Pharmaceutical aids

For B.Pharm, 4th sem

1. pharmaceutical aids

2. Definition Substances which are of little or no therapeutic value , but are necessary in the manufacture , compounding, storage, etc ., of pharmaceutical preparations or drug dosage forms. They include solvents, diluting agents, and suspending agents, and emulsifying agents, antioxidants; preservatives, pharmaceutical; colouring agents; flavouring agents; vehicles; excipients ; ointment bases. Substances added to pharmaceutical preparations to protect them from chemical change or microbial action. they include anti-bacterial agents and antioxidants.

3. Definition "Pharmaceutical aids are the drugs or substances which have no or little pharmacological effect but they are essentially used in the preparation of pharmaceutical dosage forms " (like tablets, injections, emulsions, ointments.) Substances added to pharmaceutical preparations to protect them from chemical change or microbial action. They may be plant , animal , mineral or synthetic origin.

4. Pharmaceutical Aids of natural origin CLASS EXAMPLES 1. Colouring agents: Turmeric, chlorophyll, Caramel, Cochineal insect for red colour (animal) . 2. Flavouring agents: Cardamom, cinnamon oil, rose, Orange peel, Nut-meg 3. Sweeting agents: Honey, Sucrose, Lactose, and Liquorice. 4. Binding agents: Mucilage of Acacia, Mucilage of Tragacanth 2 % starch solution. 5. Diluents:                             Lactose, starch, Arachis oil, cinnamon water, sesame oil, 6. Disintegrating  agents:                Isapgol Methylcellulose, Carboxymethylcellulose (CMC), microcrystalline cellulose, psyllium husk 7.  Lubricants:               Talc (mineral) , coca butter, and magnesium trisilicate .

5. Conti.. 8. Emulsifying Agents:          Gum tragacanth , agar, and Gum acacia. 9. Suspending agents:      Bentonite (mineral), Gelatin (animal), Gum tragacanth , Gum acacia 10. Ointment bases:        Bee wax, spermaceti, and lanolin, Carnauba wax 11. Thickening agents: Methylcellulose, pectin, Tragacanth 12. Filtering agents: Kaolin (Mineral)

6. Bentonite Synonym- anti caking agent, Bentonite - an absorbent aluminium  phyllosilicate  clay  consisting mostly of  montmorillonite It has the incredible ability to increase as much as 14 times its original volume . They mainly exist in cationic form of organic compounds such as aromatic or aliphatic hydrocarbon and are employed to modify high cations exchange capacity Bentonite is a layer of natural silicate clay mineral having numerous properties such as large specific surface area, great absorption and interlayer exchangeable cations .

7. Formation of Bentonite Bentonite is a material derived from the alteration, over geological time periods, of glassy material emitted from volcanoes (tuff or ash) , or from the alteration of silica bearing rocks such as granite and basalt. Bentonite only forms in the presence of water.

8. Types of Bentonite Two types of Bentonite are recognized, and the uses of each depend on specific physical properties. Type 1: Sodium Bentonite Sodium Bentonite is the type of swelling clay . It has single water layer particles which contain Na+ as the exchangeable ion. Type 2: Calcium Bentonite Calcium Bentonite is the non-swelling clay . It has a double water layer with Ca2+ as the exchangeable ion.

9. Distribution Rajasthan, karnataka , kerala , Gujarat, etc. Chemical constituents: Aluminium oxide(Al 2 O 3 ), Iron oxide( Fe 2 O 3 ), Magnesium oxide( MgO ), Calcium oxide( CaO ), Titanium Dioxide(TiO 2 ), Potassium oxide(K 2 O), Sodium oxide(Na 2 O)

10. Preparation Bentonite deposits are normally exploited by quarrying(large deep hole). Extracted bentonite is distinctly solid, even with a moisture content of approximately 30%. The material is initially crushed and, if necessary, activated with the addition of soda ash (Na 2 CO 3 ) . Bentonite is subsequently dried (air and/or forced drying) to reach a moisture content of approximately 15% According to the final application, bentonite is either sieved (granular form) or milled (into powder and super fine powder form). For special applications, bentonite is purified by removing the associated gangue minerals, or treated with acids to produce acid-activated bentonite .

11. Physical Properties Specific gravity=2.49-2.72 Specific surface area=370-487 Oil absorption(% by wt)=73-87 Water absorption(% by wt)=115-207 Attrition resistance(%) =80-95 Adsorption of water vapour (%) =11-17

12. Uses Based on the physical and chemical properties the Bentonite can be used in the following industries: • Bleaching of edible oil. • Oil absorption. • Odour and liquid absorbent. • Waste water treatment. • Cast iron industry. • Pelletizing( molding of material into the shape of pellet). • Filtering and clarification.

13. Kaolin Synonym - Bolus alba; China Clay; Porcelain clay; White bole; Argilla Kaolin= hydrous aluminum silicate (Al 2 O 3 .2SiO 2 .2H 2 O , Where Al 2 O 3 =39.3%, SiO 2 =46.8%, H 2 O=13.9%. Physical characters: Soft, Clay material Particle size of heavy kaolin = 20µm in diameter/ fine particle = 2µm - Slightly plastic - Normally white in colour Unctuous and soapy to touch Fusion point=1700-1800 °

14. Conti.. Formation : Kaolins are derived from pegmatites or from hydrothermal alterations. They may also occur as blanket deposits in extensive area of igneous of metamorphic rocks. Distribution: Garo Hill of Assam, Bihar, Maharastra , Madya pradesh , Delhi, Kerala. Chemical constituents: Kaolin group contains Kaolinite , Nacrite , Dickite , Annauxite and Hallosysite . All Al 2 O 3 .2SiO2. 2H 2 O with traces of Mg, Ca and Fe.

15. Preparation Kaolin is prepared when the rock in mined , excavated and the impurities are washed with water and then powdered . The rock is elutriated with water and large-sized particles are separated. On allowing the turbid to settle, heavy kaolin containing particle of large size and colloidal kaolin containing particles of small size are separated and then dried

16. Uses Dusting powder Poultice Carrier of heat Filtering agent Cleaning agent Fine kaolin is used internally as an adsorbent and to coat irritated intestinal mucosa in case of diarrhoea, dysentery and intestinal fermentation. They are also used to manufacture porcelain, pottery, bricks, Portland cement, plaster mineral, electric and heat insulators; clarifying liquids, drying and emollient agents.

17. Talc: The Softest Mineral Synonym- Talcum powder, bath powder Talc is a hydrous magnesium silicate   mineral  with a chemical composition of Mg 3 Si 4 O 10 (OH) 2 When large amounts of Fe substitute for Mg , the mineral is known as minnesotaite . When large amounts of Al substitute for Mg , the mineral is known as  pyrophyllite .

18. Talc:  Talc is a phyllosilicate mineral that cleaves into thin sheets. These sheets are held together only by van der Waals bonds , which allows them to easily slip past one another. This characteristic is responsible for talc's extreme softness, its greasy to soapy feel, and its value as a high-temperature lubricant.

19. How Does Talc Form? Talc is a mineral that is most often found in the  metamorphic rocks  of  convergent plate boundaries ( between an oceanic and continental plate) . It forms from at least two processes. First process, Most large talc is formed when heated waters carrying dissolved magnesium and silica reacted with dolomitic marbles. A second process of talc formation occurred when heat and chemically active fluids altered rocks such as dunite and serpentinite into talc.

20. Physical properties 1. Chemical Classification Silicate 2. Crystal system Monoclinic  or  triclinic 3. C olor Green, white, gray, brown, colorless 4. Rock Type Metamorphic 5. Optical properties Biaxial (-) 6. Cleavage Perfect 7. Mohs Hardness 1 8. S pecific Gravity 2.7 to 2.8 9. Chemical Composition Mg 3 Si 4 O 10 (OH) 2 10. Transparency Transparent to opaque 12. Refractive index n α  = 1.538 – 1.550 n β  = 1.589 – 1.594 n γ  = 1.589 – 1.600 13. Luster Pearly

21. VARIETIES Beaconite - A fibrous variety of Talc resembling asbestos.  Chromian Talc - A chromian variety of talc Polyphant Stone - A greyish-green potstone flecked with white and brown. Used since Norman times as an ornamental stone in churches. Pseudolite - Octahedral talc pseudomorphs after  spinel . Steatite -A massive variety of Talc with a greasy feeling, often used for ornamental carvings. Zincian Talc - Zn-bearing variety from the "Mixed Series" formation.

22. Distribution: Rajasthan, Maharastra , kerala , Gujarat, Madya pradesh , etc. Chemical composition: Talc is a hydrous magnesium silicate mineral with a  chemical composition  of Mg 3 Si 4 O 10 (OH) 2 . Although the  composition of talc  usually stays close to this generalized  formula , some substitution occurs.

23. Preparation Talc is a  metamorphic mineral  that results from the metamorphism of magnesian minerals such as  serpentine ,  pyroxene ,  amphibole , and  olivine , in the presence of carbon dioxide and water. This is known as "talc carbonation" or " steatization " and produces a suite of rocks known as  talc carbonates . Talc is primarily formed by hydration and carbonation by this reaction: 2Mg 3 Si 2 O 5 (OH) 4 (serpentine) +3CO 2 ( carbondioxide ) → Mg 3 Si 4 O 10 (OH) 2  (talc) + 3MgCO 3 ( magnesite ) +  3H 2 O(water)

24. Talc can also be formed via a reaction between dolomite and silica, which is typical of  skarnification  of dolomites by silica-flooding in contact metamorphic aureoles: 3CaMg(CO 3 ) 2 (dolomite) + 4 SiO 2  (silica) + H 2 O  (water)→ Mg 3 Si 4 O 10 (OH) 2 (talc) + 3CaCO 3  (calcite)+ 3 CO 2 (carbon dioxide) Talc can also be formed from magnesium chlorite and quartz in  blueschist  and  eclogite  metamorphism by the following  metamorphic reaction : chlorite +  quartz  →  kyanite  + talc + water In this reaction, the ratio of talc and kyanite depends on  aluminium  content, with more aluminous rocks favoring production of kyanite . Such rocks are typically white, friable, and fibrous, and are known as  whiteschist .

25. Uses Talc in Ceramics Talc in Paint A lubricant, and as a filler in paper manufacture. Talc in Cosmetics( talcum powder ), and Antiperspirants Talc in Roofing Materials Coatings In pharmaceutical products as a  glidant . Sterile talc powder: In medicine, talc is used as a  pleurodesis  agent to prevent recurrent  pleural effusion  or  pneumothorax . electric cable, electrical switchboards because of its resistance to heat and electricity

26. Gelatin & Diatomite