Ritalin. Molecular model of the stimulant drug methylphenidate, marketed as Ritalin. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), oxygen (red), nitrogen (blue).

THC drug molecule. Atoms are represented as spheres and are colour-coded: carbon (black), hydrogen (white) oxygen (red).

Kekulene hydrocarbon molecule, molecular model. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white).

Levofloxacin antibiotic, molecular model. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (dark blue), oxygen (red) and fluorine (light blue).

Caffeine molecule, illustration

Isosorbide mononitrate, molecular model. This drug is used to treat angina. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), oxygen (red) and nitrogen (blue).

Docetaxel, molecular model. This anti-cancer drug is marketed as Taxotere. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), oxygen (red) and nitrogen (blue).

Ciprofloxacin antibiotic, molecular model. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (dark blue), oxygen (red) and fluorine (light blue).

Simvastatin, molecular model. This is a cholesterol-lowering drug of the statin class. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white) and oxygen (red).

"Prednisolone corticosteroid drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (black), oxygen (red). "

Malathion, molecular model. This is an organophosphate pesticide. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), oxygen (red), sulphur (yellow) and phosphorous (orange).

Nelfinavir AIDS drug, molecular model. This is a protease inhibitor marketed as Viraceptn. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (blue), oxygen (red) and sulphur (yellow).

"Neostigmine drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Tropicamide mydriatic eye drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Kanamycin antibiotic drug molecule (aminoglycoside). Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Tetracaine local anesthetic drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Indacaterol COPD drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Tetracaine local anesthetic drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Indacaterol COPD drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Paromomycin aminoglycoside antibiotic drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Kanamycin antibiotic drug molecule (aminoglycoside). Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Tropicamide mydriatic eye drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue). "

"Lumefantrine (benflumetol) antimalarial drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue), chlorine (green). "

"Lumefantrine (benflumetol) antimalarial drug molecule. Atoms are represented as spheres with conventional colour coding: hydrogen (white), carbon (grey), oxygen (red), nitrogen (blue), chlorine (green). "

Methylprednisolone, molecular model. This is a synthetic corticosteroid drug. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white) and oxygen (red).