Pharmaceutical Inorganic Chemistry Unit 3 Notes PDF

# PHARMACEUTICAL INORGANIC CHEMISTRY ## UNIT 3 NOTES * **GASTROINTESTINAL AGENTS** **Image description:** A diagram showing the gastrointestinal tract. **Page 2** ## GASTROINTESTINAL TRACT * The gastrointestinal tract is the pathway of digestive system which helps in the digestion of food and it...

# PHARMACEUTICAL INORGANIC CHEMISTRY ## UNIT 3 NOTES * **GASTROINTESTINAL AGENTS** **Image description:** A diagram showing the gastrointestinal tract. **Page 2** ## GASTROINTESTINAL TRACT * The gastrointestinal tract is the pathway of digestive system which helps in the digestion of food and its excretion. * It starts from the mouth and end to the anus. * The main portion of GIT includes the stomach, small intestine large intestine, rectum and anus. * Now, whenever the function of GIT goes wrong, disease occurs. **Page 3** ## Diseases of GIT * Insufficient secretion of acid in the stomach can cause Achlorhydria or Hypochlorhydria. * Too much secretion of acid in the stomach can cause Hyperacidity. * The insufficient bowel movement in the intestine can leads to Constipation. * Also the growth of microbes / bacteria can affect the gastrointestinal tract. ## GASTROINTESTINAL AGENTS * Agents that are used to treat gastrointestinal disturbance / diseases are known as Gastrointestinal Agents. * Agents that are used to GIT disorders include: 1. Acidifiers (Hypochlorhydria) 2. Antacids (Hyperacidity) 3. Cathartics (Constipation) 4. Antimicrobials (Microbial Growth) **Page 4** ## ACIDIFIERS * These are the inorganic substances that are used to increase the level of gastric acid in the stomach. * They are also known as Acidifying Agents. * They either produce acid or increase the level of acid. * They work by decreasing the pH of stomach. * They are used in the treatment of Achlorhydria or Hypochlorhydria. ### Why Acid is Important in the Stomach? * It breaks down the food and helps in digestion. * It kills microbes present in the food. * It provides acidic environment needed for effective digestion. ### Types of Acidifiers There are mainly 3 types of Acidifiers 1. Gastric Acidifiers 2. Urinary Acidifiers 3. Systemic Acidifiers #### Gastric Acidifiers * They are mainly used to control the pH of stomach. * These are the drugs which are used to increase the acidity of the stomach. * These agents are mainly used in patients suffering from Achlorhydria or Hypochlorhydria. **Page 5** #### Urinary Acidifiers * They are mainly used in controlling the pH of urine. * These are the drugs which are used to remove acidic urine from the body. * These acidifiers are widely used to cure some type of Urinary Tract Infection. #### Systemic Acidifiers * They are used to control the pH of all parts of body. * These are the drugs which are able to neutralized the alkaline body fluid. * It is used to treat patient suffering from Alkalosis. **Page 6** ## AMMONIUM CHLORIDE * Molecular Formula: $NH_4Cl$. * Molecular weight: 53.49g/mol. * Synonym: Sal Ammoniac. ### Method of Preparation It is prepared by the reaction of HCl with $NH_3$ (ammonia) $NH_3 + HCl \longrightarrow NH_4Cl $ ### Physical Properties * It is a white crystalline powder * It is Odourless * It has cool saline taste * It is hygroscopic in nature. ### Chemical Properties On decomposition ammonium chloride produces ammonia gas and hydrogen chloride. $NH_4Cl \longrightarrow NH_3 + HCl$ ### Uses of Ammonium Chloride * It is used as Acidifiers * It is used as Fertilizers. * It is used in Glue. * It is also used in Buffer Solutions. **Page 7** ## DILUTE HCl * Molecular Formula: HCl. * Molecular weight: 36.46. * Synonym: Spirit of Salt. ### Preparation It can be prepared by action of concentrated $H_2SO_4$ with NaCl $NaCl + H_2SO_4 \longrightarrow HCl + NaHSO_4$. ### Properties * It is a colourless liquid. * It is strongly acidic. * It is soluble in water and alcohol. * It has pungent Odour. * On reacting with NaOH, it gives salt and water. $HCl + NaOH \longrightarrow NaCl + H_2O$. ### Uses * It is used as acidifier. * It is mainly used as an pharmaceutical aid. * Used in many Solvents. **Page 8** ## ANTACIDS * Antacids are the drugs that are used to decrease the level of gastric acid in the stomach. * They are used in the case of Hyperacidity. * They also prevent from Heart Burn and Ulcer. * Antacids are generally weak bases that reacts with the excessive acid in the stomach and convert them into salt. * They work by increasing gastric pH. * Example: $CaCO_3$, $NaHCO_3$ ### Classification of Antacids Antacids are commonly classified into two groups : 1. Systemic Antacids 2. Non- Systemic Antacids #### Systemic Antacids * Antacids which absorbs in the systemic circulation (blood circulation) are called as Systemic Antacids. * They are not very suitable antacids as they can cause Metabolic Alkalosis (Disturbance in acid- base balance) #### Non- Systemic Antacids * Antacids which are not absorbed into systemic circulation and do not affect acid- base balance of the body are called as Non- Systemic Antacids. **Page 9** ### Ideal Properties of Antacids * It should be insoluble in water and has fine particle form. * It should not cause metabolic alkalosis. * It must have its effect over a long period of time. * It should not cause constipation. * It should not cause any side effect. * It should be stable and readily available. * It should not be too expensive. ### Combination of Antacids * Systemic antacids are not used regularly as they can cause metabolic alkalosis and congestive heart failure. * Mon - systemic antacids are more effective compared to systemic alkalosis, but they also have some other side effects. * To avoid these side effect and to increase the effect and time of duration of action, antacids are generally given in combination. * Generally in the combination of antacids, one having a rapid action and other having longer duration of action. * Example: Combination of Magnesium and Aluminium as Antacid * Magnesium → Fast acting * Aluminium → Longer duration of action. **Page 10** ## SODIUM BI CARBONATE * Chemical Formula: $NaHCO_3$. * Molecular weight: 84.01 g/mol. * Synonym: Baking Soda. ### Preparation It is prepared by solvay ammonia process. $Na_2CO_3 + CO_2 + H_2O \longrightarrow 2NaHCO_3$. ### Properties * It is a white crystalline powder. * It is insoluble in ethanol but soluble in methanol. * It having saline taste. * It is alkaline in nature. * It is also soluble in water. ### Uses * It is mainly used as antacids. * It is used as electrolyte replenisher. * It is also used as disinfectant. **Page 11** ## ALUMINIUM HYDROXIDE GEL * Chemical Formula: $Al(OH)_3$. * Molecular Weight: 78.00 g/mol * Synonym: Aluminium Hydrated Powder. ### Preparation It is prepared when Aluminium Chloride is treated with Ammonium Hydroxide. $AlCl_3 + 3 NH_4OH \longrightarrow Al(OH)_3 + 3 NH_4Cl$ ### Properties * It is a white viscous suspension. * It is tasteless. * It is odourless. * It is soluble in mineral acid solution, but insoluble in water & alcohol. ### Uses * It is used as antacid. * It is used to treat heartburn. **Page 12** ## CATHARTICS * Cathartics are the drugs that are used to get relief from constipation. * These are the drugs that... accelerates defecation. * Cathartics act by increasing the fluid content of Faeces, making them softer and easier to pass. * Cathartics increases the mobility of intestine ### Types of Cathartics Cathartics are mainly classified into two categories: 1. Laxative 2. Purgative #### Laxative * Laxatives are mild acting cathartics. * They work by either: * Increasing intestinal movement. * Increasing stool bulk * Make stool softener. * Prolong use of laxative may cause habit or dependency. #### Purgative * They are strong cathartics. * They are given in very serious conditions. * They are generally given to completely remove solid materials from intestine before surgery. **Page 13** ### Classification (On the basis of mechanism) 1. Stimulant Cathartics 2. Lubricants 3. Bulk Forming 4. Saline Cathartics #### Stimulant Cathartics: They act by producing local imitation on intestinal tract. #### Lubricants: Provide lubricant effect so that stool easily passes through rectum, also known as stool softener. #### Bulk Forming: These agents increases the amount of stool production. #### Saline Cathartics: They increases the osmotic load of GIT, consumed with large amount of water. ### Uses of Cathartics * For easy defecation & other rectal diseases. * To relief from acute constipation. * To remove solid material from intestinal tract before surgery. * To avoid rise in blood pressure due to constipation. **Page 14** ## Magnesium Sulphate * Chemical Formula: $MgSO_4.7H_2O$. * Molecular Weight: 246-47 g/mol. * Synonym: Epsom Salt. ### Method of Preparation It is obtained by the action of dilute sulphuric acid ($H_2SO_4$) and magnesium carbonate ($Mg(CO_3)$). $MgCO_3 + H_2SO_4 \longrightarrow MgSO_4 + H_2O + CO_2$. ### Properties * It occurs as white crystals. * It is odourless. * It having a cool, saline, bitter taste. * It is soluble in water and sparingly soluble in alcohol. ### Uses * It is used as cathartics. * It is used in agriculture. * It is used to control seizures in pregnancy. **Page 15** ## Sodium Orthophosphate * Chemical Formula: $Na_2HPO_4.12H_2O$. * Molecular Weight: 358. 14 g/ mol. ### Preparation It is obtained by adding sodium carbonate to a hot solution of phosphoric acid. $H_3PO_4 + Na_2CO_3 \longrightarrow Na_2HPO_4 + H_2O + CO_2$. ### Properties * It occurs as colourless crystals. * It is odourless. * It having a saline taste. * It is soluble in water. * It is insoluble in alcohol. ### Uses * It is used as cathartics. * It is also used as buffers. **Page 16** ## Kaolin * Molecular/Chemical Formula: $Al_2O_3. 2SiO_2.2H_2O$. * Molecular Weight: 258.16 g/mol. * Synonym: China Clay. ### Preparation It is simply prepared from natural clay by powdering, separating and purifying process. ### Properties * It is light, white powder. * It is odourless * It is tasteless. ### Uses * It is used as cathartics. * It is used in food poisoning * It is used in dusting powders. **Page 17** ## Bentonite * Chemical Formula: $Al_2O_3.45IO_2. H_2O$. * Molecular Weight: 360.31 g/mol. * Synonym: Clay ### Preparation It occurs naturally or can be prepared from natural clay. ### Properties * It occurs as very fine, cream- colour powder. * It is odourless. * It is insoluble in water. ### Uses * It is used as cathartics. * It is used as emulsifier. * It is also used as protectives. **Page 18** ## ANTIMICROBIAL AGENTS * Antimicrobial agents are those chemical compounds or drugs that inhibits or destroys the growth of microorganism. * They can either kill or prevents the growth of bacteria. ### Classification of Antimicrobials 1. Antiseptic 2. Disinfectants 3. Germicides 4. Bacteriostatics 5. Sanitizers 6. Sterilization #### Antiseptic * Antiseptic are those antimicrobial agents that are mainly used on living cells. * They either kills or inhibits the growth of bacteria. * An ideal antiseptic agent should destroy bacteria, viruses etc and should not cause any harm to applied area. * Example: Hydrogen Peroxide, Silver nitrate etc. **Page 19** #### Disinfectant * These are the antimicrobial agents that are mainly used on Non-Living surfaces. * They can either kill or destroy bacteria. * They are mainly used in home and hospital cleaning. * Example: Sulpher dioxide #### Germicides * These are the agents that are used to kill microorganism. * The can be either use on Living or Non- living surfaces. * They can also be divided into following types: * Bactericides: To kill bacteria * Virucides: To kill viruses * Fungicides: To kill fungi #### Bacteriostatics * These are the agents that are used to prevent the growth of bacteria. * They do not kill bacteria * Can be used on living or Non- living surfaces. * Example: Chloramphenical. #### Sanitizers * Sanitizers are agents that are mainly used in cleaning & washing. * They are generally used to maintain general public health and hygiene. * Example: Soap, Alcohol etc. **Page 20** #### Sterilization * It is a process by which all the microorganism are either killed or removed. * In this process, the products, surface or area will be free from all type of microorganism. ### Mechanism of action of Antimicrobials * Microorganism mainly contains proteins (enzymes) to survive. * Anti-microbials act by changing their protein structure which results in death of microorganism. * Antimicrobials mainly act by 3 mechanism : 1. Oxidation 2. Halogenation 3. Precipitation #### Oxidation * This MOA shows by oxygen releasing compounds. * They cause oxidation of active functional groups present in proteins and inactivate them. #### Halogenation * This MOA shows by halogen (Br, Cl etc) releasing compounds. * These agents add halide atom to nitrogen present at peptide linkage of protein & inactivates them. #### Precipitation * This MOA shows by Metal containing compounds. * Metal binds with important group present in protein, change their structure & inactivates them. **Page 21** ## POTASSIUM PERMANGANATE * Chemical Formula: $KMnO_4$. * Molecular Weight: 158 g/mol. * Synonym: Condy's Crystals. ### Preparation It can be easily prepared by from potassium manganate under acidic condition. $2K_2MnO_4 + 4HCl \longrightarrow 2KMnO_4 + MnO_2 + H_2O +4KCl$. ### Properties * It is purple crystalline solid. * It is odourless. * It is soluble in both water and alcohol. ### Uses * It is used as antimicrobial agents. * It is used in treatment of various skin conditions. * It is used as antiseptic. * It is used as strong oxidizing agent. **Page 22** ## BORIC ACID * Chemical Formula: $H_3BO_3$. * Molecular Weight: 61.83 g/mol. * Synonym: Hydrogen Borate. ### Preparation It is prepared by the action of HCl on borax ($Na_2B_4O_7$) $Na_2B_4O_7 + 2HCl + 5H_2O \longrightarrow 2NaCl + 4H_3BO_3$. ### Properties * It is white crystalline solid. * It is odourless. * It having sweet taste. * It is soluble in water & slightly soluble in alcohol. ### Uses * It is used as anti- microbial agents. * It is used as preservatives. * It is also used in cosmetics. **Page 23** ## HYDROGEN PEROXIDE * Chemical Formula: $H_2O_2$. * Molecular Weight: 34.01 g/mol. * Synonyms: Hydrogen Oxide, Peroxide. ### Preparation It can be prepared by the reaction of sodium peroxide with dilute sulphuric acid. $Na_2O_2 + H_2SO_4 \longrightarrow H_2O_2 + Na_2SO_4$ ### Properties * It is clear colourless liquid. * It is odourless. * It having a bitter taste. * It is miscible with water. ### Uses * It is used as antimicrobial agent. * It is used as antiseptic. * It is used as bleaching agent. * Also used in tooth whitening. **Page 24** ## CHLORINATED LIME * Chemical Formula $Ca(OCl)_2$, $CaOCl_2$. * Molecular Weight: 142.98 g/mol, 136.98 g/mol. * Synonym: Bleaching Powder. ### Preparation It is prepared by reacting chlorine with calcium hydroxide. $Ca(OH)2 + Cl2 \longrightarrow CaOCl2 + H2O$. ### Properties * It is white or grey powder. * It has odour of chlorine. * It is partially soluble in water and alcohol. ### Uses * It is used as antimicrobial agent. * It is used as powerful bleaching agent. **Page 25** ## IODINE * Chemical Formula: $I_2$. * Molecular Weight: 253.8 g/mol. * Synonym: Halogens. ### Preparation In laboratory, it is prepared by heating the mixture of KI, $MnO_2$ and concentrated $H_2SO_4$. $2KI + MnO_2 + 3H_2SO_4 \longrightarrow I_2 + 2KHSO_4 + MnSO_4 + 2H_2O$. ### Properties * It occurs as greyish- violet or bluish- black crystals. * It has strong harsh odour. * It is volatile in nature * It is insoluble in water. * It is soluble in alcohol. ### Uses * It is used as antimicrobial agent. * It is used in iodine deficiency. * It is used in thyroid cancer.