bioassay of digitalis

Send This

Download

Comment

Favourite

more

Rating :

Rate It:

Embed :

Post a comment

Post Comment on Twitter Post Comment on SlideWorld

Comments:

Subscribe to follow-up comments

Notes

Hide Notes

Slide 1 :

Bioassay of digitalis Balaji college of pharmacy Mr.B.CHAKRAPANI M.pharm (ph.D) ASSISTANT PROFESSOR Hod of pharmacology DEPARTMENT OF PHARMACOLOGY Anantapur. 03/Aug/2012

Slide 2 :

DIGITALIS The use of D. purpurea extract containing cardiac glycosides for the treatment of heart . It is used to increase cardiac contractility. It is an antiarrhythmic agent to control the heart rate, particularly in the irregular heart beat. Digitalis is hence often prescribed for patients in atrial fibrillation, especially if they have been diagnosed with congestive heart failure.

Slide 3 :

Slide 4 :

Slide 5 :

Slide 6 :

DIGITALIS

Slide 7 :

principle Potency of the test sample is compared with that of the standard preparation by determining the action on the cardiac muscle. Any other equivalent method, which gives results similar to those obtained by this method as also valid.

Slide 8 :

Standard Preparation and Units: The standard preparation is a mixture of dried and powdered digitalis leaves (1 unit = 76 mg.) Preparation of Extracts: Exact amount of the powder is extracted with dehydrated alcohol in a continuous extraction apparatus for six hours. The final extract should contain 10 ml. (5 ml. alcohol + 5 ml. water) per 10 g. of digitalis powder. It should be stored in between 5 oC and –5 oC.

Slide 9 :

pigeon

Slide 10 :

Guinea pig

Slide 11 :

Slide 12 :

Guinea–pig Method (End point method) : Standard and test sample extracts are diluted with normal saline in such a way that 1 g of digitalis powder is diluted to 80 ml. A guinea pig is anaesthetized with a suitable anesthetic. It is dissected on the operation table. The jugular vein is traced out by removing adhering tissues and cannulated by means of venous canula. A pin is inserted in the heart, such that it gets inserted in the apex of the heart. In this way, we can observe the heart beats by up and down movements of the pin. The injection is continued through venous canula until the heart is arrested in systole.

Slide 13 :

Guinea–pig Method (End point method) -1 The amount of extract required to produce this effect is taken as the lethal dose of the extract. Another set of 19 animals of the same species are used for this experiment and the average lethal dose is determined. It is not necessary to determine the lethal dose of the std. during each time of the experiment. But it should be occasionally checked. The lethal dose of the test sample is determined in a similar way using minimum 6 guinea–pigs of the same strain. The potency of the test sample is calculated in relation to that of the std. preparation by dividing the average lethal dose of the sample to the test and expressed as units per gram.

Slide 14 :

Pigeon Method-1 Minimum 6 pigeons are used for testing each sample. They should be free from gross evidence of disease . The weight of the heaviest pigeon should not exceed twice the weight of the lightest pigeon. Food is withheld 16-28 hours before the experiment. Pigeons are divided on the basis of their sex, weight and breed, into two groups. They are anaesthetized with anaesthetic ether. One side of the wing is dissected and the alar vein is cannulated by means of a venous canula. Dilutions are made with normal saline. Average lethal dose of each sample is determined; results are tabulated and calculated as per guinea pig method.

Slide 15 :

Pigeon method -2 The lethal dose per kg. of body weight is determined for each pigeon. The potency of the test sample is determined by dividing the mean lethal dose of standard by the mean lethal dose of the test sample. In pigeons, stoppage of heart is associated with a characteristic vomiting response called ‘emesis’. The milk from the crop sac of pigeons is being ejected out. This may be taken as the end point response of digitalis.

Slide 16 :

Slide 17 :

Slide 18 :

digitalis presentation

Free Powerpoint Templates

	besthachakrapani 9 Months ago.



561 Views, 0 favourite
PowerPoint Presentation on bioassay of digitalis
More By User Flag as inappropriate Select your reason for flagging this presentation as inappropriate. If needed, use the feedback form to let us know more details. Cancel