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Chemical Permeation through Disposable Gloves
Published in Robert N. Phalen, Howard I. Maibach, Protective Gloves for Occupational Use, 2023
Seven paint stripping formulations were tested against gloves by Stull et al.91 after passing degradation resistance screening tests to measure permeation with the ASTM F 739 method for continuous contact and the ASTM F 1383 for intermittent contact. Plastic laminate (2.7 mil or 0.069 mm) and butyl rubber (16 mil or 0.41 mm) were the most effective gloves against the majority of paint stripping formulations.91 Non-disposable NR (30 mil or 0.76 mm) gloves showed rapid permeation (<15 min) for solvent-based paint strippers, while BTs were greater than 2 h for dibasic ester-based paint strippers. More gloves resisted permeation by N-methyl-2-pyrrolidone and dibasic ester-based paint strippers than conventional solvent products such as methylene chloride, methanol, isopropanol, acetone, and toluene. However, more readily available disposable thinner gloves were not tested. These results were consistent with those of Zellers and Sulewiski,107 where butyl gloves were more protective than NR gloves even at different temperatures.
Piper longum (Long Pepper or Pipli) and Tinospora cordifolia (Giloy or Heart-Leaved Moonseed)
Published in Azamal Husen, Herbs, Shrubs, and Trees of Potential Medicinal Benefits, 2022
Yashashree Pradhan, Hina Alim, Nimisha Patel, Kamal Fatima Zahra, Belkıs Muca Yiğit, Johra Khan, Ahmad Ali
Bioactive compounds of T. cordifolia viz., tinocordioside, 11-hydroxy muskatone, cordifolioside A, N-methyl-2-pyrrolidone, N formyl annonain, magnoflorine, and syringin show cytotoxic effects as well as immunomodulatory effects (Mittal et al., 2014). These compounds also increase the phagocytic capacity of macrophage (Tripathi et al., 2015). Extracts of T. cordifolia mainly increase the concentration of IgG immunoglobulin which acts as an immunity barrier against infection (Sharma et al., 2019). Water extract of giloy shows production of cytokines and activates the immune effector cells. It also increases the number as well as phagocytic activity of macrophages (Srivastava and Saxena, 2020). These immunomodulatory effects of T. cordifolia help to boost the immune system against the COVID-19 pandemic (Srivastava and Saxena, 2020).
Application of Bioresponsive Polymers in Drug Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Manisha Lalan, Deepti Jani, Pratiksha Trivedi, Deepa H. Patel
In-situ polymer precipitation based systems are those where the drug is incorporated in solution of water insoluble, biodegradable polymer in biocompatible organic solvent. When such formulation is injected, the water miscible organic solvent dissipates and water penetrate to organic layer which results in phase separation and precipitation of polymer, at site of injection. Such a method was designed by ARTIX and designated as Atrigel technology [126]. Example of such technology is EligardTM, which contain the luteinizing hormone releasing hormone agonist leuprolide acetate and poly(lactide-co-glycolic acid) (PLGA) dissolved in N-methyl-2-pyrrolidone (NMP) [126, 127]. This system is used to reduce testosterone levels in dogs. The problem with such system is the bursting out drug release after injecting drug. To control burst effect, four factors should be taken into consideration: concentration of polymers in solvents [128], molecular weight of polymers, solvent used [129] and addition of surfactants [130]. Brodbeck et al. studied that protein release is affected by type of solution formed. They studied NMP, triacetin, and ethyl benzoate ternary phase system with PLGA and water. The formulation with NMP Pyrrolidone shows rapid phase inversion and high burst while formulations containing triacetin and ethyl benzoate give low phase inversion and reduced burst of protein [131, 132].
Long-acting injectable formulation technologies: challenges and opportunities for the delivery of fragile molecules
Published in Expert Opinion on Drug Delivery, 2022
Andrea Gonella, Sylvestre Grizot, Fang Liu, Adolfo López Noriega, Joël Richard
Despite the advantages of in situ forming depot (ISFD) technologies and the simple mechanism of implant formation, only two peptide-loaded products (Eligard® and Camcevi®) based on this technology are currently commercialized. They both use the Atrigel® technology that relies on PLGA polymers that are solubilized in a biocompatible solvent, N-methyl-2-pyrrolidone (NMP) [65]. However, thanks to a counterion exchange strategy substituting mesylate with acetate that offers a better stability profile, Camcevi® comes as a ready-to-use drug product [66]. One feature of ISFD technologies, especially for those relying on a solvent exchange mechanism, is the presence of an initial burst. This is often related to the highly hydrophilic nature of proteins and peptides, which rapidly diffuse into the surrounding environment. However, advantages like higher loadings compared to microspheres or solid implants, the simple sterilization process (usually by sterile filtration) and the possibility of being removed if necessary, make them appealing for the development of future products [67].
An overview of PLGA in-situ forming implants based on solvent exchange technique: effect of formulation components and characterization
Published in Pharmaceutical Development and Technology, 2021
Tarek Metwally Ibrahim, Nagia Ahmed El-Megrab, Hanan Mohammed El-Nahas
Among the above-mentioned mechanisms, the in-situ polymer precipitation based on solvent removal or exchange is widespread. The biodegradable polymer-based ISFI delivery systems are generally liquid formulations that are transformed into gel-like or solidified depots after injection into the aqueous body fluids. The drug is dissolved or dispersed in a concentrated solution of water-insoluble biodegradable polymer and water-miscible biocompatible solvent. The solvent dissipates into the surrounding area following injection, while water penetrates the polymeric matrix. The drug is entrapped within the matrix after solidification of implants and then released by diffusion mechanism or after the implants start to biodegrade in the body (Figure 5) (Dunn et al. 1994; Vhora et al. 2021). Several formulations have been studied using various biodegradable polymers such as polylactide (PLA) (Camargo et al. 2013), PLGA (Enayati et al. 2017) or polycaprolactone (PCL) (Khodaverdi et al. 2020). Many biocompatible solvents have been mixed with these polymers such as N-methyl-2-pyrrolidone (NMP) (Patki et al. 2021), dimethyl sulfoxide (DMSO) (Wang et al. 2012) and benzyl benzoate (Wang et al. 2017).
The clinical toxicity of imidacloprid self-poisoning following the introduction of newer formulations
Published in Clinical Toxicology, 2021
Varan Perananthan, Fahim Mohamed, Seyed Shahmy, Indika Gawarammana, Andrew Dawson, Nicholas Buckley
Neonicotinoids are nicotinic acetylcholine receptor (nAChR) agonists, inducing neuromuscular paralysis. These agents are highly selective for insect nAChRs over vertebrate nAChRs, explaining its low human toxicity [3]. However, there are case reports of neuro-psychiatric sequelae, rhabdomyolysis resulting in acute kidney injury, ischemic and metabolic encephalopathy, ventricular fibrillation, multi-organ failure and even death after exposure to imidacloprid [4–16]. These features may not be due to nicotinic effects alone as the solvents in imidacloprid preparations such as N-methyl-2-pyrrolidone (NMP) and dimethylsulfoxide also contributes to its toxicity [2]. In Sri Lanka, several new formulations of Imidacloprid with unknown solvents have been introduced since we last reported on clinical outcomes [1]. We herein describe the clinical manifestations of these newer products, and compare these with our earlier observations.