| 摘要 |
<p>Biodegradable nanocapsules comprise an envelope made by polymerising an alkyl cyanoacrylate (I) and an internal cavity contg. a soln. or oily suspension of a biologically active substance (A). Pref. the diam. of the capsules is below 1 micron. The capsules are made by first dissolving (e.g. in ethanol) an oily prod. (and opt. (A)) and (I). This soln. is then injected into distilled or deionised water, opt. contg. a nonionic surfactant, then if necessary the solvent is eliminated and the resulting suspension conc. Partic. (I) is isobutyl 2-cyanoacrylate (Ia) and the soln. is introduced into the water (contg. 0.5-1% 'Pluronic F 68' (RTM)) slowly with vigorous stirring. In this stage the heat of mixing is sufficient to cause polymerisation. The capsules can contain pharmaceuticals (for human or veterinary use), allergens, enzymes, diagnostic prods. etc.; specifically 'ultra-fluid lipidol' (radio-opaque material contg. 48 g iodine/100 ml); lomustine; progesterone or insulin. They can be administered orally, subcutaneously, intradermally, intramuscularly or intravenously, and are stable against autoclaving, centrifuging, freezing and storage. (I) are polymerised under milder conditions than other acrylic derivs. and nanocapsules can be prepd. at any pH.</p> |
