Improved Flow Properties Research Articles

The Association Between the Structure of the Fatty Chain in Amides and Their Lubricating Performance in Acrylonitrile‐Butadiene‐Styrene (ABS) Resins

ABSTRACTThe exploitation of efficient lubricants for ABS resins is widely recognized as beneficial for industrial production. Fatty diamides are typically applied as the lubricants for ABS resins; however, the connection between fatty chain structures and the lubricating properties is still vague. In this work, a range of ethylenediamine‐based amide lubricants (EDA‐Cn) with different fatty chain structures were successfully prepared and chemical structures were characterized in detail by the Fourier transform infrared spectrometer and proton nuclear magnetic resonance. The rheological test results suggested that the complex viscosity and relaxation time were positively associated with the fatty chain lengths of EDA‐Cn. The dynamic mechanical analysis results confirmed that EDA‐Cn exhibited excellent compatibility with ABS resins. The lubricating effect of EDA‐Cn decreased with increasing fatty chain lengths, which was manifested by a higher glass transition temperature, and lower elongation at break of ABS resins. In comparison to EDA‐C22, the complex viscosity (angular frequency = 0.1 rad/s) and glass transition temperature of EDA‐C10 have decreased by 24.9% and 3.9%, respectively. The molecular dynamics simulations revealed the intrinsic mechanism of lubricant‐substrate interaction. The EDA‐Cn containing short fatty chain lengths reduced the interaction energy with the matrix, thereby promoting the diffusive movement of the chain segments, and resulted in the increase in the mean square displacement and improved flow properties. These findings provided sufficient theoretical basis for the rational design and preparation of lubricants for ABS resins.

SPHERICAL AGGLOMERATION OF TELMISARTAN - AN APPROACH TO IMPROVE PHYSICOCHEMICAL PROPERTIES

The study explains the preparation of spherical agglomerates (SA) of telmisartan (TLS), a BCS class II drug used to improve it’s physicochemical and bulk properties. Drugs of this class could potentially exhibit dissolution rate limited absorption. TLS spherical agglomerates were designed using hydrophilic polymer (PVP K-30), dimethyl formamide (DMF), water and ethyl acetate (bridging liquid) by solvent change method and evaluated for micromeritic properties. The SA were characterized by particle size determination, FTIR, PXRD and SEM. The results of micromeritic studies indicated that SA showed improved flow properties due to their spherical shape and bigger size. Absence of strong interaction at molecular level and alteration in the crystal structure of TLS with modification in crystallinity was confirmed by FTIR and PXRD respectively. TLS solubility characteristics were improved by this approach.

Internal friction and flowability of clay powder depend on particle moisture, size and normal stress

This work investigates the impact of changes in the moisture content of bulk materials. The regularity of moisture change in bulk materials was evaluated for three different particle size classes of clay powders. The research measures the angle of internal friction and flowability under four different normal loads, reflecting the varying pressures during bulk material storage. The influence of moisture change in bulk materials was most pronounced for the smallest particle size fraction, where even a very small moisture change in the order of tenths of a percent steeply affected flowability due to internal friction. After increasing the moisture content by a few percent, a steady state of flow occurred. Critical value was determined when water in the bulk material caused liquefaction. For larger particle size fractions, the impact of moisture change was evident only at higher values (12.5%), with no liquefaction occurring even at 30% moisture. The change in normal load, on the other hand, affected particles of larger size fractions, resulting in improved flow properties.

In Situ Hydrogel-Forming Powders Containing Eutectic Mixture of Curcumin-Arginine as a Multi-Drug Delivery System for Wound Healing Applications

Background: Curcumin (CUR) has antimicrobial, anti-inflammatory, and antioxidant bioactivities and is a promising molecule to treat chronic wounds. However, CUR shows limited oral bioavailability due to low aqueous solubility and dissolution, chemical instability, and rapid metabolism in the gastrointestinal tract and liver. Therefore, topical delivery seems to provide therapeutic concentrations of CUR in a controlled manner. Arginine (ARG) promotes the wound healing process. CUR and ARG form a eutectic mixture (EMCA) that can be used for simultaneous improvement of dissolution of CUR and combinational wound therapy. Here, we have formulated in situ hydrogel-forming powders of EMCA using hydrophilic carriers. Methods: EMCA was prepared by liquid-assisted grinding and analyzed by powder X-ray diffraction (PXRD) and Fourier transform infrared (FT-IR) methods. The formulations were prepared by mixing EMCA with sodium carboxy methyl cellulose, sodium alginate, and polyethylene glycol. Optical microscopy, flow property, dissolution rate, water uptake, hydrogel forming ability, release profile, and antioxidant activity of the formulated powders were measured and compared with raw CUR. Results: The solid-state analyses revealed the formation of EMCA. Photographs showed that EMCA exhibited a lower particle size than raw CUR and ARG. The formulation content significantly affected fluid uptake, hydrogel-forming ability, and dissolution rate. The optimized formulation (FEP5) showed a considerable enhancement in the dissolution rate of CUR and could control the release. FEP5 also demonstrated promising characteristics including high fluid uptake and suitable hydrogel-forming ability. FEP5 enhanced the antioxidant activity of CUR from 9% to 50%. Additionally, FEP5 exhibited improved flow properties compared to raw CUR, which is crucial for practical applications in wound therapy. Conclusion: Current work highlighted the potential of EMCA formulated as a hydrogel-forming powder as a novel formulation with improved dissolution, rapid fluid uptake, inexpensive components, feasible method of preparation, and easy application and removal for combinational wound therapy

Characterization of Acid Hydrolyzed Taro Boloso-I (Colocasia esculenta Cultivar) Starch as a Diluent in Direct Compression of Tablets.

Corn, wheat, rice, potato, and cassava starches have been widely used as pharmaceutical excipients. However, the search for cost-effective local starch alternatives is necessary due to the availability and usage constraints. In Ethiopia, various plant species, including Taro Boloso-I, have been explored as potential sources of pharmaceutical starch. It is a variety of Colocasia esculenta with a high tuber yield and high starch content. However, the native starch requires modifications to enhance its functionality. Therefore, this study aimed to improve the native starch through acid modification and evaluate its performance as a direct compressible tablet excipient. The native starch was treated with a 6% w/v HCl solution for 192 hours, resulting in acid-modified Taro Boloso-I starch, which was then evaluated for suitability for direct compression. XRD patterns of both the native and modified starch showed characteristic A-type crystals, with significantly higher relative crystallinity observed in the latter. Additionally, the acid-modified starch exhibited a lower moisture content and improved flow properties. The compaction study also demonstrated its improved compactibility (tensile strength: 16.82 kg/cm2), surpassing both the native starch (13.17) and Starch 1500® (11.2). The modified starch also showed a lower lubricant sensitivity compared to the native starch and Starch 1500®. Furthermore, paracetamol tablets made with the modified starch exhibited higher mechanical strength and lower friability in all paracetamol concentrations. It incorporated up to 40% paracetamol while maintaining acceptable tablet characteristics, whereas the native starch and Starch 1500® were limited to 30% (w/w). Based on these findings, the modified starch showed promise as an alternative direct compressible excipient in tablet manufacturing.

Improvement of Flow Properties of Highly Waxy Crude Oil with the application of SiO2 and Graphene Oxide nanoparticles aided by Light Crude Oil

The rheological behaviour of crude oil mixtures comprising both heavy and light components along with chemical additives is of significant interest due to its relevance in the petroleum industry. Understanding the flow properties of these mixtures is crucial for efficient transportation, processing, and refining operations. This study investigates the effectiveness of incorporating light crude oil and nanoparticles as additives to mitigate wax-related flow issues. The test involves six different waxy/heavy and light crude oil mixture concentrations along with Graphene Oxide and Silicon Dioxide nanoparticles. Rheological tests were conducted to evaluate the impact of these additives on the flow behaviour of waxy crude oil. The rheological characterization involved measuring the viscosity, yield stress, and shear rate dependencies of waxy crude oil samples with varying concentrations of light crude oil and nanoparticles. Nano-materials have emerged as promising candidates for mitigating wax deposition issues and enhancing the fluidity of crude oil. Nevertheless, the intricate nature of crude oil has made it challenging to elucidate the underlying mechanisms governing wax resolution, crystal modification, and flow improvement. The results revealed notable improvements in the rheological properties of the treated crude oil, including reduced viscosity and enhanced flowability, even at low temperatures. The incorporation of light crude oil and nanoparticles proved to be a promising strategy for modifying the rheological behaviour of waxy crude oil, ensuring improved flow assurance. This study contributes to understanding innovative approaches to address flow challenges in waxy crude oil systems, thereby offering potential solutions for the oil and gas industry.

Enhanced Apigenin Dissolution and Effectiveness Using Glycyrrhizin Spray-Dried Solid Dispersions Filled in 3D-Printed Tablets.

This study aimed to prepare glycyrrhizin-apigenin spray-dried solid dispersions and develop PVA filament-based 3D printlets to enhance the dissolution and therapeutic effects of apigenin (APN); three formulations (APN1-APN3) were proportioned from 1:1 to 1:3. A physicochemical analysis was conducted, which revealed process yields of 80.5-91% and APN content within 98.0-102.0%. FTIR spectroscopy confirmed the structural preservation of APN, while Powder-XRD analysis and Differential Scanning Calorimetry indicated its transformation from a crystalline to an amorphous form. APN2 exhibited improved flow properties, a lower Angle of Repose, and Carr's Index, enhancing compressibility, with the Hausner Ratio confirming favorable flow properties for pharmaceutical applications. In vitro dissolution studies demonstrated superior performance with APN2, releasing up to 94.65% of the drug and revealing controlled release mechanisms with a lower mean dissolution time of 71.80 min and a higher dissolution efficiency of 19.2% compared to the marketed APN formulation. This signified enhanced dissolution and improved therapeutic onset. APN2 exhibited enhanced antioxidant activity; superior cytotoxicity against colon cancer cells (HCT-116), with a lower IC50 than APN pure; and increased antimicrobial activity. A stability study confirmed the consistency of APN2 after 90 days, as per ICH, with an f2 value of 70.59 for both test and reference formulations, ensuring reliable pharmaceutical development. This research underscores the potential of glycyrrhizin-apigenin solid dispersions for pharmaceutical and therapeutic applications, particularly highlighting the superior physicochemical properties, dissolution behavior, biological activities, and stability of APN2, while the development of a 3D printlet shell offers promise for enhanced drug delivery and therapeutic outcomes in colon cancer treatment, displaying advanced formulation and processing techniques.

Alkyl ketene dimer modification of thermomechanical pulp promotes processability with polypropylene

AbstractAlkyl ketene dimers (AKDs) are known to efficiently react with cellulose with a dual polarity in their structure: a polar component and a nonpolar component. AKD of three different carbon chain lengths, 4, 10, and 16 carbons have been synthesized, and thermomechanical pulp (TMP) fibers were modified by them. The modification of TMP fibers with AKD resulted in an increased water contact angle, showing the presence of the AKDs on the TMP fibers and a new carbonyl peak in the IR spectra, suggesting modification of the TMP fibers with AKD groups. Calculating the Hansen solubility parameters of AKD and AKD conjugated to TMP in polypropylene (PP) indicates improved compatibility, especially of longer chain AKD and TMP AKD. The rheological studies of the composites showed that the AKD with the longest carbon chain decreases the melt viscosity of the PP‐TMP‐AKD composite, which combined with the shape and the color of the extruded composite filaments indicates improved flow properties and reduced stress build up during processing. The research findings demonstrate the ability of AKD to enhance the dispersibility and compatibility of natural fibers with PP.

Hamdard Institute of Pharmaceutical Sciences, Hamdard University, Pakistan

Tablet production is a very intricate process influenced by numerous process variables or parameters. This study aimed to identify the critical processing variables that affect Critical Quality Attributes (CQAs) of vitamin C film-coated caplets utilizing a statistical experimental design. A two-level complete factorial design with two central points was used to examine the process parameters that posed the greatest risk to CQAs. The process variables investigated included mesh size and duration for the lubrication process, as well as speed and main thickness for compression. Statistical results showed that mesh number, lubrication time, and their interaction significantly affect flow rate, Hausner ratio, and compressibility index. Higher mesh number and longer duration improved flow properties; lower main thickness significantly increased core caplet hardness; and lower dissolution rates were observed at higher compression speeds. Based on this study, it can be concluded that mesh number and lubrication time only significantly affected the bulk quality attributes but did not have a significant impact on the quality attributes of vitamin C caplets. On the other hand, the parameters of the compression process, such as speed and main thickness, greatly impacted the quality attributes of vitamin C caplets. In this study, the use of mesh number 20 with 7 minutes of lubrication, and a speed of 17 rpm with a main thickness scale of 2.00 were determined as the optimal process parameters. The optimal process parameters for the lubrication and compression processes were obtained from statistical analysis of the response data.

Formulation and Evaluation of Gastro-retentive Drug Delivery System of Novel Famotidine Phospholipid Complex

Famotidine is an H2 receptor antagonist belonging to the BCS Class II, characterized by low solubility and limited oral bioavailability. The current study encompasses the formulation of novel famotidine phospholipid complex (FHC) with the aid of design of experiments (Central Composite Design) using solvent evaporation technique to overcome the disadvantages of Famotidine. To further enhance the physicochemical properties of FHC, it was incorporated into gastro-retentive floating tablets (GRDDS) using direct compression technique with sodium bicarbonate as a gas generating agent and its properties were compared to famotidine floating tablets. The pre-compression parameters, namely bulk density, tapped density, Hausner’s ratio, Carr’s compressibility index and angle of repose were evaluated. The flow properties of FHC granules were found to be better than the plain famotidine granules. The postcompression parameters, namely thickness, hardness, friability, weight variation, drug content and swelling index showed better results for FHC as compared to famotidine floating tablets. In-vitro buoyancy study indicated that the floating lag time for FHC tablets (110 ± 0.021 seconds) was higher than famotidine tablets (36 ± 0.033 seconds) owing to the higher molecular weight of phosphatidylcholine. But the total floating time for FHC tablets was found to be more than 18 hours and for famotidine tablets it was ~12 hours, indicating the improved residence time and buoyancy. The in-vitro dissolution study depicted that the cumulative release for FHC tablets (99.84 ± 0.058%) was enhanced 1.07 fold than Famotidine tablets (92.73 ± 0.028%) and 1.6 fold than marketed tablet, Famocid (62.24 ± 0.023%). When kinetic modeling was performed, famotidine tablet followed zero order kinetics, whereas FHC tablet followed Higuchi model indicating a modified and sustained release pattern. The statistical analysis for %cumulative release performed using ANOVA and Dunnett’s test showed the p-value to be below 0.05 (0.0043) indicating that the analysis model was significant. An accelerated stability study was performed for a period of 6 months at 25 ± 2°C; 60 ± 5% RH. FHC tablets showed a better stability profile than famotidine tablets. In conclusion, FHC gastro-retentive floating tablets showed improved flow properties, post compression properties, better drug content, improved in-vitro buoyancy and enhanced cumulative release and stability profile.

Modified and Unmodified Jatropha Curcas Seed Oils as Pour Point Depressants for a Nigerian Waxy Crude Oil

Transportation of waxy crude oil faces great challenges in pipelines, however, pour-point depressant could be employed to improve flow properties of waxy crude oil by modifying the morphology and structure of wax crystals. In this paper, modified and unmodified jatropha curcas seed oils was used as a green pour point depressants to evaluate the flow properties of a Nigerian waxy crude oil. Jatropha curcas seed oil (49.5%) was extracted using petroleum ether and the oil was analyzed for oil quality parameters (acid value, iodine value, free fatty acid and saponification value) and subsequently modified using diethanolamine and ethylene glycol to give fatty amides and glycol esters with sulphamic acid (2% and 10% respectively) as catalysts. The modified products were characterized using Fourier transform infra-red (FT-IR) spectroscopy. The modified and unmodified Jatropha seed oils were used treat a Nigerian waxy crude oil to determine their effects on the pour point of the said crude oil. This was done by determining the viscosity and pour point of the crude oil before and after it is dosed with different concentrations of the modified and unmodified Jatropha oils. The results revealed the efficiency of the fatty amides to reduce the pour point and viscosity of the crude oil from 180C to 150C and from 3.49 cst. to 2.0 cst respectively. Both ethylene glycol-modified Jatropha seed oil and the unmodified Jatropha seed oil were able to also depress the pour point of the crude oil to the same degree showing that modification with ethylene glycol did not improve the ability of ordinary Jatropha seed oil to act as pour point depressant.

Needles to Spheres: Evaluation of inkjet printing as a particle shape enhancement tool

Active pharmaceutical ingredients (APIs) often reveal shapes challenging to process, e.g. acicular structures, and exhibit reduced bioavailability induced by slow dissolution rate. Leveraging the API particles’ surface and bulk properties offers an attractive pathway to circumvent these challenges. Inkjet printing is an attractive processing technique able to tackle these limitations already in initial stages when little material is available, while particle properties are maintained over the entire production scale. Additionally, it is applicable to a wide range of formulations and offers the possibility of co-processing with a variety of excipients to improve the API’s bioavailability. This study addresses the optimization of particle shapes for processability enhancement and demonstrates the successful application of inkjet printing to engineer spherical lacosamide particles, which are usually highly acicular. By optimizing the ink formulation, adapting the substrate-liquid interface and tailoring the heat transfer to the particle, spherical particles in the vicinity of 100 µm, with improved flow properties compared to the bulk material, were produced. Furthermore, the particle size was tailored reproducibly by adjusting the deposited ink volume per cycle and the number of printing cycles. Therefore, the present study shows a novel, reliable, scalable and economical strategy to overcome challenging particle morphologies by co-processing an API with suitable excipients.

Studies on rheological behavior of native and octenyl succinic anhydride modified buckwheat (Fagopyrum esculentum) starch gel and improved flow properties thereof

AbstractThe effect of octenyl succinic anhydride (OSA) esterification (1%–3% of dry starch) on powder flowability, functionality, pasting, and gel rheological properties of buckwheat starch (BS) was examined. The physical and flow properties like bulk density, tapped density, Hausner's ratio, Carr's index, cohesion index, and caking strength of starch improved significantly after esterification, indicating better flow behavior and storage stability. The solubility and swelling power were significantly increased, leading to a significant increase in peak viscosity and breakdown, while pasting temperature, setback, and final viscosity decreased. The esterification also restricted the retrogradation, which appeared as a lower hardness of retrograded gel. Starch gel prepared at 5%, 10%, and 15% concentrations showed shear thinning behavior. The dynamic shear properties obtained within the linear viscoelastic region showed weak gel behavior with a more elastic nature and were also demonstrated by the Power law.Practical applicationThe OSA modifies the structure and surface of starch granules to change the physical properties which help in better powder flowability of the dried starch. The findings on powder flowability of BS may help powder manufacturers to control and design powder handling and transportation equipment by preparing non‐cohesive, non‐sticky, and flowable dried starch powder. The findings of the rheological characteristics of BS gels can be exploited in the preparation and optimization of soup premix, thickening agents, food additives, and gravies. Moreover, the OSA modified gel has a low retrogradation rate, which could be used in a product like bread and cakes.

Lamotrigine Novel Cocrystals: An Attempt To Enhance Physicochemical Parameters

Background: Cocrystals are defined as multiple component structures whose components interact through non-covalent interactions.Cocrystals can enhance other essential properties of the APIs.Aim: The current research work focuses on formulating and evaluating novel co-crystals of Lamotrigine anti-epileptic drug (BCS-II)Methods: The Cocrystals of Lamotrigine drug with different cocrystals formers like Saccharin sodium, 4-Hydroxy benzoic acid, andMethyl paraben used with molar ratios (1:1) were prepared by solvent drop method, co-grinding method, and solvent evaporationmethod.Results: The results signify the establishment of intermolecular interaction within the cocrystals. In the novel cocrystals, Lamotriginewas determined to be engaged in the hydrogen bond interaction with the complementary functional groups of Saccharin sodium, 4-Hydroxy benzoic acid, and methyl paraben. Compared with the pure Lamotrigine flow properties for prepared co-crystal by usingsolvent evaporation method crystals are showing excellent flow properties. LTG-SAC CF I, LTG-HBA I, and LTG-MP III showed49.6 folds, 7.4 folds, and 3.36 folds improved solubility respectively. The dissolution test showed that the LTG-SAC CF I, LTG-HBAI, and LTG-MP III cocrystals exhibited a 1.09-fold, 1.08-fold, and 1.07-fold higher dissolution rate than the pure Lamotrigine.Conclusions: LTG-SAC CF I, LTG-HBA I, and LTG-MP III cocrystals showed modification in the chemical environment,intermolecular interactions were established, improved flow properties with enhanced intrinsic solubility and in-vitro dissolution ratethan pure drug.

Development of a sustainable binder made of recycled high-performance concrete (HPC)

The high consumption of ordinary Portland cement (OPC) in high-performance concrete (HPC), combined with the growing accumulation of construction and demolition wastes (CDW), raises severe environmental and economic concerns. This study addresses both issues by proposing a novel sustainable binder made of milled recycled HPC (mRHPC). A series of HPC mix designs (R-HPC) was developed replacing OPC by mRHPC (0–100%), and characterized in fresh and hardened states. The residual reactivity of mRHPC was detected using X-ray diffraction, calorimetry, and rheological oscillatory measurements (SAOS). Replacement up to 30% resulted in comparable 28-day compressive and flexural strengths to that of the OPC reference specimen while slightly improving fresh properties. Furthermore, the performance of steel fiber reinforced R-HPC overlays was investigated in repair application, and 30% replacement ratio enhanced the tensile bond strength by a factor of 2.4. The measured improved flow properties and reduced drying shrinkage can explain this remarkable result.

Application of Novel Fruit Extract for Flow Assurance of Indian Field Waxy Crude Oil

Summary This research article deals with the application of shikakai fruit (Senegalia rugata) extract (SE) used as a novel bio-additive for improving flow properties of waxy crude oil (WCO) to reduce pumping cost during pipeline transportation. SE was synthesized using solvent extraction method, which is one of the most common economic extraction processes. Bio-additive was characterized by Fourier transform infrared spectroscopy (FTIR) spectroscopy, carbon, hydrogen, nitrogen, sulfur (CHNS) analysis, gas chromatography-mass gas chromatography-mass spectroscopy (GC-MS), differential light scattering, and thermogravimetric analysis (TGA). Pour point of WCO was decreased by 12°C due to addition of 1,000 ppm of SE on crude oil. Viscosity of WCO reduced significantly after addition of a bio-additive. It was found that viscosity of SE beneficiated crude oil (1,000 ppm dosage) at 30°C is less than that of pure crude at 50°C. So, addition of SE may be an alternative of heating during flow of WCO. Microscopic studies confirm that wax and other solid particles become smaller and more dispersive so that the particles are not able to come closer and form a three-dimensional network. Consequently, flow becomes easier and pumping cost gets reduced. Experimental data related to viscosity better fitted with Casson model and Bingham model before addition of SE depict that significant yield stress is required to restart the flow of crude oil. Due to the addition of SE, yield stress was deceased significantly and crude oil beneficiated with bio-additive tends to behave like a Newtonian fluid. This article also investigates wax deposition through laboratory-designed wax depositional setup. The wax deposition of crude oil after addition of 1,000 ppm SE was comparatively 56 and 75% lower than untreated crude oil when deposition studies were performed for 2 and 4 hours, respectively, at 25°C. Wax crystals of SE-treated crude oil decreased in diameter and disoriented the particles, preventing the formation of three-dimensional networks so that crude oil can easily flow through pipelines. Considering the efficacy of extracted bio-additive and its cost effectiveness, the same can be applied for flow assurance of WCO through pipelines even at very low temperatures.

Four stroke diesel engine performance and emission studies of ethanol recovered from Kappaphycus alvarezii reject -solid food waste mixed substrates and its blends

Bioethanol is an eco-friendly green fuel, owing to its production from sustainable bio-based sources. In this study, bioethanol (BE) is produced from Kappaphycus alverezii reject (KR) blended with Solid Food Waste (SFW). This bioethanol is blended with petroleum-based diesel (PBD) in the following proportions: 15%, 20% and 25% for further studies. Performance characteristics, specifically Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTE), Brake Power (BP) and exhaust emissions, mainly Carbon monoxide (CO), Carbon dioxide (CO2), Smoke Opacity (SO), hydrocarbons (HC) and oxides of Nitrogen (NOX) have been investigated. The blended test fuels show better results, which is confirmed by the performance characteristics of BTE being lower than PBD. The emission report shows lesser CO (0.12%) and SO (59.6%) compared to PBD (0.14% and 67.2%), signifying the clean-burning tendency of BE blends. From the findings, PBD75: BE25 is an excellent fuel blend for improving flow properties, engine performance, and emission characteristics.

The Potential of Macroporous Silica-Nanocrystalline Cellulose Combination for Formulating Dry Emulsion Systems with Improved Flow Properties: A DoE Study.

The objective of this study was to explore the possible use of a new combination of two excipients, i.e., nanocrystalline cellulose (NCC) and macroporous silica (MS), as matrix materials for the compounding of dry emulsion systems and the effects these two excipients have on the characteristics of dry emulsion powders produced by the spray drying process. A previously developed liquid O/W nanoemulsion, comprised of simvastatin, 1-oleoyl-rac-glycerol, Miglyol 812 and Tween 20, was employed. In order to comprehend the effects that these two matrix formers have on the spray drying process and on dry emulsion powder characteristics, alone and in combination, a DoE (Design of Experiment) approach was used. The physicochemical properties of dry emulsion samples were characterised by atomic force microscopy, scanning electron microscopy, mercury intrusion porosimetry, energy-dispersive X-ray spectroscopy and laser diffraction analysis. Additionally, total release and dissolution experiments were performed to assess drug release from multiple formulations. It was found that the macroporous silica matrix drastically improved flow properties of dry emulsion powders; however, it partially trapped the oil—drug mixture inside the pores and hindered complete release. NCC showed its potential to reduce oil entrapment in MS, but because of its rod-shaped particles deposited on the MS surface, powder flowability was deteriorated.

Preliminary Characterization of Co-processed Excipients of Okra (Abelmoschus esculentus) Mucilage and Pregelatinized Potato Starch

Background: Okra mucilage is highly viscous with good binding properties in tablets. Pregelatinized starches have significantly improved flow properties but produce tablets of poor mechanical strength.Objective: Preliminary evaluation of co-processed excipients of Okra mucilage and pregelatinized potato starch as directly-compressible excipients.Methods: Polymers were characterized for morphology (SEM), crystallinity (FT-IR) and flow properties. Coprocessed excipients were developed with Okra mucilage and pregelatinized potato starch at different ratios of starch: mucilage (95:5, 90:10, 85:15, 80:20, 70:30), using the co-fusion method. The flow, packing and compaction properties of the co-processed excipients were evaluated using density measurements, angle of repose, angle of internal friction, Kawakita model, consolidation index (C) and consolidation rate (K).Results: Larger agglomerates of the co-processed excipients indicated formation of a new polymer. FT-IR spectra showed retention of all the major peaks of individual polymers. Okra mucilage imparted swelling while starch improved flow in the co-processed excipients (Hausner’s ratio 1.12-1.20). Values from Kawakita plots revealedcohesiveness and compressibility were imparted to the co-processed excipients (a = 0.300–0.329; b = 0.078–0.361) suggesting good compactibility. Consolidation index and rate were observed to increase with Okra mucilage content, implying improved rate of packing as well as enhanced flow (C = 0.566-1.389; K = 0.123-0.424). The batch containing starch: mucilage 70:30 gave the best properties of good flow, cohesiveness and compactibility, essential parameters required in directly-compressible excipients.Conclusion: The co-processed excipients of Okra mucilage and pregelatinized potato starch could therefore be used as excipients for direct compression in tablet formulations.

Pulmonary Drug Delivery of Antimicrobials and Anticancer Drugs Using Solid Dispersions.

It is well established that currently available inhaled drug formulations are associated with extremely low lung deposition. Currently available technologies alleviate this low deposition problem via mixing the drug with inert larger particles, such as lactose monohydrate. Those inert particles are retained in the inhalation device or impacted in the throat and swallowed, allowing the smaller drug particles to continue their journey towards the lungs. While this seems like a practical approach, in some formulations, the ratio between the carrier to drug particles can be as much as 30 to 1. This limitation becomes more critical when treating lung conditions that inherently require large doses of the drug, such as antibiotics and antivirals that treat lung infections and anticancer drugs. The focus of this review article is to review the recent advancements in carrier free technologies that are based on coamorphous solid dispersions and cocrystals that can improve flow properties, and help with delivering larger doses of the drug to the lungs.