 
|
|
|
|
MEDICAL GRADE LANOLINS Lanolin is an extraordinary
natural emollient, able to imitate and augment many of the functions of human
skin lipids. Lanolin is an unctuous soft solid with emollient properties that have
been renowned and used in skin care for at least two millennia. Its efficacy as a medical material and
acceptance in Pharmaceutical Industry is reflected in the fact that all major
Pharmacopeias contain monographs for lanolin. The Croda-Westbrook range
of medical grade lanolin products offer exceptional purity, exceeding monograph
compliance, and have achieved unrivalled clinical performance. These ingredients provide outstanding
therapeutic benefits, even for the most sensitive of dermatological applications.
Recent studies have provided clinical evidence of the efficacy and safety of
our high purity lanolin products.1 Key Benefits
Product
Range
MEDILAN™ USP MODIFIED
(Modified Lanolin USP) is an exceptionally pure grade of medical
lanolin and offers outstanding efficacy in dermatological applications, as well
as proven safety in use. MEDILAN™ USP MODIFIED has been designed for the
treatment of severely compromised skin conditions, such as eczema, psoriasis
and open wounds. The intensive repair properties of medical lanolin are widely
used in topical pharmaceuticals, infant products and skin care formulations for
nursing mothers. Clinical trials have
demonstrated that MEDILAN™ products cause no allergic or irritant
reactions, even in patients with severely compromised skin.2 MEDILAN™
USP MODIFIED contains a maximum of 3% free lanolin alcohol. A free lanolin alcohol content of less than
3% is the determinant for a material's hypoallergenicity and for the product's
suitability in the treatment of on hypersensitive patients. MEDILAN™ USP
MODIFIED complies with the USP monograph for Modified Lanolin, which limits
total pesticides to less than 3 ppm; additionally, no individual pesticide may
exceed 1 ppm. As such, Modified Lanolin
can be used NEAT (full strength) on the skin. In addition to its use as
an Active Pharmaceutical Ingredient (API), MEDILAN™ USP MODIFIED can
also be used as an excipient. In fact,
the beneficial attributes exhibited by this product have made it the premier
lanolin for drug delivery applications.
MEDILAN™ USP MODIFIED is also ideal for ophthalmic use. MEDILAN™ ULTRA (Modified Lanolin USP) is an ultra‑pure
grade of medical lanolin. The product
is an odorless, white soft solid offering, with superior aesthetic properties
and low drag. MEDILAN™ ULTRA
complies with the USP Modified Lanolin monograph. PHARMALAN USP (Lanolin USP) is the traditional
pharmaceutical grade of lanolin and conforms to the requirements of the USP
monograph for Lanolin. Medical Grade Liquid Lanolin Liquid lanolin is that
fraction of the lanolin matrix that is liquid at typical ambient
temperatures. Consequently, it retains
the emollient and emulsification properties of lanolin itself, but in a liquid
form. There is no Pharmacopeia monograph for liquid lanolin, but LIQUID
MEDILAN™ and LIQUID MEDILAN™ ULTRA are high purity materials
suitable for topical pharmaceutical and dermatological applications. Clinical trials have demonstrated the safety
and suitability of our LIQUID MEDILAN™ products for severely compromised
skin2. Given
its exceptional purity, LIQUID MEDILAN™ complies with the low
pesticide limits of 1ppm. It conforms
to the maximum free lanolin alcohol limit of 3%, meaning it is suitable for use
on hypersensitive skin. LIQUID MEDILAN™ ULTRA is a Super Refined®
ultra-pure lanolin oil consisting of liquid lanolin sterol ester. Croda's Super Refining process yields an
odorless; almost water white, clear oily liquid and removes undesirable
non-polar components. LIQUID MEDILAN™ ULTRA, complies with
the pesticide limits of 1 ppm maximum. Clinical benefits of the Croda-Westbrook Medilan™ Product Range Bioequivalence
and Biocompatibility The intercellular lipids
of the epidermis form a structured, semi-permeable layer that helps control the
hydration level and barrier function of the skin. MEDILAN™ USP MODIFIED possesses a number of chemical and
physical similarities to human stratum corneum lipids. MEDILAN™ USP MODIFIED
and human skin lipids both contain cholesterol, fatty acids, fatty esters and
hydrocarbons and both exist in liquid and solid phases at skin
temperature. These similarities are one
reason MEDILAN™ USP MODIFIED is so effective as a moisturizing
emollient.
Freeze fracture SEM
studies have shown that MEDILAN™ USP MODIFIED consists of a mass of liquid crystalline material. Lamellar liquid crystals are of particular
interest since they are an essential structural component of the epidermis. In
cross‑polarized light microscopy studies, MEDILAN™ USP MODIFIED was
shown to form structures identical to the multi-lamellar vesicles formed by
stratum corneum lipids. It is well
known that the incorporation of ‘bound water' into the stratum corneum involves
the formation of multi-lamellar vesicles.3
Given
their chemical and physical similarities, MEDILAN™ USP MODIFIED is
highly compatible with human skin. The
absorption of MEDILAN™ USP MODIFIED into the human stratum corneum has
been demonstrated and quantified using tape stripping.4 In another
study using full-thickness human skin, electron opaque samples of MEDILAN™ USP
MODIFIED were topically applied and shown to penetrate the epidermis
as far as the stratum granulosum.
Hydration
and Emollience The moisturization properties of MEDILAN™ USP MODIFIED and lanolin itself are well documented3. MEDILAN™ USP MODIFIED spontaneously emulsifies water and can hold over 200% of its own weight of water, acting as an in vivo moisture reservoir to help maintain the hydration of the skin. In fact, the long-term emollient effect of MEDILAN™ USP MODIFIED is partly attributable to this secondary moisture reservoir that complements the epidermal water. MEDILAN™ USP MODIFIED provides pronounced and persistent emollience, lasting for more than eight hours after application1. Researchers have reported
on some of the beneficial effects of MEDILAN™ USP MODIFIED in
formulations. Petersen found that a product containing MEDILAN™ USP MODIFIED
provided skin hydration that was maintained for at least two days after
application, compared to the hydrating effect of petrolatum, which could not be
detected ten hours after application. The same MEDILAN™ USP MODIFIED formulation
was also found to be more effective than petrolatum in hydrating stratum
corneum, increasing the level by about 35%. 5
Barrier
Repair MEDILAN™ USP MODIFIED is known to create semi‑permeable (partially occlusive) films. Lanolin and lanolin oil films of ~ 50 μm in thickness have been shown to reduce the rate of transepidermal water loss (TEWL) by ~32 and 22%, respectively.6,7 The formation of semi permeable films is important in restoring barrier function and in wound healing. The ability of MEDILAN™ USP MODIFIED to help repair skin barrier function has been shown superior to ceramides. Elias et al3 have shown that the effect of 3% MEDILAN™ USP MODIFIED in an inert vehicle (i.e., propylene glycol and ethanol) is similar to that achieved by an optimized ratio of physiological lipids (ceramides, cholesterol and fatty acids). Further studies using 15% MEDILAN™ USP MODIFIED found the material to be nearly twice as effective as the physiological lipids. In the same study, the barrier restoring effects of MEDILAN™ USP MODIFIED were also found to be superior to those of glycerol and petrolatum3. Ideal
Wound Healing Environment Hydration plays an
important role in wound healing. Re-epithelialization, dermal repair and
angiogenesis are known to occur more rapidly under moist conditions.8
However, it has been reported that some moisturizers can interfere with normal
wound healing.9 Clinical studies have shown that MEDILAN™ USP
MODIFIED does not adversely interfere with the many
sensitive processes involved in full-thickness wound healing.10
What's more, MEDILAN™ USP MODIFIED possesses many of the attributes of
an "ideal wound dressing". MEDILAN™
USP MODIFIED can be easily applied to wound sites; it
acts as a barrier to secondary infection, allows bi‑directional vapors
permeability, provides thermal insulation, and is free of particulate and toxic
contaminants. Chvapil et al showed that a lanolin‑containing cream
increased the rate of epithelial healing by 35%, stating that it probably did
so by creating a moist wound-healing environment9. Purity standard
The methods employed in conventional lanolin refining are
designed to remove particulate matter, free lanolin acids, coloring species and
detergent residues. However, woolgrease contains pesticide residues due to
sheep being treated against parasitic attack. These pesticide residues are
highly lipophilic and, consequently, persist throughout the stages of
conventional lanolin refining. To
purify lanolin to the low pesticide grade that complies with the international
Pharmacopoeia, additional processing is required, such as what is done in the
manufacture of our MEDILAN™ USP MODIFIED
grades
and PHARMALAN USP. Croda-Westbrook pioneered low pesticide grades of lanolin, but no official limits for pesticides in lanolin were mandated until 1992 when the United States Pharmacopoeia modified its monograph for lanolin and set limits for 34 pesticides. The monograph requires that the concentration of no individual pesticide can exceed 10 ppm and the total pesticide concentration cannot exceed 40 ppm. The United States Pharmacopoeia also introduced a monograph entitled "Modified Lanolin" describing the specifications for a grade of lanolin; it considers suitable for use neat or in the "undiluted" form. This monograph includes limits for the same 34 pesticides but has a more stringent requirement that restricts the concentration of individual pesticides to no more than I ppm and the total pesticide concentration to no more than 3 ppm. In 2001, the European Pharmacopoeia introduced
pesticide residue limits to its monograph for Wool Fat. This requirement is
more exacting than that of the USP Modified Lanolin monograph, as it extends
the USP list of pesticides and imposes lower concentration limits. Applications
The Croda-Westbrook range of medical grade lanolin
offers a number of functional benefits to today's pharmaceutical and personal
care products. Our high purity lanolin can be used neat and in a variety of
formulation types, such as:
The MEDILAN™ range is highly recommended for the treatment of severely compromised and diseased skin, especially in drug delivery applications. Typical uses include:
THE
MEDILAN™ ULTRAS also find applications in personal care,
particularly in skin care where the product's aesthetics is of paramount
importance. PHARMALAN USP is typically used
in topical pharmaceuticals for human and animal health.
Further
information Samples and additional information on
Croda-Westbrook's range of medical grade lanolin may be obtained by contacting
your Croda representative or visiting the pharmaceutical section of our
website, www.crodausa.com.
References
1.
Medilan
Clinical Support Document, V 118, Croda Oleochemicals.
2.
Clinical
study to evaluate the suitability of the Medilan range for the treatment of
dermatological disorders, V 126, Croda Oleochemicals
3.
Udo
Hoppe, Ed, The Lanolin Book, Beiersdorf AG, Hamburg, 1999.
4.
Clark
EW, "Short term penetration of Lanolin into human stratum comeum.", J.,
Soc.-Cosmet.-Chem. 1992, 43, 219‑227.
5.
Peterson
EN, "The hydrating effect of a cream and white petrolatum measured by
optothermal infrared spectrometry in vivo". Acta‑ Derm. Venereol.
(Stockh), 1991, 71, 373‑376.
6.
Powers
DH, and Fox C. "A study of the effect of cosmetic ingredients, creams and
lotions on the rate of moisture loss from the skin"., Proc. Sci.
Toilet. Goods Assoc, 1957, 28, 21‑26.
7.
Spruit
D, "Interference of some substances with water vapour loss from human
skin". Amer. Perfurn. Cosmet., 1971, 86, 27‑32.
8.
Leow
Y‑H and Maibach HI, "Effect of occlusion on skin". J. Derm.
Treatments 1997, 8, 139‑142.
9.
Chvapil
M, Gaines JA, and Gilman T, "Lanolin and epidermal growth factor in healing
of partial pig wounds"J. Burn Care Rehab, 1988, 9 (3), 279‑284
10.
Steel I and Marks R, "The effect of lanolin on
wound healing in normal human volunteer subjects", Poster #342, American Academy
of Dermatology, Washington D.C., 1996
|
