Introduction to diarrhea Types of diarrhea Causes Classification Invivo screening model Invitro screening model

1. NOIDA INSTITUTE OF ENGINEERING AND
TECHNOLOGY(PHARMACY INSTITUTE)
Pharmacological Screening of Anti Diarrheal Agent
Presented by- Submitted to-
BHAWANA SHARMA Dr. Saumya Das
M.Pharma (Pharmacology) Professor
( HOD PHARMACOLOGY)

2. INTRODUCTION
DIARRHEA
Diarrhea is characterized by increased frequency of bowel movement, wet stool and abdominal pain.
Diarrhea, also spelled diarrhoea , is the condition of having at least three loose, liquid, or watery bowel movements each
day. It often lasts for a few days and can result in dehydration due to fluid loss .Signs of dehydration often begin with loss of the
normal stretchiness of the skin and irritable behaviour . This can progress to decreased urination, loss of skin color, a fast, heart
rate, and a decrease in responsiveness as it becomes more severe. Loose but non-watery stools in babies who are exclusively
breastfed, however, are normal.

3. TYPES OF DIARRHEA
• ACUTE DIARRHEA
• Self limiting.
• Last from 2 days to 3 weeks.
• Sudden onset on previously healthy person.
• Resolve with sequelae.
• CHRONIC DIARRHEA
• Last more than 4 weeks.
• Associated with recurring passage of diarrheal stools, fever, loss of appetite, nausea, vomiting.

4. CAUSES OF DIARRHEA
ACUTE DIARRHEA
• Bacterial
• Viral
• Drug induced
• Nutritional
• Protozoal
CHRONIC DIARRHEA
• Tumors
• Diabetes
• Addison’s Disease
• Hyperthyroidism
• Irritable Bowel Syndrome

6. Opioid agonists-Loperamide, diphenoxylate,
difenoxin, racecadotril
Anticholinergics -hyoscyamine and dicycloamine
(α)2-adrenergic receptor agonist-clonidine
Somatostatin analogue-Octreotide
Adsorbant drugs- kaolin, pectin, bismuth
subsalicylateAnd lactose

7. Screening Model
In vivo model
• Castor oil-induced diarrhea
• Gastrointestinal motility test
• Castor oil-induced enterpooling
• Magnesium sulfate-induced diarrhea

8. CASTOR OIL-INDUCED DIARRHOEA
• Rats were fasted for 18hrs and divided into five groups of six animals per group.
• Castor oil at a dose of 1 ml/ animals orally, was given to all groups of animals for the
induction of diarrhea.
• Thirty minutes after castor oil administration, the first group (control group)
received vehicle (0.5% v/vTween 80 in distilled water)
• While the second, third and fourth groups were given petroleum ether extract at
doses of 25, 50 and 100 mg/kg body weight respectively by oral route.
• The fifth group received the reference drug, diphenoxylate (50mg/kg body weight)
• Animals of all groups were placed separately in individual cages lined with filter
paper.
• The filter papers were changed every hour and the severity of diarrhea was assessed
hourly for six hours.
• The total number of faeces excreted and the total weight of faeces were recorded
within a period of six hour and compared with the control group.
• The total number of diarrheal facces of the control group was considered 100%
• The results were expressed as percentage of inhibition of diarrhea

9. GASTROINTESTINAL MOTILITYTEST
• This experiment was done by using charcoal meal as a diet.The rats were divided
into five groups of six animals each and fasted for eighteen hours before the
experiment.
• The first group (the control group) was orally administered the vehicle (0.5%Tween
80 in distilled water).
• The second third and fourth groups orally received petroleum ether extract at doses
of 25, 50 and 100 mg/kg body weight respectively.
• The fifth group received the standard drug, atropine sulfate (0.1 mg/kg body weight
intraperitoneal)
• Thirty minutes later each animal was given 1 ml of charcoal meal (10% activated
charcoal in 5% gum acacia) orally.
• Each animal was sacrificed thirty minutes after administration of charcoal meal.
• The distance covered by the charcoal meal in the intestine was expressed as a
percentage of the total distance traveled from the pylorus to the cecum.

10. CASTOR OIL INDUCED ENTEROPOOLING
• Over night fasted rats were divided into five groups of six animals each.
• Group 1 which received normal saline (2ml/kg intraperitonial) served as the
control group.
• Group 2 received atropine (3 mg/kg intraperitoneal) and groups. 3, 4 and 5
received extract of 25, 50 and 100mg/kg intraperitoneal, respectively, one hour
before the oral administration of castor oil (1ml).
• Two hours later, the rats were sacrificed.
• The small intestine was removed after trying the ends with threads and weighed.
• The intestinal content was collected by milking into a graduated cylinder and
their volume was measured.
• The intestine was reweighed and the difference between the full and empty was
calculated.

11. MAGNESIUM SULFATE-INDUCED DIARRHEA
• Animals are fasted for a period of 12-18 hours and are grouped into
control, reference, and test groups.
• After I hour of treatment, animals are dosed with magnesium
sulfate.
• Then they are housed in their separate cages for 4 hours.
• Using this technique, magnesium sulfate was administered 30
minutes before treatment.
• This is a curative approach unlike the preventive approach where
the test substance is administered before induction of diarrhea.

12. EVALUATION
• With anti-diarrheal agents dose-response curve are obtained for decrease
of hyper-secretion (stool weight) and increase of the diarrhea-free period
are obtained.
• Inhibitors of prostaglandin biosynthesis increase the diarrhea free period
but do not affect early diarrheal secretion

13. INVITRO MODELS

14. InVitro Model
• Guinea pig ileum strip 5cm in length is taken.
• It is closed at oral length and connected at the aboral end to a
pressure bottle and placed at suitable water bath at 37.5 C.
• Pressure bottle maybe raised or lowered that would increase or
decrease the intraluminal pressure.
• Increase intraluminal pressure will induce a peristaltic wave.
• After induction of peristalsis, the process is continued for a short
time(2 mins).
• Then the bottle is lowered so as to cease the persistaltic activity.

15. Contd…
• Drugs that after the tone of the intestinal muscle will change the pressure
reqd. to induce peristalsis.
• Thus with heightened tone, as after a drug, the pressure bottle will not have
to be raised to the same height as it is necessary for the control state before
peristalsis is induced.

16. Canine SlowTransit Constipation Model:
• Baseline data were measured in 8 beagle dogs, randomly dividing these
animals into the control group and model group.
• A diet of canned meat and a mixture of compound diphenoxylate and
alosetron hydrochloride for 5 weeks were provided to the dogs in the model
group.
• With no special intervention,dogs in the control group were provided an
ordinary diet.
• The tool frequency and consistency were noted and recorded daily, and
every week, the gastrointestinal transit time (GITT) was evaluated

17. Contd…
• All animals underwent midline laparotomy, and the colonic tissues were
taken from the rectosigmoid colon,
• then investigated by light microscopy, electron microscopy, and immune-
histochemistry to assess changes in the protein gene product 9.5.

18. EVALUATION
• With anti-diarrheal agents dose-response curve are obtained for decrease of
hyper-secretion (stool weight) and increase of the diarrhea-free period are
obtained.
• Statistical analysis was done with ONEWAY ANOVA.

19. REFERENCE
• Tripathi KD (ed.). Essentials of Medical Pharmacology (6th ed.). New
Delhi: Jaypee Publications.
• Bimlesh K, Kalyani D, Prashant T, Manoj S, Diwakar G. Evaluation of
antidiarrheal effect of aqueous and ethanolic extracts of fruit pulp of
Terminalia belerica in rats. Int J Drug Dev Res 2010.
• www.slideshare.com
• https://www.researchgate.net/publication/32604740