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International Journal of Pharmaceutical Studies and Research E-ISSN 2229-4619

Review Article ROUTES OF ADMINISTRATION

P. Verma (1) *, A.S. Thakur (1) , K. Deshmukh (2) , Dr. A.K. Jha (1) S. Verma (2)

Address for Correspondence

1. Shri Shankaracharya Institute of Pharmaceutical Science Bhilai (C.G) India 2. Institute of , RITEE, Raipur (C.G) India. Email: [email protected] ABSTRACT The is the way through which the is administered into the body for treatment of various diseases and disorders. Various routes of administrations play a marked role in the of the active drug in the body. In present review these routes are included with their advantages and limitations. This is an attempt for the initials of field to familiarize with the routes of administrations with their significances. KEYWORDS Route, Bioavailability, Drug.

Definition:- (1) Oral Route: - A route of administration in pharmacy is the In this route the drug is placed in path by which a drug is taken into the body. the mouth and Swallowed. It is (1) also called per oral (p.o.) Classification:- Advantages of Oral Route The various routes of administrations are • Convenient - Can be self- classified into following categories:- administered, pain free, easy to take 1. Systemic Route • - Takes place along the A) Enteral route (b) Parenteral whole length of the gastro intestinal route tract 1. Oral 1. Intravascular • Cheap - Compared to most other 2. Sublingual 2. Intramuscular parenteral routes 3. 3. Subcutaneous Disadvantages of Oral Route 4. • Sometimes inefficient - only part of the drug may be absorbed 2. Local Route

1. Systemic Route: - • First-pass effect - absorbed In Systemic route the drug reaches to the orally are initially transported to the systemic circulation (Blood). So that it is via the portal called systemic route. • Irritation to gastric mucosa - nausea Systemic Route is again classified into and two classes:- • Destruction of drugs by gastric acid (A) Enteral Route: - and digestive juices In this route the drug is placed in the • Effect too slow for emergencies and then it absorbs to • Unpleasant taste of some drugs the blood. • Unable to use in unconscious patient This route is further classified into three classes:

IJPSR/Vol. I/ Issue I/July-September,2010/Pg.54-59

International Journal of Pharmaceutical Studies and Research E-ISSN 2229-4619

First-pass effect:- delivered to the liver via the portal This is effect which occurs with oral circulation. The greater the first-pass route of administration. The first-pass effect, the less the agent will reach the effect is the term used for the hepatic systemic circulation when the agent is of a pharmacological agent administered orally. (2, 3, 4 and 5) when it is absorbed from the gut and

Figure 2

IJPSR/Vol. I/ Issue I/July-September,2010/Pg.54-59

International Journal of Pharmaceutical Studies and Research E-ISSN 2229-4619

Examples of drugs which undergo Advantages marked First Pass Effect:- Advantages of Sublingual and Buccal Route • , of Administration are :- • , • Rapid absorption:- It absorbs in the • . (1) mouth so that its absorption Examples:- • Drug stability: - As in this route the The example of dosage forms which are drug does not go to the so it is used by oral route include not destroyed by the and 1. acids present in the stomach so that it 2. Capsules is stable. 3. etc. • Avoid first-pass effect. Sublingual/Buccal route: - Disadvantages In this route of administration the drug is Disadvantages of Sublingual and Buccal placed under the . And it is taken Route of Administration are :- without the use of water. When it is placed • Inconvenient: - In this route the drug under the tongue it disintegrates there and is kept in the mouth so it is then absorption occurs in mouth. The inconvenient. tablets are small in size which is to be used • Small Doses: - Small size is required (6) through the sublingual route. Example of to keep the drug in the mouth. Sublingual tablet is Nitroglycerine tablets • Unpleasant taste of some drugs: - Buccal Route The drugs having unpleasant taste can In this route of administration the drug is cause problem because the drug is kept kept in the buccal cavity where it in the mouth. disintegrates and absorption occurs in the mouth. (7)

Figure 3 Sublingual Route

Figure 4 Buccal Route

IJPSR/Vol. I/ Issue I/July-September,2010/Pg.54-59

International Journal of Pharmaceutical Studies and Research E-ISSN 2229-4619

Rectal Route: - 2. Absorption may be variable. Many drugs that are administered orally can Examples:- also be administered rectally as a 1. . In this form, a drug is mixed 2. Vaginal Bogies with a waxy substance that dissolves or 3. Urethral Bogies liquefies after it is inserted into the rectum. Parenteral Routes:- Because the rectum's wall is thin and its In this route of administration the drug does blood supply rich, the drug is readily not pass through the gastrointestinal tract. It absorbed. A suppository is prescribed for directly reaches to the blood. (11) people who cannot take a drug orally It can further be classified into two classes:- because they have nausea, cannot swallow, 1. With injections:- in this class the drugs or have restrictions on , as is required are administered with the use of after many surgical operations. Drugs that injections are irritating in suppository form may have e.g. Intravascular, to be given by . (8) Intramuscular, Vaginal Route: Subcutaneous Some drugs may be administered vaginally 2. Without injections: - in this class the to women as a , tablet, , , drugs are administered without use of suppository, or ring. The drug is slowly injections. absorbed through the vaginal wall. This e.g. . route is often used to give to With Injections:- women at menopause, because the drug 1. Intravascular :- helps prevent thinning of the vaginal wall, In this route of administration the drug is an effect of menopause (see menopause: directly taken into the blood with the help of hormone therapy).(9) injection. Absorption phase is bypassed. Urethral Route:- Advantages:- Some drugs are given through the urethra. 1. Precise, accurate and almost This route is called urethral route of drug immediate administration.(10) 2. Large quantities can be given, fairly Advantages:- pain free Advantages of rectal/urethral/vaginal route 3. Can be given to unconscious are as follows:- patients. 1. Unconscious patients and children:- 4. Quick action If the patient is unconscious then it is 5. Drugs having unpleasant taste can not possible to give the drug orally. So be given. in this situation the drug can be given Disadvantages:- through rectal/urethral/vaginal route. 1. Pain at the site of injection. 2. If patient is having nauseous or 2. Greater risk of adverse effects vomiting A. High concentration attained Disadvantages:- rapidly 1. May cause irritation b. Risk of

IJPSR/Vol. I/ Issue I/July-September,2010/Pg.54-59

International Journal of Pharmaceutical Studies and Research E-ISSN 2229-4619

Figure 5 Injectable Route of Administration

2. Intramuscular:- 1. Rapid onset of action due to rapid In this route of administration the drug is access to circulation. given into the muscles with the help of 2. Pain not occurs because injection is injection. Drug once reaches to the muscles, not used. absorbs into the blood. Examples:- 1. Very rapid absorption of drugs in 1. aqueous solution 2. Aerosols 2. Depot and slow release preparations Local/Topical Route of Drug 3. Pain at injection sites for certain drugs Administration 3. Subcutaneous:- In this route the drug is applied on the In this route of administration the drug is and for the local action. given into the subcutaneous layer with the (12) help of injection. Drug once reaches to the • Mucosal membranes (eye drops, subcutaneous layer crosses the membrane antiseptic, sunscreen, callous removal, and absorbs into the blood. nasal, etc.) Without Injections:- • Skin In this class the drug is administered to the • Dermal - Rubbing in of oil or blood without going to the gastrointestinal ointment (local action). tract. In this class the drug is not • - Absorption of drug administered with the help of injections . (1) through skin (systemic action) In this administration the drug is i. Stable blood levels administered in the gaseous form. ii. No first pass metabolism Advantages:- iii. Drug must be potent

IJPSR/Vol. I/ Issue I/July-September,2010/Pg.54-59

International Journal of Pharmaceutical Studies and Research E-ISSN 2229-4619

Figure 6 Topical route of drug administration Examples 5. Fromm M F, Busse D, Kroemer H K, and Eichelbaum M (1996) Differential 1. Creams induction of prehepatic and hepatic 2. metabolism of by rifampin. 3. etc. Hepatology 24: 796–801. 6. Rawas-Qalaji M M, Simons F and Onset of Action- Simons K, Fast-disintegrating The length of time needed for a medicine to Sublingual Tablets: Effect of Epinephrine Load on Tablet give its action. This time varies for different Characteristics, PharmSciTech. 2006; types of routes of administrations.(13) 7(2): Article 41. 7. Lewis S, Subramanian G, Pandey S and Onset of action of different routes is as Udupa N, Design, evaluation and follows:- pharmacokinetic study of • Intravenous 30-60 seconds mucoadhesive buccal tablets of for cessation, 2006: 68:6: 829- • Intraosseous 30-60 seconds 831. • Inhalation 2-3 minutes 8. Bioavailability of allopurinol oral and rectal dosage forms, Chang S L, • Sublingual 3-5 minutes Kramer W G, Feldman S, Ballentine R • Intramuscular 10-20 minutes and Frankel L S, American Journal of Hospital Pharmacy, Vol 38, Issue 3, • Subcutaneous 15-30 minutes 365-368. • Rectal 5-30 minutes 9. Ceschel G C, Maffei P, Lombardi • Oral 30-90 minutes Borgia S, Ronchi C, Rossi S. Development of a mucoadhesive • Topical/transdermal (topical) dosage form for vaginal administration, variable (minutes to hours) Drug Dev Ind Pharm. 2001 Jul;27(6):541-7. REFERENCES:- 10. Michael B and Chancellor M D, Future 1. www.wikipedia.com. Assessed on Trends in the Treatment of Urinary august 2010. Incontinence, Rev Urol. 2001; 3(Suppl 2. Kwan K C, Oral bioavailability and 1): S27–S34. first-pass effects, and 11. www.fpnotebook.com/ER/Pharm/Prntrl Disposition,Vol. 25, 12. DrgDlvry.htm 3. Petri N, Bergman E, Forsell P, 12. Greenstein G, Polson A, The role of Hedeland M, Bondesson U, Knutson L local in the management and Hans Lennernäs H, First-pass of periodontal diseases: a effects of verapamil on the intestinal comprehensive review. J Periodontol. absorption and liver disposition of 1998 May;69(5):507-20. fexofenadine in the porcine model, 13. Atreya I and Markus F, September 2010, 38 (9). NeurathUnderstanding the delayed 4. Dresser G K, Kim R B, and Bailey D onset of action of azathioprine in IBD: G, Effect of grapefruit juice volume on are we there yet? Gut 2009;58:325-326 the reduction of fexofenadine doi:10.1136/gut.2008.163485. bioavailability: possible role of organic anion transporting polypeptides. Clin Pharmacol Ther 2005, 77: 170–177.

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