<prompt> 100 bioavailability is seen with which routeOralIntravenousRectalSubcutaneous  <response>: Ref: Katzung Pharmacology, 10th ed. Ch 3Bioavailability is defined as the fraction of unchanged drug reaching the systemic circulation following administration by any route.In case a drug is given orally, the bioavailability shall be less than 100. This is due toIncomplete extent of absorptionFirst pass metabolismRoutes of administration, bioavailability, and general characteristicsRoute of AdministrationGeneralcharacteristicsBioavailabilityIntravenousOnset of action is fastest100IntramuscularPainful75-100SubcutaneousLesser volumes can be given compared to intramuscular route75-100Per oralMost convenient from patients perspective MC used route5 to 100First pass metabolism limits blood levelsPer rectalLess first pass metabolism than peroral30 to 100TransdermalVery slow absorption.Lack of first pass effectProlonged duration of action80-100 