Advanced Transdermal Drug Delivery (Franz Cells) Experiment

This lab report details an experiment on advanced transdermal drug delivery, focusing on in vitro drug release using Franz cells. The introduction highlights the advantages of transdermal drug delivery over conventional methods, including improved patient compliance and avoidance of first-pass metabolism. The discussion covers the mechanisms of drug absorption through the skin, including keratin package, intercellular absorption, and appendage absorption, and the use of in vitro methods to measure chemical infiltration. The report includes instructions for preparing an ibuprofen calibration curve and using a spectrophotometer to measure absorbance. The experiment aims to understand the principles of drug release studies using a membrane barrier, distinguish between rate-limiting and semi-permeable membranes, and analyze experimental data using mathematical expressions. Factors influencing drug release from solutions and semi-solid states are also discussed, with an emphasis on the physical and chemical properties of both the drug and the vehicle. This comprehensive report provides a detailed overview of the experimental setup, procedures, and analysis related to transdermal drug delivery.

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Advanced Transdermal Drug Delivery
Name
Institutional Affiliation

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Introduction
Transdermal and dermal drug delivery aids as an attractive substitute to
conventional therapy in avoiding problems like meager patient compliance, 1st
pass metabolism and side effects. It is also beneficial over hypodermic injections
that is very painful, pose disease transmission risks by needle use and generation
of hazardous medical wastes. In additional the system is non-invasive thus, self-
administered. Transdermal system is generally cheap and provides release for
long time up to 1 week. In developing appropriate application formulation, there
is a robust requirement and validation in vitro models and techniques that enables
accurate prediction of drug’s fate in vivo. Data reproduced on percutaneous
human absorption is required in predicting systemic risk from chemical exposure
such as cosmetic ingredient and agrochemicals. In the common practices, the
percutaneous absorption does not contribute a meaningfully total bioavailability.
Skin absorption determination is considered as human risk evaluation (Zhan,
2015).
Many drugs applied to the surface of the skin penetrates to some range into layers
of the skin, where there impacts are expected. Transdermal formulation
discharges drugs that infiltrate through the skin into systemic circulation (Baert,
2010). Significant drug concentrations are absorbed to active plasma
concentration. Drug permeation is targeted to some body parts close to action site
example, blood vessels, articulation and the muscles. Cutaneous absorption
characterizes the total amount of drug that penetrates the skin (Andrew, 2013).
Discussion

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Chemicals are transported through the skin in three main mechanism of
absorption which includes, keratin package, intercellular absorption and
appendage absorption. Keratin package occurs during transcellular fascination of
chemicals and partitioned to and out of cell membrane. Chemical permeation
through stratum corneum is a diffusion practice in which process of active
transport does not involve. High resistant layer to diffusion is rate-limiting
membrane (Ashtikar & Matthaus, 2013).
Vitro method is used in measuring the infiltration of chemicals into and
successive infusion across the skin to fluid reservoir. Receptor fluid have
sufficient capacity to solubilize substance tested which is kept in contact with skin
(under side) from application time to the end of receptor fluid collection. Static
cell receptor fluid is well stirred and the composition of receptor fluid stability
and solubility is investigated. For long-term infusion of skin experiment, there is
need for the addition of sodium azide (preservative). Assessing the skin
preparation makes a visual investigation of physical damage. Time of exposure
reflects use conditions, which varies from few minutes to a maximum of 24 hours
(Pannatier, 2014).
Ibuprofen Calibration Curve
1) Use the provided ibuprofen stock solution (1 mg/mL) to prepare standards for the
ibuprofen calibration curve. First dilute this stock solution 1 in 10 to produce a
solution containing 100 μg/mL (Novotn, 2011).
Calculation

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Equation of the curve y=0.0071 x
Where y -OD @ 272nm and x -Ibuprofen concentration
at concentration of 100 μ g
mL OD valuescan be calculated ¿ the equation
y=0.0071 x 100
¿ 0.71 @272 nm
2) From this, prepare standard solutions with the following concentrations:
a) 80 μ g
mL
y=0.0071 x 80
¿ 0. 57 @272 nm
b) 60 μg /mL
y=0.0071 x 60
¿ 0. 43 @272 nm
c) 40 μg /mL
y=0.0071 x 40
¿ 0. 28 @272 nm
d) 20 μg /mL
y=0.0071 x 20
¿ 0. 14 @272 nm
e) 10 μg /mL
y=0.0071 x 10
¿ 0. 07 @272 nm
f) 5 μg /mL
y=0.0071 x 5

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¿ 0. 04 @272 nm
3) Use the Franz cell medium as a blank for absorption readings at 272 nm.
The vertical diffusion cell is used for reproducible test for measure of vitro drug
discharge from ointments, gels and creams. The test is applied to membrane
through top chamber-donor section.
4) Use the spectrophotometer to measure absorbance for each of these standard solutions at
272nm.
Here the absorbance standard equation is used which is A=εx │ xc ,
Wherea−amount of light absorbed by the sample for agiven wavelength,
ε −molar a bsorptivity ,
│−distance that light travels through the solution∧¿
c−concentrationof t h e absorbing species per unit volume

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References
Andrew, J. P. (2013). Transdermal delivery of molecules is limited by full epidermis, not just
stratum corneum. Pharm. Res, 1099-109.
Ashtikar, & Matthaus, S. (2013). Non-invasive depth profile imaging of the stratum corneum
using confocal Raman microscopy. Eur. J. Pharm. Sci, 601-608.
Baert, D. S. (2010). Quality analytics of Internet pharmaceuticals. Anal. Bioanal. Chem, 125-36.
Novotn, K. ,. (2011). Ammonium carbamates as highly activ e transdermal permeation enhancers
with a d ual mechanism of action. J. Control. Release, 164-70.
Pannatier, J. n. (2014). The skin as a drug metabolizing organ. Drug Metab, 319-343.
Zhan, M. C. (2015). Formulation and evaluation of transdermal drug-delivery system of
isosorbide dinitrate. Braz. J. Pharm. Sci, 373-382.