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Marine Polysaccharides in Pharmaceutical Applications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Riyasree Paul, Sourav Kabiraj, Sreejan Manna, Sougata Jana
Sarwar et al. have reported the synthesis of alginate- and polyethylene glycol–based membranes using a solvent casting method. A commonly used antibiotic, ciprofloxacin hydrochloride, was incorporated in the developed membrane. Maximum ciprofloxacin hydrochloride reported was found around 80% in pH 1.2 within 70 to 120 minutes. At pH 7.4, 75% drug release was reported within 90 to 120 minutes (Sarwar et al. 2020). A study conducted by Güncüm reported the fabrication of sodium alginate and polyvinyl alcohol based NPs for controlled release of amoxicillin. The average size of developed NPs was reported between 336 and 558 nm. pH-responsive drug release was observed with an initial sudden release of amoxicillin. The minimum inhibitory concentration values indicated a comparable antimicrobial efficacy with pure amoxicillin (Güncüm et al. 2018). Youssef et al. have attempted to prolong the gastric residence time for metronidazole by developing a raft forming system using alginate and gellan gum based in in situ gel. The gellan gum based formulation exhibited less gelation ability. Floating lag time varied from few seconds to 1 minute, whereas floating duration was found to be more than 24 hours (Youssef et al. 2015).
Application of Bioresponsive Polymers in Drug Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Manisha Lalan, Deepti Jani, Pratiksha Trivedi, Deepa H. Patel
Ion responsive systems are another approach for designing in situ gels by using ion responsive agents. Gellan gum, an anionic polysaccharide, undergoes gelation in presence physiological cations. Gelling occurs due to double helical junction zones formation and inter-helical interaction, generating a three-dimensional network via cations complexation. The presence of cations, especially Ca2+, in nasal fluids, can catalyze in situ gelation of gellan gum formulations in nasal cavity to sustain their residence and improve drug absorption [69]. Cao et al. explored gellan gum formulations for trans-nasal transport of an anti-muscarinic agent. The same group also investigated further in the same line to improve the nasal absorption efficacy of mometasone furoate. The gellan gum-based formulations were safe for nasal administration and displayed good formulation stability [70, 71].
Thickening Agents
Published in Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters, Cosmetic Formulation, 2019
Ricardo D’Agostino Garcia, Antony O’Lenick, Vânia Rodrigues Leite-Silva
Gellan gum is a water-soluble anionic polysaccharide manufactured by microbial fermentation using the bacterium Sphinomonas elodea. It is a gelling agent, effective at extremely low use levels, forming solid gels at concentrations as low as 0.1%. It can be used to form fluid gels, which represents a unique way of stabilizing suspensions and emulsions without adding viscosity. Higher levels will result in the formation of firm, transparent, mechanically robust and brittle gels. Gels are stable over a wide pH range; are compatible with anionic, amphoteric and nonionic surfactants; and are easily combined with most other rheology modifiers.
In vivo assessment of bone repair by an injectable nanocomposite scaffold for local co-delivery of autologous platelet-rich plasma and calcitonin in a rat model
Published in Drug Development and Industrial Pharmacy, 2022
Saeedeh Ahmadipour, Jaleh Varshosaz, Batool Hashemibeni, Maziar Manshaei, Leila Safaeian
Many types of artificial and natural polymer substances have been used as scaffolds for tissue regeneration. Gellan gum is a water-soluble natural polysaccharide obtained from the bacterium Sphingomonas elodea with carboxylic acid functional groups. The backbone of this polymer consists of a tetrasaccharide repeating unit comprising two residues of D-glucose and a D-glucuronic acid and L-rhamnose. It is widely used as a food additive, cosmetic and pharmaceutical excipient with different roles like thickener, emulsifier, and stabilizer. A small number of articles have been reported on the pharmacology of materials, such as gellan gum hydrogels. Sebria et al. [6] reported that hydrogel of gellan gum exhibited a slight antibacterial property toward Staphylococcus aureus with inhibition zone measured. During the time of implantation, the hydrogels of gellan gum-methacrylated and photo-crosslinked gellan gum-methacrylated could control the invasion of blood vessels and infiltration of endothelial cells [7].
In vitro and in vivo evaluation of an ionic sensitive in situ gel containing nanotransfersomes for aripiprazole nasal delivery
Published in Pharmaceutical Development and Technology, 2021
Somayeh Taymouri, Shabnam Shahnamnia, Azadeh Mesripour, Jaleh Varshosaz
To increase the contact time with the nasal surface and prevent rapid mucociliary clearance, in-situ gels have been suggested. These formulations exhibit the sol-to-gel phase transition in response to changes occurring in temperature or pH or the presence of cations upon intranasal administration. Thus, they have advantages of liquids such as ease of administration and exact dosing, along with the favorable retention time of a gel (Galgatte et al. 2014). Gellan gum is exocellular, deacetylated bacterial polysaccharide consisting of the tetrasaccharide repeating unit of 1β-l-rhamnose, 1β-d-glucuronic acid and 2β-d-glucose. Gellan gum has wide applications in the pharmaceutical industry thanks to some unique properties including biocompatibility, widespread availability and low production costs. Because of its anionic nature, gellan gum can form an in-situ gel when it is in contact with liquids containing a physiological concentration of the cationic ions. The formation of in-situ gels is the result of the formation of double-helical junction zones followed by the inter-helical association, forming a three-dimensional network via cross-linking with cations. Since the human nasal mucosa contains a sufficient concentration of sodium, potassium and calcium ions, upon contact with the nasal mucosa, the polymer solution changes conformation, producing a gel (Osmałek et al. 2014; Salunke and Patil 2016). However, the poor water solubility of lipophilic drugs such as APZ reduces their dispersion in liquid-based gels (Tanigo et al. 2010; Racine et al. 2017).
Liposomes as vehicles for topical ophthalmic drug delivery and ocular surface protection
Published in Expert Opinion on Drug Delivery, 2021
José Javier López-Cano, Miriam Ana González-Cela-Casamayor, Vanessa Andrés-Guerrero, Rocío Herrero-Vanrell, Irene Teresa Molina-Martínez
Gellan gum is another biocompatible and biodegradable polymer widely used in the pharmaceutical industry. In a study with liposomes loaded with timolol maleate, the derivative-deacetylated gellan gum (DGG) was employed. DGG is an anionic polymer that forms a gel in the presence of a positive charge. In this study, liposomes were incorporated into the DGG to form an ion-sensitive gel in situ and the formulation was compared to commercial drops of timolol maleate. The researchers reported a 1.93-fold increase in the apparent partition coefficient when compared to conventional eye drops. Furthermore, in vitro release studies comparing formulations with DGG and conventional liposomes showed a longer release profiles due to DGG. In vivo studies in rabbits after 50 µL of topical administration showed an absence of eye irritation and a longer corneal retention time of the DGG liposomal formulation relative to eye drops, timolol maleate liposomes, and gel formulations view by fluorescence imaging. Furthermore, intraocular pressure measurements in rabbits after the topical administration of 50 µL eye drops or DGG liposomes (0.25% timolol maleate) showed greater long-term efficacy for the liposomal gel, obtaining a minimum IOP of 11.96 ± 0.74 mm Hg (1 hour after instillation) and an effect duration of 300 minutes for the liposomal formulation with DGG, and a minimum of 13.61 ± 0.95 mm (2 hours after instillation) and an effect duration of 180 minutes for eye drops [195].