The invention provides methods of synthesizing compounds in an asymmetric or enantioenriched fashion, wherein the compounds are useful intermediates in the synthesis of viral protease inhibitors.

The invention provides methods of synthesizing compounds in an asymmetric or enantioenriched fashion, wherein the compounds are useful intermediates in the synthesis of viral protease inhibitors.

The present invention relates to novel intermediate(s), which are useful for the preparation of Rivastigmine compound of formula (I) and its pharmaceutically acceptable salts. The present invention further relates to the processes for the preparation of such novel intermediate(s) and preparation of Rivastigmine using such novel intermediate(s).

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The present invention relates to novel intermediate(s), which are useful for the preparation of Rivastigmine compound of formula (I) and its pharmaceutically acceptable salts. The present invention further relates to the processes for the preparation of such novel intermediate(s) and preparation of Rivastigmine using such novel intermediate(s).

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The present invention provides a method for producing an active ingredient for a rivastigmine free base transdermal patch having preparing a rivastigmine free base; and adding an acidic substance to the rivastigmine free base and subjecting the acidic substance and the rivastigmine free base to a mixed reaction to form a mixture having a pH value from 6.0 to 8.5 as the active ingredient; and a rivastigmine free base transdermal patch having a drug layer comprising the active ingredient. The rivastigmine free base transdermal patch has a stable transdermal transmission time equal to or longer than 48 hours and equal to or less than 168 hours. The active ingredient produced by the method and the transdermal patch having the active ingredient allow effective and smooth release of rivastigmine free base and prolongs the release time to meet the clinical application needs.

The present invention provides a method for producing an active ingredient for a rivastigmine free base transdermal patch having preparing a rivastigmine free base; and adding an acidic substance to the rivastigmine free base and subjecting the acidic substance and the rivastigmine free base to a mixed reaction to form a mixture having a pH value from 6.0 to 8.5 as the active ingredient; and a rivastigmine free base transdermal patch having a drug layer comprising the active ingredient. The rivastigmine free base transdermal patch has a stable transdermal transmission time equal to or longer than 48 hours and equal to or less than 168 hours. The active ingredient produced by the method and the transdermal patch having the active ingredient allow effective and smooth release of rivastigmine free base and prolongs the release time to meet the clinical application needs.

The invention provides methods of synthesizing compounds in an asymmetric or enantioenriched fashion, wherein the compounds are useful intermediates in the synthesis of viral protease inhibitors.

The invention provides methods of synthesizing compounds in an asymmetric or enantioenriched fashion, wherein the compounds are useful intermediates in the synthesis of viral protease inhibitors.

The invention provides methods of synthesizing compounds in an asymmetric or enantioenriched fashion, wherein the compounds are useful intermediates in the synthesis of viral protease inhibitors.

Shell-and-tube strippers for stripping a urea/carbamate mixture, related systems, methods, and uses. The stripper includes a shell, a plurality of tubes disposed within the shell, and a heating fluid distributor for homogenizing the flow of a heating fluid near a heating fluid inlet. The heating fluid distributor includes an edge wall and a laterally disposed heating fluid distribution plate. Related systems, methods, and uses are also provided.