Permapen Isoject

Generic name:penicillin G benzathine
Dosage form: Injectable Suspension 1,200,000 units
Drug class:Natural penicillins

Medically reviewed by Drugs.com. Last updated on Mar 22, 2022.

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Permapen Isoject Description

Permapen® (Penicillin G Benzathine) Injectable Suspension, a sterile antibacterial agent, is a repository penicillin compound which provides blood levels for long periods following its intramuscular injection. This property is the result of its extremely low solubility in water. Each milliliter contains 600,000 units of penicillin G benzathine; 0.006 grams sodium citrate; 0.003 grams polyvinylpyrrolidone; 0.010 grams lecithin, and 0.003 grams sodium carboxymethylcellulose in an aqueous suspension. Permapen also contains methylparaben 0.09% and propylparaben 0.01% as preservatives.

Chemically, Permapen is 3,3-dimethyl-7-oxo-6-(2-phenylacetamido)-4 thia-l azabicyclo [3.2.0] heptane-2-carboxylic acid compound with N,N'-dibenzylethylenediamine (2:1) tetrahydrate. It is prepared by the reaction of dibenzyl-tetrahydrate-ethylenediamine with 2 molecules of penicillin G.

It has a molecular weight of 981.19 and the following chemical structure:

Formula

C16H20N2•2C16Hl8N2O4S•4H2O

Penicillin G benzathine occurs as a white crystalline powder and is very slightly soluble in water.

The pH of the injectable suspension is between 5.0–7.5.

Permapen Isoject - Clinical Pharmacology

Intramuscular penicillin G benzathine is absorbed very slowly into the blood stream from the intramuscular site and converted by hydrolysis to penicillin G. This combination of hydrolysis and slow absorption results in blood serum levels much lower than those of other parenteral penicillins.

Approximately 60% of penicillin G is bound to serum protein. The drug is distributed throughout the body tissues in widely varying amounts. Highest levels are found in the kidneys with lesser amounts in the liver, skin, and intestines. Penicillin G penetrates into all other tissues and the spinal fluid to a lesser degree. ...