ROUTE OF DRUG ADMINISTRATION

ROUTE OF DRUG ADMINISTRATION: 

ROUTE OF DRUG ADMINISTRATION Oral Preparations Buccal & Sublingual Tablets Rectal Preparations Parenteral Products Aerosol Preparations Transdermal Preparations

CONSIDERATIONS IN THE DESIGN OF A DRUG DOSAGE FORM: 

The intended route of administration The anatomic & physiologic characteristics of the administration site, such as membrane permeability & blood flow The physicochemical properties of the site, such as pH, osmotic pressure, presence of physiologic fluids The interaction of the drug & dosage form at the administration site, including alteration of the administration due to drug &/or dosage form. CONSIDERATIONS IN THE DESIGN OF A DRUG DOSAGE FORM

ORAL PREPARATIONS: 

Advantages: The convenience of administration and the elimination of discomforts involved with injections. The hazard of rapid intravenous administration causing toxic high concentration of drug in the blood is avoided Disadvantages: The potential problems of reduced & erratic bioavailability due to either incomplete absorption or drug interaction Nausea or stomach discomfort may occur with some drugs that cause local gastrointestinal irritation. ORAL PREPARATIONS

ORAL PREPARATIONS: 

Absorption of lipid-soluble drugs These lipophilic drugs are more soluble or oily vehicles. Lipid soluble drugs are given with fatty excipients mix with digested fatty acids which are emulsified by bile in the small intestine. The emulsified drug is then absorbed through the GI mucosa or through the lymphatic system. Gastrointestinal side effects Many orally administered drugs are irritating to the stomach. These drugs may cause nausea or stomach pain when taken to an empty stomach. Alternatively, the drugs may be enteric coated to reduce gastric irritation ORAL PREPARATIONS

BUCCAL & SUBLINGUAL TABLETS: 

Buccal cavity refers to the space in between the mandibular arch & the oral mucosa, an area well supplied with blood vessels for efficient drug absorption. Buccal tablet is a tablet designed for release in this area. Sublingual tablet – a tablet designed for release under the tongue. Contain a fast-dissolving excipient such as mannitol so that the drug is released rapidly. BUCCAL & SUBLINGUAL TABLETS

RECTAL PREPARATIONS: 

Rectal preparation may be administered either in solid & liquid form,. Rectal administration is preferred with drugs that cause nausea or in situations where it is not possible to give the drug orally. RECTAL PREPARATIONS

PARENTERAL PRODUCTS: 

Intravenous administration – an aqueous solution is injected directly into the vein. Drugs injected intravenously go directly to the blood and circulate to all parts of the body within a few minutes. Intramuscular administration – preformed deep into the skeletal muscles, generally the gluteal or lumbar muscles. A drug injected intramuscularly involves an absorption delay in which the drug travels from the injection site to the bloodstream. PARENTERAL PRODUCTS

AEROSOL PREPARATIONS: 

The lungs provide an excellent absorbing surface for the administration of gases and for aerosol mist of very minute particles of liquids or solids. Drugs administered into the respiratory system, such as antiasthmatics, may be formulated into aerosols or inhalation solutions. With suitable propellant, it can administer drug rapidly into bronchial region. AEROSOL PREPARATIONS

TRANSDERMAL PREPARATION: 

Transdermal administration refers to the delivery of a drug to the body system through the skin. This route of administration may release the drug over an extended period of several hours without discomforts of gastrointestinal side effects. TRANSDERMAL PREPARATION