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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
Carbomers are high molecular weight cross-linked polymers of acrylic acid, which when neutralized have the ability to absorb and retain water, resulting in a viscous gel or liquid. The dried carbomer comes in the form of a lightweight white powder. The resulting product of neutralization has a number of applications in cosmetics, with different carbomers being suited to different products. These products include gels, creams and lotions, shampoos, moisturizers, body washes and sunscreens. It provides viscosity, stabilization and suspension properties. They are an extremely efficient rheology modifier capable of providing high viscosity, and form sparkling clear, water-based or hydroalcoholic gels and creams.
Process Development Considerations for Topical and Transdermal Formulations
Published in Marc B. Brown, Adrian C. Williams, The Art and Science of Dermal Formulation Development, 2019
Marc B. Brown, Adrian C. Williams
The manufacturing process for gels is largely dependent on the type of polymer used. For example, cellulose-based polymers tend to be dispersed or dissolved in a pre-heated portion of the water, or the organic phase (for example, propylene glycol or polyethylene glycol) before the remainder of the formulation (cold) is added. Similarly, carbomers are usually pre-dispersed in water and then the remainder of the formulation is added. Neutralisation of the carboxyl groups completes the hydration of the polymer. In all cases, it is recommended to review the guidelines from the polymer manufacturer, although most of these assume the use of simple aqueous solutions. Since the preferred log P of most drugs for skin permeation is <3.5, then low or non-aqueous formulations may be required, and this may well heavily influence the selection of gelling agent and commensurate process.
Integrating network pharmacology and experimental validation to decipher the mechanism of the Chinese herbal prescription JieZe-1 in protecting against HSV-2 infection
Published in Pharmaceutical Biology, 2022
Tong Liu, Qingqing Shao, Wenjia Wang, Yonggui Ma, Tianli Liu, Ximing Jin, Jianguo Fang, Guangying Huang, Zhuo Chen
All the medicinal materials (Table 1) were purchased from Hubei Shengdetang Prepared Slices of Chinese Crudo Drug Co., Ltd. (Xiaogan, China). The medicinal materials were identified by the Associate Professor of Pharmacy Yonggui Ma and Professor of Pharmacy Jianguo Fang. Voucher specimens were prepared for identification and deposited in the traditional medicine collection centre for Department Pharmacy of Tongji Hospital (Tongji Medical College, Huazhong University of Science and Technology). The voucher number was presented in Table 1. JZ-1 was prepared as described previously (Duan et al. 2020). The extract was concentrated to a relative density of 1.20 under 60 °C, and then carefully weighed. Carbomer was dissolved with quantitative ddH2O. An appropriate amount of final mixed liquid and Dryobalanops aromatica. were added to the carbomer. The carbomer formed a gel by using sodium hydroxide solution (5 M) to adjust the pH. The concentration of drug gel was calculated. High-performance liquid chromatography fingerprinting was used to evaluate the stability of quality. The fingerprinting data are published elsewhere (Duan et al. 2020). As a commonly used clinical anti-HSV-2 drug, acyclovir was used as a positive control drug in the study. The acyclovir (Hubei Wushi Pharmaceutical Co., Ltd., Anlu, China) was prepared as 0.03 g/mL (3%) gels before use (O’Brien and Campoli-Richards 1989).
Formulation and rheological evaluation of liposomes-loaded carbopol hydrogels based on thermal waters
Published in Drug Development and Industrial Pharmacy, 2022
Romaissaa Mokdad, Ali Aouabed, Vincent Ball, Feriel Fatima Si Youcef, Noureddine Nasrallah, Béatrice Heurtault, Abdelkader HadjSadok
The most commonly used polymers to form the gel network for liposomal hydrogels are carbomers. The latter, also known by the commercial name of Carbopol®, are synthetic acrylic acid polymers, cross-linked with polyalkenyl ethers or divinyl glycol, with a linear, coiled and uncoiled structure [36]. Moreover, carbomers are anionic polymers with hydroxyl groups that expand upon neutralization in aqueous medium using an organic amine neutralizer [37]. Various grades of carbomers are commercialized that differ from each other depending on their chemical composition, molecular weight and cross-link types [31]. Carbomer polymers are commonly used to obtain hydrogels and liposomal hydrogels because of their biocompatibility, low toxicity, low irritancy and their excellent physical and rheological properties [32]. Several studies have already proved the effectiveness of carbomer gels as carrier for lipid vesicles in transdermal applications [38–40]. Furthermore, liposomal Carbopol hydrogels were found to act as reservoirs which release the drug in a sustained manner [39].
Eprinomectin nanoemulgel for transdermal delivery against endoparasites and ectoparasites: preparation, in vitro and in vivo evaluation
Published in Drug Delivery, 2019
Yujuan Mao, Xiaolan Chen, Bohui Xu, Yan Shen, Zixuan Ye, Birendra Chaurasiya, Li Liu, Yi Li, Xiaoling Xing, Daquan Chen
EPR (B1a + B1b ≥ 95%, B1a ≥ 90%) was purchased from North China Pharmaceutical Group Aino Co., Ltd (Shijiazhuang, China). Tween 80 (CP) and ethanol was from Nanjing Chemical Reagent Co., Ltd (Nanjing, China). Sodium hydroxide was obtained from Sinopharm Chemical Reagent Co., Ltd (Shanghai, China). Carbomer 940-1 was provided from Nanjing Weier Pharmaceutical Co., Ltd (Nanjing, China). Castor oil (CP) was purchased from Shanghai Lingfeng Chemical Reagent Co., Ltd (Shanghai, China). Caprylocaproyl Macrogolglycerides (Labrasol®) was purchased from Gattefossé Corporation (Lyon, France). Acetonitrile (high performance liquid chromatography [HPLC] grade, 99.9%) was supplied by Tedia Chemical (Fairfield, OH). Fluorescein isothiocyante and 4% polyformaldehyde were obtained from ShanghaiYuanye Bio-Technology Co., Ltd (Shanghai, China).