Composition containing cationic hydroxyethyl cellulose

A method of delivering a drug into a tissue and/or a bloodstream of a living body, wherein:

• said method comprising applying an aqueous solution to a mucosal surface in a nasal cavity and allowing the drug to permeate through the mucosal surface;
• the aqueous solution comprises:
• (a) a cationic polymer dissolved in water, wherein said cationic polymer comprises a hydrophobic quaternary ammonium group covalently attached to a hydroxyethyl cellulose polymer backbone, and comprises no non-hydrophobic quaternary ammonium group covalently attached to the hydroxyethyl cellulose polymer backbone, and
• (b) one or more drugs;
• the cationic polymer comprises repeat units of Structure II:
• n is 10 or higher;
• each of Ra, Rb, and Rc is H or [CH2CH2O]x—R1, and at least one of Ra, Rb, and Rc is [CH2CH2O]x—R1;
• each x is selected from 0, 1, 2, 3 and 4, and at least one repeat unit has at least one of Ra, Rb, and Rc in which x is 1, 2, 3 or 4;
• each R1 in Ra, Rb, and Rc is H or Structure III, and at least one R1 is Structure III:
• —Rd— is a bivalent organic group;
• —Re is either a hydrogen atom or a hydroxyl (OH) group;
• —R2 and —R3 is each an alkyl group with 3 or fewer carbon atoms;
• —R4 is an alkyl group with 10 or more carbon atoms;
• and
• X is an anion of valence v.