Development of NLCs and nanoemulsions with monoacyl-phospholipids and investigation of their skin penetration and influence on skin barrier structure in vitro and in vivo
Martin Wolf (PhD fellow sponsored by the PRC) – Department of Pharmaceutical Technology and Biopharmacy, University of Vienna
Mag. Dr. Victoria Klang – Department of Pharmaceutical Technology and Biopharmacy, University of Vienna
Phospholipids are main compounds of dermal formulations.1) In the present project, a set of monoacyl phospholipids (lyso lipids) will be used to prepare nanostructured lipid carriers (NLCs) and nanoemulsions (fluid and semi solid) with different amounts of monoacyl phosphatidylcholine.2)3) Their skin penetration and interaction as well as their influences on skin penetration of incorporated model drugs will be investigated. The penetration depth of the phospholipids directly being an indicator for skin irritation will be analyzed on porcine skin by attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy.4) As a final step, in vivo experiments on the forearms of test persons will be performed by the noninvasive RAMAN spectroscopy for the first time. Moreover, the impact of the phospholipids on skin hydration will be monitored by direct analysis of natural moisturizing factor (NMF). An in vitro/in vivo correlation will be acquired.
Benefit for the community
The results of the proposed work will contribute to the general knowledge in the field of dermal and transdermal drug delivery especially of phospholipids. Moreover, public relations work will be done, and new scientific contacts will be created by interdisciplinary networking. Thus, feedback will be collected from colleagues within this and related fields of research and this interdisciplinary exchange will stimulate new creative approaches towards scientific use of natural phospholipids in dermal formulations as well as for natural cosmetics.
Results and Outcome
The produced monoacyl phospholipid-based nanostructured lipid carriers and nanosized emulsion systems represent an interesting approach for incorporation of drugs with intermediate to slightly elevated HLB (hydrophilic/lipophilic balance) value. We found that an intermediate monoacyl phospholipid content of 65% w/w is most useful to obtain stable formulations with satisfying storage stability. During daily application such systems appear to affect in vivo skin properties by increasing TEWL (transepidermal water loss) values and lowering urea and NMF content. These observations indicate a temporarily impaired barrier function, which is however reversible within short time after cessation of the treatment. This effect might be advantageous since it could promote penetration of incorporated drugs from monoacyl phospholipid-based systems into the skin during the envisioned treatment period.
The use of natural and synthetic phospholipids as pharmaceutical excipients
Eur. J. Lipid Sci. Technol. 116, 1088-1107
Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) in cosmetic and dermatological preparations
Adv. Drug Del. Rev. 54, S131-S155
Nanostructured Lipid Carriers (NLC): The Second Generation of Solid Lipid Nanoparticles
In: Dragicevic N, Maibach H (eds) Percutaneous Penetration Enhancers Chemical Methods in Penetration Enhancement, Springer, Berlin, Heidelberg
Monitoring the Distribution of Surfactants in the Stratum Corneum by Combined ATR-FTIR and Tape-Stripping Experiments
Skin Pharmacol. Physiol. 28, 167-175
Distribution of phospholipid based formulations in the skin investigated by combined ATR-FTIR and tape stripping experiments
Int. J. Pharm. 519, 198-205
Monoacyl-phosphatidylcholine nanostructured lipid carriers: Influence of lipid and surfactant content on in vitro skin permeation of flufenamic acid and fluconazole
J. Drug Delivery Sci. Technol. 41, 419-430
Monoacyl-phosphatidylcholine based drug delivery systems for lipophilic drugs: Nanostructured lipid carriers vs. nano-sized emulsions
J. Drug Delivery Sci. Technol. 46, 490-497
NLC versus nanoemulsions: Effect on physiological skin parameters during regular in vivo application and impact on drug penetration
Int. J. Pharm. 549, 343-351