Ointments excipients

With transdermal dosage forms being of great importance of late, it is advisable to test for compatibilities with ointment excipients and with polymers (e.g., ethylvinyl polymer, if that is the desired barrier). 

Ophthalmic ointments usually contain petrolatum as the base. The petrolatum is sterilized by dry heat and combined with the sterile dmg powder under aseptic conditions. Ophthalmic suspensions contain very fine (- 10 ji) particle sized soHds suspended in an aqueous vehicle. The vehicle is adjusted to isotonicity and viscosity-increasing excipients, chelating agents, and surfactants also may be needed. The aqueous vehicle in these cases is generally autoclaved and mixed with sterile dmg powder asceptically (30). 

When an ophthalmic ointment is manufactured, all raw material components must be rendered sterile before compounding unless the ointment contains an aqueous fraction that can be sterilized by heat, filtration, or ionizing radiation. The ointment base is sterilized by heat and appropriately filtered while molten to remove extraneous foreign particulate matter. It is then placed into a sterile steam-jacketed kettle to maintain the ointment in a molten state under aseptic conditions, and the previously sterilized active ingredients) and excipients are added aseptically. While still molten, the entire ointment may be passed through a previously sterilized colloid mill for adequate dispersion of the insoluble components. 

The solubility of C60 and C70 fullerenes in vegetable oils will permit to employ these molecules for topical use in creams, lotions and ointments, which are adsorbed by skin. Vegetable oils, especially olive oil, are considered excellent excipients for injectable preparation where the active principle is soluble in fats. Their absorption in the subcutaneous tissues is slow and limited and ensures a gradual release of the active principle (Adami, 1960). 

Purified drug substances are mixed with excipients into finished dosage forms sohds, liquids, parenterals, inhalants, and ointments and creams, then packaged and labeled and shipped for distribution. 

Pharmaceuticals, for the purpose of this book, means chemical compounds that are used in pharmaceutical production. This can comprise the active ingredient, which is also called active pharmaceutical ingredient (API) or drug substance or drug product and the inert pharmaceutical ingredients (excipients) that are used to formulate a drug product in the form of tablets, capsules, ointments, creams, lotions, parenterals, inhalers, and a variety of drug delivery systems. 

Several dosage forms carry an increased risk of degradation or adjunct formation. Products such as injections and aerosols are more likely to interact with volatiles or extractables from packaging and closure systems. Tablets have the potential to form adjuncts with excipients (specifically, lactose has been shown to form adjuncts in tablets). Non-CFC propellants in aerosols have a large number of impurities that typically do not interact with drug substances, but the potential for these interactions does still exist. Creams, ointments, lotions, and other such products will each have specific interactions that should be considered while evaluating the impurity profile of a drug product. 

In this case the selective extraction of oily excipients from the cream is made somewhat easier by the fact that the miconazole (p/fa 6.5) is almost fully ionised at pH 4.0 the econazole internal standard used differs from miconazole by only one chlorine atom (Fig. 12.13). Thus a preliminary extraction can be made with hexane to remove much of the basis of the ointment and then the sample can be simply diluted with mobile phase, filtered and analysed. 

The use of excipients goes back to centuries. Even before the advent of the capsule and later the tablet, the available botanical drugs were made into powders or mixtures to make them more convenient for the patient, although sometimes not that palatable. Ointments and salves, with similarities to topical formulations that have been used in more recent times, were known in Ancient Greece. However, the scientific basis for the use of certain excipients has emerged only in the last few decades for example, tablet lubricants—until a few years ago we knew they were needed and when to use them, but not why they functioned as they do. 

Transdermal delivery of certain APIs is now common for the treatment of some medical conditions, and there are several excipients that are promoted as transdermal penetration enhancers. One of the earlier materials developed was laurocapram (Azone ). There is a detrimental interaction between laurocapram and mineral oil (liquid paraffin) whereby when both are included in the same formulation, the skin penetration-enhancing properties of laurocapram are lost. Such interactions have implications for extemporaneous mixing of different cream and ointment formulations in the pharmacy. 

Structure Forming Excipient An excipient which participates in the formation of the structural matrix which gives an ointment, cream or gel etc., its semisolid character. Examples are gel fonning polymers, petrolatum, certain colloidal inorganic solids (e.g., bentonite), waxy solids (e.g., cetyl alcohol, stearic acid), and emulsifiers used in creams. 

G. Creams or ointments Semisolid preparations intended for topical application. Excipients include petrolatum, isopropyl... 

Alternatively, absorbing excipients or opacizers can be added to the drug preparation, thus protecting the drug outside the package this is the only choice with creams, ointments, and liquid preparations. The effectiveness... 

Besides using a simple mobile phase requiring little or no method development, the sample preparation steps can be simplified. This has been shown in the analysis of benzocaine ointment which is dissolved in tetrahy-drofuran, filtered, and injected (Figure 5.11). Using an identical approach, a solution of the corticosteroid halcinonide is resolved from the excipi-... 

R. A. Kenley, S. Chandry, and G. C. Visor, An automated columnswitching HPLC method for analyzing active and excipient materials in both cream and ointment formulations, Drug Dev. Ind. Pharm., 4 1781 (1985). 

Fromder, A. and Lippold, B.C., Water vapour transmission and occlusivity in vivo of lipophilic excipients used in ointments, Int. J. Cosmet. Sci., 15, 113, 1993. 

The fact that most vegetable oils and fats are nontoxic allows them to be used as reliable excipients or carriers in many pharmaceutical formulations. Vegetable oils and fats have been approved as excipients to facilitate delivery of bioactive compounds, to act as fillers, binders, lubricants, solubilizers, emulsifiers, and emollients in a variety of delivery forms including tablets, capsules, suppositories, emulsions (enteral/parenteral), ointments, creams, and lotions. Other nondirect applications include artificial blood, gene delivery, diagnostic imaging, and medical devices (27). 

Testosterone Cypionate injection Tetracaine and Menthol ointment Tiletamine and Zolazepam for injection Tocopherols excipient... 

This chapter is a comprehensive review of the excipients included in the injectable products marketed in the United States, Europe, and Japan. A review of the literature indicates that only a few articles that specifically deal with the selection of parenteral excipients have been published. However, excipients included in other sterile dosage forms not administered paren-terally, such as solutions for irrigation, ophthalmic or otic drops, and ointments, will not be covered. 

As a pharmaceutical excipient, chloroxylenol is commonly used in low concentrations as an antimicrobial preservative in topical formulations such as creams and ointments. Chloroxylenol is also used in a number of cosmetic formulations. 

Mineral oil is used primarily as an excipient in topical pharmaceutical formulations, where its emollient properties are exploited as an ingredient in ointment bases see Table I. It is additionally used in oil-in-water emulsions,as a solvent, and as a lubricant in capsule and tablet formulations, and to a limited extent as a mold-release agent for cocoa butter suppositories. It has also been used in the preparation of microspheres. " ... 

Simple, nonpharmacologic, preventive measures should be recommended for all patients with AD. Clinicians should be attuned to the various types of moisturizer classes, including occlusives, humectants, and emollients. Each has a different mechanism of action on the epidermis, and thus treatment should be tailored to an individual patient need. Generally speaking, an ointment is more occlusive than a cream or a lotion, and thus can retain more moisture in contact with the skin. Avoidance of extraneous fragrances, dyes, and preservatives, as well as understanding a potential role of excipient contact allergy is also of importance in emollient selection (Table 97-1). 

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