Dried-Down Solution Methods

To increase the deposition surface for phospholipids or to make much thinner Llms, a method has been developed in which the lipids are dried down onto a Lnely divided particulate support such as powdered sodium chloride, sorbitol, lactose, or polysaccharide, giving a product known as proliposomes. When hydrating the dry powder while mixing with a whirl mixer, the phospholipids swell whereas the support rapidly dissolves to give a liposomal suspension of MLVs in an aqueous solution. 

About 10% of the sample was concentrated in a vacuum centrifuge to give an estimated concentration of 1 pmol/pl if possible. Samples were not dried down completely to avoid sample loss. The MALDI matrix was a saturated solution of a-cyano-4-hydroxy cinnamic acid dissolved in water/acetonitrile (7 3) [8]. A 0.5-pl aliquot of the matrix solution was placed on the stainless steel probe and mixed with an equal volume of sample solution. The mixture was left to dry at room temperature prior to introduction into the mass spectrometer. A new sample preparation method which decouples matrix surface preparation and sample handling was also used [9]. 

However, LDI methods use solid-phase, dried-down samples, whereas chromatographic separations use solution phase samples. Thus, the liquid stream from the chromatograph... 

Liposphere formulations are prepared by solvent or melt processes. In the melt method, the active agent is dissolved or dispersed in the melted solid carrier (i.e., tristearin or polycaprolactone) and a hot buffer solution is added at once, along with the phospholipid powder. The hot mixture is homogenized for about 2 to 5 min, using a homogenizer or ultrasound probe, after which a uniform emulsion is obtained. The milky formulation is then rapidly cooled down to about 20°C by immersing the formulation flask in a dry ice-acetone bath, while homogenization is continued to yield a uniform dispersion of lipospheres. 

Method A. A slurry of 3.15 g d-lysergic acid monohydrate (monohydrate means dry) and 7.3 g of diethylamine (or 0.1 mole of similar amine) in 150 ml of pure chloroform is heated to reflux. After the lysergic acid is dissolved (a few min) cool the mixture down to where reflux has stopped by removing the heat. Before the mixture cools any further 2 ml of phosphorous oxychloride is added at such a rate as to give reflux (about 2 min). After addition, reflux for 4-5 min further until an amber-colored solution results. Cool to room temp and wash the mixture with 200 ml of 1 M ammonium hydroxide. The chloroform solution was dried with MgSC>4 (this would have to be after separation), filtered, and concentrated by evaporation in vacuo under a temp of 38° (at no time let the temp go over 40°). The last traces of solvent are removed at 2-5 mm. Dissolve the residue in a minimum amount of methanol and acidify with freshly prepared solution of 20% maleic acid in methanol (not aqueous) to precipitate the LSD in its maleate form. Filter the fluffy white needles, wash with cold methanol and air dry to get 2.2 g of LSD that requires no further purification. 

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