osen ▁m uc us ▁in ▁patients ▁present ing ▁with ▁ac ute ▁or ▁chron ic ▁bron ch itis , ▁and ▁related ▁conditions . ▁It ▁is ▁derived ▁from ▁sources ▁such ▁as ▁oil ▁of ▁tur pent ine , ▁or eg ano , ▁th yme ▁and ▁eu cal y pt us . ▁It ▁was ▁popular ▁in ▁the ▁United ▁States ▁since ▁the ▁late ▁nin ete enth ▁century , ▁but ▁was ▁removed ▁from ▁market ed ▁medic ations ▁in ▁the ▁ 1 9 9 0 s ▁after ▁the ▁U . S . ▁Food ▁and ▁D rug ▁Administration ▁( F DA ) ▁found ▁a ▁lack ▁of ▁evidence ▁of ▁safety ▁and ▁effect iveness . ▁Eli x irs ▁of ▁ter pin ▁hyd rate ▁are ▁still ▁available ▁with ▁a ▁pres cription , ▁but ▁must ▁be ▁prepared ▁by ▁a ▁comp ounding ▁ph arm acy . ▁It ▁can ▁be ▁prepared ▁from ▁other ▁vol atile ▁o ils ▁like ▁Ger ani ol , ▁L inal ol ▁and ▁N er ol ▁by ▁adding ▁D il ute ▁ac ids ▁( 5 % ▁H 2 SO 4 ) ▁to ▁them . ▁ ▁Medical ▁uses ▁Ter pin ▁hyd rate ▁is ▁an ▁expect or ant , ▁used ▁in ▁the ▁treatment ▁of ▁ac ute ▁and ▁chron ic ▁bron ch itis , ▁p neum onia , ▁bron ch ie ct asis , ▁chron ic ▁ob struct ive ▁pul mon ary ▁disease , ▁inf ect ious ▁and ▁infl am mat ory ▁dise ases ▁of ▁the ▁upper ▁resp ir atory ▁tract . ▁It ▁is ▁typically ▁form ulated ▁with ▁an ▁ant it uss ive ▁( e . g