Natural Preservatives
Philip A. Geis in Cosmetic Microbiology, 2020
Citric acid can be found in citrus extracts. Citric acid is widely used as an acidulent in creams and gels. It also has chelating activity, which may contribute some portion of its antimicrobial activity. Benzoic acid occurs naturally in many plants and is found in many berries, particularly cranberries. Benzoic acid and its salts and esters find usage in the formulation of oral products, including toothpastes, mouthwashes and dentifrices. It is also used in creams and lotions when these products are formulated with a sufficiently low pH to elicit antimicrobial activity. Sorbic acid was first isolated from the berries of Sorbus aucuparia (the Rowan tree), from which it derives its common name. Salicylic acid is found in a number of plant materials. Its most prominent natural source is willow bark extract.
Effervescent Granulation
Dilip M. Parikh in Handbook of Pharmaceutical Granulation Technology, 2021
Citric acid is the more often used acidic ingredient because of its good solubility and pleasant taste. It is mainly commercially available in powder and is either colorless or in white crystals. The particle size grades are coarse, medium, fine, and powder (only anhydrous). It is very soluble in water and soluble in ethanol [14]. It can be used as a monohydrate or anhydrate, depending on the selected equipment technology and process conditions. Anhydrous citric acid is less hygroscopic than the monohydrate [15]. However, caking of the anhydrous ingredient may occur upon prolonged storage at humidity greater than 70%. Citric acid monohydrate is used in the preparation of effervescent granules, while the anhydrous form is widely used in the preparation of effervescent tablets; the monohydrate melts at 100°C and releases the water of hydration at 75°C. For this reason, it can be used as a binder source in hot-melt granulation.
Melons of Central Asia
Raymond Cooper, Jeffrey John Deakin in Natural Products of Silk Road Plants, 2020
Other products are melon syrup (called melon honey in Russian and locally known as pekmez), melon jam, and pastila, which is a type of confectionary made with egg whites. Melon syrup is prepared by crushing and pressing pulp. The juice is then boiled. Melon syrup contains 60% sugars, and the final yield is 5%–8% by weight of the starting raw materials. Melon jam is prepared by cutting fruit into pieces, sieving, mixing with sugar or molasses and then boiling to the desired consistency. Citric acid (at a rate of 6–10 g/1 kg of product) is added to improve taste. The yield of jam is typically 25%–35% of the weight of the raw melon. Melon may also be stored by freezing. Pieces of melon are placed in jars immersed in 30% sugar or honey syrup, which is then frozen at a temperature of −16°C to −17°C.
Dissolving microneedle patch-assisted transdermal delivery of methotrexate improve the therapeutic efficacy of rheumatoid arthritis
Published in Drug Delivery, 2023
Weiman Zhao, Lijie Zheng, Jianhui Yang, Zihui Ma, Xinyi Tao, Qingqing Wang
PVP K90 was purchased from BASF (Germany). Methotrexate (MTX, Mw = 454.44 Da) (purity >98%) was obtained from Heowns OPDE Biochemical Technology Co. Ltd. (Tianjin, China). HA was purchased from Huaxi Biotechnology Co. Ltd. (Jinan, China). Dextran (Dex) was provided by Thermo Fisher Scientific (USA). Bacillus Calmette-Guerin was purchased from the Chengdu Institute of Biological Products Co., Ltd (Sichuan,China). Trypan Blue, stearic acid, and stearyl alcohol were provided by Sinopharm Chemical Reagent Co., Ltd (China). The reagents of acetonitrile (chromatographic grade), anhydrous sodium hydrogen phosphate, liquid paraffin, Span 80, polysorbate 80, glycerinum, and sorbic acid were provided by Macklin (Shanghai, China). Citric acid was from Biotechnology Co. Ltd. (Tianjin, China).
Nanoparticle-based chewable gels of praziquantel
Published in Pharmaceutical Development and Technology, 2023
M. Alejandra Gonzalez, M. Verónica Ramírez-Rigo, Noelia L. Gonzalez Vidal
Nomenclature, qualitative and quantitative composition of chewable gels, can be observed in Table 1. Gelatine was incorporated at two concentrations (8% and 12%), within the recommended range for this hydrocolloid, to evaluate the influence of this parameter over the texture properties of the gelled systems (Hartel et al. 2018). Water was added for the moistening of the gelatine and the progress of gelation method. Glycerine and sorbitol were added to provide a sweet taste to the formulation, and to reduce stiffness and improve the flexibility of the gel, due to their plasticizing effect (García Sanchez and Santos Buelga 2001). The incorporation of citric acid improves the taste of the final formulation and provides a lower pH, required to prevent microbial contamination. Besides, PZQ was added to the soft mixture of excipients from the following intermediate products (IP):IPa: NS containing PZQ and stabilized with PVP and P188, in a drug to stabilizers ratio of 1:1 (Gonzalez et al. 2018). The concentration of PZQ in the NS was 1% (w/v).IPb: Nanocomposite microparticles obtained by spray-drying of IPa (Gonzalez et al. 2019) and dispersed in water to obtain two final PZQ concentrations: 2% and 12% (w/v).
Development and in vivo evaluation of intranasal formulations of parathyroid hormone (1-34)
Published in Drug Delivery, 2021
Dan Wang, Yimeng Du, Wenpeng Zhang, Xiaolu Han, Hui Zhang, Zengming Wang, Nan Liu, Meng Li, Xiang Gao, Xiaomei Zhuang, Jing Gao, Aiping Zheng
Overall, this study aimed to develop an intranasal formulation of PTH(1-34). The research work first determined the optimal aqueous environment to be 0.008 M ABS, exhibiting preferable conformation and chemical PTH(1-34) stability. Citric acid and Kolliphor® HS·15 were investigated as permeation enhancers. Due to severe mucosal toxicity, formulations containing citric acid were excluded from promising intranasal formulations. On the other hand, Kolliphor® HS·15 exhibited good biosafety and significant permeation enhancement in in vivo studies. An intranasal formulation of PTH(1-34) with 10% Kolliphor® HS·15 produced high bioavailability (30.87%) in a preclinical animal model. In conclusion, this intranasal formulation is an attractive alternative to the injection formulation of PTH(1-34). It is worthwhile to promote future research on Kolliphor® HS·15-based intranasal PTH(1-34) formulations, including a comprehensive evaluation of the formulation, investigation of slightly higher Kolliphor® HS·15 concentrations and even advancement to early clinical trails.
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