Bacteria
Julius P. Kreier in Infection, Resistance, and Immunity, 2022
Capsules are very important to the growth, survival, virulence, and potential success of treatment of diseases caused by many pathogenic bacteria. For example, the encapsulated pathogen: Haemophilus influenzae is estimated to account for approximately 800,000 human infections per year worldwide, with 145,000 of those resulting in death. Encapsulated Streptococcus pneumoniae is estimated to cause 100 million cases of pneumonia per year with 10 million fatal, most in Third World countries. Capsules may interfere with phagocytosis or may prevent activation of complement by the alternative pathway. In addition, capsules are known to concentrate many chemical substances including organic nutrients, toxins, and metalions from dilute solution. They also aid in cell survival by retarding desiccation when the organism is in a dry environment. The relative non pathogenicity of noncapsulated strains of Haemophilus influenzae and Streptococcus pneumoniae attests to the role of capsules in promoting virulence. The capsule is not the only virulence factor of those pathogens, however. It is known that at least three other surface structures contribute to the pathogenicity of bacteria. These are outer membrane LPS, outer membrane protein, and surface pili.
Transepidermal Water Loss
Enzo Berardesca, Peter Elsner, Klaus-P. Wilhelm, Howard I. Maibach in Bioengineering of the Skin: Methods and Instrumentation, 2020
The evaporimeter (Figure 1) consists of a main signal processing unit to which a cable-detachable measuring probe is connected by a cable. The Teflon capsule of the probe head has a cylindrical measuring chamber, 12 mm in diameter and a height of 15 mm, open at both ends, with a pair of sensor units (hygrosensors paired with thermistors), at two fixed heights of 3 and 9 mm above the skin surface.9 The purpose of the capsule is to protect the measurement area from disturbing drafts. When the measuring head of the probe is placed on the skin, a small area (1 cm2) for measuring the TEWL is delimited. Using the signals derived from these transducers the instrument computes first the partial pressure of the water vapor at the two distances from the surface, then the partial pressure gradient, and finally the evaporation rate, which is presented on the digital display of the main body.9 These parameters are converted and quantified by operating tangent switches on the instrument panel.
Reactor-Produced Radionuclides
Frank Helus, Lelio G. Colombetti in Radionuclides Production, 2019
Two types of packages, Type A and Type B, are specified. Type A packaging shall mean a packaging that is designed to withstand the normal conditions of transport as demonstrated by the retention of the integrity of containment and shielding after certain specified tests. Type B packaging shall mean a packaging that is designed to withstand the damaging effects of transport accident as demonstrated by the retention of the integrity of containment and shielding after certain specified tests. Type A is again classified into special form radioactive material — A1 and others and A2. Special form radioactive material shall mean either an indispersible solid radioactive material or a sealed capsule containing the radioactive material. The sealed capsule shall be so constructed that it can be opened only by destroying the capsule. A Type A package, since its contents are limited to A1 or A2 does not require competent authority approval. The A1 and A2 values for some of the important radionuclides of interest as tracers in biology and medicine are given in Table 20.
Mathematical modelling of drug-diffusion from multi-layered capsules/tablets and other drug delivery devices
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Saqib Mubarak, M. A. Khanday
In the past recent years, various innovations are adopted to structure and construct layer-by-layer spherical capsules and cylindrical tablets (Kaoui et al. 2018), to make the drug application effective and to deliver the required drug dose to the target site in a more productive manner. To understand the dynamics of drug release and control, a mathematical model has been devised to estimate the drug release and diffusion from the multi-layered capsules/tablets. Usually, a capsule consists of a drug-loaded (fluid or solid) core surrounded by one or more hydrogel layers. This type of encapsulation having multi-layers increases the capsule’s mechanical stability, its bioavailability, shields the active ingredients from external chemical aggression and premature degradation and enhances the imperishable drug release (McGinty and Pontrelli 2015; Kaoui et al. 2018; Carr and Pontrelli 2018, 2019).
Effect of formula factors on the properties of HPMC plant hollow capsule film
Published in Drug Development and Industrial Pharmacy, 2021
Huipu Ding, Shulei He, Wenqin Luo, Liping Liu, Sa Wang, Xuhan Chen
Capsule is the main type of drug preparation. The quality of hollow capsule (capsule shell) and its material will directly affect the safety and effect of capsule clinical use [1]. Hollow capsules are mainly divided into gelatin hollow capsules and plant hollow capsules. With the ‘Chinese Pharmacopoeia’ (2020 edition) increasing the number of hollow vegetable capsules (in addition to the existing starch hollow capsules, pullulan and cellulose hollow capsules will be added), indicating that plant hollow capsules will be the development trend of the industry [2]. Compared with gelatin capsule film, the capsule film made of modified starch is stable, not easy to absorb moisture, and does not cross-link with drugs [3]. The key is that starch is cheap, but the mechanical properties and strength of the capsule membrane prepared by starch are low [3]. The capsule film made by pullulan has the advantages of low air permeability (oxygen, carbon dioxide and other gases are almost impermeable), low moisture absorption and high gloss. However, the mechanical strength of the film is not satisfactory, and the price is relatively high [4]. The capsule film made of cellulose has low water content and high chemical stability, which is especially suitable for the filling of herbal medicine products [5]. Its water vapor and oxygen permeability are better than gelatin too [5]. Among the three kinds of plant hollow capsules, hydroxypropylmethylcellulose (HPMC) is the most studied and accepted by the market. In the global hollow capsule Market, the annual growth rate of HPMC hollow capsule is more than 25% [6].
Olive oil and oleic acid-based self nano-emulsifying formulation of omega-3-fatty acids with improved strength, stability, and therapeutics
Published in Journal of Microencapsulation, 2021
Abhay Tharmatt, Shubham Thakur, Amrinder Singh, Manjot Kaur, Navid Reza Shahtaghi, Divay Malhotra, Subheet Kumar Jain
In recent times, a lot of attention has been given to lipid-based formulations for bioavailability enhancement particularly Self-nano emulsifying drug delivery systems (SNEDDS) (Singh et al. 2020). These are known as thermodynamically stable isotropic mixtures of oils, surfactants, and co-surfactants that spontaneously form a nanoemulsion when they come into contact with aqueous gastrointestinal (GI) fluids. The fine droplet mean diameter produced upon dilution would facilitate permeation in the GI tract. It also increases the predictive solubility of luminous drugs, decreases gastric transit, and promotes intestinal lymph transfer via inhibiting the first-pass metabolism in the GI tract (Mohsin et al. 2009). Further, these can be filled in single dosage types, such as soft/hard capsules, which boosts their market feasibility, patient compliance, tolerability and minimises palatability-related issues (Date et al. 2010). Moreover, it is easy to control the organoleptic properties of emulsions by selecting numerous kinds of natural flavours and sweeteners that can solve the problem of palatability by masking the unpleasant taste and smell.
Related Knowledge Centers
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