Paste (rheology)

From Self-sufficiency

For other meanings of paste see Paste (disambiguation)

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In physics, a paste is a substance that behaves as a solid until a sufficiently large load or stress is applied, at which point it flows like a fluid. In rheological terms, a paste is an example of a Bingham plastic fluid.

Pastes typically consist of a suspension of granular material in a background fluid. The individual grains are jammed together like sand on a beach, forming a disordered, glassy or amorphous structure, and giving pastes their solid-like character. It is this "jamming together" that gives pastes some of their most unusual properties; this causes paste to demonstrate properties of fragile matter.

In pharmacology, paste is basic pharmaceutical form. It consists of fatty base (e.g., petroleum jelly) and at least 25% solid substance (e.g., zinc oxide).

Examples include starch pastes, toothpaste, mustard, and putty.

Mucous membranes are used by the human body to absorb the dosage for all routes of administration, except for "Dermal" and "Injection/Infusion".
Administration routes can also be grouped as Topical (local effect) or Systemic (defined as Enteral = Digestive tract/Rectal, or Parenteral = All other routes).

v t e Routes of administration
Gastrointestinal	Oral · Buccal · Sublabial · Sublingual · Rectal
Respiratory system	Pulmonary · Nasal
Visual system / Auditory system	Ocular (Ocular-topical / Intravitreal / Transscleral) · Otologic (Oto-topical)
Reproductive system	Intracavernous · Intravaginal · Intrauterine (Extra-amniotic)
Urinary system	Intravesical
Peritoneum	Intraperitoneal
Central nervous system	Intracerebral · Intrathecal · Epidural
Circulatory system	Intravenous · Intracardiac
Musculoskeletal system	Intramuscular · Intraosseous
Skin	Epicutaneous · Intradermal · Subcutaneous