Inorganic Chemical Pollutants
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
Hydrazine (N2H4) is added to anticorrosion agents for heating oil tanks, boiler tubes, and borehole pipes. It has an ammonia odor, very unstable, and highly toxic. When combined with liquid oxygen, hydrazine is a valuable fuel for rocket propulsion. This reaction is accompanied by a large heat of combustion which is responsible for the high thrust. Hydrazine is often used as a foaming agent for rubber, thermoplastics, and other expanded products. The effect of hydrazines is due to the nitrogen gas liberated. Derivatives of hydrazine are important intermediates in the synthesis of special dyes, pharmaceutical products, and plastics. In particular, hydrazine plays an important part in the production of intermediates for the synthesis of polyamides such as nylon. Hydrazine also has a stabilizing effect on products made from natural rubber of styrene.
Catalog of Herbs
James A. Duke in Handbook of Medicinal Herbs, 2018
Bark used for washing clothes in South America, contains circa 10% saponin; used in manufacture of commercial saponins; used in mineral water industry, shampoo liquids, etc. as a foaming agent.20 Has been suggested as a substitute for senega and sarsaparilla. Used in mouthwash, shampoos, and toothpowders.33 As a shampoo — 1 part bergamot, 5 parts powdered quillaja, and 20 parts alcohol, has been recommended to promote the growth of hair. Also, used extensively as a foaming agent in cocktail mixes and root beers. Highest maximum use level averages around 0.01% for such beverages. Also, reported in baked goods, candy, frozen dairy desserts, gelatins, and puddings.29
Surfactants in Cosmetic Products
Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters in Cosmetic Formulation, 2019
The amount of foam produced by a surfactant under a predetermined set of conditions increases with its concentration in the solution to a maximum which occurs near the cmc. Apparently, then, the critical micellar concentration of a surfactant can be used as a parameter to predict the foaming power of a material, but not necessarily the persistence of the foam. Any structural modification leading to lowering the cmc of a class of surfactants is expected to increase its efficiency as a foaming agent, such as an increase in its hydrophobic chain. In contrast, the branching of the hydrophobic chain, which increases the cmc, results in a lower foaming efficiency.
An acryl resin-based swellable microneedles for controlled release intradermal delivery of granisetron
Published in Drug Development and Industrial Pharmacy, 2018
Guozhong Yang, Meilin He, Suohui Zhang, Man Wu, Yunhua Gao
The PDMS mold was prepared by casting the mixture of dimethyl siloxane and initiator onto a steel master with array of 400 (20 × 20) pyramid tips over an area of 10 × 10 mm2 which each microneedle is a pyramid with 0.3 mm in base length and 0.55 mm in height. EUDRAGIT RL100 resin was dissolved in ethanol to a certain concentration. A certain amount of PEG 400, granisetron, and rhodamine B were dissolved in the resin alcohol solution while the pore foaming agent was dispersed in it. To fabricate the microneedles, 0.1 ml of a resin solution was pipetted onto the PDMS mold and the mold was vacuumed at −80 kPa for two minutes then dried for 60 min at 20% relative humidity (RH). Later, the pressure sensitive adhesive patch (1525 L, 3 M) was placed on the microneedle backing, the acryl resin-based microneedles were obtained by removing them from the mold.
Enhanced dissolution of sildenafil citrate as dry foam tablets
Published in Pharmaceutical Development and Technology, 2019
Somchai Sawatdee, Apichart Atipairin, Attawadee Sae Yoon, Teerapol Srichana, Narumon Changsan
The extragranular disintegrant (croscarmellose sodium) and diluent (lactose monohydrate) were added to maintain an equivalent weight. Magnesium stearate was passed through #60 sieve before use. Dry foam granules were blended with croscarmellose sodium for 5 min in a plastic bottle, and then, the mixture was blended with sieved magnesium stearate for 3 min in the same bottle. The final mixtures of granules were compressed into 600 mg tablets using a single punch tableting machine (small tablet press machine Model SP-KR, Charatchai machinery, Thailand) with a round punch and a die diameter of 12 mm. The compression forces were kept constant in order to compare other properties. Figure 2 illustrated the whole process of this experiment. In addition, physical mixing without the granulating process (F9) and formulation without the foaming agent (F10) were preparedin a similar manner as for dry foam process as a control. Briefly, sildenafil and all excipients were mixed and compressed powder into a tablet as F9. The F10 was prepared by mix sildenafil citrate and other excipients, and then, purified water was added as a granulating solvent and mixed to obtain wet mass. The damp mass was sieved and dried by hot air oven (70 °C) and passed through sieve #14, mixed with an extragranular excipient and compressed granules into tablets. The details of each formula are shown in Table 1.
The preparation, characterization, and application of porous core–shell composite particles produced with laboratory-scale spray dryer
Published in Drug Development and Industrial Pharmacy, 2023
Zhe Li, Lin Zhu, Fu-Cai Chen, Yong-Mei Guan, Li-Hua Chen, Ji-Wen Zhang, Zhi-Xuan Mao, Liang-Shan Ming, Wei-Feng Zhu
In summary, it is clear to see that the particles prepared with NH4HCO3 have higher TS, larger SSA, smaller PV, and diameter than those prepared with NaHCO3. This is mainly due to the different molecular compositions of the two pore-forming agents. Under the same mass condition, one molecule of NH4HCO3 releases three molecules of gas, and two molecules of NaHCO3 releases two molecules of gas when the materials were heated at high temperature. Therefore, it could be concluded that the compactibility of materials is mainly affected by the pore-foaming agent. Moreover, choosing NH4HCO3 to prepare porous particles was more conducive to the compactibiliy than NaHCO3.
Related Knowledge Centers
- Colloid
- Detergent
- Shampoo
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- Foam
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- Soap