Marine Polysaccharides in Pharmaceutical Applications
Se-Kwon Kim in Marine Biochemistry, 2023
Chawla et al. have investigated the efficacy of alginate-based mucoadhesive microbeads for delivering naproxen sodium. Emulsification method was employed to synthesize calcium chloride cross-linked alginate microbeads. Eudragit S-100 was used to coat the developed microbeads. The core microbeads showed an enhanced mucoadhesive property in respect to coated microbeads. The uncoated microspheres exhibited pH-dependent sustained drug release following Higuchi kinetics, where s the coated microspheres demonstrated Korsmeyer-Peppas kinetics (Chawla et al. 2012). Alginate-gellan gum based microspheres were synthesized for oral delivery of aceclofenac by Jana et al. The average size of the microparticles was reported between 270 and 490 μm. An in vitro drug release study revealed a sustained release of aceclofenac over 6 hours following Korsemeyer-Peppas kinetics. An in vivo study performed on a rabbit model revealed sustained absorption of drug with an excellent anti-inflammatory effect (Jana et al. 2013). Another study conducted by Jana et al. reported the development of alginate and locust bean gum based interpenetrating polymeric network (IPN) microspheres for oral delivery of aceclofenac. The ionic gelation technique was employed to develop calcium ion cross-linked microspheres. An in vitro study revealed sustained release of aceclofenac over 8 hours in pH 6.8 phosphate buffer. An increased polymer concentration has decreased the aceclofenac release percentage, as shown in Figure 5.3. Pharmacodynamic analysis exhibited a sustained anti-inflammatory effect after oral administration (Jana et al. 2015).
Spray Drying and Pharmaceutical Applications
Dilip M. Parikh in Handbook of Pharmaceutical Granulation Technology, 2021
Despite the availability of numerous crystal engineering techniques, generating drug-rich microparticles with a predetermined size, morphology and crystallinity still represent a challenge. Among many techniques, spray drying, due to its ability to control the size, shape, and other properties of the resulting particles, has become a versatile technology for the preparation of microparticles and more importantly, nanoparticles for the pharmaceutical/biotech applications. For example, in a study, it was shown that the adsorption of excipients onto micron size drug substrates using a spray drying process was found to be an attractive approach to engineer drug-rich microparticles with characteristics suitable for drug delivery [106]. In another recent study, a fast-dissolving mucoadhesive microparticulate delivery system was developed using a spray drying method for piroxicam, which is a drug with low water solubility and high membrane permeability [107]. It is known that such delivery systems intended for sublingual administration could be a suitable alternative to fast-dissolving tablets because the sublingual adsorption can be improved as a consequence of prolonging residence time on the mucosa and reducing the amount of swallowed drug [108].
Nanomedicines for Ocular NSAIDs: State-of-the-Art Update of the Safety on Drug Delivery
Lajos P. Balogh in Nano-Enabled Medical Applications, 2020
Microparticles consist of micronized drug particles for intravitreal injection, but also consist of micronized polymer/drug matrix-like structures (microspheres) or polymer-coated microparticles (microcapsules), that are applied topically to the eye surface. Microparticles are solid drug carriers (1–1000 µm) capable of providing sustained and controlled release of loaded active agents. According to their structure, microparticles can receive the name of microcapsules (reservoir structure) and microspheres (matrix structure). They can be too large for intravitreal injections where nanoparticles with diameters of less than 200 nm have been shown to result in more effective drug delivery to the retina than larger particles [82, 195]. The use of microparticles for topical therapies is not very common due to their short contact time on the ocular surface, and it is also important to know that the size of microparticles has to be controlled to be less than 10 µm to avoid possible eye irritation [196, 197]. The advantage of microparticles for intraocular administrations is that they can be injected in the form of suspensions by using conventional needles. Microparticles are typically dispersed in a physiological vehicle (phosphate buffer or balanced salt solutions), but sometimes viscous vehicles, such as hyaluronic acid or hydroxypropylmethyl cellulose, are used to improve the injectability of the suspensions [198].
Novel formulations for topical delivery of tranexamic acid: assessing the need of epidermal targeting for hyperpigmentation disorders
Published in Expert Opinion on Drug Delivery, 2023
Piyush Verma, Khushwant S. Yadav
Microparticles are the micro-sized polymeric particulate drug delivery systems, in which different drugs can be encapsulated. Control drug delivery via topical route can be achieved by using microparticles formulated using biodegradable polymers such as poly(lactic-co-glycolic acid) (PLGA) and chitosan [46,47]. Microparticles are being exploited for formulating sustained release systems for topical delivery [48]. Ming-Hsi Huang et al. prepared tranexamic-acid-loaded charged PLGA polymer-based microparticles for studying the release of the molecule [38]. A double emulsion solvent evaporation process was used by them for the preparation of particles. For inducing charge on microparticles, they used quaternary ammonium compound (cetyltrimethylammonium bromide). Prepared microparticles were spherical in shape. It was found that charged polymeric microparticle had longer and better release as compared to uncharged polymeric microparticles. Release was fastest in alkaline media because of PLGA because of faster degradation of PLGA in alkaline environment.
Tight junction and kidney stone disease
Published in Tissue Barriers, 2023
Papart Rungrasameviriya, Aticha Santilinon, Palita Atichartsintop, Sudarat Hadpech, Visith Thongboonkerd
KSD is one of the most widespread urologic diseases in all areas of our globe8. The data collected during 1990–2019 from 21 regions covering 204 countries have revealed that the total number of KSD cases and its disability-adjusted life years (DALYs) and deaths have been increasing over time9. Additionally, the high recurrence rate of KSD remains one of the unsolved global healthcare problems10. All of these factors contribute to healthcare-associated economic burden globally8. Common risks for KSD development include hypercalciuria, hyperoxaluria, hypocitraturia and low urine volume10,11. In addition, middle-age, male gender and acidic urine pH also increase the KSD risk10,11. Among KSD patients or commonly called “stone formers” with recurrent stones, most of them have metabolic disorders, i.e., overweight, hyperlipidemia, hyperglycemia and hyperuricemia10,12. KSD is a complex disease that is affected not only by metabolic state but also by hereditary and environmental influences13–15. Furthermore, dietary style/pattern, lifestyle (e.g., excessive exercise and smoking), and geographical factor also affect the KSD risk16–18. Interestingly, emerging evidence has pointed out the significant role of air pollution from microparticle matters (PM2.5) in KSD development19.
Current trends in the use of human serum albumin for drug delivery in cancer
Published in Expert Opinion on Drug Delivery, 2022
Milan Paul, Asif Mohd Itoo, Balaram Ghosh, Swati Biswas
Nano spray drying is a continuous, single-step, cost-effective, reproducible, and scalable process of producing dry nanoparticles from a pre-mixed liquid feed. The liquid can be in any form, including solution, suspension, emulsion, slurry, paste, or melt. Spray drying is a well-established process to produce microparticles suitable for drug delivery applications. However, producing nanoparticles of large yield and narrow size distribution is challenging using conventional spray drying technology. The spray-drying process involves atomizing liquid feed into a spray dryer, where the droplets encounter contact with the hot air. The dried particles are collected in an electrostatic particle collector as air comes out of the chamber. The atomization of the liquid feed into droplets is a crucial step in modulating the particle size. Due to the low collection efficiency for fine particles less than 2-micron size, the conventional spray drying process faces challenges in preparing protein nanoparticles [48]. Usually, the particles are agglomerated to larger-sized microparticles via a two-step approach for collection. However, the method suffers challenges in producing NPs after redispersion of the microparticles.
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