Provided are mucolytic compounds that are more effective, and/or absorbed less rapidly from mucosal surfaces, and/or are better tolerated as compared to N-acetylcysteine (NAC) and DTT. The compounds are represented by compounds of Formula I which embrace structures (Ia)-(Ib): ##STR00001##
where the structural variables are as defined herein.

Provided are mucolytic compounds that are more effective, and/or absorbed less rapidly from mucosal surfaces, and/or are better tolerated as compared to N-acetylcysteine (NAC) and DTT. The compounds are represented by compounds of Formula I which embrace structures (Ia)-(Ib): ##STR00001##
where the structural variables are as defined herein.

A method for producing an organic mercapto compound or an intermediate thereof according to the present invention has a reaction step of reacting an alcohol compound including a sulfur atom with a thioamide compound having a structure in which an organic group is bonded to at least one bonding hand of a thioamide group, under acidic conditions.

The present invention relates to a cationic lipid having one or more biodegradable groups located in a lipidic moiety (e.g., a hydrophobic chain) of the cationic lipid. These cationic lipids may be incorporated into a lipid particle for delivering an active agent, such as a nucleic acid. The invention also relates to lipid particles comprising a neutral lipid, a lipid capable of reducing aggregation, a cationic lipid of the present invention, and optionally, a sterol. The lipid particle may further include a therapeutic agent such as a nucleic acid.

The present invention relates to a cationic lipid having one or more biodegradable groups located in a lipidic moiety (e.g., a hydrophobic chain) of the cationic lipid. These cationic lipids may be incorporated into a lipid particle for delivering an active agent, such as a nucleic acid. The invention also relates to lipid particles comprising a neutral lipid, a lipid capable of reducing aggregation, a cationic lipid of the present invention, and optionally, a sterol. The lipid particle may further include a therapeutic agent such as a nucleic acid.

The present invention relates to a cationic lipid having one or more biodegradable groups located in a lipidic moiety (e.g., a hydrophobic chain) of the cationic lipid. These cationic lipids may be incorporated into a lipid particle for delivering an active agent, such as a nucleic acid. The invention also relates to lipid particles comprising a neutral lipid, a lipid capable of reducing aggregation, a cationic lipid of the present invention, and optionally, a sterol. The lipid particle may further include a therapeutic agent such as a nucleic acid.

The present invention relates to a cationic lipid having one or more biodegradable groups located in a lipidic moiety (e.g., a hydrophobic chain) of the cationic lipid. These cationic lipids may be incorporated into a lipid particle for delivering an active agent, such as a nucleic acid. The invention also relates to lipid particles comprising a neutral lipid, a lipid capable of reducing aggregation, a cationic lipid of the present invention, and optionally, a sterol. The lipid particle may further include a therapeutic agent such as a nucleic acid.

Provided are mucolytic agents represented by formula (Ia)-(Id):

##STR00001##

where the structural variables R.sub.1, R.sub.2, R.sub.5 and R.sub.6 are as defined herein. Also provided are a variety of methods of treatment which take advantage of the mucolytic properties of the compounds represented by formula (Ia)-(Id).

Provided are mucolytic agents represented by formula (Ia)-(Id):

##STR00001##

where the structural variables R.sub.1, R.sub.2, R.sub.5 and R.sub.6 are as defined herein. Also provided are a variety of methods of treatment which take advantage of the mucolytic properties of the compounds represented by formula (Ia)-(Id).

The present invention relates to a cationic lipid having one or more biodegradable groups located in a lipidic moiety (e.g., a hydrophobic chain) of the cationic lipid. These cationic lipids may be incorporated into a lipid particle for delivering an active agent, such as a nucleic acid. The invention also relates to lipid particles comprising a neutral lipid, a lipid capable of reducing aggregation, a cationic lipid of the present invention, and optionally, a sterol. The lipid particle may further include a therapeutic agent such as a nucleic acid.