1/31/2017

Mcqs

Labels:

posted by Dr. Shirish Nagansurkar @ January 31, 2017  

1/30/2017

MCQs Test on Tablets.

Pharmaceutics MCQs

Pharmaceutics MCQs
You may also like,
1) MCQ Test on Microscopy.                                                        
2) MCQ Test on History of Microbiology.                                 
3) MCQ Test on Preservation of Cultures.                                   

4) MCQ Test on Manufacturing Defects of Tablets.               



For attempting MCQs test on tablets first enter your name and email address and after completion please don't forget to press "Submit" button.

Pharmaceutics MCQs

Pharmaceutics MCQs

Labels: ,

posted by Dr. Shirish Nagansurkar @ January 30, 2017  

1/29/2017

Rotary Tablet Press: Multiple Station Tablet Machine.

Rotary Tablet Press.



  • It is also called multi-station tablet press.

  • Multi-station presses are termed rotary because the head of the machine that holds the upper punches, dies and lower punches in place rotate.

  • As the head rotates the tablet granulation runs from the hopper through the feed frame into dies.

  • Feed frame promotes a uniform fill of the die.

  • Compression takes place as the upper and lower punches pass between a pair of rollers.

  • The up and down movement of the punches is guided by fixed cam tracks.

  • The portion of the head that hold the upper and lower punches are called upper and lower turrets and the portion holding the dies are called the die table.

  • Rotary Tablet Press

  • At the start of a compression cycle, granules from hopper empty into the feed frame, which has several interconnected compartments.

  • These compartments spread the granules over a large area to provide time for the dies.

  • Weight Adjustment cam guides the lower punches to the bottom of their vertical travel, allowing the die to the cam, which reduces the fill in the dies to the desired amount.

  • A wipe-off blade at the end of the feed frame removes the excess granulation and backs it into the front of the feed frame.

  • Next, the lower punch travel over the lower compression roll and upper punches ride below the upper compression roll.

  • The upper punch enters a fixed distance into the dies, while the lower punches are raised and compact the granules within the dies.

  • To regulate the upward movement of the lower punches, the height of the pressure roll is changed.

  • After compression, the upper punches are withdrawn by upper punch raising cam and lower punch ride up by the cam, which brings the tablet above the surface of the dies.

  • The tablet strikes a sweep off blade attached at the front of the feed frame and slides down to the receiver.

  • At the same time, the lower punch reenters the pull-down cam and the cycle is repeated.

Labels:

posted by Dr. Shirish Nagansurkar @ January 29, 2017  

1/28/2017

Tablet Compression Machine

Tablet Compression Machine


Tablets are made by compressing a formulation containing a drug or drugs with or without excipients on stamping machine called presses.

Tablet presses are designed including following basic components:

  • Hopper for holding and feeding granules.

  • Dies that define the size and shape of the tablet.

  • Punches for compressing the granules within the dies.

  • Cam tracks for guiding the movement of the punches.

  • A feeding mechanism for moving granules from hopper into the dies


Tablets presses are classified either single punch or multi-station rotary presses.

Tablet compression machine

In the case of single punch machines, all of the compression is applied by the upper punch while lower punch acts as a supporter, making the single punch machine a “stamping press”.

  1. Single punch tablet press is also called as an eccentric press or single station press.

  2. It is the simplest machine for tablet manufacturing.

  3. Single station tablet press employs a single tooling station that is a die and a pair punches (upper and lower punch).

  4. This tablet press is available as both manually operated and power driven.

  5. In this single punch tablet press, the compaction force on the fill material is exerted by only the upper punch while the lower punch is immovable such as action equivalent to hammering motion.

  6. The tablet press contains fallowing compartments,

  7. HOPPER: HopPer may be one or more in number which serves two purposes 1.Firstly to hold granulated feed 2. Secondly to pass it to the feed frame.

  8. For subsequent compressing the hopper can be filled manually or by using mechanical equipment.

  9. FEEDING MECHANISM: The feeding mechanism helps in the guiding granulated feed from the hopper into the die cavities.

  10. In the single punch, a feed shoe which is connected to the hopper is laid down on die table.

  11. Tooling set: The basic mechanical and functional unit of tablet presses is the tooling set which comprises of the die cavity and a pair of upper and lower punches.


[caption id="attachment_377" align="aligncenter" width="200"]tooling set tooling set[/caption]

  1. The tooling set comprises a pair of upper and lower and a die cavity which is also called as a station.

  2. Tooling sets are available in various shapes in following sizes,

  3. tooling types

  4. Dies that define the size and shape of the tablet.

  5. Punches for compressing the granules within the die.

  6. Cam track guides the position of the punches there connected to the head of the punches.

  7. The mechanism involved in tablet press is that the compaction of powder blend is accomplished by exerting the pressure via upper and lower punches, the resultant tablets are formed in the die cavity.

  8. Working process can be divided into three stages,




    • Ejection

    • Compression

    • Filling

    • Filling: The lower punch falls in the die leaving a cavity into which granules flows under the influence a gravity from the hopper.

    • Compression: The upper punch, drops, and its tip enters the die.

    • The porosity of the contents of the dies progressively reduced, and the particles are forced into the over closer proximity to each other.

    • Ejection: The upper punch is withdrawn from the die, lower punch rises upwards simultaneously feed shoe comes over die and moves the compressed tablet from the site.

    • Cycle continues.





  • Advantages :



  1. The machine structure is simple and small,

  2. Very easy to operate.

  3. Less noisy.

  4. Takes lesser surface area.

Labels:

posted by Dr. Shirish Nagansurkar @ January 28, 2017  

1/26/2017

Pharmacognosy: Antitussive Drugs.

Antitussive Drugs.


A cough is a protective reflex stimulated by the body to remove the unwanted particles from the respiratory tract. However, a cough can be pathological and may disturb the daily routine work of individual and hence when it becomes disturbing has to be stopped.

Antitussives the name is derived from,

Anti means "Aganisnt"


"Tussis" means "a cough", and hence anticough.


Antitussives can be defined as the drugs which ae used in treatment of cough.




  • A cough can be categorized into a dry cough or a wet cough.

  • A dry cough is also called as "Smokers Cough" and is not associated with mucus and hence called as "Dry", it produces a characteristic sound while coughing.

  • A dry cough responds well to centrally acting cough suppressants.

  • A wet cough is always associated with mucus and produces a wheezing sound during coughing, its is also called as "a productive cough."

  • A wet cough usually responds well to the expectorants.


Classification of Antitussive Drugs:



  • Based on Mechanism of Action.




  1. Centrally acting cough center depressants:





  • These drugs depress the cough center located in CNS.

  • They are potent drugs usually associated with sedation.

  • They are useful in the treatment of a dry cough.

  • e.g. Codeine and Noscapine from Opium.


              2. Demulcents:



  • These are usually viscous in nature and act by soothing the irritating membrane of the pharynx.

  • These are particularly useful in the treatment of "sore throat".

  • e.g. Honey.


             3. Expectorants:



  • These drugs make thick mucus flowable and hence helps to expel it out during coughing.

  • e.g Ipecac, Vasaka, Balsam of Tolu etc.


            4. Mucolytics:



  • These drugs breakdown "disulfide" linkage in the mucus making it free to flow.

  • e.g. Vasaka.


A) Vasaka:



  • Synonym:

  • Adulsa, Vasaka Leaves.


 

  • Biological Source: 

  • Vasaka consists of dried as well as fresh leaves of the plant known as Adathoda vasika belonging to the family Acanthaceae.


 

  • Physical characteristics:

  • Color: Green to dark green.Antitussive drugs

  • Odor: Characteristic.

  • Taste: Bitter.

  • Size: 10 to 30 cm X 4 to 10 cm.

  • Shape: Lanceolate, entire margin, symmetrical base.



  • Chemical Properties:

  • Vasaka contains active chemical constituents as "Quinazoline Alkaloids."

  • The chief active constituents of the drug are "Vasicine and Vasicinone."

  • Vasicine has a tendency to get autoxidized to vasicinone.

  •  Vasaka also contains less active chemical constituents as "Vasakin, Adathodic acid and Vol. oils."

  • The inert chemical constituents of the drug are "Starch, calcium oxalate crystals, proteins etc."


 

  • Uses:

  • Antitussive: As an Expectorant and Mucolytic.

  • Bronchodilator.

  • As an oxytocic.


 

  • Adulterants:

  • 1) Alianthus excelsa. 2)Adathoda badonine.



2) Tulsi:



  • Synonym: Tulas, Holy Basil, Sacred Basil.


 

  • Biological Source:

  • Tulsi consists of dried as well as fresh entire herb known as "Ocimum sanctum" belonging to family "Labiatae."


 

  • Physical Properties:

  • Color: Green to dark green.Tulsi

  • Odor: Characteristic aromatic.

  • Taste: Pungent characteristic.

  • Size: leaves are 3cmto 5cm long.

  • Shape: Leaves are petiolate and ovate in shape.


 

 

 

  • Chemical Properties:

  • Tulsi contains "Volatile Oils" as active chemical constituents.

  • Active constituents from volatile oil of Tulasi are oleanolic acid, ursolic acid,rosmarinic acid, eugenol, carvacrol, linalool, β-caryophyllene (about 8%), β-elemene (c.11.0%), and germacrene D (about 2%).

  • It also contains thymol and safrole.


 

  • Uses:

  • Tulsi is useful as an expectorant antitussive.

  • It is reported to have Antibacterial and Antiviral actions.

  • Volatile oil of Tulsi is insect repellent.

  • Tulsi is one of the major ingredients in many Ayurvedic formulations.




3)

Labels:

posted by Dr. Shirish Nagansurkar @ January 26, 2017  

1/25/2017

Tablets: Manufacturing Defects.

1.Capping & Lamination:

  • Complete or partial loss of top and bottom crowns of a tablet from the main body is called capping. 

  • The separation of a tablet into two or more distinct layers is called lamination.

  • These problems occur immediately after compression, however may occur after several hours or days.

Causes:

1. Air entrapment.

2. Deep concave punch.

3. Claw formation of Punch.

4. Wear ring formation in die wall.

5. Incorrect setting of the press.

6. Compression of too dry material

Solutions:

1. Precompression

2. Reduction in speed of machine.

3. Reduction in final compression force.

4. Using flat punches.

5. Using hygroscopic materials to maintain proper moisture level eg. - PEG-4000 and Methyl Cellulose.

2.Picking & Sticking:

  • Surface materials from a tablet that is sticking to the punch and being removed from the tablet surface is picking.

  • Sticking refers to tablet materials adhering to the die wall.

  • When sticking occurs, additional force is required to overcome the friction between the tablet and die wall during ejection. 

Cause:

1. Picking occurs when punch tips are engraving or embossing. Small enclosed areas in letters A.

2. Wear and tear of the machine.

3. Improper cleaning before starting the batch.

Solutions:

1. Periodically checking and changing of punches and dies.

2. Proper cleaning and maintenance of the machine before batch operation.

3.Mottling:

  • It is an unequal distribution of colors on a tablet.

Causes:

1. Use of a drug whose color differs from tablet excipients.

2. Use of a drug whose dehydration products are colored.

Solutions:

1. The use of colorant may solve the problem but can create another Problem.

A dye can cause mottling by migration to the surface of a Granulation during drying to overcome this difficulty. Change the Solvent system, reduce drying temperature.

2. Disperse a dry color additive during powder binding steps.

4. Weight Variation:

  • Variation of tablet weight also causes variation of active medicaments, which changes the bioavailability.

Causes:

(a) Granule size & size distribution:

  • Variations in the ration of small to large granules and difference in granule size determine how the void space between particles are filled.

  • Since volume of die cavity remain same , different proportions of large and small particles may change  the weight of fill in each die.

(b) Poor Flow:

  • The die fill process in based on a continuous and uniform flow of granules from the hopper through the feed frame.

  •  When the granulation does not flow uniformly some dies are incompletely filled.

  • Dies are also not filled properly when machine speed is in excess of granulations flow capability.

  • For correcting poor flow the addition of a glidant such as talcum or colloidal silica may be helpful.

(c) Punch Variation:

  • When length of lower punches is unequal, the fill in each die varies which causes weight variations of tablet.

(d) Poor Mixing:

  • Some times lubricants and glidants are not thoroughly distributed.

  • The flow of particles then impaired and the granules do not  move efficiently into the dies.

5.Hardness Variation:

  • Hardness depends on the weight of materials and space between upper and lower punch at the moment of compression.

  •  If the volume of materials and distance between the punches varies hardness also alters.

6.Double Impression:

  • This involves only punches that have monogram or engraving.

  • If the monogram present in upper punch, slight rotation of punch after precompression produce double impression. If monogram present in lower punch after compression is over lower punch move slightly downward to free the tablet and produce double impression. This problem can overcome using non-rotating cam track.

That's all for today if I have missed any important one kindly comment bellow, Thank U.

Solve MCQs on Manufacturing defects of Tablets:     

Labels:

posted by Dr. Shirish Nagansurkar @ January 25, 2017  

1/19/2017

Online Test: Pharmacognosy #1.








Online Test: Pharmacognosy #1.


pharmacognosy online tests
User email id

Plz provide ur mail id to get ur marks and answer sheet,



All questions are compulsory.







1) Morphine is obtained from.















2) Ergot does not contain the followings except.


(identify among below the only chemical present in Ergot.)













3) Mayer;s Reagent is...















4) Nutmeg belongs to the family,















5) Digitalis should not contain % moisture more than...














6) Shogaol is chemical constituent of,














7) Identify the type of adulteration: Presence of amber colored glass pieces in Colophony.














8) Microscopic characteristic of Fennel is....














9) Foxglove leaves is a synonym of ...














10) Hydnocarpic acid is a chemical constituent of...























Labels: ,

posted by Dr. Shirish Nagansurkar @ January 19, 2017  

1/18/2017

Notes on "Tablets"


According to the Indian Pharmacopoeia, Pharmaceutical tablets are solid, flat or biconvex dishes, unit dosage form, prepared by compressing a drug or a mixture of drugs, with or without diluents.




  • Tablets can be defined as a compressed solid dosage form containing medicaments with or without excipients.

  • As they are usually made by compression technology they are also called as "Compressed Tablets."


Notes on Tablets

Advantages of Tablets as a dosage form:



  1. Dosage accuracy.

  2. Economical.

  3. Lighter and compact.

  4. Easiest and cheapest for packing and transportation: Again reduces the final cost of the product.

  5. Easy to swallow with a little amount of water.

  6. Convenient to carry and administer.

  7. Release patterns of the drug can be modified from fast release to sustained release.

  8. Objectionable odor and bitter taste can be masked by a coating technique.

  9. Suitable for large scale production.

  10. Greatest chemical and microbial stability overall oral dosage form.


Disadvantages of Tablets as dosage form:



  1. Difficult to swallow in case of children and unconscious patients.

  2. Some drugs resist compression into dense compacts, owing to amorphous nature and/ low-density character.

  3. Drugs with poor wetting, slow dissolution properties, may be difficult to formulate or manufacture as a tablet.

  4. Bitter testing drugs, drugs with an objectionable odor or drugs that are sensitive to oxidation or photodegradation may require encapsulation or coating.


Ideal properties for Tablets as dosage form: 



  1. A tablet should have elegant look and should be free from manufacturing defects like chipping, cracking, mottling, etc.

  2. Should have sufficient strength to withstand mechanical shock during its production packaging, shipping, and handling.

  3. Should have the chemical and physical stability.

  4. The tablet must be able to release the medicinal agents in a predictable and reproducible manner.


Types of tablets:-


A) Tablets Ingested Orally:-



  1. Compressed Tablets.

  2. Multiple compressed tablets

  3. Multilayered Tablets.

  4. Sustained action tablets.

  5. Enteric coated tablets.

  6. Sugar coated tablets.

  7. Film-coated tablets.

  8. Chewable tablets.

  9. Effervescent tablets.


B) Tablets used in the Oral Cavity:-



  1. Buccal tablets.

  2. Sublingual Tablets.

  3. Lozenges.

  4. Dental cones.


C) Tablets administered by other routes:



  1. Implantation tablets.

  2. Vaginal tablets.


D) Tablets used to prepare solutions:



  1. Effervescent tablets.

  2. Dispensing tablets.

  3. Hypodermic tablets.

  4. Tablet triturates.


Tablet Ingredients



  • In addition to active ingredients, tablets contain plenty of inert materials known as additives or excipients.

  • Different excipients used in tablet manufacturing are:



  1. Diluents.

  2. Binders and adhesives.

  3. Disintegrants.

  4. Lubricants and glidants.

  5. Colouring agents.

  6. Flavoring agents.

  7. Sweeteners.


 

  1. Diluents:



  • Most drugs doses are in milligrams which are not suitable to compress into tablets.

  • Diluents are fillers used to make the required bulk of tablets when the drug dosage itself is low to produce the bulk.

  • Another reason is to provide better tablet properties like, improve adherence, to allow use of direct compression technique or to promote flow.

  • A diluent should have following properties:



  1. They must be nontoxic.

  2. They must be commercially available in required grades.

  3. Economical and easy to obtain.

  4. They must be physiologically inert.

  5. They must be physically & chemically stable by themselves & in combination with the drugs.

  6. They must be free from microbial contamination.

  7. They should not alter the bioavailability of the drug.

  8. They must be color compatible in the formulation.

  9. They should not interfere with absorption of drugs.



  • Commonly used tablet diluents



  1. Lactose-anhydrous and spray dried lactose

  2. Directly compressed starch-Sta Rx 1500

  3. Hydrolyzed starch-Emdex and Celutab

  4. Microcrystalline cellulose-Avicel (PH 101and PH 102)

  5. Dibasic calcium phosphate dehydrate

  6. Calcium sulfate dihydrate

  7. Mannitol

  8. Sorbitol

  9. Sucrose- Sugartab, DiPac, Nutab

  10. Dextrose



  • Lactose:

  • Most commonly used diluent in tablet formulation.

  • It is compatible with most of the drugs, whether it is used in a hydrous or anhydrous form.

  • Anhydrous lactose has an advantage over lactose that it does not undergo "Maillard reaction" which is browning & discoloration of the tablet due to the interaction of amine drug with lactose.

  • Spray dried lactose in concentration 20-25% of active ingredient is used for direct compression.


 

  • Starch:

  • Obtained from corn, wheat, potatoes is used as a diluent, binder and as a disitegrant.

  • Starch is an inert polysaccharide available abundantly in the plant kingdom.

  • Sta-Rx 1500 is free flowing, directly compressible starch used as diluent, binder and /or disintegrating agent.

  • Two hydrolyzed starch Emdex and Celutab, which in the combination of 90-92% of dextrose and 3-5% of maltose, are free-flowing and directly compressible.


 

  • Sucrose:

  • It is used as diluent.

  • Some sugar-based diluents are used for direct compression.

  • These are:



  1. Sugartab: 90-93% sucrose and 7-10% invert sugar

  2. DiPac: 97%sucrose and 3% modified dextrin

  3. Nu Tab: 95%sucrose & 4% invert sugar with small amount of cornstarch & magnesium stearate.



  • Microcrystalline cellulose: (MCC)

  • Trade name Avicel is used for direct compression.

  • These are of two types: PH101 (Powder) and PH102 (Granules).



  • Dibasic calcium phosphate and calcium sulfate

  • Used as diluents but reduce the bioavailability of tetracyclines.

  • DCP is considered as a good diluent and used commonly in industries.


 

  1. Binders and Adhesives:



  • These materials are added either in dry or in wet- form to form granules or to form cohesive compacts for the directly compressed tablet.

  • Binders keep all granules together after compression and keep tablet intact after compression.

  • Deficient addition leads to "Capping."

  • Example: Acacia, tragacanth- Solution for 10-25% Conc.

  • Cellulose derivatives- Methyl cellulose, Hydroxy propyl methyl cellulose (HPMC), Hydroxy propyl cellulose (HPC).

  • Gelatin- 10-20% solution.

  • Polyvinylpyrrolidone (PVP)- 2% conc.

  • Starch paste-10-20% solution.

  • Sodium alginate.

  • Sorbitol


 

  1. Disintegrants:



  • Added to a tablet formulation to facilitate its breaking or disintegration when it comes in contact with water.

  • e.g.: Starch- 5-20% of tablet weight.

  • Starch derivatives – Primogel and Explotab (1-8%).

  • Cellulose derivatives- Carboxymethyl Cellulose

  • Superdisintegrants:

  • Swells up to ten fold within 30 seconds when contact water hence called as superdisintegrants.

  • e.g.: Croscarmellose- cross-linked cellulose,

  • Crosspovidone- cross-linked povidone (polymer),

  • Sodium starch glycolate- cross-linked starch.

  • These cross-linked products swell up to 10n fold within 30 seconds when in contact with water.


A portion of disintegrant is added before granulation and a portion before compression, which serve as glidants or lubricant. Evaluation of carbon dioxide in effervescent tablets is also one way of disintegration


  1. Lubricant and Glidants:



  • Lubricants are intended to prevent adhesion of the tablet materials to the surface of dies and punches.

  • They reduce inter-particle friction and improve the rate of flow of the granules.

  • Glidants are intended to promote flow of granules or powder material by reducing the interparticulate friction.

  • Example: Lubricants- Stearic acid, Magnesium stearate, Talc, PEG (Polyethylene glycols), Surfactants.

  • Glidants- Corn Starch – 5-10% conc., Talc-5% conc., Silica derivative - Colloidal silicas.



  1. Coloring agents:



  • The use of colors and dyes in a tablet has three purposes:

  • Masking of off-color drugs.

  • Product Identification.

  • Improve the appearance of the product.

  • All coloring agents must be approved and certified by FDA.

  • Two forms of colors are used in tablet preparation – FD &C and D & C dyes.

  • These dyes are applied as solutions in the granulating agent or Lake form of these dyes.

  • Lakes are dyes adsorbed on hydrous oxide and employed as dry powder coloring.

  • Example: FD & C yellow 6-sunset yellow, FD & C yellow 5- Tartrazine.



  1. Flavoring agents:



  • For chewable tablets- flavor oils are used


                7) Sweetening agents:

  • For chewable tablets: Sugar, mannitol.

  • Saccharine (artificial): 500 time’s sweeter than sucrose: Disadvantage: Bitter aftertaste and carcinogenic

  • Aspartame (artificial) Disadvantage: Lack of stability in presence of moisture.



Granulation:



  • The process of conversion of small powder particles into aggregates is called as granulation.

  • It can be discussed under three steps:



  1. Weighing of Ingredients:



  • All required ingredients are weighed by using a calibrated good quality weighing balance.

  • This process is double checked in order to avoid human errors.



  1. Mixing the powdered ingredients and excipients:



  • It is done to ensure the formation of uniform tablets containing a homogeneous mixture of medicines and excipients.

  • The mixing is done in ascending order of weights.



  1. Conversion of the mixture in granules:



  • The granules are preferred over fine powder to prepare compressed tablets because,


 










Sr.No
Fine Powder
Granules

1
Requires large area for storage
Requires comparatively less area.

2
Loss during operation is more
Less loss during operation.

3
Problem of dusting during operation
Very less dusting during operation

4
Chances of separation of powders during operation because of vibrations of machine separates powders of different densities: results in loss of uniformity of contents.
Even though the size of granules may be big or small contents are always uniform: No loss of uniformity of contents of tablets.

5
Air entrapment during operation may result in capping and breaking during transportation and handling.
Have more knitting power hence form a strong tablet.

6
Can cause sticking, as powder being light blown out of die during compression.
Granules being heavier does not blow out of die during compression and hence doesn’t stick to the machine.

7
Can produce loss of weight uniformity: different powders with different density doesn't flow evenly through the hopper.
Being of uniform size flow evenly and help produce the tablets of uniform weight.



 

METHODS OF GRANULATION:


There are three common methods of granulation

  • Wet granulation or Moist Granulation.

  • Dry Granulation.

  • Direct compression/ Slugging.


Read more »

Labels:

posted by Dr. Shirish Nagansurkar @ January 18, 2017  

Pharmacology Online Test:1



Pharmacology Online Test 1.

Labels:

posted by Dr. Shirish Nagansurkar @ January 18, 2017  

1/16/2017

General Anesthetics.

General Anesthetics.



  • General anesthetics are the pharmacological agents which on administration produce loss of all modalities of sensations along with a reversible loss of consciousness.

  • They are used to perform major surgeries.

  • e.g. Anesthetic ether, Midazolam.


Anesthesia: -



  • Anesthesia is a medical technique of producing a reversible loss of sensations and awareness.

  • Anesthesia is of 3types

  • General Anesthesia:-

  • It is a total reversible loss of senses, reflex & consciousness.

  • It is used for major surgeries.

  • Local anesthesia:-

  • It is a localized reversible loss of sensation without affecting the consciousness of a patient.

  • It is used for minor surgical procedures like tooth extraction.

  • Spinal anesthesia:-

  • It is achieved by injecting a local anesthetic into spinal column at L2-L3- position (in subarachnoid space).

  • It is useful for surgeries of lower limb & gynecological procedures.

Classification of General Anesthetics:



  • General anesthetics can be classified as per their chemistry and pharmacology.

  • The pharmacological classification of general anesthetics is as follows,
Sr. No.

   Class                    Examples
A

Volatile or Inhalational Anesthetics

1)    Volatile Liquids.

·        Diethyl ether

·        Chloroform

·        Halothane.
2)    Gases.·        Nitrous Oxide.

·        Cyclopropane.
B
Non-Volatile or Intravenous Anesthetics

1)    Barbiturates·        Thiopentone Sodium.

·        Methohexitone Sodium.
2)    Benzodiazepines.·        Midazolam.

·        Diazepam.
3)    Opioid Analgesics.·        Fentanyl.
4)    Other·        Ketamine.

Ideal properties of general anesthetics:-



  • Faster induction of anesthesia.

  • Smooth recovery.

  • Easy to administer.

  • It should be non- inflammable & non- irritant.

  • Should produce good analgesia & adequate muscle relaxation.

  • Should have a wide margin of safety & there should be no side effects.

  • Should have sufficient duration of action.

  • Should not affect the liver, kidney, lungs & heart.

Stages of anesthesia:-


Stage 1:- Stage of analgesia.

Stage 2: Stage of delirium.

Stage 3: Stage of surgical anesthesia.

Stage 4: Stage of medullary paralysis.


Stage 1: Stage of analgesia.



  • It starts from beginning of anesthetic inhalation to loss of consciousness.

  • Pain is progressively reduced.

  • The patient remains conscious, can hear & see & feels a dream-like state.

  • Reflexes & respiration are normal.

  • Minor surgical procedures such as incision of abscess, dental extraction can be carried out during this stage.

Stage of delirium:-



  • This stage extends from loss of consciousness to the beginning of regular respiration.

  • The patient is in the excited state.

  • Breathing is rapid and jerky.

  • Heart rate, blood pressure may rise.

  • This stage is not suitable for any type of operative procedure.

  • Preanaesthetic medication is used to control the stage.

Stage 3: Stage of surgical anesthesia



  • It starts from the onset of regular respiration to end of spontaneous breathing.

  • It is characterized by steady respiration, fixed eyeballs with lost corneal and light reflexes.

  • This stage is suitable for major surgical operations as,

                                      Muscle tone is decreased.

                                      Breathing is regular.

                                      All reflexes are lost.

Stage 4: Stage of Medullary Paralysis



  • It starts from the cessation of breathing to the failure of circulation & death.

  • The patient should not reach this stage for which doses of anesthetics should be adjusted.

  • It is characterized by dropped respiration, heart rate, blood pressure.

  • Only prompt and vigorous efforts can save the life of a patient.

Mechanisms of action of  General Anesthetics:



  1. Inhalational anesthetics: potentiate GABA-A receptor linked chloride channel in thalamus & reticular activating system. Nitrous oxide inhibits excitatory glutamate receptor.

  2. Thiopentone, methohexitone & Midazolam are agonists of GABA-A receptor and act by opening the linked chloride ion channels to cause CNS depression.

  3. Ketamine inhibits excitatory glutamate receptor.

  4. Fentanyl is an agonist of Opioid receptors.

Preanesthetic Medication:



  • The medication given prior to anesthesia to make induction and recovery smoother is known as pre-anesthetic medication.

  • Objectives of pre-anesthetic medication:-

  • To reduce the dose of anesthetics.

  • To minimize adverse effects of anesthetics.

  • Proper preparation of the patient for anesthesia.

  • Relief from anxiety.

  • To reduce salivary & respiratory secretion.

  • To produce antiemetic effect extending to postoperative period.

  • To potentiate analgesic effect.

  • To produce adequate muscle relaxation prior to surgery.

  • Different classes of drugs are used as pre-anesthetic medication depending on the need of patient which is as follows….AnalgesicsE.g. Morphine (10 mg i.m.) or pethidine (50 mg i.m.) are used to potentiate analgesic effect.

    Antianxiety:

    E.g. Diazepam (5-10 mg oral) or lorazepam (2 mg i.m.) are used to reduce the anxiety of patient.

    Antisecretory:

    E.g. Atropine (0.6 mg i.m./i.v.) is used to reduce salivary & tracheobronchial secretion.

    H2 blocker:

    Ranitidine (150 mg oral) or famotidine (20 mg oral) is given to prevent gastric acidosis & stress ulcers.

    Antiemetic:-

    Metoclopramide (10-20 mg i.m.) is used to reduce postoperative vomiting. Ondansetron (4-8 mg i.v. ) is highly effective.

    Skeletal muscle relaxant. Succinylcholine or vecuronium or atracurium are used as musical relaxants.

  • Imagine Operations Without Anesthetics:

  •  

Labels:

posted by Dr. Shirish Nagansurkar @ January 16, 2017  

1/15/2017

Drugs acting on Nervous System.

​Drugs acting on Nervous System.

  • Nervous System is devided into two main branches 



  1. Central Nervous System 

  2. Peripheral Nervous System.



  • Central Nervous System is further devided into,

  • Brain and Spinal Cord.

  • Peripheral Nervous System is further devided into,

  • Autonomous Nervous System and Somatic Nervous System.

  • The drugs acting on CNS are listed below, we will be seeing those drugs in detail in next notes.



  1. General Anesthetics.

  2. Analgesics (Narcotic Analgesics)

  3. Non-narcotic Analgesics. (NSAIDs).

  4. Hypnotic and Sedatives.

  5. Anti epileptics.

  6. Anti Parkinson's.

  7. Antipsychotics.

Labels:

posted by Dr. Shirish Nagansurkar @ January 15, 2017  

1/14/2017

Resins, Combinations of Resins.

Resins




  • They cannot be defined clearly.

  • They can be described as mixtures of organic acids, alcohols, and esters.

  • Physical Properties:

  • They are amorphous, non- crystallizable, transparent, solids or semi-solids.

  • They are insoluble in water & soluble in organic solvents.

  • When heated they melt & burn with a sooty flame.

  • They are produced in plants in the special type of glands.

  • On boiling with alkalis they form resin soaps.

  • They are nonnitrogenous.

  • They are hard, heavier than water and nonconductive.

  • On trituration with water they form emulsion

Classification: -



  • According to the principal components present, they can be classified as follows:-

Class.Drug.Examples.
1 Acid Resin.Colophony, Myrrh.Abietic acid,

Commiphoric acid.
2. Ester Resin.Benzoin, Storax.Benzyl benzoate.

Benzyl cinnamate.
3. Resin alcohols.Balsam of Peru, GurjanbalsamPeruresinotannol, Gurjuresinol.

Resin Combinations: -


1) Oleoresins: -

  • Homogenous mixtures of volatile oils & resins are called as oleoresins.

  • e.g. Oleoresin of Ginger.

2) Oleo- gum- Resin: -

  • Homogenous mixtures of volatile oils, gums & resin.

  • e.g. Myrrh, Asafoetida.

3) Glyco resins: -

  • Homogenous mixtures of sugars & resins.

  • e.g. Jalap, Resin of Ipomoea

4) Balsams: -

  • If the resin contains cinnamic &/ or benzoic acid it is called as balsam.

  • e.g. Benzoin, Balsam of Tolu.

Isolation Of Resins: -



  1. By heating the crude drug. Ex. Guaiacum.

  2. By collecting the fossil resins. Ex. Kauri

  3. By making incisions on the plant. Ex. Asafoetida, Myrrh.

  4. By distillation. Ex. Colophony

  5. By extraction with alcohol. Ex. Oleoresin of Ginger & oleoresin of capsicum.

Chemical Tests:


A) Benzoin (Styrax benzoin Styraceae.)

1. Heat a small amount of benzoin slowly in a dry test tube -----> melts and white fumes are produced.

2.  Benzoin when heated with potassium permanganate solution -----> odor of benzaldehyde. (Sumatra benzoin)

3. Benzoin is extracted with alcohol and to the extract add water ------>milky white solution is formed.4. Digest benzoin with few drops of petroleum ether for 5

B) Asafoetida: (Ferula foetida Umbelliferae.)

  1. Powdered drug triturated with water –--> yellowish emulsion is produced.

  2. Combined umbelliferone test –The drug is boiled with HCL for 5 minutes, it is filtered and ammonia is added to the filtrate –----> A blue fluorescence is observed.

  3. The drug is treated with few drops of 50% HNO3 –---> green color is produced.

  4. The drug is treated with few drops of sulphuric acid – red color is produced which changes to violet on washing with water.

Labels:

posted by Dr. Shirish Nagansurkar @ January 14, 2017  

मकर संक्रांति कि हार्दिक शुभ कामनाये . Happy Makar Sankranti .

Mandir ki ghanti, Arti ki thali,Nadi k kinare suraj ki lali,


Jindige me aye khushiyo ki bahar,
Aapko mubarak ho sankrant ka tyohar.






from,

Pharmanotes Family.

posted by Dr. Shirish Nagansurkar @ January 14, 2017  

1/13/2017

Volatile Oils & Terpenoids.

Volatile Oils.



  • Synonyms: (Ethereal oils, Essential oils)

  • Volatile oils are odorous principles of plants & animal origin chemically they are made of isoprene units (C5H8).

  • Isoprene units (C5H8) combines to form monoterpenes (C10H16), Sesquiterpenes (C15H24) & diterpenes (C20H32).

  • The characteristic odor of volatile oil is due to oxygenated compounds of terpenes.

  • They evaporate of room temp without producing stain on the paper.

  • As they evaporate at room temperature they are called as "Ethereal Oils".

  • As they represent an essence of the plant they are also called as "Essential Oils."


  • Physical Properties
    • They are insoluble in water, soluble in organic solvent. Except for clove oil they are lighter than H2O
    • They have a high refractive index.
    • They are found in various plant families like, Zingiberaceae, Lauraceae, Umbelliferae, Labiatae.

  • Uses: -

  • They are used as a carminative,

  •  Favoring agent,

  • Counter-irritant,

  • Dental analgesic,

  • Diuretic.

  • Classification of volatile oils:
    1. Alcohol: Peppermint, Cardamom, rose, sandalwood.
    2. Aldehyde: Cinnamon, lemon, Orange peel lemon grass, bitter almond.
    3. Ester: Gaultheria, lavender, mustard.
    4. Hydrocarbons: Turpentine, black pepper, hops
    5. Ketones: Caraway, spearmint, buchu, camphor.
    6. Oxides: Chenopodium, eucalyptus
    7. Phenolic ether: Anise, fennel, nutmeg.
    8. Phenol volatile oil: Clove, thyme, creosotes.

  • Chemical Tests for Volatile oil

  • The presence of volatile of oil can be detected by the following tests.

1) Take a thin section of the drug & add a drop of tincture alkana. The red color is produced which indicates the presence of volatile oil.
2) Take a thin Section of drug & add an alcoholic solution of Sudan III – Red color, which indicates the presence of volatile oil.



Extraction of Volatile Oils:
1. Hydro distillation Method: -


  • The drug is powdered & kept in a distillation plant, which is made of copper or stainless steel.

  • The steam is introduced into the boiler around the crude drug.

  • The volatile oil comes out with the steam, which is collected. The layer of volatile oil is separated from the water.

2. Enfleurage method: -


  • This method is used for extraction delicate volatile oil.

  • Petals of the flower are spread on a layer of fat present on glass sheets.

  • The fat absorbs the volatile oil.

  • After few days old petals are removed & fresh petals are spread on the fat.

  • This process is continued till fat becomes saturated with the volatile oil, the fat with the volatile oil is known as the pomade.

  • The volatile oil is extracted from the pomade.

3) Ecuelle Method: -


  • In this method, there is round bowl to which a hollow pipe is attached. Inside the bowl, there are pointed projections Peel of lemon or orange is kept in a bowl.

  • Bowl is rotated with the machine.

  • The projections break oil glands of the peel.

  • The volatile oil and liquid are collected from the pipe.

  • The volatile oil is separated from the liquid.

  • e.g. Household juice extractors.

4) Sponge Method: -

  • The sponge is kept in water.

  • Peel of lemon or orange is brought near the sponge by hands and squeezed mechanically.

  • The sponge is removed & pressed to collect volatile oil & water. The volatile oil is separated from water by distillation.

TERPENOIDS



  • The term Terpene represents hydrocarbons (C5 H8 )n.

  • While terpenoids include hydrocarbons, as well as their oxygenated derivatives.

  • Terpenes & Terpenoid are found in all volatile oil.

  • Properties of terpenes & terpenoid: -

  • Terpenes and terpenoid are found in all essential oils.

  • Therefore their properties are similar to them.

Classification of terpenoids


Name of classNo. of Isoprene units(C5H8 )Formula
Isoprene1C5 H8
Monoterpenes2C10 H16
Sesquiterpens3C15 H24
Diterpenes4C20 H32
Triterpenes6C30 H48
Tetraterpenes8C40 H64
Pentaterpens9C50 H80
PolyterpensN(C5 H8 )n
  • Uses: -

  • They are used as carminatives, flavoring agents, counter-irritants, deodorants, analgesics, stimulants, and diuretics. etc.

Labels:

posted by Dr. Shirish Nagansurkar @ January 13, 2017