Osmolarity and Sterilization Processes Quiz

Tonicity Adjustment

• Tonicity adjustment is based on comparing colligative properties to a standard.
• Lacrimal fluid and human blood have a specific isotonicity value.
• Solutions with the same colligative properties are considered isotonic.

Osmosis

• Osmosis is the movement of water through a semipermeable membrane, from an area of high water concentration to an area of low water concentration.
• An aqueous solution in contact with body fluids and tissue membranes.
• Isotonic solutions result in balance.
• Hypotonic solutions result in hydration, while hypertonic solutions result in dehydration.
• Aqueous solutions must be isotonic.

Osmotic Pressure of Solutions

• Van't Hoff equation: π = R * T * m * n
• π... osmotic pressure (kPa)
• R... universal gas constant (J/mol·K)
• T... absolute temperature (K)
• m... molality of the solution (mol/kg)
• n... number of particles resulting from dissolution.
• The equation only applies to non-electrolytes.

Modification for Electrolytes

• Van't Hoff equation for electrolytes: π = R * T * m * i
• i... Van't Hoff's factor for correction
• i depends on the dissociation level and concentration of particles (ions)
• Interionic attractions and solvation influence the value of i.
• Calculating i theoretically is challenging.

Modification for Electrolytes (Dissociation Level)

• Influence of dissociation level: i = 1 + a(n-1)
• a... coefficient of dissociation
• n... number of particles (ions).

Colligative Properties

• Colligative properties depend only on the number of particles in the solution.
• Colligative properties include osmotic pressure elevation, boiling point elevation, vapor pressure depression, and freezing point depression.
• These properties are often used for tonicity adjustment.

Freezing Point Depression

• Freezing point depression of an aqueous solution: ΔT = K_f * i * m
• ΔT...freezing-point depression
• K_f...molal freezing-point depression constant of water.
• i...Van't Hoff's factor for correction.

Estimation of ΔT

• For diluted aqueous solutions, molality (m) can be replaced by molar concentration (c).
• The value of ΔT_iso depends on the valency of the electrolyte.

Law of Colligative Properties

• Solutions with the same colligative properties are isotonic.

Tonicity Adjustment of Eye Drops

• Eye drop compounding requires the addition of necessary excipients, adhering to general pharmacopoeial requirements.
• Adding isotonic solution adjusters as necessary is a critical part of compounding eye drops.
• Practitioners must also adhere to specific requirements.
• Also consider buffering of eye drops to maintain appropriate pH levels, and adjusting viscosity as needed.

Estimation of Freezing-Point Depression

• Isotonic solutions have a specific ΔT value.
• Any solution with the same ΔT value is also isotonic.
• Solutions with ΔT values lower or higher than this isotonic value are considered hypotonic or hypertonic, respectively.

Determination of Tonicity Adjusting Agent

• The amount of tonicity adjusting agent can be determined in various ways, including the freezing-point depression method (ΔT, D-value), the sodium chloride equivalent method (E-value), and the isotonic solution method (V-value).

Basic Steps for Tonicity Adjustment of Eye Drops

• Estimate drug contribution
• Estimate the “gap” in isotonicity
• Determine the concentration of the adjusting agent
• Calculate the mass of the adjusting agent
• Edit the final eye drop prescription.

Prescription

• Pilocarpine hydrochloride (0.20 g) is a sample prescription for eye drops.
• Water for injection (to 10.0 mL) is measured for the stated prescription.

Tonicity Adjustment (Drug Contribution)

• Determine the percent concentration of the drug/compound in a table.
• Read the D-value (AT) caused by the compound.
• Calculate the D-value (AT) caused by the prescribed concentration of the compound/drug
• It is important to verify this is hypotonic when compared to the isotonic solution.

Tonicity Adjustment (Estimation of “Gap”)

• Subtract the compound D-value from the desired isotonic D-value (AT) in an isotonic solution.
• Decide on the appropriate tonicity adjuster, e.g., sodium chloride (NaCl)

Tonicity Adjustment (Concentration of Adjuster)

• Read the D-value (AT) caused by NaCl in the table.
• Calculate the concentration of sodium chloride needed to give the remaining freezing point depression to achieve isotonicity for the eye drops.

Tonicity Adjustment (Mass of Adjuster)

• Calculate the mass of sodium chloride needed for the desired volume of eye drops (e.g., 10 mL).

Editing Eye Drop Prescription

• Write a total composition of the eye drops, including the drug, sodium chloride, preservative, and water.

Compounding

• Compounding Procedures for eye drops.

TASK

• Homatropine hydrobromide (0.1 g) and water for injection (to 10.0 mL) is part of a Task to calculate the mass of the tonicity adjustment needed for multidose eye drops and compose the complete recipe.

Composition of Infusions

• Infusions involve direct application of substances into the bloodstream.
• Infusion solutions are aqueous.

Effects of Infusions on Hydration

• Osmolality is the concentration of solutes per kilogram of solvent.
• Osmolarity is the concentration of solutes per liter of solution.
• Hyperosmolality may result in a loss of water.
• Hypoosmolality may result in a loss of some ions.
• Colloidal osmotic pressure influences fluid balance.

Osmotic Effect

• Osmotic pressure is affected by the concentration of particles.
• Effective osmolarity uses either osmol/kg or osmol/L, whichever is appropriate.

Theoretical Osmolarity

• The theoretical osmolarity of a solution depends on its constituents' molarity and particle number.

Theoretical Osmolarity - Example

• Calculate the theoretical osmolarity of glucose and sodium chloride solutions.

Estimation of Osmolarity

• Example calculation of osmolarity of a Ringer-lactate solution
• Ringer-Lactate solution is composed of NaCl, KCl, CaCl2.6H2O, and Na lactate
• Consider the composition, molar mass, molar concentration, and ion count when calculating osmolarity.

Effects of Dissolves Substances

• Small molecules and ions are non-metabolized after administration.
• Macromolecules exert a minimum osmotic effect.
• The rate of metabolism of molecules determines their osmotic effect, which can decrease over time as metabolites are changed.

Sterilization of Eye Drops

• Appropriate sterilization methods for eye drops.

Efficiency of Bacteria Retentive Filtration Methods

• Factors influencing the efficiency of bacteria retentive filtration, including contamination level, filter reliability, filtration capacity, and filtration pressure limits.

Laminar Air-Flow Cabinet (LAC)

• Class A refers to aseptic conditions.
• Air should be HEPA filtered and laminar to prevent contamination.
• The LAC must be cleaned and disinfected regularly.

Aseptic Technique Rules

• Proper cleaning and disinfection procedures for the LAC.

Arrangement of Devices

• Essential materials should be kept close together within the LAC for proper airflow during the aseptic process.

Sterilization by Filtration

• Instructions for sterilizing solutions by filtration, including safety precautions.

Manufacturing of Parenterals

• Principles of pyrogen prevention to prevent contamination for parenteral products during manufacturing.

Controlled Working Environment

• Maintaining a sterile working environment is critical to preventing microbial contamination.
• The clean room's total particulate count (of a given size) is the critical parameter.
• EU Guidelines specify requirements for the clean room environment.
• Specific rules apply for the proper handling and movement of materials within each designated zone to prevent contamination.

Monitoring Microbial Contamination

• Methods for measuring microbial contamination levels, including CFU/m³.

Technological Operations

• Procedures for the preparation of working areas and equipment.
• Steps for the preparation of containers, closures, and products.

Quality of Product

• Procedures to ensure that the final product meets quality standards, including microscopic and in-process tests.

Test your knowledge on osmolarity, osmotic pressure, and the sterilization process. This quiz covers fundamental concepts and definitions that affect ion and molecule balance in biological systems, as well as contamination prevention in sterilized environments.