Table 2.

The advantages and disadvantages of traditional drug delivery methods [3,8,11,112,113].

Traditional Drug Delivery Methods	Advantages	Disadvantages
Oral delivery	Convenience in administration Non-invasive Accurate and measured dose Unit dosage form Higher compliance Cheap for the patient	Unconscious patients cannot take a dose Low permeability Degradation by gastro-intestinal enzymes First pass metabolism Irregular absorption
Buccal or sublingual delivery	Bypass first pass metabolism Rapid absorption Low enzymatic activity	Discomfort during dissolution Probability of swallowing—loss of effect Small doses
Rectal delivery	Bypass first pass metabolism Useful for kids and children	Absorption depends on disease state Degradation by bacterial flora Uncomfortable
Intravenous delivery	Drug 100% bioavailable Rapid response Can administer drugs degradable in stomach By-passes first pass metabolism	Invasive Trained personnel Possible toxicity due to incorrect dosing Sterility
Subcutaneous delivery	Patient self-administration Slow complete absorption Bypass first pass metabolism when placed at lower part of rectum	Invasive Irritation Inflammation Maximum dose volume—2 mL
Intramuscular delivery	Drug is absorbed slowly, so prolonged effect Larger volume than subcutaneous Bypass first pass metabolism	Invasive—patient discomfort Irritation Inflammation May require some training