 with percentage of 86.01%.

Bio-based i-carrageenan aerogels as efficient adsorbents for heavy metal ions and acid dye from aqueous solution

Iota-Carrageenan (i-carrageenan) was cross-linked with Polyamidoamine hyperbranched polymer generation 1 (PAMAM). The resulted hydrogels were dried using freeze-drying technique to give new bio-based i-carrageenan aerogels. These aerogels were characterized using FT-IR and their nitrogen contents were determined using Kjeldahl method. The morphology and the surface areas of the aerogels were investigated using scanning electron microscope and Brunauer–Emmett–Teller method, respectively. The ability of the aerogels to remediate different metal ions e.g. Cr(VI), Mn(II), Co(II), Cu(II), or Cd(II) and alphanol fast blue dye (acid dye) from aqueous medium was carefully investigated. The removal investigation was conducted without pH adjustment in case of metal ions and at pH 2 for acid dye. The aerogel with the higher nitrogen content (CAR4) exhibited the highest remediation efficiency of both metal ions and acid dye.

Optimization of microencapsulation conditions of transglutaminase by freeze drying.

Transglutaminase (TG), which is an important enzyme for food processing, can enhance the firmness, viscosity and water binding capacity of food products by catalyzing the cross-linking reaction of proteins. Since preservation of the enzyme activity is essential, the production of microencapsulated powder form of TG can be a great challenge to maintain its initial activity. In this study, TG was microencapsulated using a freeze drying technique and the effects of homogenization conditions and coating material ratios on the enzyme activity were investigated using D-optimal combined design. Mannitol, gum arabic and casein were chosen as coating materials and different homogenization times (1-5min) and homogenization rates (11,200-20,000rpm) were applied. The optimum conditions which ensure the maximum enzyme activity have been determined as 11,200 rpm of homogenization rate, 1.27min of homogenization time, and in addition a mixture of mannitol, gum arabic and casein with ratios 38.2, 40.2, and 21.6%, respectively. Most of the activity loss occurred in the homogenization stage and the coating materials preserved enzyme activity during freeze drying. At the optimum point, the remaining activity of the microencapsulated TG was 93% while that of the crude (without coating materials) TG was 64% at the same drying conditions. Moreover, the effects of the microencapsulation conditions on the physical properties of powder such as moisture content, color, particle, bulk and tapped densities, porosity and flowability were determined.

Effective mRNA pulmonary delivery by dry powder formulation of PEGylated synthetic KL4 peptide

Pulmonary delivery of messenger RNA (mRNA) has considerable potential as therapy or vaccine for a range of lung diseases. Inhaled dry powder formulation of mRNA is particularly attractive as it has superior stability and dry powder inhaler is relatively easy to use. A safe and effective mRNA delivery vector as well as a suitable particle engineering method are required to produce a dry powder formulation that is respirable and mediates robust transfection in the lung. Here, we introduce a novel RNA delivery vector, PEG12KL4, in which the synthetic cationic KL4 peptide is attached to a monodisperse linear PEG of 12-mers. The PEG12KL4 formed nano-sized complexes with mRNA at 10:1 ratio (w/w) and mediated effective transfection on human lung epithelial cells. PEG12KL4/mRNA complexes were successfully formulated into dry powder by spray drying (SD) and spray freeze drying (SFD) techniques. Both SD and SFD powder exhibited satisfactory aerosol properties for inhalation. More importantly, the biological activity of the PEG12KL4 /mRNA complexes were successfully preserved after drying. Using luciferase mRNA, the intratracheal administration of the liquid or powder aerosol of PEG12KL4 /mRNA complexes at a dose of 5μg mRNA resulted in luciferase expression in the deep lung region of mice 24h post-transfection. The transfection efficiency was superior to naked mRNA or lipoplexes (Lipofectamine 2000), in which luciferase expression was weaker and restricted to the tracheal region only. There was no sign of inflammatory response or toxicity of the PEG12KL4 /mRNA complexes after single intratracheal administration. Overall, PEG12KL4 is an excellent mRNA transfection agent for pulmonary delivery. This is also the first study that successfully demonstrates the preparation of inhalable dry powder mRNA formulations with in vivo transfection efficiency, showing the great promise of PEG12KL4 peptide as a mRNA delivery vector candidate for clinical applications.

Formulation and characterization of cyclophosphamide injections using lyophilization technique

Introduction: The parenteral route of administration is generally adopted for rapid onset of action and 100% bioavailability especially for the drugs which have poor bioavailability through peroral route. Newly developed drugs often show poor solubility and require novel dosage forms such as liposomes, nanoparticles to minimize solubility problems and side effects due to toxicity. These dosage forms are often inherently labile due to agglomeration, sedimentation etc., and can be stabilized and manufactured by freeze drying. Lyophilization is the most common method for manufacturing solid pharmaceuticals products and is central to the preservation of materials which must be dried thoroughly in order to ensure stability and require a gentle, easily sterilizable process. Materials and Methods: The current research work involves the formulation of cyclophosphamide injections using lyophilization technique by using different concentrations of cyclophosphamide. The formulated cyclophosphamide injections are further subjected to different evaluation tests such as melting point, differential scanning calorimetry, dissolution rate study, solution stability, pH stability, rubber stopper compatibility and photostability. Results: The moisture content of the formulation is greatly reduced to as low as 0.9% (w/w) thus enhancing the stability of the product. Conclusion: The lyophilized technique proved to be an advantage for the development of stable injectable dosage form of Cyclophosphamide. Keywords: Lyohilization, Stability, Sterilized, cyclophosphamide, Mannitol.

Application of encapsulated natural bioactive compounds from red pepper waste in yogurt

Aim: The aim of this study was to encapsulate red pepper waste (RPW) bioactives and monitor their stability in yogurt.Methods: RPW extract was encapsulated in whey protein using spray and freeze-drying techniques. Physicochemical characteristics of encapsulates were evaluated, and better encapsulates were used to develop functional yogurt. Retention of bioactives was followed over 21 days of storage, and sensory analyses were assessed.Results: Freeze-dried encapsulates (FDE) showed better characteristics like water activity, moisture content, solubility, flowing and colour properties, and, therefore, incorporated in yogurt. Yogurt with FDE successfully retained carotenoids (71.43%) and caused increasing of polyphenol retention (up to 123.73%). This yogurt exhibited higher sensory and general acceptability scores compared to control sample. The fortification of yogurts had a positive influence on maintaining the initial number of lactic acid bacteria during storage.Conclusion: Freeze drying and utilisation of pepper waste are efficient for functional food development, with improved nutritional, colour and bioactive properties.

Grain boundary strengthened W-ZrB2 alloy via freeze-drying technique and spark plasma sintering

Using new dispersant (PVP), freezing drying technique and spark plasma sintering (SPS), W-(0–1.0)ZrB2(wt.%) alloys were fabricated. Compared with pure tungsten, the mechanical properties of W-ZrB2 alloys were remarkably improved. The highest strength was increased by 300% and the highest hardness was increased by 88%. Analysis showed that dispersion particles were evenly distributed in the grain interior and boundary in all W-ZrB2 alloys, no significant agglomerations were observed. More importantly, complete transgranular fracture morphology was observed in all W-ZrB2 alloys which was very different from common sintered tungsten alloys. Based on experiments and literature research, it was speculated that a considerable amount of ZrB2 decomposed and reacted with carbon and oxygen elements remaining in tungsten. Through decomposition, purification, regeneration mechanism, the formation of W-Zr-Bx-Cy-Oz and interaction between W and ZrB2 could effectively purify the grain boundary and increase the grain boundary cohesion.