Use of prodrugs of 3-hydroxymorphinans to prevent bitter taste upon buccal, nasal or sublingual administration

Claim 1

A pharmaceutical composition consisting essentially of (i) a therapeutically effective amount of a 3-hydroxymorphinan analgesic, agonist-antagonist, or narcotic antagonist of the formula: ##STR32## or a pharmaceutically acceptable acid addition salt thereof, wherein: a is a single bond, or double bond; R is methyl, allyl, methylallyl, cyclopropylmethyl, or cyclobutylmethyl; R 1 is H, or OH; R 2 is H, OH, ═O, or ═CH 2 ; R 3 and R 4 are hydrogen, or taken together are ----O------; R 5 is alkanoyl of 2-18 carbon atoms; alkenoyl of 2-18 carbon atoms; mono- or dialkylcarbamoyl where each alkyl group contains 1-18 carbon atoms; alkylsulfonyl of 1-18 carbon atoms; alkylcarbonates where the alkyl group contains 1-18 carbon atoms; benzoyl, phenylsulfonyl; phenylcarbamoyl; substituted benzoyl; where the benzene ring contains 1-2 substituents individually selected from alkyl of 1-12 carbon atoms, OR 7 , NHR 7 and NR 7 R 8 , Cl, F, Br, I, trifluoromethyl; substituted phenylsulfonyl or phenylcarbamoyl, where the benzene ring contains 1-2 substituents individually selected from alkyl of 1-12 carbon atoms, alkoxy of 1-12 carbon atoms, Cl, F, Br, I, CF 3 ; R 6 is t-butyl or n-propyl; R 7 is H, alkyl of 1-4 carbon atoms or COR 9 ; R 8 is alkyl of 1-4 carbon atoms or COR 9 ; and R 9 is H, or alkyl of 1-4 carbon atoms; and (ii) a pharmaceutically acceptable carrier suitable for buccal, nasal, or sublingual administration.