Pharmaceutical Substances and Their Classifications

Unorganized Drugs

• Classified according to physical characteristics
• Latex (e.g., Opium)
• Extracts (e.g., Agar, Gelatin)
• Juice (e.g., Aloes)
• Gums (e.g., Gum Acacia, Gum Tragacanth, Guar gum)
• Resin (e.g., Colophony)
• Oleogumresin (e.g., Myrrh, Olibanum, Guggul, Asafoetida)
• Balsams (e.g., Benzoin, Tolu balsam)
• Saccharin derivatives (e.g., Honey, Bee propolis, Bee venom, Royal jelly)

Opium

• Air-dried latex from unripe capsules of Papaver somniferum L.
• Contains at least 10% morphine and 2% codeine.
• Collection and preparation: Incisions are made in the capsules when green, using special knives (in the afternoon). The incision should not penetrate the interior of the capsules (the endocarp).
• Exuded milky latex rapidly coagulates and turns brown.
• Collection and preparation: Latex is collected in the early morning, scraped and shaped with poppy leaves.

Notes

• Opium: Mixture of alkaloids derived from Papaver somniferum.
• Opiate: Natural narcotic alkaloids found in opium poppy plant (e.g., morphine, codeine).
• Opioid: Natural or synthetic compounds with morphine-like action (e.g., enkephalins, endorphins).

Alkaloids

• Phenanthrene group (e.g., Morphine)
  • Effective pain killer (cancer, pre/post-anesthesia)
  • Antiperistaltic (constipation)
  • Respiratory depressant
  • Addictive
  • Pupil constrictor, slight temp drop, sweating
• Heroin (Diacetylmorphine):
  • Highly addictive morphine substitute
  • Less respiratory depressant properties
  • Rapid dependence due to potent lipophilic properties that cross the blood-brain barrier
  • Administered by injection, snorting, or smoking

Alkaloids Continued

• Benzyl isoquinoline alkaloids (e.g., Papaverine)
  • Non-addictive
  • Smooth muscle relaxant (GIT, cough)
  • Cerebral and peripheral vasodilator
• Phenyl alkyl amines (e.g., Narceine)
• Codeine: Cough sedative (short duration)

Tests

• Meconic Acid:

  • To 1g powdered drug add 5ml water, shake for 5min, filter.
  • Add 0.25ml ferric chloride solution.
  • A red color develops that does not disappear with dilute hydrochloric acid.

• Morphine:

  • Evaporate 1ml of the filtrate to dryness.
  • Add 1 drop of formaldehyde and 2 drops of sulfuric acid to the residue.
  • A crimson red color is produced.

Extracts

• Agar-agar (Japanese Isinglass):

  • Polysaccharides from Rhodophyceae (red algae), primarily Gelidium.
  • Collected from beaches, bleached, boiled, concetrated, dried and cut
  • Constituents: Agarose (neutral jelling), Agaropectin (non-jelling, affects viscosity)
  • Chemical tests: crimson red color with N/50 iodine solution; white precipitate with barium chloride.
  • Uses: Suspending, thickening and emulsifying agent; bulk laxative; bacteriological cultures; electrophoresis; chromatography

• Gelatin:

  • Soluble protein produced from partial hydrolysis of collagenous byproducts like skin, bone and tendons of cattle and sheep.
  • Contains glutin, with 19 amino acids, but lacks essential amino acids, thus incomplete.
  • Should not contain chondrin .
  • Pharmaceutical uses: suppositories, tablets, hard gelatin capsules, suspending/stabilizing/thickening agent, microencapsulation, bacteriological culture medium.
  • Clinical uses: plasma substitute, hemostatic dressing.
  • Chemical tests: yields ammonia odour when powder is tested with soda lime, and white precipitate from tannic acid solution.

Gums

• Polysaccharides or salts of polysaccharides produced by plants in reaction to injury or unfavorable growth conditions
• Heterogenous polysaccharides that yield a mixture of sugars other than glucose and uronic acids when hydrolyzed.
• Insoluble in organic solvents, but viscous or jelly-like in water
• Gum Acacia:
  • Air-dried gummy exudate from Acacia senegal (family Leguminosae)
  • Constituents: Calcium salt of Arabic acid(Arabin), hydrolysis produces L-arabinose, D-galactose, D- glucuronic acid and L-rhamnose.
  • Uses: suspending agents, cough/cold/wound healing preparations, sore throat, catarrh, and diarrhea treatment.
• Gum Tragacanth:
  • Air-dried gummy exudate from Astragalus gummifer (family Leguminosae)
  • Constituents: Water soluble fraction (Tragacanthin; no methoxyl groups), water insoluble fraction (Bassorin; ~5% methoxyl groups)
  • Uses: suspending & binding agent for tablets/cosmetics; highly viscous solutions; denture adhesives; acidic conditions.
• Guar Gum:
  • Extracted from Cyamopsis tetragonolobus.
  • Polysaccharide (Galactomannan) that yields galactose and mannose on hydrolysis.
  • Uses: tablet binder, suspending agent; managing blood glucose; laxative.
  • Adverse reactions: flatulence; affecting absorption of concomitant drugs; esophageal obstruction.

Juices

• Fluid plant saps containing dissolved substances; usually located in cells (e.g., aloe) or cavities (e.g., orange)
• Dried by evaporating water
• Aloe:
  • Concentrated dried juice of leaves from various Aloe species (family Liliaceae)
  • Contains ≥28% hydroxyanthracene derivatives (e.g., barbaloin)
  • Preparation: leaves are cut transversely and juice is boiled for concentration.
  • Chemical tests: Bornträger test (aglycones give rose-red color), Modified Bornträger test, oxidative hydrolysis with FeCl3/HCl yields free aglycones.
  • Uses: stimulant laxative; carminative/antispasmodic; antiseptic/antibacterial; heals burns; treatment for respiratory conditions (e.g., as tincture combined with benzoin, aloes, & storax).