Compounding Ointment (Unguentum) Dr. Muslim Suardi, MSi., Apt. Faculty of Pharmacy University of Andalas

Ointment “A highly viscous or semisolid preparation usually containing medication, used on the skin as a cosmetic, emollient, or medicament” “a homogeneous, viscous, semi-solid preparation, most commonly a greasy, thick oil with a high viscosity, that is intended for external application to the skin or mucous membranes”

Topical Medication “a medication that is applied to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes including but not limited to creams, foams, gels, lotions & ointments”

Ointment Ointments are used topically for several purposes as: Protectants Antiseptics Emollients Antipruritics Keratolytics Adstringents

Ointment The vehicle or base of an ointment is of prime importance if the finished product is expected to function as any one of the above categories. In the case of a protective ointment, it serves to protect the skin against moisture, air, sun rays and other external factors.

Ointment It is necessary that the ointment neither penetrates the human skin barriers nor facilitates the absorption of substances through this barrier. An antiseptic ointment is used to destroy or inhibit the growth of bacteria.

Ointment Frequently bacterial infections are deeply seated; a base which has the capacity to either penetrate/dissolve & release the medication effectively is therefore desired. Ointments used for their emollient effect should be easy to apply, be non-greasy & effectively penetrate the skin

Types of Ointment Bases Hydrocarbon bases: hard paraffin, soft paraffin, microcrystalline wax, ceresine Absorption bases: wool fat, beeswax Water soluble bases: macrogols 200, 300, 400 Emulsifying bases: emulsifying wax, cetrimide Vegetable oils: olive oil, coconut oil, sesame oil, almond oil & peanut oil

Ointment Bases “5 classes of ointment bases which are differentiated on the basis of their physical composition” Oleaginous bases Absorption bases W/O emulsion bases O/W emulsion bases Water soluble/miscible bases

Evaluation of Ointments Drug content Release of medicament from base Medicament penetration Consistency of the preparation Absorption of medicament into blood stream Irritant effect

Properties Affect Choice of An Ointment Base Stability Penetrability Solvent property Irritant effects Ease of application & removal

Percutaneous Absorption The potential of the drug to cross the stratum corneum The potential of the drug to leave the formulation The influence of the formulation on the stratum corneum.

Percutaneous Absorption The larger surface area, the higher the drug absorbed Incresing the hydration of formulations or dressings on the skin generally enhance percutaneous absorption The greater the amount of rubbing, the greater the absorption The longer the contact, the greater the absorption

Percutaneous Absorption Affords an ease of administration not found in other routes, & patient compliance is generally good with dermatological formulations. There is also the possibility of continuous drug administration exemplified by the transdermal patches. Dermatological formulations can be easily removed if necessary

Methods of Preparation of Ointments Trituration Fusion

The Major Disadvantage Drug absorbed limited to ±2 mg/day Become a significant limitation if the route is being considered for systemic therapy. Several chemicals have been found that promote the percutaneous absorption of drugs (called penetration enhancers).

Penetration Enhancers Improve the solubility of the active drug in the stratum corneum & facilite the diffusion of the drug through the barrier into the systemic circulation Below is a list of penetration enhancers used in dermatological formulations. Commonly used enhancers: DMSO, urea, & TEA.

Penetration Enhancers Chemical Classification Examples Alcohols MetOH, EtOH, propanol, octanol Fatty Alcohols Myristyl, cetyl, & stearyl alcohol Fatty Acids Myristic, stearic, & oleic acid Fatty Acid Ester Isopropyl, & isopropyl palmitate Polyols Propylene glycol, PEG, glycerol Anionic surfactants Na lauryl sulfate Cationic surfactant Benzalkonium, & cetylpyridinium chloride Amphoteric surfactants Lecithins Nonionic surfactants Spans, Tweens, poloxamers, Miglyol

Advantages

Advantages

Disadvantages

Hard Gelatin Capsules