[Research on Subcutaneous Diffusion of Drug Solution in Pneumatic Needle-Free Injectors]

Non-oral extravascular routes, which encompass sublingual, buccal, topical, intramuscular, and inhalation methods, primarily utilize passive diffusion to transport drugs into the systemic circulation. The absorption rates and effectiveness of these routes depend on the drug's physicochemical properties, as well as the patient's anatomical and pathophysiological state.
Lipophilic drugs that are stable at salivary pH (6) and exhibit minimal binding to the oral mucosa are absorbed more effectively...

Parenteral drug delivery systems play a crucial role in modern therapeutics by enabling the direct administration of drugs into the systemic circulation, bypassing the gastrointestinal tract. These systems are particularly valuable for poorly absorbed oral medications that are unstable in the digestive environment or require rapid onset or sustained therapeutic levels. Delivery is achieved through intravenous, intramuscular, or subcutaneous routes, each selected based on the drug's properties...

Drug delivery methods like oral inhalation, nasal sprays, transdermal patches, eye drops, intravitreal injection,  and rectal administration provide localized effects with reduced toxicity.
Oral inhalation and nasal sprays swiftly transfer drugs across the respiratory epithelium's mucosal layer. Inhaled glucocorticoids and bronchodilators directly target lung conditions such as asthma, while fluticasone nasal spray mitigates allergic rhinitis.
Transdermal patches transport drugs through the...

The parenteral route is a critical method of drug administration. It delivers compounds directly into the systemic circulation and bypasses the gastrointestinal tract. This approach is particularly advantageous for drugs that exhibit poor absorption or instability when administered orally.
There are three primary parenteral routes: intravenous (IV), intramuscular (IM), and subcutaneous (SC). The IV route introduces the drug directly into the bloodstream, ensuring immediate action. The IM route...

The administration of drugs via parenteral routes allows for direct drug introduction into the systemic circulation, resulting in high bioavailability because the medication bypasses the harsh conditions of the gastrointestinal tract and hepatic metabolism.
The intravenous route (IV) of drug administration can be further categorized into two types. The bolus injection administers the entire dose rapidly, while an intravenous infusion slowly delivers smaller doses steadily.
The IV route is often...

In situ experiments, such as the Doluisio method and Single-Pass Perfusion technique, provide critical insights into drug uptake by simulating in vivo conditions for drug absorption.
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...