Triphasic

U. Lachnit-Eixson, Tbe Development of aMew Triphasic Oral Contraceptive, MTP Press, Lancaster, U.K., 1980, p. 23. 

Phases. Often there are two Hquid phases (Hquid—Hquid PTC) or one soHd, one Hquid (soHd—Hquid PTC). If the catalyst is bound to a polymeric matrix this may comprise a third phase (triphase catalysis). Examples of gas—Hquid, gas—soHd, and soHd—soHd PTC are stiH relatively rare. In the latter two cases, a small amount of Hquid, eg, water, is probably present as an uimoticed third phase. 

In practice, 1—10 mol % of catalyst are used most of the time. Regeneration of the catalyst is often possible if deemed necessary. Some authors have advocated systems in which the catalyst is bound to a polymer matrix (triphase-catalysis). Here separation and generation of the catalyst is easy, but swelling, mixing, and diffusion problems are not always easy to solve. Furthermore, triphase-catalyst decomposition is a serious problem unless the active groups are crowns or poly(ethylene glycol)s. Commercial anion exchange resins are not useful as PT catalysts in many cases. 

Secondary alcohols ate oxidi2ed to ketones in good yields under mild conditions in a triphasic system using an inert solvent, soHd Ca(OCl)2, and a hypochlorite resin as catalyst (175). 

DreikSrper, -apparat, m. triple-effect apparatus. Dreileiter-. (Elec.) three-wire, dreimal, adv. three times, ttirice. dreimalig, a. done three times, triple. Dreiphssenstrom, m. (Elec.) triphase current, dreiphssig, a. three-phase, triphase, dreipolig, a. three-pole. 

Seddon s group described the option of carrying out Heck reactions in ionic liquids that do not completely mix with water. These authors studied different Heck reactions in the triphasic [BMIM][PFg]/water/hexane system [91]. While the [BMIM]2[PdCl4] catalyst used remains in the ionic liquid, the products dissolve in the organic layer, with the salt formed as a by-product of the reaction ([H-base]X) being extracted into the aqueous phase. 

The asymmetric epoxidation of enones with polyleucine as catalyst is called the Julia-Colonna epoxidation [27]. Although the reaction was originally performed in a triphasic solvent system [27], phase-transfer catalysis [28] or nonaqueous conditions [29] were found to increase the reaction rates considerably. The reaction can be applied to dienones, thus affording vinylepoxides with high regio- and enantio-selectivity (Scheme 9.7a) [29]. 

Estrogens and progestins (combination oral contraceptives) are used as oral contraceptives. There are three types of estrogen and progestin combination oral contraceptives monophasic, biphasic, and triphasic. The monophasic oral contraceptives provide a fixed dose of estrogen and progestin throughout the cycle The biphasic and triphasic oral contraceptives deliver hormones similar to the levels naturally produced by the body (Table 52-1). 

Fhase one 35 meg ethinyl estradiol, 0.5 mg norethindrone Fhase two 35 meg ethinyl estradiol, 1 mg norethindrone Triphasic Oral Contraceptives... 

The catalysts mentioned above are soluble. Certain cross-linked polystyrene resins, as well as alumina and silica gel, have been used as insoluble phase-transfer catalysts. These, called triphase catalysts, have the advantage of simplified product work up and easy and quantitative catalyst recovery, since the catalyst can easily be separated from the product by filtration. 

The influence of polymer composition and molecular weight on the estrus-suppressing activity of the microspheres in female rats was determined. A triphasic release pattern was observed. An initial rapid release over the first few days was attributed to diffusion from superficial areas of the microspheres. A second phase of lower release levels then occurs and continues until the onset of the third, major phase of release. This phase is facilitated by the onset of erosion of the polymer matrix. 

The triphasic pattern was more pronounced with copolymers of higher lactide content (longer bioerosion time). The 45 50 copolymer afforded efficacy in the rat over 5 weeks. The studies confirmed the homogeneous (bulk) rather than heterogeneous (surface) eroskn of the polymer. Subsequent studies (121) with 3-mm implants... 

The second phase occurs when the polymer undergoes significant biodegradation. Broad molecular weight compositions were proposed as one method of reducing the triphasic nature of these release patterns. ... 

LJ, a 25-year-old-woman with complex partial seizures, presents a prescription to the pharmacy for a triphasic oral contraceptive containing ethinyl estradiol and norgestimate. A review of her medication profile shows that she is taking carbamazepine extended-release 1200 mg/day. Her last refill for this prescription was 2 weeks ago. She reports that she has not had a seizure for a year and that she just became engaged. She is planning to be married in 4 months. 

TABLE 11.3 Examples of Biphasic and Triphasic MudPIT Analyses... 

Application Buffer Bi/Triphasic Mass spectrometer Database search engine Reference... 

Bovine microtubule bicarbonate Ammonium acetate Biphasic/triphasic LCQ SEQUEST (McDonald et al., 2002)... 

S. cerevisiae protein complexes Ammonium acetate Triphasic LCQ DECA SEQUEST (Graumann et al., 2004)... 

From 10 to 20% of an oral dose of miconazole is excreted in the urine, mainly as metabolites, within 6 days. About 50% of an oral dose may be excreted mainly unchanged in the feces. The elimination pharmacokinetics of miconazole have been described as triphasic, with a biological half-life of about 24 h. With an initial half-life of about 0.4 h, and intermediate half-life of about 2.5 h and elimination half-life of 24 h. Very little miconazole is removed by haemodialysis [3]. 

Crown ethers attached to insoluble polymeric substrates (see the following discussion for examples) have been used as phase transfer catalysts for liquid/liquid systems. In using such systems, the catalyst forms a third insoluble phase the procedure being referred to as triphase catalysis (Regen, 1979). This arrangement has the advantage that, on completion of the reaction, the catalyst may be readily separated from the reaction solution and recycled (Montanari, Landini Rolla, 1982). As... 

Immobilized cryptates. Like the crowns, cryptates have been immobilized on polymeric backbones. A typical system is given by (221) (Cinquini, Colonna, Molinari, Montanari Tundo, 1976). In this case, the polymeric matrix is polystyrene cross-linked with p-divinyl benzene and the cage is connected to this matrix via a long-chain aliphatic spacer group. This reagent is quite effective as a (triphase) transfer catalyst. 

About 3% (0.8 jg) of the deposited silver was 1 found in liver and blood 6h after exposure. Clearance from the lung to the blood was triphasic, with half-times of 1.7, 8.4, and 40 days... 

Painless thyroiditis has a triphasic course that mimics that of painful subacute thyroiditis. Most patients present with mild thyrotoxic symptoms lid retraction and lid lag are present but exophthalmos is absent. The thyroid gland may be diffusely enlarged, but thyroid tenderness is absent. 

In subacute thyroiditis, thyroid function tests typically run a triphasic course in this self-limited disease. Initially, serum T4 levels are elevated due to release of preformed thyroid hormone from disrupted follicles. The 24-hour RAIU during this time is less than 2% because of thyroid inflammation and TSH suppression by the elevated T4 level. As the disease progresses, intrathyroidal hormone stores are depleted, and the patient may become mildly hypothyroid with an appropriately elevated TSH level. During the recovery phase, thyroid hormone stores are replenished and serum TSH elevation gradually returns to normal. 

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