محاضرة في تكنولوجيا الأدوية 1

Pharmaceutical Technology Lecture 1

Aqueous Solutions Containing Aromatic Principles (Waters, Syrups, and Juices): Two important classes of aqueous pharmaceutical preparations are syrups and juices. These often include aromatic principles.
Syrups: Defined as viscous, aqueous liquids specifically designed for oral administration of medicine.
Juices: Liquids obtained by pressing fresh plant parts. The United States Pharmacopeia (USP) includes cherry and raspberry juices. In the past, juices were frequently used as bases for syrups.
Aromatic Waters: The simplest dosage forms, consisting only of water and a volatile solute.
Juices Complexity: Juices can be complex in composition and their characteristics are not easily controlled by pharmacists as they are derived from natural sources..
Syrups as Formulations: Syrups are formulated preparations that often contain ingredients (adjuvants) to improve the product's quality.
Pharmaceutical Elegance: A pharmaceutical formulation is considered "elegant" if it meets three quality standards: stability, palatability, and therapeutic effectiveness.
Stability: Pharmaceutical preparations are stable if they do not lose therapeutic potency or undergo undesirable chemical and physical changes over time. Shelf life is defined as the time it takes for a product to degrade to 90 percent of its labeled potency at room temperature (usually 25°C).
Factors Affecting Stability: Environmental factors impacting stability include microbial contamination, light, atmospheric oxygen, humidity, and temperature. Chemical changes involve hydrolytic degradation and autoxidation. Physical changes involve precipitation and alterations in color, odour, and viscosity.
Palatability: A pharmaceutical is palatable if it has a pleasant taste. The selection of flavors considers factors like the intended age group, the color of the preparation, and the taste to be masked.
Syrups and aromatic waters are designed to provide palatable medicinal products.
Dosage Form Impact: The therapeutic efficacy of dosage forms depends on their ability to quickly release medicinal agents.

Aromatic Waters

Definition (BP): Clear, saturated aqueous solutions of volatile oils or other aromatic/volatile substances.
Characteristics: Typically saturated solutions of volatile substances with low water solubility.
Use: They provide a pleasantly flavored medium for water-soluble drug administration and for the liquid phase of emulsions and suspensions.
Low Potency: Aromatic waters are not therapeutically potent due to the low proportion of active ingredients.

Official Aromatic Waters

The specific aromatic waters listed (Cinnamon water, Orange flower water, Stronger rose water, Peppermint water, Camphor water, and Chloroform water) have designated purposes.

Examples of Aromatic Waters

Uses and Properties: Aromatic waters are prepared from essential oils. Chloroform water was formerly used in expectorant preparations. Rose water, and Hamamelis water (Witch Hazel) have various cosmetic and medicinal uses. Examples of Aromatic water's use include soothing coughs.

Preparation of Aromatic Waters

Distillation: A common method involving placing odoriferous plant material in a still with water; distilling the water, carefully; and then separating aqueous and excess oil phases. Some, like Stronger rose water, orange flower water, and Hamamelis water are prepared solely by distillation.
Solution: Another method using agitation with purified water for saturation, then filtration to remove excess volatile materials.
Disadvantages of Solution Method (and Alternate): Repeated filtration does not guarantee exceptionally clear preparations. The filtered material may also be too finely subdivided to remain contained properly through the filtration procedure.

Essential Oils

Complex Mixtures: Essential oils are complex mixtures of hydrocarbons, alcohols, ethers, aldehydes, and ketones.
Terpenes: The hydrocarbon fraction of many oils are composed of terpenes.
Water Solubility: The components of essential oils are largely insoluble in water; these components act as "aroma carriers".

Stability of Aromatic Waters

Mold Growth: Many aromatic waters support mold growth. Preservatives rarely added.
Light and Temperature Instability: Exposure to light and temperature changes reduces desirable characteristics of aromatic waters, particularly impacting their aroma over time.
Volatility: The solutes are volatile materials; prolonged exposure leads to aroma loss due to vaporisation.
Saturated Solutions: Aromatic waters are saturated solutions which are susceptible to cloudiness when exposed to temperature changes. These temperature changes can cause the aromatic components to precipitate out resulting in cloudiness.
Salting Out: Aqueous solutions of aromatics containing electrolytes may "salt out" the aromatic materials. This process can also impart an unpleasant burning taste to the first dose.
Oxidation: Many aroma-bearing solutes and terpenes are susceptible to oxidation, especially via dissolved atmospheric oxygen, catalyzed by iron and copper. This can occur when the water is exposed to light. This decomposition is evident in the production of phosgene.

Terpeneless Oils

Preparation: Terpeneless oils are made through fractional distillation and extraction processes.
Properties: Terpeneless oils are concentrated and more soluble in their aroma; are often more stable compared to natural oils.
Clarification: Use of terpeneless oils in preparation leads to reduced clarification issues, although these oils are often more expensive.