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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
Hydroxypropyl methylcellulose (HPMC) is a modified natural carbohydrate polymer derived from cellulose. The hydroxypropyl and methyl group substituents impart water solubility and surface activity to the polymer. A variety of HPMC types are commercially available, and their properties determined by the degree of methyl and hydroxypropyl substitution, as well as their molecular weight. HPMC is a multifunctional additive that offers a broad range of impressive properties addressing multiple needs in rinse-off applications even at low use levels. The most important properties include a foam-boosting effect, a significantly improved skin feel, and viscosity control in cleansing and conditioning personal care formulations. The incorporation of HPMC reduces the required amount of certain ingredients, such as surfactants, other thickeners and emollients, without sacrificing performance.
Gastrointestinal Function and Toxicology in Minipigs
Published in Shayne C. Gad, Toxicology of the Gastrointestinal Tract, 2018
Maria R. Jones, Alain Stricker-Krongrad
Vehicles themselves can cause toxic effects, and those should be considered when selecting formulations. One example used in minipigs is Miglyol 812. When dosed with 2 mL/kg/day animals showed gastrointestinal symptoms such as loss of appetite, dry/dark feces, or few feces. Abdominal spasms and vomiting occurred during preliminary studies when dosing minipigs at 10 mL/kg. Histopathological changes to the GI system were considered incidental and not associated with Miglyol 812. However, the primary lesions described were to the lungs, and could be due to regurgitation and subsequent aspiration of the viscous material dosed by oral gavage (Le Bars et al. 2015). Understanding potential adverse reactions of a vehicle is crucial in making toxicology determinations. Short-term oral administration of low levels (0.5% in distilled water) of carboxymethylcellulose or hydroxypropyl methylcellulose did not show any adverse reactions when orally dosed in minipigs (at 8 mL/kg and 5 mL/kg, respectively). However, 90-day daily administration of Transcutol has been shown to be toxic when orally dosed in minipigs, causing liver and kidney damage, with the NOAEL being 167 mg/kg/day. Mixtures of vehicles with low levels of trascutol for short-term oral dosing have shown mild transient diarrhea after initial dose, but a different formulation showed no adverse reactions. A summary of safety assessments of orally dosed vehicles is presented in Table 7.2 (Gad et al. 2016).
Therapeutic Approach in Fungal Keratitis
Published in Mahendra Rai, Marcelo Luís Occhiutto, Mycotic Keratitis, 2019
Victoria Díaz-Tome, María Teresa-Rodríguez Ares, Rubén Varela-Fernández, Rosario Touriño-Peralba, Miguel González-Barcia, Laura Martínez-Pérez, María Jesús Lamas, Francisco J. Otero-Espinar, Anxo Fernández-Ferreiro
There is an ophthalmic formulation commercialized in India called Aurozole®. Besides that, currently, there are several research and lines focused on new ocular econazole-release-systems development, such as: Chitosan and sulfobutilether-β-cyclodextrin mucoadhesive nanoparticles, which have shown a controlled drug release and a drug-residence-time increase, improving its fungal activity compared with the econazole nitrate solution currently used (Mahmoud et al. 2011).Ion-sensitive and mucoadhesive hydrogels, which are controlled-release devices that improve the econazole permanence in the eye (Díaz-Tomé et al. 2018).PLGA (poly-lactic-co-glycolic acid) contact lenses containing econazole, that have shown a good efficacy against Candida albicans (Ciolino et al. 2011).Econazole nitrate nanoparticles with cyclodextrins and different stabilizers, prepared by using a nanospray-dryer. These nanoparticles have shown a better bioavailability than the drug suspension due to the nanoparticles solubility in the tear (Maged et al. 2016).Econazole ocular nanoemulsifier systems with hydroxypropyl methylcellulose as a precipitation inhibitor, which can stabilize the supersaturation state created, improving ocular drug bioavailability (Elkasabgy 2014).
Poloxamer sols endowed with in-situ gelability and mucoadhesion by adding hypromellose and hyaluronan for prolonging corneal retention and drug delivery
Published in Drug Delivery, 2023
Ling-Chun Chen, Shyr-Yi Lin, Wei-Jie Cheng, Ming-Thau Sheu, Chi-Yun Chung, Chen-Hsuan Hsu, Hong-Liang Lin
Hyaluronic acid (HA) can relieve irritation, moisturize the ocular surface, and overcome the sodium hyaluronate deficiency in the tear film, thus alleviating DED symptoms. Hence, HA is the main ingredient in artificial tear formulations currently used for treating DED and Sjögren’s syndrome (Yang et al., 2021). Moreover, the mucoadhesive property and high viscosity of HA (Sudha & Rose, 2014) prevents the rapid washout of the drug by tears, thus prolonging the residence of drug and increasing ocular drug availability (Salwowska et al., 2016). Besides, the high molecular weight (MW) of HA inhibits inflammation by suppressing the production of inflammatory cytokines (Ruppert et al., 2014), which is beneficial for DED (Yamaguchi, 2018). The advantages of the cellulose derivatives of hydroxypropyl methylcellulose (HPMC) include safety, biocompatibility, and mucoadhesive property, which make them suitable for use as ODDS. Moreover, the mucoadhesive property of HPMC enables long contact time, allowing the drug to easily permeate the eye tissue (Tundisi et al., 2021). Therefore, we hypothesize that the addition of HPMC and HA would convert nongellable P407 aqueous solution into an in-situ gellable hydrogel with enhanced mucoadhesive characteristics. Accordingly, we developed P407-based thermosensitive in-situ hydrogels combined with HPMC and HA to reduce the desired concentration of P407 required for maintaining the formation of in-situ hydrogels with an enhanced mucoadhesive property to increase residence time for the continuing ocular delivery of solubilized testosterone in this study.
Design and evaluation of glimepiride hydrogel for transdermal delivery
Published in Drug Development and Industrial Pharmacy, 2022
Haiying Li, Jiajia Wang, Qianru Xu, Shuya Tian, Wenzhi Yang
Many naturally existing and synthetic materials, such as gelatin, carbopol, polyvinyl alcohol (PVA) and cellulose derivatives, can be used as hydrogel matrix [14]. Hydroxypropyl methylcellulose (HPMC) has been widely employed in the pharmaceutical industry because of its nontoxicity, good biocompatibility, film-forming capability and biodegradability [10,15]. The blend system of HPMC and other materials has superior properties [16,17]. Pullulan (Pu) is an extracellular microbial polysaccharide, which possesses good aqueous solubility, high adhesion and distinct film-forming ability [17]. In addition, Pu shows excellent biocompatibility and mechanical properties and has been approved by FDA for a wide application in the food and pharmaceutical industries [18]. Therefore, HPMC and Pu were chosen as combined matrices based on their good activity, and they were mixed physically to form transparent hydrogel with film-forming properties.
Design and optimization of a probiotic tablet for gastrointestinal tolerance by a simplex-centroid mixture
Published in Drug Development and Industrial Pharmacy, 2021
Mohd Akmal Azhar, Mimi Sakinah Abdul Munaim
In the tablet production process, biopolymers can be used as an excipient in the formulation. Alginate is one of the most common compounds integrated as an excipient for probiotic encapsulation because of its nontoxicity and biocompatibility. Moreover, this biopolymer is popular because of its low cost. It forms a gel when interacting with an aqueous medium and acts as a diffusion barrier for the probiotic cells as an active component in the formulation [10]. Hydroxypropyl methylcellulose (HPMC) is another essential biopolymer in the development of probiotic tablets. It forms a hydrogel layer by hydrating and swelling once it comes in contact with a liquid medium [11]. Therefore, it can regulate the diffusion of liquid into the tablet core, thus controlling the dissolution of the active ingredient inside the tablet. Carboxymethylcellulose (CMC) is another excellent biopolymer that improves the diffusion or dissolution system of tablet matrix design [12]. Generally, it facilitates the release of the active ingredient by hydrating the matrices, then diffusing the active ingredient into the bulk solution. It can achieve a constant delivery rate of active ingredient by partial dissolution or erosion. The chemical structures of alginate, HPMC, and CMC are shown in Figure 1.