Topical, Rectal, and Vaginal Pharmaceutical Formulations

Topical Excipients

1. Vehicles

• Hydrophobic: Silicones (bentonite, dimethicone), alcohols, hydrocarbons (liquid paraffin, petrolatum), sterols (lanolin), and carboxylic acid esters.
• Cosolvents: Polyols (propylene glycol, glycerin, sorbitol) and esters (polyethylene or polypropylene).

2. Functional Agents

• Emulsifiers: W/O (esters, phenols, mono- or polyesters); O/W (lauryl sulfate, polyoxyethylene sorbitan).
• Preservatives: Phenols (to inhibit microorganism growth).
• Viscosity Agents
• pH Regulators
• Moisturizers
• Antioxidants: BHA, BHT, ascorbic acid.

3. Powder Processing

1. Identify heavy constituents.
2. Sift each component.
3. Mix in a mortar (verify weight) or industrial V-mixer.
4. Sift the final mixture (verify weight).
5. Dosing and distribution: Volumetric dosing.
6. Packaging: Plastic (heat-sealed) or aluminum (waterproof).
7. Labeling.

Rectal and Vaginal Preparations

Excipients

• Soluble (Dissolve in biological media):
  • Glycerogelatinous: Gelatin, glycerin, and water (rectal).
  • Glycerosaponaceous: Glycerol stearate and sodium (rectal).
  • Macrogols: Polyethylene glycol mixture (vaginal).
• Soluble (Melt): Melting temperature below 37°C. Ideal for suppositories (e.g., Mass Esteanium, Witepsol, Suppocire). Keeps the active pharmaceutical ingredient (API) in suspension.

Officinal Preparations

Use porcelain or stainless steel equipment. Utilize a water bath and stir the emulsion with a glass rod.

1. Dilute the heated excipient.
2. Add the API and mix.
3. Fill the mold.
4. Cool in the refrigerator.
5. Remove excess material before solidification.
6. Release, perform quality checks, and condition.

Industrial Manufacturing

The process is similar to blister packaging. We use preformed molds or non-preformed systems where the machine creates alveoli to hold the suppository.