Capping technique

Because of these product sensitivities, most ophthalmic pharmaceutical products are aseptically manufactured and filled into previously sterilized containers in aseptic environments using aseptic filling-and-capping techniques. This is the case for ophthalmic solutions, suspensions, and ointments, and specialized technology is involved in their manufacture. 

The work on rate-constants by Higashimura s group includes studies by the stopped-flow technique and also by the end-capping technique, and these are included in this section. 

LIVING POLYMERS, AND ELECTRON TRANSFER PROCESSES, Interscience Publishers, 1968, persumably pp. 499 and 500) has himself recently used this Technique albeit without acknowledging the original or later association work, the development of the capping technique which he has exploited, nor his faulty commentary."... 

The somewhat higher values of N exhibited by the polybuta-dienyl lithium were ascribed to the occurrence of some cross-linking during the polymerization of this monomer, and this was confirmed by use of a special "capping" technique, as shown later. 

The a,ft)-asymmetric polymers are available by the combination of the functional initiator and functional terminator methods. By the rational combination of haloboration-initiation and capping techniques, a series of a.w-asymmetrically functionalized PlBs have been prepared [139, 140]. Polymers prepared by haloboration-initiation invariably carry an alkylboron head group [42, 141, 142], which can easily be converted into a primary hydroxy [141] or a secondary amine group [139, 140]. To functionalize the (W-living ends, the functionalization strategy shown in Scheme 26.2 is applicable and has been used to incorporate methoxycarbonyl groups as w-functionahty [143]. 

The environment for the water treatment can be in the presence of liquid water, steam, or humidified air as long as it contains more than 2% by weight of water. One approach is to heat aqueous slurry of the polymer slurry capping. Another technique is to treat the polymer with steam or humidified heated air vapor capping). In the slurry capping technique, the polymer is mixed with sufficient water to form slurry under sufficient pressure to keep the water in liquid form at the reaction temperatures (ca. 200°C). Salt or base is dissolved in the aqueous phase. The inorganic compound is blended with the polymer in the solid phase, which is heated to the reaction temperature. The moisture, usually carried by air and sometimes in the form of steam, is passed over and through the polymer. 

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