After reading this article you will learn about the various drugs acting on gastrointestinal tract. Sialagogues: Sialagogues or sialics are the salivary stimulants which increase the volume and fluidity of saliva. Uses: (i) Iatrogenic (drug-induced) hypoptyalism. (ii) Xerostomia (dryness of the mouth due to lack of normal secretion) resulting from other causes such as radiotherapy of the buccal cavity and [...]
This article throws light upon the three main factors decreasing the bioavailability of drugs. The factors are: 1. Inactivation 2. First Pass Effect 3. Enterohepatic Recycling. Factor # 1. Inactivation: Inactivation by gastric acid enzymes, bacterial flora. Factor # 2. First Pass Effect: Drug absorbed distal to the oral cavity and proximal to the rectum enters the portal circulation and [...]
This article throws light upon the six main formulations of drugs for oral use. They are: 1. Powders 2. Pills 3. Tablets 4. Bolus 5. Capsules 6. Suppositories. 1. Powders: Powders are solid dosage of medicament in finely divided form for internal and external use and are available in crystalline or amorphous form. The particle size of powders is significant [...]