Lecture 3 Medicinal Plants PHG 1101 PDF

1. Cultivation ‫زراعة‬ Collection ‫حصاد‬ 2. Dr ying ‫تجفيف‬ 3. Packing ‫تغليف‬ 4. Storage ‫تخزين‬ 5.  For the success of cultivation and production of crude drugs with good quality). It is necessary to:  Study conditions under which...

1. Cultivation ‫زراعة‬ Collection ‫حصاد‬ 2. Dr ying ‫تجفيف‬ 3. Packing ‫تغليف‬ 4. Storage ‫تخزين‬ 5.  For the success of cultivation and production of crude drugs with good quality). It is necessary to:  Study conditions under which medicinal plants flourish in the wild state and reproduce these conditions or improve them. 3  Preparation of Drugs from Plants to Pharmaceuticals B- Collection of crude drugs  The collection of crude drugs at: 1- The proper time. 2- The proper part of the plant. 3- The proper stage of development. 4  B- Collection of crude drugs Factors affecting collection: 1. Time of the year: -Rhubarb ‫ الراوند‬in winter it contains no anthraquinone (only anthranols less active) but in summer contains maximum amount anthraquinone (oxidized form, more active). - Colchicum autumnale ‫ اللحالح‬in Autumn (flowering) it is free of bitterness used as food due to absence of colchicine alkaloid but in in summer it is very bitter due to (alkaloids) and used as anti inflammatory drug.  2. Time of the day: - Digitalis plant should be collected in the afternoon because the active constituents is formed late in the day. - Belladonna are collected in the morning.  3. Stage of maturity and age:  Clove: Is collected in the bud form.  Santonica: Unexpanded flower-heads are rich in Santonine (expel worms) which decrease upon flowering.  Solanaceous: Leaves are collected when the plant is in the flowering stage.  🞂Leaves:  Leaves collected when the flowers are just beginning to expand.  Tea leaves: collected when folded in the bud.  Coca leaves: collected when nearly ready to fall from the stem. 🞂Flowers: must be collected in dry weather  Before expansion: Cloves (in bud).  Fully expanded: Chamomile. 8 Leaf bud clove bud 🞂 Stem barks: are collected in spring or in early summer (it can be easily stripped off from the trunk and branches). Wood Bark 1 0  C- Drying of crude drugs:  Collected fresh organs are either:  Used as such instantaneously (quickly or directly as possible).  Dried to be used later.  “An Absolutely dried drug” = is that drug which is completely free from water. 1 Preparation of drugs before drying: Cleaning: underground organs must be free from soil by shaking, brushing, washing (Valerian) or peeling (Liquorice). Garbling: removal of sand or unofficial parts of plants. Bleaching: alter the appearance of certain drug Ginger and Nutmeg are coated with a layer of CaCO3 or CaSO4. 8 Objective of drying: 1. Stop enzymatic hydrolysis which change A.C. 2. Aids in preservation of the drugs (e.g. Digitalis the presence of moisture and oxidase enzymes deteriorate the A.C.). 3. Avoid deterioration on storage by preventing microorganisms growth (bacteria & fungi). 4. To facilitate grinding. 5. To reduce bulk and weight so facilitate packing, storage and transport. 1  Use temperature as low as possible to carry out drying as rapid as possible.  Dr ying by increasing temperature may increase enzymatic activity till 45 oC then enzyme is destructed by heat (protein denaturation). N.B. (Digitalis leaves are dried immediately after collection with vacuum drying below 60℃ till 1 moisture content not more than 5%) 4  Types of drying 15 By using climatic heat, i.e.  Shade drying retain natural drug colour & preserve sensitive constituents.  Sun drying for drugs not affected by sun. Low cost and suitable for small quantities. When the drug exposed to air it absorbs 8-10 % moisture and is called “Air-dry drug” May be: A- Physical: using elevated temperature, vacuum (reduced pressure), radiation (infra-red, radio frequency wave length). 1  B- Chemical, using desiccants (charcoal and silica gel).  N.B. Artificial drying has the advantage over air-drying because it immediately stops enzymatic action, e.g. Digitalis. 1  Example of Artificial drying: 1. Direct fire. 2. Heated stove (oven). 3. Drying chamber (hot air pipes). 4. Vacuum drying(hot air source, ventilator, thermostat, vacuum). 1 8  5. Freeze drying (lyophilization)  Reduce temperature and then vacuum to sublime water.  Prevents chemical and enzymatic changes in A.C.  Applied to biological fluid (fruits, vitamins, vaccines) 1 (flash drying at very high temperature. (800oC) for 1-3 seconds. e.g.:Digitalis leaves 1. Decrease of Size & weight (80-90 % water). 2. Shape & appearance: some drugs shrink or surface gets wrinkled e.g., black pepper. 3. Texture: organs become harder e.g. some roots. 4. Colour: Tea leaves  Rapid drying Green tea (green)  Slow drying Fermentation Black tea (copper y- 2 red) 5. Odour: Vanilla fragrant odour pods No odour (dried) (fresh ) 6. Taste: Gentian very pleasant taste (dried) bitter (fresh ) 2 7. Constituents: Vanilla pods contains gluco-vanillin glycoside Drying hydrolysis Vanillin 2