Pharmaceutical Sciences: Key Concepts and Technologies
Factors Affecting Immunity
Phagocytosis
Phagocytosis is the process of engulfing bacterial mass, whether living or dead. The body cells responsible for this process are called phagocytes. There are two types of phagocytes:
- Cells of the reticuloendothelial system
- White blood cells
Antibody Production
Phagocytosis alone is not a reliable method for destroying pathogens. The body produces other substances for protection, called antibodies. Antibodies are substances formed in the body in response to foreign proteins and certain other materials in tissues. The materials that trigger antibody production are called antigens. There are three types of antibodies:
- Alpha antibody
- Beta antibody
- Gamma antibody
Most antibodies are gamma globulins compared to beta.
Injections (Parenterals)
Parenterals are sterile, pyrogen-free preparations intended for administration by injection into one or more layers of skin or mucous membrane.
Advantages
- Immediate physiological response
- Prolonged action
- Useful for unconscious patients
- Useful for uncooperative and nauseous patients
- 100% bioavailability
Disadvantages
- Administration requires trained personnel
- Painful administration
- High production cost
- Difficult to reverse psychological effects
Calibration
Calibration is the measurement of a critical value of equipment function, ensuring it falls within the optimum range of its working capacity.
Validation
Validation is establishing documented evidence that provides a high degree of assurance that a specific process will consistently produce a product meeting its predetermined specifications and quality attributes.
Types of Validation
1) Equipment Validation
Equipment validation establishes documented evidence that provides a high degree of assurance that a specific process will consistently produce a product meeting its predetermined specifications and quality attributes. It is a regulatory requirement for cost reduction. Installation of new equipment, changes in equipment location, and instrument modifications all fall under equipment validation.
2) Design Qualification
The instrument and its parts should be delivered according to the customer’s requirements in the purchase order. This should be verified by the manufacturer or supplier before dispatching the instrument.
3) Installation Qualification
The instrument and its parts should be delivered according to the customer’s requirements in the purchase order. The facilities for instrument installation should meet its specifications.
4) Operational Qualification
The newly installed equipment should operate according to the manufacturer’s specifications. All instrument functions should be operationally tested. For example, HPLC (High Performance Liquid Chromatography).
5) Method Validation
Method validation provides a high level of assurance that a method will consistently yield accurate and reproducible results within established specifications. To minimize product quality variations, different preparation methods should be properly applied from raw material to the finished product.
Principles of Premises Area
Ancillary Areas
Canteen, washroom, cloth storage room, changing room.
Warehousing Area
Storage areas should have sufficient capacity to store various categories of materials and products, including raw materials, packaging materials, bulk and finished products, released, rejected, and unused items. Released, rejected, and unused materials should be stored in a locked area. Dispensing areas should be separate for active and raw materials.
Production Area
Laboratory area, packaging area.
Quality Control Area
Testing laboratories.
Quality Assurance, Drainage System, Disposal of Waste
Novel Drug Delivery Systems (NDDS)
NDDS are advanced drug delivery systems that improve drug potency and control drug release to provide sustained therapeutic effects.
Classification of NDDS
- Nanoparticles: Particles ranging from 40-500 nanometers in diameter, invisible to the naked eye.
- Microparticles: Particles ranging from 0.5-200 micrometers. They encapsulate both water-insoluble and water-soluble agents. Examples include microcapsules and microspheres.
- Niosomes: Vesicles of non-ionic surfactants incorporating cholesterol as an excipient. Used for drug delivery to achieve desired therapeutic effects.
- Liposomes: Sacks of phospholipid molecules enclosing a water droplet, often formed artificially to carry drugs or other substances into tissues.
- Phytosomes: Complexes of natural ingredients, essentially single small cells.
- Dendrimers: Highly ordered, branched polymeric molecules with a spherical three-dimensional morphology.
Hammer Mill
Principle
Operates on the principle of impact, where the material is stationary and struck by a high-speed object. It consists of a metal casing enclosing a central shaft with four or more hammers attached. The lower part of the casing has a screen for material passage and collection.
Working
Material is fed into the hopper, powdered to the desired size by the rotating hammers, and collected under the screen. Heat generation can damage the material, so hammer rotation speed must be controlled.
Cyclone Separator
Principle
A sedimentation technique that uses vortexing to separate fluid and solid particles. Fine particles are separated using a sieve.
Construction
A short, vertical, cylindrical vessel with a conical base, a tangential inlet at the top, a solid outlet at the base, and a fluid outlet at the center of the top, extending inward to prevent air short-circuiting.
Working
Solids suspended in a gas stream are introduced tangentially at high velocity, creating rotary movement. Centrifugal force and vortexing throw solids to the walls. As air speed decreases, particles fall to the base and are discharged. The fluid escapes through the central outlet.
Difference Between Hard and Soft Gelatin Capsules
Hard Gelatin Capsules
- Consist of two parts: body and cap.
- Cylindrical shape.
- Contents are usually powder or granules.
- Sealed after filling to prevent leakage.
Soft Gelatin Capsules
- Become a single unit after sealing.
- Round or oval shape.
- Contents are usually liquid or paste.
- Filled and sealed by machines.
Classification of Powders According to IP
Solid dosage forms intended for external use. Powders are classified as follows:
- Coarse powders: Pass through sieve #10 (1700 μm), not more than 40% through sieve #44 (355 μm).
- Moderately coarse powders: Pass through sieve #22 (710 μm).
- Moderately fine powders: Pass through sieve #44 (355 μm).
- Fine powders: Pass through sieve #85 (180 μm).
- Very fine powders: Pass through sieve #120 (125 μm).
- Microfine powders: Pass through sieve #350 (75 μm).
Specialized Tablets
Buccal or Sublingual Tablets
Designed to be placed under the tongue, releasing the drug for absorption through the oral mucosa into the bloodstream. Faster onset of action compared to oral tablets. Dissolve completely in 15-30 minutes.
Lozenges
Designed to treat throat infections. Dissolve in the oral cavity for prolonged action. Do not require disintegrating agents. Dissolve completely in about 15 minutes.
Solution Tablets
Dissolve in a specific volume of fluid to produce a solution of a definite concentration.
Enteric-Coated Tablets
Coated with a material that resists dissolution in the stomach but dissolves in the intestine. Used to delay drug release.
Layered Tablets
Consist of two or more layers of materials compressed into a single tablet. Also known as laminated tablets. Designed to mask drug incompatibility.
Time-Release or Prolonged-Release Tablets
Designed to provide medication over a longer period in a controlled manner.
Standards of Sieves
Common standards include US standard sieve, British standard sieve, German standard sieve, IP standard sieve, and International test sieve.
Specifications for Pharmacopeial Testing
- Sieve number: Sieve number 125 is commonly used.
- Aperture size: The distance between two wires.
Capsules
Solid dosage forms where the drug is enclosed in a hard or soft soluble container, usually made of gelatin.
Liniment
A liquid rubbed into the skin to reduce pain or relieve stiffness, such as aches from arthritis and muscle stiffness.
Freeze Drying
Also known as lyophilization, it involves freezing water and removing it through sublimation. Widely used to preserve thermolabile substances.
Principle
Based on sublimation, where water transitions directly from solid (ice) to vapor without passing through the liquid phase.
Construction
Three types: manifold, rotary, and tray-style. Components include a vacuum pump, condenser, and vacuum chamber with shelves.
Working
The sample is frozen and placed under vacuum, allowing frozen water to sublimate. This occurs at low temperature and pressure below the triple point. Stages include sample preparation, freezing, primary drying, secondary drying, and packing.
Difference Between Flocculated and Deflocculated Suspensions
| Flocculated | Deflocculated |
|---|---|
| Particles have undergone flocculation. | No flocculation occurs. |
| High sedimentation rate. | Low sedimentation rate. |
| Loosely packed particles forming a hard, dense cake that is difficult to redisperse. | Closely packed sediment that is easily redispersed. |
| Rapid sediment formation. | Slow sediment formation. |
Vanishing Cream and Cold Cream: Differences Explained
1. Emulsion Types
- Vanishing Cream: Oil-in-water emulsion.
- Cold Cream: Water-in-oil emulsion.
2. Composition
- Vanishing Cream: Higher percentage of water, lower percentage of oil. Light and non-greasy.
- Cold Cream: Higher percentage of oil, lower percentage of water. Thick and emollient.
3. Functionality
- Vanishing Cream: Day cream or makeup base. Provides hydration with a matte finish.
- Cold Cream: Night cream or moisturizer for dry and sensitive skin. Deeply moisturizes and soothes. Also used for makeup removal.
Packaging Materials
Pharmaceutical packaging is crucial for ensuring the safety, purity, and efficacy of pharmaceutical products.
Glass Containers
Commonly used in pharmaceutical packaging.
- Borosilicate glass: Highly resistant and chemically inert.
- Treated soda-lime glass: Dealkalized soda-lime glass, often used for bottles. Resistant for extended periods.
- Regular soda-lime glass: Used for parenteral preparations, offering better chemical resistance.
- Non-parenteral: General-purpose soda-lime glass for topical or oral products.
Plastic Containers
Advantages
- Lightweight and easy to handle.
- Easy to transport.
- Available in various shapes and sizes.
- Unbreakable.
Disadvantages
- Sensitive to light and heat.
- Not easily biodegradable, posing environmental and health risks.
- Expensive compared to other containers.
Metal Containers
Used for packaging chemicals that do not react with aluminum or other metals.
Advantages
- Lightweight compared to glass.
- Easy to print labels on.
- Durable and not easily broken.
Disadvantages
- Some metals can react with products and cause poisoning.
- Rusting can occur due to moisture absorption.