Making & using external preparations is all part of what attracts us to herbal medicine in the first place: you can make them yourself from simple ingredients; there are almost limitless creative combinations to be discovered & made; they visibly work; the process is alchemical. Making things like ointments and creams at home is one of the most satisfying ways to spend an afternoon. All you really need to get started is a heatproof bowl, a pot of hot water, some basic ingredients & some jars. You can always add to your materials and equipment later.

But first, a few definitions: –

  • Aqueous: describes water itself and also all constituents that can be mixed with or dissolved in water, e.g. herbal infusions & decoctions, floral waters (such as rose water), tinctures & fluid extracts, vinegars, syrups, glycerine & glycerites, vinegar and honey.
  • Oleaginous: describes oils and all constituents that are soluble in oil, e.g. Fixed oils, infused oils, essential oils, paraffins (soft or liquid), fats, greases, waxes & resins.
  • Ointment: (or salve): a semi-solid non-aqueous preparation; in other words, contains only oleaginous (‘oily’) constituents.
  • Paste: an ointment (or sometimes a cream) that incorporates finely powdered herb(s).
  • Emulsion: a mixture of oleaginous & aqueous (oil-based & water-based) ingredients.
  • Emulsifier (or emulgent – what a brilliant word): an agent that makes it possible to form a stable mixture of oils and water, e.g. borax, beeswax, soap, lanolin, some gums, and egg. Proprietary emulsifying agents such as Lanette Wax & Emulsifying Wax BP are also available – less natural but more efficient.
  • Phase: when making emulsions, one refers to the oleaginous phase (all the oily constituents mixed together) and the aqueous phase (all the water-soluble constituents mixed together). When they have been combined (in the presence of an emulsifier), you will either have caused the aqueous phase to be suspended in tiny droplets surrounded by oil, or the oleaginous phase to be suspended in tiny globules surrounded by water.
  • Cream: the most popular form of emulsion, usually containing oil globules suspended in water (o/w) but sometimes water droplets suspended in oil (w/o).
  • Vegetable oil: (sometimes called a ‘fixed’ oil).  Extracted from a nut, seed or other plant source. Popular examples are Sunflower, Olive and Sweet Almond oils. The best quality is cold pressed, cheaper forms are extracted with solvents (often after an initial cold pressing). Fixed oils are not to be confused with essential oils!
  • Infused oil (or macerated oil): a vegetable oil in which fresh or dried herbs have been infused. This may be a hot or cold process.
  • Essential oil: volatile oils from aromatic plants, usually extracted by distillation but occasionally by pressing (e.g. citrus fruit peel) or by dissolving into fats & then separating (‘absolutes’). Not to be confused with vegetable oils!

We will in due course be detailing liniments, plasters, compresses, poultices, pessaries, suppositories, ears drops, herbal baths, washes and more – but will give appropriate definitions as we go.

Next, as we’re doing lists at the moment, a key to some of the terms and abbreviations used in formulas: –

  • aa            of each, (i.e. the same amount of each item in the list).
  • gutte            drops (there are approximately 20 drops in 1ml)
  • EO            essential oil
  • VO            vegetable oil
  • TR            Tincture

Understanding the effects of oils & waters

A popular misconception to dispel is the idea that, for instance, a ‘moisturising cream’ must contain a high proportion of water. Not so! Water on the skin is innately drying – we dry up suppurating skin conditions quickest with a simple infusion or decoction (as a wash or compress). Instead, it’s oils & fats that are essentially moisturising, as they provide a temporary occlusive barrier, enabling the skin’s own natural secretions to build up beneath. This is an important concept to grasp – watery preparations (e.g. lotions) to dry the skin, mixed ones such as a well-balanced cream for a neutral effect, and oily preparations (e.g. ointments) to moisturise. Of course, this will also depend on the therapeutic activities of herbal constituents, but there is no point in countering their effects with the wrong sort of preparation.

The next important concept is the degree of adhesion provided by the preparation. Obviously a lotion will dry out very quickly and be gone, whilst a solid wax (as in a plaster) could be held in place for days. Between these extremes, (and the main reason why there are so many different formulas for ointments, creams & the like), lie many compromises between the ease with which a preparation can be spread evenly onto the skin, how comfortable and convenient it will be once applied (e.g. not unpleasantly sticky), and how long it can stay there.

Natural v. unnatural ingredients

Herbalists of course want to make external preparations with ingredients sourced from the plant world, perhaps with the occasional use of a little beeswax – everything natural, like our internal medicines. It can be done, often is, and to quite a high degree of sophistication. We certainly like to make our own cosmetics and medicaments for home use this way, and there is no harm in doing the same for our patients, within sensible limitations. By comparison, the stock external preparations appearing on practitioners shelves are likely to contain some non-vegetative constituents, for the following reasons: –

  • Shelf-life: All-natural products can’t be relied on to keep for very long – and you may need to make things that will keep on your own shelves for weeks, then in a patient’s home environment for months or more.
  • Infection: Many external preparations are prescribed for application to infected skin, or damaged skin that is vulnerable to infection. There is a very real problem here that all-natural products will themselves form a substrate for infection, particularly if an efficient preservative has not been incorporated.
  • Allergy: Allergic or sensitivity reactions are common with external preparations of all kinds. As paraffins in particular are inert, using them as the prime excipient in external preparations limits this potential.  
  • Absorption: Natural constituents are usually absorbed into the skin quite quickly (an essential therapeutic effect). However, it’s often equally useful to provide an occlusive barrier (e.g. to protect the skin) with constituents which will not be absorbed, such as paraffins.

Preservatives

Oils, ointments and other non-aqueous preparations usually need no preservative. Anything containing water such as creams will have a very short shelf life without. There’s nothing more alarming than to find you’ve given somebody a cream and it’s become infected, quite possibly making the problem it was designed to treat worse. Some herbs, like Pot Marigold and St John’s Wort are naturally antimicrobial. You might also get away with it if you incorporate a high proportion of tinctures, or the right sort of essential oils to inhibit infection – but then there’s the problem that significant quantities of either may well interfere with getting a cream to emulsify, and may also prove unacceptably irritant if applied to broken skin or rashes. So you may have to give in and use an artificial preservative. Parabens is the most common cosmetic preservative currently available, (but concerns have recently been raised regarding possible interference with oestrogen metabolism) or you may be able to track down some Preservative 12, which so far seems problem-free, (or even newer, Preservative Eco).

A careful approach

No matter what the constituents of the external preparations you make, there is always a potential for irritation, allergic or sensitivity reactions. When treating children, people with thin or damaged skin, or those know to be reactive, always recommend a ‘patch test’ with a small quantity on the inside wrist, 24 hours before proceeding. Also recommend that if a reaction develops later, application should stop immediately and you should be contacted.

Hygiene

The longer you want something to last, the more scrupulous you have to be about keeping everything clean. Ultimately, this is a matter of common sense – even the most efficient preservatives will fail if there’s already a vibrant bacterial community in your external preparations, and there’s plenty of time for them to colonise. Also bear in mind when you’re supplying ointments, creams etc. to others, you might need to mention: –

  • External preparations will keep a lot longer whilst they remain unopened, and are thereafter carefully re-lidded.
  • Often it’s best to keep things in the ‘fridge, but at the very least they should be kept in a cool, dark cupboard.
  • The most common cause of external preparations becoming infected is dolloping them out with dirty fingers!

Measuring and Weighing

One of the unfamiliar problems encountered making external preparations is how to measure or weigh constituents that don’t pour easily. Here’s some tips: –

  • Fixed oils, glycerine and other viscous liquids can be measured by volume in a measuring cylinder or similar, but expect 5-10% of it to be left sticking to the vessel, so measure out generously to compensate for this.
  • Creams, soft paraffin, and other semi-solid ingredients are messy and subject to a lot of wastage if you try to weigh them out in the normal fashion. Instead, weigh the jar that it’s already in, and dollop it out a little at a time with a spoon or spatula until the required weight has been lost. (Example: you need 40g of honey for the cream you’re making. A partly used pot of honey is placed on the scales and found to weigh 329g. Portions are removed with a pallet knife until the weight is reduced to 289g. There you are, you’ve taken out 40g).

Tools & Equipment

Generally speaking pots, pans, bowls, & hand tools are exactly the same as you use in the kitchen. But it’s best to aim to have separate ones for making herbal preparations so you can keep them scrupulously clean and also avoid any cross-contamination with food preparation (see ‘Hygiene’ above). You may additionally consider: –

  • A good spatula is a thing of beauty and makes all the difference – get one from a laboratory supplier – one with a 10-12cm steel blade is ideal.  Glass stirring rods are invaluable – 15cms long with a disc-shaped end is the most useful. Tongue depressors are great for stirring ointments & creams, and can be disposed of afterwards.
  • Measuring liquids: Kitchen jugs and the like seldom measure accurately enough – get kitted out from a laboratory supplier with measuring cylinders, graduated beakers & jugs.
  • Weighing solids: Kitchen scales can be acceptably accurate but the only way to find out is to check them. Small electronic commercial scales designed to weigh postal packets and the like are excellent and multi-purpose. A ‘tare’ function (where having placed an empty container on the scales it can be reset it to zero, so only the contents are weighed) is very useful.
  • Measuring temperature: A cook’s or ‘jam’ thermometer will do but is difficult to clean and soon gets gummed up. A digital ‘chef’s’ thermometer with a stainless probe is not much more expensive, gives quick, accurate readings and is simplicity itself to keep clean.
  • Heating: Some processes are conducted satisfactorily on a hob or in the oven, but often one needs to work over water to avoid too high a temperature or burning at the bottom of the pan. Invest in a double boiler  or a bain marie  or water bath (these are effectively all the same thing). These are available from cook-shops –­ or you might even jury-rig something your self. It probably doesn’t warrant the expense of chef or lab equipment that have built-in heaters/thermostats. A cheap option is a porringer, which works slightly differently as it’s effectively heated by steam – cheap and handy, although it’s unlikely to get the contents of the pan much hotter than 75°C.
  • Agitating: (that’s the glop, not yourself!). Ointments, creams etc. need to be stirred, whisked, blitzed or whatever during the making process. Many recipes can simply be stirred with a wood/plastic spatula (or tongue depressor), others need a slightly more vigorous approach with a hand whisk – the type with a horseshoe of tightly coiled wire is perfect. Motorised laboratory stirrers are probably too expensive to consider. A hand blender can be used, (having adjustable speeds and a ‘pulse’ function is ideal) but some models may introduce too much air, and beware that you can so easily spray much of what you are making to the four corners if you lose concentration. A bowl blender is a satisfactory solution – but you’ll need to invest in a sturdy one with plenty of adjustability. Blenders aren’t really designed to be operated for more than a few seconds at a time, so the heavy and extended use required for cream-making can easily jam or burn out cheap blenders.
  • Cleaning: Wipe off as much residue of oil, cream etc. as possible from pots & pans with kitchen towel before a hot wash with detergent. If your product contains a lot of volatiles, wash up in two or more changes of cold soapy water to avoid the whole house smelling of it. Use washing soda crystals to clean off oil that has been baked on or hardened with time on your utensils & bottles.
  • Storage:  Liquids should be kept/dispensed in amber glass bottles – get in a stock of round ones so they don’t get confused with the ‘amber medicals’ used for internal medicine. For ointments, creams etc, you can choose between amber glass or opaque plastic pots. Choose between storing in bulk in large pots, or filling lots of smaller ones straight away. It’s very important not to seal anything until it has fully cooled – otherwise condensation forming under the cap or lid will be a first step towards infection. Be careful to spatula stiff ointments & creams into pots carefully to avoid trapping pockets of air. Likewise with thin creams, rap the pot a few times hard on the worktop so that air bubbles surface. Use common sense regarding stocking – well preserved products can happily sit on dispensing shelves, otherwise choose a cool dark place, or even a ‘fridge.
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