Formulation studies for mirtazapine orally disintegrating tablets

Abstract

Objective: Orally disintegrating tablets (ODTs) recently have gained much attention to fulfill the needs for pediatric, geriatric, and psychiatric patients with dysphagia. Aim of this study was to develop new ODT formulations containing mirtazapine, an antidepressant drug molecule having bitter taste, by using simple and inexpensive preparation methods such as coacervation, direct compression and to compare their characteristics with those of reference product (Remereon SolTab).

Materials and methods: Coacervation method was chosen for taste masking of mirtazapine. In vitro characterization studies such as diameter and thickness, weight variation, tablet hardness, tablet friability and disintegration time were performed on tablet formulations. Wetting time and in vitro dissolution tests of developed ODTs also studied using 900?mL 0.1?N HCl medium, 900?mL pH 6.8 phosphate buffer or 900?mL pH 4.5 acetate buffer at 37?±?0.2?°C as dissolution medium.

Results: Ratio of Eudragit® E-100 was chosen as 6% (w/w) since the dissolution profile of A1 (6% Eudragit® E-100) was found closer to the reference product than A2 (4% Eudragit® E-100) and A3 (8% Eudragit® E-100). Group D, E and F formulations were presented better results in terms of disintegration time. Dissolution results indicated that Group E and F formulations showed optimum properties in all three dissolution media.

Discussion: Formulations D1, D4, D5, E3, E4, F1 and F5 found suitable as ODT formulations due to their favorable disintegration times and dissolution profiles.

Conclusion: Developed mirtazapine ODTs were found promising in terms of showing the similar characteristics to the original formulation.     

A non-contact method for part-based process performance monitoring in end milling operations

Surface response to excitation (SuRE) method was originally developed for structural health monitoring (SHM) applications. SuRE was used to evaluate the performance of completed milling operations. The method generates surface waves on the plate and studies the spectrum changes at selected points to detect defects and change of compressive forces. In this study, the length, depth, and width of a slot were changed step by step. The surface of the aluminum plate was excited in the 20–400 kHz range with a piezoelectric element. A laser scanning vibrometer was used to monitor the vibrations at the predetermined grid points after the dimensions of the slot were changed methodically. The frequency spectrums of measured vibrations were calculated by using the Fast Fourier Transformation (FFT). The sums of the squares of the differences (SSD) of the spectrums were calculated to evaluate the change of the spectrums. The SuRE method was able to determine if the dimensions were changed in each case at all the selected points. The scanning laser vibrometer is not feasible to be used at the shop floor. However, the study demonstrated that a piezoelectric element attached to any of the grid points would be able to evaluate the completed machining process.     

Genes Involved in the Endoplasmic Reticulum N-Glycosylation Pathway of the Red Microalga Porphyridium sp.: A Bioinformatic Study

N-glycosylation is one of the most important post-translational modifications that influence protein polymorphism, including protein structures and their functions. Although this important biological process has been extensively studied in mammals, only limited knowledge exists regarding glycosylation in algae. The current research is focused on the red microalga Porphyridium sp., which is a potentially valuable source for various applications, such as skin therapy, food, and pharmaceuticals. The enzymes involved in the biosynthesis and processing of N-glycans remain undefined in this species, and the mechanism(s) of their genetic regulation is completely unknown. In this study, we describe our pioneering attempt to understand the endoplasmic reticulum N-Glycosylation pathway in Porphyridium sp., using a bioinformatic approach. Homology searches, based on sequence similarities with genes encoding proteins involved in the ER N-glycosylation pathway (including their conserved parts) were conducted using the TBLASTN function on the algae DNA scaffold contigs database. This approach led to the identification of 24 encoded-genes implicated with the ER N-glycosylation pathway in Porphyridium sp. Homologs were found for almost all known N-glycosylation protein sequences in the ER pathway of Porphyridium sp.; thus, suggesting that the ER-pathway is conserved; as it is in other organisms (animals, plants, yeasts, etc.).     

Flexible poly(styrene-ethylene-butadiene-styrene) hybrid nanofibers for bioengineering and water filtration applications

Among the thermoplastic elastomers that play important roles in the polymer industry due to their superior properties, styrene-based species and polyurethane block copolymers are of great interest. Poly(styrene-ethylene-butadiene-styrene) (SEBS) as a triblock copolymer seems to have the potential to meet many demands in different applications due to various industrial requirements where durability, biocompatibility, breaking elongation, and interfacial adhesion are important. In this study, the SEBS triblock copolymer was functionalized with natural (Satureja hortensis, SH) and synthetic (nanopowder, TiO₂) agents to obtain composite nanofibers by electrospinning and electrospraying methods for use in biomedical and water filtration applications. The results were compared with thermoplastic polyurethane (TPU) composite nanofibers, which are commonly used in these fields. Here, functionalized SEBS nanofibers exhibited antibacterial effect while at the same time improving cell viability. In addition, because of successful water filtration by using the SEBS composite nanofibers, the material may have a good potential to be used comparably to TPU for the application.     

Conductivity enhancement by controlled percolation of inorganic salt in multiphase hexanoyl chitosan/polystyrene polymer blends

Hexanoyl chitosan and polystyrene blends are immiscible by the elucidation of the glass transition temperature (T_g) as well as the viscometric and morphological analyses. Selective localization of the lithium salt in hexanoyl chitosan phase as the percolation pathway enhanced the conductivity in the blends as compared to the neat hexanoyl chitosan. The ionic conductivity of a polymer electrolyte is described by σ = enμ. Thus, estimation of charge carrier density (n) and mobility (μ) is important in order to assess the performance. In this work, these parameters are calculated using impedance spectroscopy and FTIR.     

Review of Dendritic Cells,Their Role in Clinical Immunology,and Distribution in Various Animal Species

Dendritic cells (DCs) are cells derived from the hematopoietic stem cells (HSCs) of the bone marrow and form a widely distributed cellular system throughout the body. They are the most efficient, potent, and professional antigen-presenting cells (APCs) of the immune system, inducing and dispersing a primary immune response by the activation of naïve T-cells, and playing an important role in the induction and maintenance of immune tolerance under homeostatic conditions. Thus, this review has elucidated the general aspects of DCs as well as the current dynamic perspectives and distribution of DCs in humans and in various species of animals that includes mouse, rat, birds, dog, cat, horse, cattle, sheep, pig, and non-human primates. Besides the role that DCs play in immune response, they also play a pathogenic role in many diseases, thus becoming a target in disease prevention and treatment. In addition, its roles in clinical immunology have also been addressed, which include its involvement in transplantation, autoimmune disease, viral infections, cancer, and as a vaccine target. Therefore, based on the current knowledge and understanding of the important roles they play, DCs can be used in the future as a powerful tool for manipulating the immune system.     

A review on energy scenario and sustainable energy in Indonesia

The global energy consumption is likely to grow faster than the population growth. The fuel consumption was growing from 6630 million tons of oil equivalents (Mtoe) in 1980 to 11,163 Mtoe in 2009. This projected consumption will increase 1.5% per year until 2030 and reach 16,900 Mtoe and the main drivers of this growth are mostly developing countries in Asia. Indonesia is one of the developing countries and energy supply is an important factor for all-around development. The country's energy consumption still depends on non-renewable energy such as crude oil, coal and natural gas as sources of energy. Utilization of fossil fuel continuously contributes to huge amount of greenhouse gases emission that leads to climate change. Facing such an unfavorable situation, the government of Indonesia prioritizes on energy supply securities by diversification of energy resources. The energy mixes in Indonesia based on five main resources; these are crude oil, natural gas, coal, hydropower, and renewable energy. Although the country encourages utilizing renewable energy, the contribution is only around 3%. Considering natural condition and geography, this country is blessed with great potential of renewable energy such as solar energy, wind energy, micro hydro and biomass energy. Noting the potential of renewable and sustainable energy resources in the country, the government must pay more attention on how to utilize it. Many efforts have been done to promote renewable energy such as to create energy policy and regulations, yet it still did not give any satisfactory result. Government, non-government agencies and the public should take a more proactive step to promote and use renewable energy in order to achieve the secure and environmentally sustainable energy resources.     

Microstructure and Hardness Properties Investigation of Ti and Nb Added FeNiAlCuCrTi x Nb y High Entropy Alloys

Properties of pure metals can be enhanced by alloying with other metallic or non-metallic elements according to the need. However, as multiple alloying elements in an alloy may lead to the formation of many intermetallic compounds with complex microstructures and poor mechanical properties, new types of metallic alloys called high entropy alloys with at least five elements with equimolar ratios were developed. In this study, FeNiAlCuCrTi _x Nb _y (x, y = 0, 0.5, 1.0, 1.5) alloys have been prepared using Ar arc melting technique. Microstructural studies using scanning electron microscope and XRD showed that Ti addition promoted secondary BCC₂ phase whereas, Nb acted as FCC stabilizer. Samples with combined Nb and Ti addition showed FCC₁ and FCC₂ structure with Nb-rich FCC₂ dendritic phase as dominant phase. Though, individual Nb and Ti additions have resulted in increased hardness, combined additions have resulted in highest hardness of 797 HV under 1 kg load.