Green and renewable thermoplastic polyvinyl alcohol/starch blend film fabricated by melt processing.

In this study, the PVA/starch blend films were prepared by dry melting method. The microstructure showed that the starch existed in the continuous PVA matrix in granular structure. When the amount of starch was 30 wt%, the tensile strength increased from 12.8 to 14.7 MPa, and the elastic modulus increased from 15.4 to 20.5 MPa, and the water absorption increased by about 2 %. The addition of starch increased the Tmax by 8.1-29.64 °C compared to pure PVA. Considering the mechanical, hydrophilic and optical properties of the blend films, PVA/starch at 7:3 was the most promising packaging material. Notably, the blend films exhibit great reusability and renewability. Overall, these findings highlight the potential of PVA/starch blend films as environmentally friendly materials with enhanced properties.

A novel gelatin composite film with melt extrusion for walnut oil packaging.

Gelatin have excellent film-forming and barrier properties, but its lack of biological activity limits its application in packaging. In this study, fish gelatin incorporated with apple polyphenol/cumin essential oil composite films were successfully prepared by melt extrusion. The cross-linking existed in gelatin and apple polyphenol improved the thermal stability and oxidation resistance of the film. The synergistic effect of apple polyphenols and cumin essential oil decreased the sensitivity of the film to water, especially the water solubility decreased from 41.60 % to 26.07 %. The plasticization of essential oil nearly doubled the elongation at break while maintaining the tensile strength of the film (11.45 MPa). Furthermore, the FG-CEO-AP film can inhibit peroxide value to extend the shelf life about 20 days in the walnut oil preservation. In summary, the apple polyphenol/cumin essential oil of FG film exhibits excellent comprehensive properties and high preparation efficiency for utilization as an active packaging material.

Artificial Trabecular Meshwork Structure Combining Melt Electrowriting and Solution Electrospinning.

The human trabecular meshwork (HTM) is responsible for regulating intraocular pressure (IOP) by means of gradient porosity. Changes in its physical properties, like increases in stiffness or alterations in the extracellular matrix (ECM), are associated with increases in the IOP, which is the primary cause of glaucoma. The complexity of its structure limits the engineered models to one-layered and simple approaches, which do not accurately replicate the biological and physiological cues related to glaucoma. Here, a combination of melt electrowriting (MEW) and solution electrospinning (SE) is explored as a biofabrication technique used to produce a gradient porous scaffold that mimics the multi-layered structure of the native HTM. Polycaprolactone (PCL) constructs with a height of 20-710 µm and fiber diameters of 0.7-37.5 µm were fabricated. After mechanical characterization, primary human trabecular meshwork cells (HTMCs) were seeded over the scaffolds within the subsequent 14-21 days. In order to validate the system's responsiveness, cells were treated with dexamethasone (Dex) and the rho inhibitor Netarsudil (Net). Scanning electron microscopy and immunochemistry staining were performed to evaluate the expected morphological changes caused by the drugs. Cells in the engineered membranes exhibited an HTMC-like morphology and a correct drug response. Although this work demonstrates the utility of combining MEW and SE in reconstructing complex morphological features like the HTM, new geometries and dimensions should be tested, and future works need to be directed towards perfusion studies.

Fabrication of high performance poly(vinyl alcohol)/straw composite film used for package via melt casting and biaxial stretching.

A high performance poly(vinyl alcohol)/straw (PVA/SP) composite film for package was fabricated in this study by using thermal processing technology of PVA established in our research group and biaxial stretching technology. The introduction of SP disrupted the original hydrogen bonds in modified PVA by forming new hydrogen bonds with the hydroxyl groups of each component in modified system, thus promoting the stable melt casting of PVA/SP composites and also endowing the obtained PVA/SP precursor sheets with good drawability. Upon biaxial stretching, SP reinforced the crystalline structure and orientation of PVA through their hydrogen bonds with PVA, improving the mechanical strength, crystallinity and thermal stability of PVA/SP films. The film with 3.0 × 3.0 stretching ratios demonstrated the exceptional tensile strength (62.2 MPa), tear strength (119.7 kN/m), low heat shrinkage (5.2 %), and oxygen permeability coefficient (1.38 × 10-16 cm3·cm/cm2·s·Pa), which surpassed most conventional plastic films used in food packaging field. This research not only pioneered an environmentally friendly packaging solution, but also offered a novel strategy for solid-state high-value, large-scale and economical utilization of waste crop straw, greatly avoiding the adverse effects of its burning on the environment.

Improved accuracy of continuum surface flux models for metal additive manufacturing melt pool simulations.

Computational modeling of the melt pool dynamics in laser-based powder bed fusion metal additive manufacturing (PBF-LB/M) promises to shed light on fundamental mechanisms of defect generation. These processes are accompanied by rapid evaporation so that the evaporation-induced recoil pressure and cooling arise as major driving forces for fluid dynamics and temperature evolution. The magnitude of these interface fluxes depends exponentially on the melt pool surface temperature, which, therefore, has to be predicted with high accuracy. The present work utilizes a diffuse interface finite element model based on a continuum surface flux (CSF) description of interface fluxes to study dimensionally reduced thermal two-phase problems representative for PBF-LB/M in a finite element framework. It is demonstrated that the extreme temperature gradients combined with the high ratios of material properties between metal and ambient gas lead to significant errors in the interface temperatures and fluxes when classical CSF approaches, along with typical interface thicknesses and discretizations, are applied. It is expected that this finding is also relevant for other types of diffuse interface PBF-LB/M melt pool models. A novel parameter-scaled CSF approach is proposed, which is constructed to yield a smoother temperature field in the diffuse interface region, significantly increasing the solution accuracy. The interface thickness required to predict the temperature field with a given level of accuracy is less restrictive by at least one order of magnitude for the proposed parameter-scaled approach compared to classical CSF, drastically reducing computational costs. Finally, we showcase the general applicability of the parameter-scaled CSF to a 3D simulation of stationary laser melting of PBF-LB/M considering the fully coupled thermo-hydrodynamic multi-phase problem, including phase change.

Scope and Application of Hot Melt Extrusion in the Development of Controlled and Sustained Release Drug Delivery Systems.

Controlled-release drug delivery systems (CRDDS) are more beneficial than conventional immediate release (IRDDS) for reduced intake, prolonged duration of action, lesser adverse effects, higher bioavailability, etc. The preparation of CRDDS is more complex than IRDDS. The hot melt extrusion (HME) technique is used for developing amorphous solid dispersion of poorly water soluble drugs to improve their dissolution rate and oral bioavailability. HME can be employed to develop CRDDS. Sustained release delivery systems (SRDDS), usually given orally, can also be developed using HME. This technique has the advantages of using no organic solvent, converting crystalline drugs to amorphous, improving bioavailability, etc. However, the heat sensitivity of drugs, miscibility between drug-polymer, and the availability of a few polymers are some of the challenges HME faces in developing CRDDS and SRDDS. The selection of a suitable polymer and the optimization of the process with the help of the QbD principle are two important aspects of the successful application of HME. In this review, strategies to prepare SRDDS and CRDDS using HME are discussed with its applications in research.

In-situ tensile testing of fracture and strain in a selective laser melted AlSi10Mg alloy.

The melt pools, the most basic units of the components fabricated by the selective laser melting (SLM) technology, play an important role in the mechanical properties of the structures. A self-developed in-situ tensile observation platform was used to carry out the in-situ tensile test of SLMed AlSi10Mg alloy specimens under the observation of optical microscope. With a series of obtained experimental data on mechanical properties and metallurgical images, combined with the digital image correlation(DIC) technology, the melt pool of the specimen and the strain of defects were analyzed, and the deformation and fracture mechanism of the SLMed AlSi10Mg alloy specimens was obtained. The results show that the proposed method successfully obtains the deformation field evolution data of the melt pool and defects, which provides experimental and theoretical support for the further study of crack extension characteristics and fatigue life prediction of SLMed metallic material components.

Preparation, Characterization and Evaluation of Nintedanib Amorphous Solid Dispersions with Enhanced Oral Bioavailability.

The dissolution and bioavailability challenges posed by poorly water-soluble drugs continue to drive innovation in pharmaceutical formulation design. Nintedanib (NDNB) is a typical BCS class II drug that has been utilized to treat idiopathic pulmonary fibrosis (IPF). Due to the low solubility, its oral bioavailability is relatively low, limiting its therapeutical effectiveness. It is crucial to enhance the dissolution and the oral bioavailability of NDNB. In this study, we focused on the preparation of amorphous solid dispersions (ASD) using hot melt extrusion (HME). The formulation employed Kollidon® VA64 (VA64) as the polymer matrix, blended with the NDNB at a ratio of 9:1. HME was conducted at temperatures ranging from 80 °C to 220 °C. The successful preparation of ASD was confirmed through various tests including polarized light microscopy (PLM), X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). The in-vitro cumulative release of NDNB-ASD in 2 h in a pH 6.8 medium was 8.3-fold higher than that of NDNB (p < 0.0001). In a pH 7.4 medium, it was 10 times higher (p < 0.0001). In the in-vivo pharmacokinetic experiments, the area under curve (AUC) of NDNB-ASD was 5.3-fold higher than that of NDNB and 2.2 times higher than that of commercially available soft capsules (Ofev®) (p < 0.0001). There was no recrystallization after 6 months under accelarated storage test. Our study indicated that NDNB-ASD can enhance the absorption of NDNB, thus providing a promising method to improve NDNB bioavailability in oral dosages.

Rheological Property Modification of a Molten-State Polyamide through the Addition of an α-Olefin-Maleic Anhydride Copolymer.

The rheological properties of a polyamide (PA) resin with low crystallinity were modified by melt-mixing it with a small amount of an alternative α-olefin-maleic anhydride copolymer as a reactive compound. Because PA has a low melting point, rheological characterization was performed over a wide temperature range. Owing to the reaction between PA and the alternative α-olefin-maleic anhydride copolymer, the blend sample behaved as a long-chain branched polymer in the molten state. The thermo-rheological complexity was obvious owing to large flow activation energy values in the low modulus region, i.e., the rheological time-temperature superposition principle was not applicable. The primary normal stress difference under steady shear was greatly increased in the wide shear rate range, leading to a large swell ratio at the capillary extrusion. Furthermore, strain hardening in the transient elongational viscosity, which is responsible for favorable processability, was clear. Because this is a simple modification method, it will be widely employed to modify the rheological properties of various polyamide resins.

Investigation of the Impact of Single and Double Filtration Systems on Post-Consumer PE Film Waste.

Due to the diversity of plastic film waste streams available on the market and the associated variety of contaminants' size and number, the use of melt filtration is necessary. Currently, single and double filtration systems are state of the art in the plastic recycling industry, depending on the application of the produced post-consumer recyclate (PCR). Using PCR for thin films demands small contamination sizes, which are easier to reach using a second filtration step. In the case of relatively clean post-consumer input materials, it must be investigated whether the additional load from the second filter has a counterproductive effect on the material and whether single filtration would be sufficient. For this paper, polyethylene (PE) film waste stemming from a separate post-consumer collection in Austria was processed using an industrial-sized recycling machine with different combinations of filter sizes and systems. Melt flow rate (MFR), ash content, oxidation onset temperature (OOT), and optical contaminant detection were measured to investigate the influence of single and double filtration systems. The investigation showed that, even though the contamination amount and size were reduced, the second filter had a distinct effect on specific properties.

Effects of Contamination with Selected Polymers on the Mechanical Properties of Post-Industrial Recycled Polypropylene.

The effect of contamination of polypropylene (PP) with selected polymers is studied to simulate the effect of mis-sorting in recycling streams. Polystyrene (PS), polyethylene terephthalate (PET), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), and polylactic acid (PLA) were compounded with PP at different concentrations varying between 3 and 10%. Infrared spectroscopy proved the absence of chemical bonds between the constituents. Generally, melt flowability, except for the PP/PLA blend, and crystallinity were only slightly affected by the incorporation of the contaminating polymers. Samples of the polymer blends were injection moulded and further tested for their tensile and impact properties. Critical behaviour was induced by the introduction of a weld line as a result of the application of multiple gating points during injection moulding. Results generally show the applicability of PP mixtures within the investigated range of contamination, without much sacrifice in mechanical performance. However, in the case of ABS and PLA, more care should be taken when designing complex parts with weld lines, due to reduced toughness.

Enhancing the Quality of Polypropylene Recyclates: Predictive Modelling of the Melt Flow Rate and Shear Viscosity.

The extensive use of polypropylene (PP) in various industries has heightened interest in developing efficient methods for recycling and optimising its mixtures. This study focuses on formulating predictive models for the Melt Flow Rate (MFR) and shear viscosity of PP blends. The investigation involved characterising various grades, including virgin homopolymers, copolymers, and post-consumer recyclates, in accordance with ISO 1133 standards. The research examined both binary and ternary blends, utilising traditional mixing rules and symbolic regression to predict rheological properties. High accuracy was achieved with the Arrhenius and Cragoe models, attaining R2 values over 0.99. Symbolic regression further enhanced these models, offering significant improvements. To mitigate overfitting, empirical noise and variable swapping were introduced, increasing the models' robustness and generalisability. The results demonstrated that the developed models could reliably predict MFR and shear viscosity, providing a valuable tool for improving the quality and consistency of PP mixtures. These advancements support the development of recycling technologies and sustainable practices in the polymer industry by optimising processing and enhancing the use of recycled materials.

Amorphous Polymer-Phospholipid Solid Dispersions for the Co-Delivery of Curcumin and Piperine Prepared via Hot-Melt Extrusion.

Curcumin and piperine are plant compounds known for their health-promoting properties, but their use in the prevention or treatment of various diseases is limited by their poor solubility. To overcome this drawback, the curcumin-piperine amorphous polymer-phospholipid dispersions were prepared by hot melt extrusion technology. X-ray powder diffraction indicated the formation of amorphous systems. Differential scanning calorimetry confirmed amorphization and provided information on the good miscibility of the active compound-polymer-phospholipid dispersions. Owing to Fourier-transform infrared spectroscopy, the intermolecular interactions in systems were investigated. In the biopharmaceutical properties assessment, the improvement in solubility as well as the maintenance of the supersaturation state were confirmed. Moreover, PAMPA models simulating the gastrointestinal tract and blood-brain barrier showed enhanced permeability of active compounds presented in dispersions compared to the crystalline form of individual compounds. The presented paper suggests that polymer-phospholipid dispersions advantageously impact the bioaccessibility of poorly soluble active compounds.

Commercialization of the Xalkori Pediatric Multiparticulate Product Using Quality-by-Design Principles.

A pediatric dosage form for crizotinib (Xalkori) was commercialized using quality-by-design principles in a material-sparing fashion. The dosage form consists of spherical multiparticulates (microspheres or pellets) that are coated and encapsulated in capsules for opening. The crizotinib (Xalkori)-coated pellet product is approved in the US for pediatric patients 1 year of age and older and young adults with relapsed or refractory, systemic anaplastic large cell lymphoma (ALCL) and unresectable, recurrent, or refractory inflammatory myofibroblastic tumor (IMT) that is ALK-positive. The product is also approved in the US for adult patients with non-small cell lung cancer (NSCLC) who are unable to swallow intact capsules. The lipid multiparticulate is composed of a lipid matrix, a dissolution enhancer, and an active pharmaceutical ingredient (API). The API, which remains crystalline, is embedded within the microsphere at a 60% drug loading in the uncoated lipid multiparticulate to enable dose flexibility. The melt spray congealing technique using a rotary atomizer is used to manufacture the lipid multiparticulate. Following melt spray congealing, a barrier coating is applied via fluid bed coating. Due to their particle size and content uniformity, this dosage form provides the dosing flexibility and swallowability needed for the pediatric population. The required pediatric dose is achieved by opening the capsules and combining doses of different encapsulated dose strengths, followed by administration of the multiparticulates directly to the mouth. The encapsulation process was optimized through equipment modifications and by using a design of experiments approach to understand the operating space. A limited number of development batches produced using commercial-scale equipment were leveraged to design, understand, and verify the manufacturing process space. The quality by design and material-sparing approach taken to design the melt spray congeal and encapsulation manufacturing processes resulted in a pediatric product with exceptional content uniformity (a 95% confidence and 99% probability of passing USP <905> content uniformity testing for future batches).

Amorphous Solid Dispersions: Implication of Method of Preparation and Physicochemical Properties of API and Excipients.

The present study investigated the effect of different polymers and manufacturing methods (hot melt extrusion, HME, and spray drying, SD) on the solid state, stability and pharmaceutical performance of amorphous solid dispersions. In the present manuscript, a combination of different binary amorphous solid dispersions containing 20% and 30% of drug loadings were prepared using SD and HME. The developed solid-state properties of the dispersions were evaluated using small- and wide-angle X-ray scattering (WAXS) and modulated differential scanning calorimetry (mDSC). The molecular interaction between the active pharmaceutical ingredients (APIs) and polymers were investigated via infrared (IR) and Raman spectroscopy. The in vitro release profile of the solid dispersions was also evaluated to compare the rate and extend of drug dissolution as a function of method of preparation. Thereafter, the effect of accelerated stability conditions on the physicochemical properties of the solid dispersions were also evaluated. The results demonstrated higher stability of Soluplus® (SOL) polymer-based solid dispersions as compared to hydroxypropyl methylcellulose (HPMC)-based solid dispersions. Moreover, the stability of the solid dispersions was found to be higher in the case of API having high glass transition temperature (Tg) and demonstrated higher interaction with the polymeric groups. Interestingly, the stability of the melt-extruded dispersions was found to be slightly higher as compared to the SD formulations. However, the down-processing of melt-extruded strands plays critical role in inducing the API crystal nuclei formation. In summary, the findings strongly indicate that the particulate properties significantly influence the performance of the product.

Impact of Hot-Melt Extrusion on Glibenclamide's Physical and Chemical States and Dissolution Behavior: Case Studies with Three Polymer Blend Matrices.

This research work dives into the complexity of hot-melt extrusion (HME) and its influence on drug stability, focusing on solid dispersions containing 30% of glibenclamide and three 50:50 polymer blends. The polymers used in the study are Ethocel Standard 10 Premium, Kollidon SR and Affinisol HPMC HME 4M. Glibenclamide solid dispersions are characterized using thermal analyses (thermogravimetric analysis (TGA) and differential scanning calorimetry), X-ray diffraction and scanning electron microscopy. This study reveals the transformation of glibenclamide into impurity A during the HME process using mass spectrometry and TGA. Thus, it enables the quantification of the extent of degradation. Furthermore, this work shows how polymer-polymer blend matrices exert an impact on process parameters, the active pharmaceutical ingredient's physical state, and drug release behavior. In vitro dissolution studies show that the polymeric matrices investigated provide extended drug release (over 24 h), mainly dictated by the polymer's chemical nature. This paper highlights how glibenclamide is degraded during HME and how polymer selection crucially affects the sustained release dynamics.

Scalability of API-Loaded Multifilament Yarn Production by Hot-Melt Extrusion and Evaluation of Fiber-Based Dosage Forms.

Fiber-based technologies are widely used in various industries, but their use in pharmaceuticals remains limited. While melt extrusion is a standard method for producing medical fibers such as sutures, it is rarely used for pharmaceutical fiber-based dosage forms. The EsoCap system is a notable exception, using a melt-extruded water-soluble filament as the drug release trigger mechanism. The challenge of producing drug-loaded fibers, particularly due to the use of spinning oils, and the processing of the fibers are addressed in this work using other approaches. The aim of this study was to develop processes for the production and processing of pharmaceutical fibers for targeted drug delivery. Fibers loaded with polyvinyl alcohol and fluorescein sodium as a model drug were successfully prepared by a continuous melt extrusion process and directly spun. These fibers exhibited uniform surface smoothness and consistent tensile strength. In addition, the fibers were further processed into tubular dosage forms using a modified knitting machine and demonstrated rapid drug release in a flow cell.

The comparison of melt technologies based on mesoporous carriers for improved carvedilol dissolution.

High-shear (HS) melt granulation and hot melt extrusion (HME) were compared as perspective melt-based technologies for preparation of amorphous solid dispersions (ASDs). ASDs were prepared using mesoporous carriers (SyloidⓇ 244FP or NeusilinⓇ US2), which were loaded with carvedilol dispersed in polymeric matrix (polyethylene glycol 6000 or SoluplusⓇ). Formulations with high carvedilol content were obtained either by HME (11 extrudates with polymer:carrier ratio 1:1) or HS granulation (6 granulates with polymer:carrier ratio 3:1). DSC and XRD analysis confirmed the absence of crystalline carvedilol for the majority of prepared ADSs, thus confirming the stabilizing effect of selected polymers and carriers over amorphous carvedilol. HME produced larger particles compared to HS melt granulation, which was in line with better flow time and Carr index of extrudates. Moreover, SEM images revealed smoother surface of ASDs obtained by HME, contributing to less obstructed flow. The rougher and more porous surface of HS granules was correlated to larger granule specific surface area, manifesting in faster carvedilol release from SyloidⓇ 244FP-based granules, as compared to their HME counterparts. Regarding dissolution, the two HS-formulations performed superior to pure crystalline carvedilol, thereby confirming the suitability of HS melt granulation for developing dosage forms with improved carvedilol dissolution.

Development of poly (lactic-co-glycolic acid) (PLGA) based implants using hot melt extrusion (HME) for sustained release of drugs: The impacts of PLGA's material characteristics.

Hot melt extrusion (HME) processed Poly (lactic-co-glycolic acid) (PLGA) implant is one of the commercialized drug delivery products, which has solid, well-designed shape and rigid structures that afford efficient locoregional drug delivery on the spot of interest for months. In general, there are a variety of material, processing, and physiological factors that impact the degradation rates of PLGA-based implants and concurrent drug release kinetics. The objective of this study was to investigate the impacts of PLGA's material characteristics on PLGA degradation and subsequent drug release behavior from the implants. Three model drugs (Dexamethasone, Carbamazepine, and Metformin hydrochloride) with different water solubility and property were formulated with different grades of PLGAs possessing distinct co-polymer ratios, molecular weights, end groups, and levels of residual monomer (high/ViatelTM and low/ ViatelTM Ultrapure). Physicochemical characterizations revealed that the plasticity of PLGA was inversely proportional to its molecular weight; moreover, the residual monomer could impose a plasticizing effect on PLGA, which increased its thermal plasticity and enhanced its thermal processability. Although the morphology and microstructure of the implants were affected by many factors, such as processing parameters, polymer and drug particle size and distribution, polymer properties and polymer-drug interactions, implants prepared with ViatelTM PLGA showed a smoother surface and a stronger PLGA-drug intimacy than the implants with ViatelTM Ultrapure PLGA, due to the higher plasticity of the ViatelTM PLGA. Subsequently, the implants with ViatelTM PLGA exhibited less burst release than implants with ViatelTM Ultrapure PLGA, however, their onset and progress of the lag and substantial release phases were shorter and faster than the ViatelTM Ultrapure PLGA-based implants, owing to the residual monomer accelerated the water diffusion and autocatalyzed PLGA hydrolysis. Even though the drug release profiles were also influenced by other factors, such as composition, drug properties and polymer-drug interaction, all three cases revealed that the residual monomer accelerated the swelling and degradation of PLGA and impaired the implant's integrity, which could negatively affect the subsequent drug release behavior and performance of the implants. These results provided insights to formulators on rational PLGA implant design and polymer selection.

Genotyping SNPs and Indels: A method to improve the scope and sensitivity of High-Resolution melt (HRM) analysis based applications.

High-resolution melt (HRM) analysis is a closed-tube technique for detecting single nucleotide polymorphisms (SNPs). However, it has limited use in high-resolution melting devices, even those with high thermal accuracy (HTA). In addition to the cost of switching to these specialized devices, the presence of nearest neighbour neutral changes (class III, IV SNPs and small indels) made HRM-based assays a challenging task due to reduced sensitivity. This study aimed to design a common modified competitive amplification of differently melting amplicons (CADMA)-based assay to address these challenges by generating allele-specific qPCR products that are detectable on most qPCR platforms. For this study, SNPs were selected from all four classes of SNPs (class I: C/T or G/A mutation; class II: C/A or G/T mutation; class III: G/C mutation; class IV: A/T mutation). A single base pair and 19 bp indels were also chosen to simulate how CADMA primers could be designed for indels of varying lengths. The melting temperatures (Tm) were determined using IDT oligoAnalyzer. qPCR and melt data acquisition were performed on the CFX96 qPCR platform, and the melt curve data were analyzed using Precision Melt software (Bio-Rad, USA). The clusters for different genotypes were successfully identified with the aid of the control samples, and Tm predictions were carried out using the uMelt batch and Tm online tools for comparison. Using HRM-qPCR assays based on the modified CADMA method, genotyping of various SNPs was successfully carried out. For some SNPs, similarly shaped melt curves were observed for homozygotes and heterozygotes, making shape-based genotype prediction difficult. The Tm values calculated via the Blake and Delcourts (1998) method were the closest to the experimental Tm values after adjusting for the salt concentration. Since HRM assays usually depend on the ΔTm caused by mutations, they are prone to a high error rate due to nearest neighbour neutral changes. The technique developed in this study significantly reduces the failure rates in HRM-based genotyping and could be applied to any SNP or indel in any platform. It is crucial to have a deep understanding of the melt instrument, its accuracy and the nature of the target (SNP class or indel length and GC content of the flanking region). Furthermore, the availability of controls is essential for a high success rate.