Pharma Easy Notes @Pharmacy

Physicochemical Properties of Drugs & Their Role in Drug Action ⭐ Why This Topic Matters Before a drug shows any action in the body, it must reach the site , bind to the receptor, and stay stable . All this depends on… 👉 Physicochemical Properties This lecture will make these concepts super easy so you can score high in exams AND understand drug design better. 🔥 What You Will Learn in This Lecture ✔ What pKa tells about drug absorption ✔ Why LogP is the “passport” to cell membranes ✔ Why some drugs dissolve easily and some don’t ✔ How hydrogen bonding changes drug behaviour ✔ What makes a drug cross BBB ✔ What are isosteres and bioisosterism (exam favourite!) ✔ How stereochemistry can change a drug from medicine to poison 🧠 1. Ionization & pKa: The Real Reason Why Drugs Work pKa = the pH at which 50% drug is ionized and 50% unionized . Why is this important? Forms Properties Ionized form More soluble, less permeable Unionized form Less soluble, ...

📌 Introduction The Limit Test of Nitrate is performed to ensure that nitrate impurities present in inorganic substances are within acceptable limits. Excess nitrate is harmful and may alter chemical properties of drugs. This test is important in Pharmaceutical Inorganic Chemistry (B.Pharm – 1st Year) . 🎯 Purpose (Aim) To perform the Limit Test of Nitrate as per IP and compare the amount of nitrate impurity in the sample with the standard solution. 🧪 Principle Nitrate reacts with brucine (an alkaloid) in presence of sulphuric acid , producing a yellow to reddish brown color . If sample contains nitrate impurity → stronger color form If nitrate is within limit → sample color ≤ standard color 👉 Color comparison = Result of limit test 🧫 Reagents Required Reagent Purpose Brucine Solution Color development Concentrated Sulphuric Acid Reaction medium Sample Solution Test solution Standard Nitrate Solution Comparison Distilled Water Dilution 🧪 Apparatus Used Nessl...