Abstract: A method for generating a plurality of drug-containing microcapsules employs one or more atomizers to form the microcapsules by the phenomenon of solvent exchange. A plurality of microdroplets of an aqueous solution is contacted with a plurality of microdroplets containing a polymer dissolved in a hydrophilic solvent under conditions whereby the polymer solution envelops the aqueous microdroplet. Exchange of solvent molecules between the aqueous core and its polymer-containing shell deposits the polymer as a membrane around the aqueous core. A preferred atomizer is a coaxial ultrasonic atomizer. Microcapsules can be generated in air as well as when submersed in a collection bath. Desired properties of the microcapsules, e.g., controlled release, can be achieved by providing protective excipients within the aqueous core, providing a hydrophilic polymer capable of undergoing a sol-to-gel transition within the aqueous core, optimizing selection of the polymer solvent, adjusting relative flow rates, and the like.

Abstract: A solvent exchange method is employed to provide microencapsulated compositions, such as microcapsules of pharmaceutical preparations. The method is based on an exchange of water and a hydrophilic organic solvent, whereby a decline in solvent quality for the organic solvent causes a polymer dissolved therein to be deposited onto an aqueous core. Optimal results are rationalized in terms of a balance of water solubility and surface tension for the organic solvent. In a preferred embodiment, microcapsules of selected drugs are formed by contacting microdroplets of an aqueous solution containing the drug with the organic solvent containing a polymer dissolved therein. A preferred method employs biodegradable poly(lactic acid-co-glycolic acid) (PLGA) dissolved in acetic acid, ethyl acetate, methyl acetate, or ethyl formate, to form a PLGA membrane around an aqueous drug core. The method is particularly attractive for encapsulating protein-based drugs without substantial denaturation.

Abstract: A solvent exchange method is employed to provide microencapsulated compositions, such as microcapsules of pharmaceutical preparations. The method is based on an exchange of water and a hydrophilic organic solvent, whereby a decline in solvent quality for the organic solvent causes a polymer dissolved therein to be deposited onto an aqueous core. Optimal results are rationalized in terms of a balance of water solubility and surface tension for the organic solvent. In a preferred embodiment, microcapsules of selected drugs are formed by contacting microdroplets of an aqueous solution containing the drug with the organic solvent containing a polymer dissolved therein. A preferred method employs biodegradable poly(lactic acid-co-glycolic acid) (PLGA) dissolved in acetic acid, ethyl acetate, methyl acetate, or ethyl formate, to form a PLGA membrane around an aqueous drug core. The method is particularly attractive for encapsulating protein-based drugs without substantial denaturation.

Abstract: The present invention is to provide a method and a transdermal drug delivery device for treating erectile dysfunction which comprises a patch containing pharmaceutically active ingredient and being directly apply to the male glans penis and its support and the rings for constricting the base part of the penis to aid the erection. The patch according to the present invention may be divided into two types, i.e. a cylinder type patch and a multi-reservoir type patch. The transdermal drug delivery patch device of the present invention is painless and safely to use and may be effectively produced and maintained erection of the penis without the adverse side effects and with a high degree of patient acceptability in the case of male impotence.