Effects of Breed, Season, Temperature, and Solvents on the Permeability of Frozen and Reconstituted Cattle Skin to Levamisole

Pitman, Ian H.; Rostas, Susan J.; Downes, Leanne M.

doi:10.1002/jps.2600720304

Cited by 7 publications

(7 citation statements)

References 8 publications

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“…This may be explained due to seasonal variation in skin permeability [21–23]. Therefore, only pig skin batches that yielded low negative control ERs were utilized in this study (i.e.…”

mentioning

confidence: 99%

Fluorescent penetration enhancers for transdermal applications

Seto

Polat

VanVeller

et al. 2012

Journal of Controlled Release

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Chemical penetration enhancers are often used to enhance transdermal drug delivery. However, the fundamental mechanisms that govern the interactions between penetration enhancers and skin are not fully understood. Therefore, the goal of this work was to identify naturally fluorescent penetration enhancers (FPEs) in order to utilize well-established fluorescence techniques to directly study the behavior of FPEs within skin. In this study, 12 fluorescent molecules with amphiphilic characteristics were evaluated as skin penetration enhancers. Eight of the molecules exhibited significant activity as skin penetration enhancers, determined using skin current enhancement ratios. In addition, to illustrate the novel, direct, and non-invasive visualization of the behavior of FPEs within skin, three case studies involving the use of two-photon fluorescence microscopy (TPM) are presented, including visualizing glycerol-mitigated and ultrasound-enhanced FPE skin penetration. Previous TPM studies have indirectly visualized the effect of penetration enhancers on skin by using a fluorescent dye to probe the transdermal pathways of the enhancer. These effects can now be directly visualized and investigated using FPEs. Finally, future studies are proposed for generating FPE design principles. The combination of FPEs with fluorescence techniques represents a useful novel approach for obtaining physical insights on the behavior of penetration enhancers within skin.

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“…This may be explained due to seasonal variation in skin permeability [21–23]. Therefore, only pig skin batches that yielded low negative control ERs were utilized in this study (i.e.…”

mentioning

confidence: 99%

Fluorescent penetration enhancers for transdermal applications

Seto

Polat

VanVeller

et al. 2012

Journal of Controlled Release

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“…The apparent diffusion coefficient ( D app , cm 2 /h) was estimated according to the following equation (Pitman et al. , 1983; Henning et al.…”

Section: Methodsmentioning

confidence: 99%

“…where, J is the flux as mentioned above (ng ⁄ h) and C i is drug concentration at the beginning of the experiment in the donor chamber (ng ⁄ mL) (Organisation for Economic Co-operation and Development (OECD), 2004). The apparent diffusion coefficient (D app , cm 2 ⁄ h) was estimated according to the following equation (Pitman et al, 1983;Henning et al, 2009):…”

Section: Kinetic and Statistical Analysesmentioning

confidence: 99%

Comparative in vitro characterization of moxidectin and doramectin percutaneous absorption through bovine skin

Sallovitz

Nejamkin

Lifschitz

et al. 2011

Vet Pharm & Therapeutics

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Topical formulations have achieved worldwide acceptance in veterinary medicine because their administration is an easy, less labor-intensive and nonstressing form. Any chemical compound that comes in contact with the skin has the potential to be locally and/or systemically absorbed. However, many factors related to the features of animal skin, composition of the topical formulation and to the drug itself can determine marked differences in the percutaneous absorption process. The aim of the current work was to characterize the pattern of in vitro percutaneous absorption for moxidectin (MXD) and doramectin (DRM), two of the most worldwide used topical macrocyclic lactone antiparasitic compounds in cattle. The work included the development of a simple and inexpensive in vitro assay useful to predict in vivo drug percutaneous absorption in cattle. Both drugs were administered as the commercial formulations intended for their topical administration to cattle. The in vitro studies were carried out using modified Franz-type vertical diffusion cells. Cattle skin slices of 500 μm thickness were prepared using a dermatome to separate the stratum corneum and upper epidermis from dermis and subcutaneous tissue. The receptor medium was sampled up to 72 h postadministration and drug concentrations were measured by HPLC. The parameters used to estimate the comparative in vitro skin permeation showed marked differences between DRM and MXD. A 5.29-fold longer lag time (T(lag)) was observed for DRM. Similarly, the flux (J) (2.93-fold) and the permeation coefficients (K(p) ) (2.95-fold) in cattle skin were significantly higher (P < 0.05) for DRM compared to those obtained for MXD. Additionally, the data obtained from the in vitro permeation studies was correlated with the plasma concentrations of both compounds achieved in vivo in cattle treated with the same topical formulations. Correlation coefficients between percentage of drug permeated in vitro vs. percentage of drug absorbed in vivo (up to 48 h post-treatment) were 0.856-0.887 (MXD) and 0.976-0.990 (DRM). However, the highest in vitro-in vivo correlations for both molecules were observed up to 24 h post-treatment A rapid screening method for testing different topical formulations can be achieved with the simple in vitro cattle skin permeation technique described here, which has been successfully adapted to test the comparative percutaneous absorption of MXD and DRM.

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“…, 2011). Hence, absorptive behavior of the skin in any individual animal may present additional interindividual variation depending on the anatomical region and the physiological status of the skin (particularly when considering weather conditions) (Pitman et al. , 1983).…”

Section: Within‐subject Variability In the Disposition Of Pour‐on Formentioning

confidence: 99%

“…Even though the skin sections used for in vitro experiments were obtained from the same animal and anatomical region (withers), flux values showed a large variability (84% for MOX and 81% for DOR) (Sallovitz et al, 2011). Hence, absorptive behavior of the skin in any individual animal may present additional interindividual variation depending on the anatomical region and the physiological status of the skin (particularly when considering weather conditions) (Pitman et al, 1983).…”

Section: Within-subject Variability In the Disposition Of Pour-on Formentioning

confidence: 99%

Should licking behavior be considered in the bioavailability evaluation of transdermal products?

Toutain

Modrić

Bousquet‐mélou

et al. 2012

Vet Pharm & Therapeutics

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Antiparasitic drugs, and especially macrocyclic lactones (MLs), are often formulated as pour-on products because of their ease of administration, convenience, and reduction of stress in treated animals. However, because of self- and allo-grooming, much of a drug administered transdermally may be systemically absorbed via the oral route, creating highly variable pharmacokinetic and pharmacodynamic response in treated (and untreated) animals. Testing bioequivalence (BE) of pour-on drugs in cattle under laboratory conditions (with restricted licking) ignores a major factor of drug disposition of these drugs and thus fails to predict therapeutic equivalence in the target population under clinical conditions of use. Therefore, the interanimal and intra-animal variability associated with licking behavior should be considered as a biological fact, rather than a noise that needs to be reduced or eliminated. As a result, it is recommended that the BE testing for pour-on products in cattle be conducted by evaluating both the mean and distribution of bioavailability parameters between the reference and test products when animals are not prevented from allo- and self-licking.

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Effects of Breed, Season, Temperature, and Solvents on the Permeability of Frozen and Reconstituted Cattle Skin to Levamisole

Cited by 7 publications

References 8 publications

Fluorescent penetration enhancers for transdermal applications

Fluorescent penetration enhancers for transdermal applications

Comparative in vitro characterization of moxidectin and doramectin percutaneous absorption through bovine skin

Should licking behavior be considered in the bioavailability evaluation of transdermal products?

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