Excipients In Liquid Dosage Forms Flashcards
What are types of excipients in liquid dosage forms?
Solvents
Preservatives
Stabilizers/ anti-oxidant
Buffers
Isotonicity modifiers
Sweeteners
Flavors
Colors
What are the types of solvents?
Water
Ethyl alcohol
Glycerol
What are the advantages of water?
Cheap
Tasteless, odorless and colorless
Inert
Neutral
Physiologically compatible
Lack of toxicity
Available
Compatible with so many liquids
Can dissolve many drugs
What are disadvantages of water?
Support growth of microorganisms when contaminated
Favorable medium for many chemical reaction
A medium for all the degradation processes
May contain minerals
Dissolve sugars, proteins → encourage growth of microorganisms
What are the types of water?
Tap water (potable water)
Purified water
Water for injection
Bacteriostatic water for injection
What is tap water?
It contains minerals and microorganisms
Not permitted to be used for liquid dosage forms for dispensing of pharmaceutical dosage forms
Used in the preparation of purified water
Why tap water is not permitted to be used for liquid dosage forms for dispensing of pharmaceutical dosage forms?
Due to its possible bacterial contamination and the presence of dissolved salts that destroy the active ingredients or enhance their decomposition
What is the microbiological specification of tap water?
Contains not more than 500 cfu/ml
Absence of individual pathogenic microorganisms, escherichia coli, salmonella, staphylococcus aureus and pseudomonas aeruginosa per 100 ml
What is purified water?
Water free from minerals total solids < 10ppm
Prepared by distillation or ion exchange resins
Containers, closures and machine parts may be washed with portable water followed by suitably filtered purified water
Stored in stainless steel tanks or plastic tanks
What is the microbiological specification for purified water?
Contains not more than 100 cfu per ml and indicates absence of pathogenic microorganisms
What is water for injection?
Prepared from portable/purified water
Free from bacteria
Free from pyrogen
Free from minerals < 10ppm
Used for sterile products
WFI is sterile water may be found in containers of one liter
What is microbiological specification for water for injection ?
Contains not more than 10 cfu per 100 ml
Shall have an endotoxin level of not more than 0.25 eu/mi
What is bacteriostatic water for injection?
All characters of water for injection
Contains a bacteriostatic at specific concentration
Used for vials or multiple dose products
Volume must not exceed 30ml
What are advantages of ethyl alcohol
Kills microbes
Used to extract alkaloid and glycosides
More specific for dissolving materials
What are disadvantages of ethyl alcohol?
Volatile
Affects CNS, liver, git
Dissolves resins
Restricted use
What are advantages of glycerol?
Not volatile
Not toxic
Antimicrobial activity
Viscosity is high
Effect is better because duration is more
What are disadvantages of glycerol?
Hygroscopic
Dissolves gums, albumins, and tannins
What is the definition of preservatives?
Agents used to prevent the growth of microbes found into or allowed to inter in the container
What are examples of preservatives?
Benzoic acid 0.1 - 0.2%
Sodium benzoate 0.1 - 0.2%
Methyl parabens and propyl parabens 0.1 - 0.2%
Phenyl mercuric nitrate 0.002 - 0.01%
What are characteristics of preservatives?
Antimicrobial agents
Toxic
Required for multiple dose administration
What are properties of preservatives?
Must be used in the effective concentration
Must be safe, soluble and stable
Doesn’t interact with container or cover
Doesn’t interact with the drug or other ingredients in the formulation
What are the factors enhancing degradation?
Light
Heat
Catalyst
Drugs degradation occurs due to what?
Oxidation
Hydrolysis
Photo-degradation