Pharma Easy Notes @Pharmacy

  🧪 Limit Test of Arsenic – Principle, Procedure, Reaction, and Viva Questions 🔹 Aim: To carry out the Limit Test for Arsenic as per the Indian Pharmacopoeia (IP) standards. 🔹 Principle: The limit test for arsenic is based on the formation of a yellow stain when arsine gas (AsH₃), generated from arsenic in the sample, reacts with mercuric chloride paper . The intensity of the yellow stain produced is compared with a standard to determine if the sample meets the permissible limit. 🔹 Apparatus Required: Arsenic Test Apparatus (Arsenic Test Bottle) Glass Tube with a narrow end Mercuric Chloride Paper Nessler Cylinder (2) for comparison 🔹 Chemicals Required: Arsenic-free zinc granules Lead acetate solution Hydrochloric acid Potassium iodide Stannous chloride Standard arsenic solution Water 🔹 Reaction Involved: Reduction of Arsenic compound: A s 2 O 3 + 6 Z n + 12 H C l → 2 A s H 3 + 6 Z n C l 2 + 3 H 2 O As_2O_3 + 6Zn + 12HCl → ...

  🧪 Limit Test for Lead (Heavy Metals) Subject: Pharmaceutical Inorganic Chemistry Experiment Type: Qualitative Analysis Aim: To carry out the Limit Test for Lead in a given sample using dithizone reagent and to ensure that lead impurities are within the permissible limit as per I.P. standards. ✨ Principle Lead (Pb²⁺) in solution reacts with dithizone (diphenylthiocarbazone) in chloroform. A pink to violet color develops if lead is present. The intensity of color in the sample is compared with that of a standard lead solution. If the test solution shows less or no color compared to the standard, the sample passes the test. Reaction: P b 2 + + D i t h i z o n e ⟶ L e a d - D i t h i z o n a t e   C o m p l e x ( P i n k / V i o l e t ) Pb^{2+} + Dithizone \longrightarrow Lead\text{-}Dithizonate\ Complex (Pink/Violet) P b 2 + + D i t hi zo n e ⟶ L e a d - D i t hi zo na t e   C o m pl e x ( P ink / Vi o l e t ) ⚗️ Materials Required Test sample ...

💊 Drug of the Day – 4 : Amoxicillin 📅 Series: Drug of the Day (PharmaEasyNotes) 📖 Category: Pharmacology | Antibiotics 🔹 Introduction Amoxicillin is a broad-spectrum β-lactam antibiotic belonging to the penicillin group . It is one of the most commonly prescribed antibiotics worldwide due to its high efficacy, oral bioavailability, and safety profile . 🔹 Structure 🧪 Amoxicillin is a semi-synthetic derivative of ampicillin with an added hydroxyl group. 🔹 Mechanism of Action (MOA) Inhibits bacterial cell wall synthesis Binds to penicillin-binding proteins (PBPs) Prevents peptidoglycan cross-linking Leads to cell lysis and bacterial death 👉 It is bactericidal in action. 🔹 Pharmacokinetics Absorption: Well absorbed orally Distribution: Wide distribution, including respiratory tract, middle ear, urine Metabolism: Partial hepatic metabolism Excretion: Renal excretion (mainly unchanged drug) 🔹 Uses / Indications ✅ Respiratory tract infe...

  💊 Drug of the Day – 5 : Ciprofloxacin 📅 Series: Drug of the Day (PharmaEasyNotes) 📖 Category: Pharmacology | Antibiotics 🔹 Introduction Ciprofloxacin is a fluoroquinolone antibiotic widely used for treating Gram-negative bacterial infections . It is especially effective in urinary tract infections, gastrointestinal infections, and respiratory infections . 🔹 Structure 🔹 Mechanism of Action (MOA) Belongs to 2nd generation fluoroquinolones Contains a fluorine atom at C-6 that enhances antibacterial activity 🔹 Mechanism of Action (MOA) Inhibits DNA gyrase (Topoisomerase II) and Topoisomerase IV Prevents bacterial DNA replication & transcription Leads to bacterial cell death 👉 Bactericidal in action 🔹 Pharmacokinetics Absorption: Good oral bioavailability Distribution: Penetrates well into tissues and fluids Metabolism: Partially hepatic Excretion: Mainly via kidneys (renal excretion) 🔹 Uses / Indications ✅ Urinary tr...

📌 Aim: To carry out the limit test for heavy metals present in pharmaceutical substances as an impurity. 🎯 Principle The test is based on the reaction of heavy metals (like lead) with hydrogen sulfide (H₂S) in an acidic medium, producing a brownish-black coloration of metal sulfides . The intensity of this color is compared with a standard lead solution prepared simultaneously. 🧰 Materials Required Nessler cylinders Test sample solution Standard lead solution (Pb²⁺) Dilute acetic acid Hydrogen sulfide (H₂S) water or thioacetamide reagent 🧪 Procedure Take the sample solution in a Nessler cylinder. Add dilute acetic acid to adjust the pH. Add a few drops of thioacetamide reagent (or pass H₂S gas) . Prepare a standard solution of lead in another Nessler cylinder. Keep both cylinders side by side for comparison. 🔬 Reaction Involved P b 2 + + H 2 S    →    P b S ↓    ( b r o w n i s h − b l a c k p r e c i p i t a t e ) Pb^{2+} + H_2S \; \...

🎯 Aim To perform the Limit Test of Iron (Fe³⁺ ions) as per Indian Pharmacopoeia (IP) standards. 🔬 Principle Iron reacts with thioglycolic acid in an alkaline medium to form a purple-colored complex . The intensity of this color is compared with that of a standard iron solution using Nessler cylinders. Reaction: F e 3 + + T h i o g l y c o l i c   a c i d + N H 3    ⟶    P u r p l e   C o m p l e x Fe^{3+} + Thioglycolic \, acid + NH_3 \; \longrightarrow \; Purple \, Complex F e 3 + + T hi o g l yco l i c a c i d + N H 3 ​ ⟶ P u r pl e C o m pl e x 🧰 Requirements Sample solution (suspected iron impurity) Standard Iron solution (20 ppm Fe³⁺) Thioglycolic acid Ammonia solution Distilled water Nessler cylinders ⚗️ Procedure Test Solution Dissolve given sample in distilled water. Add 2 mL thioglycolic acid . Make alkaline with dilute ammonia. Dilute to 50 mL with distilled water. Standard Solution Prepare a solution of 20 ppm Fe³⁺ . ...