Absorption: The process of assimilating substances into cells or across the tissues through diffusion or osmosis. In the case of compounded topical medications this assimilation could happen with the active pharmaceutical ingredient or with the excipient.
Active pharmaceutical ingredient (API): Any substance that is represented for use in a drug and that, when used in the manufacturing, processing, or packaging of a drug, becomes an active ingredient or a finished dosage form of the drug. Such substances are intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure and function of the body of humans or other animals. Elements of a drug that are not API are called inert pharmaceutical ingredients.1,2
Acute pain: A complex, unpleasant emotional, cognitive, and sensory experience that is usually correspondent with the degree of tissue damage and that lessens as the injury heals.
Adjuvant: A medication that enhances the effectiveness of pain treatments.
1 Definition from the United States Pharmacopeia.
2 Definition adapted from the U.S. Food and Drug Administration (FDA).
Adverse event: An adverse event is any undesirable experience associated with the use of a medical product or preparation in a patient.3
Analgesia: A loss of pain sensation in an individual.4
Anesthesia: A process that reduces or eliminates pain and sensation, usually given during a painful procedure. Anesthesia may be local, regional, or general.
Bioavailability: The fraction of the administered dose of a drug that reaches the bloodstream for systemic circulation.
Bioequivalence: The therapeutic and pharmacokinetic uniformity of two drug products delivered at the same molar dose and under the same conditions.
Breakthrough pain: A sudden increase in pain that “breaks through” pain relief provided by ongoing analgesia. The duration is usually short, and while the level of pain may be severe the type of pain and the source of pain are usually not a symptom of a new or worsening condition. Typically the type of pain and the location of pain in these cases are shared with the chronic or acute pain condition that proceeded the breakthrough. Also called a pain flare.
Bulk drug substance: Any substance that is intended for incorporation into a finished drug product or preparation and is intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body, but the term does not include intermediates used in the synthesis of such substances.5
Cancer pain: Can be caused by the cancer itself or by the surgery, treatments, or tests used to diagnose and treat cancer. The amount and duration of pain varies, depending on the source. Pain from the cancer tumor can be caused by pressing on nerves, bones, or organs. There is no distinction between cancer pain and acute or chronic pain in the underlying neural processes.
3 Definition adapted from FDA.
4 Definition from the International Association for the Study of Pain.
5 Definition adapted from FDA.
Chronic pain: Pain that extends beyond the period of healing or pain that is not explained by the identified pathology. It is pain that often disrupts sleep and normal living, ceases to serve a protective function, and instead degrades health and functional capability. Although injury often initiates chronic pain, factors (pathogenetic, physical, environmental, or affective) may perpetuate it and lead to disability and maladaptive behavior.
Chronic regional pain syndrome: A chronic pain condition that most often affects one limb, usually after injury, and is characterized by prolonged or excessive pain and changes in skin color, temperature, and/or swelling.
Clinical trial: Any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcomes.
Compounded preparation: A nonsterile or sterile drug or nutrient preparation that is formulated in a licensed pharmacy, outsourcing facility, or other health care–related facility in response to or anticipation of a prescription or a medication order from a licensed prescriber. Federal law permits compounding; however, these drugs are not U.S. Food and Drug Administration approved for safety and effectiveness.
Compounder: An individual who makes compounded preparations. Compounders can be pharmacists, physicians, or individuals under the supervision of a pharmacist, and may practice in a variety of health care facilities, including pharmacies, hospitals, clinics, and outsourcing facilities.
Compounding: Drug compounding is often regarded as the process of combining, mixing, or altering ingredients to create a medication tailored to the needs of an individual patient. Compounding includes the combining of two or more drugs. Compounded drugs are not U.S. Food and Drug Administration approved.6
Compounding pharmacy: A pharmacy that makes compounded preparations in response to or anticipation of a prescription order for an individual patient.
Cream: A semisolid oil-in-water emulsion for application to the skin. Creams are spreadable and easily rub into the skin without a greasy residue, and can be washed off with water.
6 Definition from FDA.
Difficult to compound: A condition of both sections 503A and 503B of the Federal Food, Drug, and Cosmetic Act that precludes the use in compounding of those drugs appearing on the list of drugs with a demonstrable difficulty to compound.
Drug: For the purposes of this report, considered a substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease by affecting the structure or any function of the body.7
Erythromelalgia: A rare vascular peripheral pain disorder characterized by episodes of pain, redness, and swelling in various parts of the body, particularly the hands and feet.
Evidence based: Evidence for efficacy or effectiveness should be based on designs that provide significant confidence in the results. The highest level of confidence is provided by multiple well-conducted randomized experimental trials, and their combined inferences should be used in most cases. When evaluations with such experimental designs are not available, evidence for efficacy or effectiveness cannot be considered definitive.
Excipient: A pharmacologically inactive ingredient used in the formulation of a drug that lends various functional properties to the drug formulation (i.e., dosage form, drug release, etc.).
Formulation: A selection and mixture of active pharmaceutical ingredients and inactive ingredients, which ideally takes stability, form, and strength into consideration.
Gel: Also referred to as jellies, is a semisolid dosage form that appears transparent or translucent, and employs either a hydrophobic or hydrophilic base.
Inert pharmaceutical ingredients: An inert, or inactive, ingredient is any substance, other than an active ingredient, which is intentionally included in a product. It is important to note, the term inert does not imply that the chemical is nontoxic.
Local: Refers to a specific site on the body. Local effects are achieved by administering a drug directly to the location where a therapeutic effect is desired, while avoiding absorption into circulating biological fluids.
7 Definition from FDA.
Lotion: While similar to a cream, this dosage form has a more liquid consistency. The lower viscosity may provide a cooling effect to the area where applied as solvents in the lotion evaporate.
Mechanism of action: Describes the process by which a drug functions to produce a pharmacological effect.
Neuropathic pain: A type of pain that results from a lesion or a disease of the somatosensory system.
Nociceptive pain: A type of pain that results from somatosensory signals from an intact nervous system in response to potential or actual tissue damage.
Nociplastic pain: A type of pain that may arise without any clear evidence of actual or threatened tissue damage.
Off-label: A drug is considered off-label, for example, when an approved drug product is prescribed for a condition, or in a dose other than that for which it received its approval.
Ointment: A greasy semisolid dosage form that exerts occlusive properties over the outer layer of the skin, thereby increasing drug transfer across the skin.
Outsourcing facility: A facility that is engaged in the compounding of nonsterile or sterile drugs that has elected to register as an outsourcing facility per requirements of section 503B of the Federal Food, Drug, and Cosmetic Act. An outsourcing facility may or may not obtain prescriptions for identified individual patients.
Pain: An unpleasant sensory and emotional experience associated with subjective perception and interpretation of actual or potential tissue damage, or stimuli described in terms of such damage. There are many medically recognized qualifiers to pain including acute, chronic, myofascial, musculoskeletal, neuropathic, and high impact.8
Paste: A stiff semisolid dosage form that contains finely powdered solids. Some pastes may also have occlusive properties.
8 Definition from the International Association for the Study of Pain.
Patch: A patch (not preferred terminology, but it is commonly used) or transdermal delivery system is a preparation of drug substance(s) in a carrier device that is applied topically. The drug substance is designed to be released in a controlled manner over a specified period of time. The carrier device is removed after use.9
Penetration enhancer: An excipient or a vehicle that aids in absorption through the skin.
Permeation: Penetration of and spreading throughout an organ, tissue, or space.
Pharmacokinetics: The science of drug absorption, distribution, metabolism, and excretion.
Systemic: Refers to the entire body. Systemic effects rely on the distribution of drugs by biological fluids that circulate throughout the body.
Tolerance: The capacity of the body to endure or become less responsive to a substance (such as a drug) or a physiological insult especially with repeated use or exposure.
Topical: A drug delivery method of applying the drug to the skin that aims to confine the therapeutic effect to the surface of the skin or within the skin, with no or minimal systemic absorption.
Transdermal: A drug delivery method of applying the drug to the skin that relies on absorption across the skin to blood vessels in deeper layers of the skin in order to achieve systemic distribution, which results in systemic delivery of the drug and systemic therapeutic effects.
U.S. Food and Drug Administration (FDA)-approved drug product: The finished dosage form that contains a drug substance, generally, but not necessarily in association with other active or inactive ingredients, and has received FDA approval for safety and effectiveness. An FDA-approved drug product will appear in FDA’s Orange Book.
Vehicle: A component of the excipients that is used as a carrier or diluent in which liquids, semisolids, or solids are dissolved or suspended.
9 Definition from the International Association for the Study of Pain.