The Fundamental Role of Lipids in Polymeric Nanoparticles: Dermal Delivery and Anti-Inflammatory Activity of Cannabidiol

This report presents a nanoparticulate platform for cannabidiol (CBD) for topical treatment of inflammatory conditions. We have previously shown that stabilizing lipids improve the encapsulation of CBD in ethyl cellulose nanoparticles. In this study, we examined CBD release, skin permeation, and the capability of lipid-stabilized nanoparticles (LSNs) to suppress the release of IL-6 and IL-8. The nanoparticles were stabilized with cetyl alcohol (CA), stearic acid (SA), lauric acid (LA), and an SA/LA eutectic combination (SALA). LSN size and concentration were measured and characterized by differential scanning calorimetry (DSC), in vitro release of loaded CBD, and skin permeability. IL-6 and IL-8 secretions from TNF-α-induced HaCaT cells were monitored following different LSN treatments. CBD released from the LSNs in dispersion at increasing concentrations of polysorbate 80 showed non-linear solubilization, which was explained by recurrent precipitation. A significant high release of CBD in a cell culture medium was shown from SALA-stabilized nanoparticles. Skin permeation was >30% lower from SA-stabilized nanoparticles compared to the other LSNs. Investigation of the CBD-loaded LSNs' effect on the release of IL-6 and IL-8 from TNF-α-induced HaCaT cells showed that nanoparticles stabilized with CA, LA, or SALA were similarly effective in suppressing cytokine release. The applicability of the CBD-loaded LSNs to treat topical inflammatory conditions has been supported by their dermal permeation and release inhibition of pro-inflammatory cytokines.

[Transdermal intoxication through broken opioid ampules : Accidental intoxication in a paramedic]

This article presents the case of an accidental transdermal opioid intoxication in a paramedic. During an ambulance flight mission for patient repatriation several ampules containing opioids were broken unnoticed inside the ampule kit in the outside pocket of the work trousers of the paramedic. He developed the typical clinical picture of opioid intoxication with clouding of consciousness, miosis, and respiratory depression. This necessitated continuous monitoring of vital signs as well as repetitive administration of naloxone under the improvised circumstances of a mission abroad.

Formulation study of topically applied lotion: in vitro and in vivo evaluation

INTRODUCTION

This article presents the development and evaluation of a new topical formulation of diclofenac diethylamine (DDA) as a locally applied analgesic lotion.

METHODS

To this end, the lotion formulations were formulated with equal volume of varying concentrations (1%, 2%, 3%, 4%; v/v) of permeation enhancers, namely propylene glycol (PG) and turpentine oil (TO). These lotions were subjected to physical studies (pH, viscosity, spreadability, homogeneity, and accelerated stability), in vitro permeation, in vivo animal studies and sensatory perception testing. In vitro permeation of DDA from lotion formulations was evaluated across polydimethylsiloxane membrane and rabbit skin using Franz cells.

RESULTS

It was found that PG and TO content influenced the permeation of DDA across model membranes with the lotion containing 4% v/v PG and TO content showed maximum permeation enhancement of DDA. The flux values for L4 were 1.20±0.02 μg.cm(-2).min(-1) and 0.67 ± 0.02 μg.cm(-2).min(-1) for polydimethylsiloxane and rabbit skin, respectively. Flux values were significantly different (p < 0.05) from that of the control. The flux enhancement ratio of DDA from L4 was 31.6-fold and 4.8-fold for polydimethylsiloxane and rabbit skin, respectively. In the in vivo animal testing, lotion with 4% v/v enhancer content showed maximum anti-inflammatory and analgesic effect without inducing any irritation. Sensatory perception tests involving healthy volunteers rated the formulations between 3 and 4 (values ranging between -4 to +4, indicating a range of very bad to excellent, respectively).

CONCLUSION

It was concluded that the DDA lotion containing 4% v/v PG and TO exhibit the best performance overall and that this specific formulation should be the basis for further clinical investigations.

Development and evaluation of α-asarone transdermal patches based on hot-melt pressure-sensitive adhesives

A hot-melt, pressure-sensitive adhesive (HMPSA) based on styrene-isoprene-styrene was prepared, and its compatibility with various transdermal penetration enhancers was investigated. The effect of penetration enhancers on the adhesion properties of HMPSA was also studied. A drug-in-adhesive patch was formulated using α-asarone as a model drug, and penetration enhancers were screened by an in vitro transdermal study across excised pig skin. The pharmacokinetics in rabbits was also studied. The results show that HMPSA was miscible with most penetration enhancers (azone, menthol, isopropyl myristate, 1-methyl-pyrrolidinone, N,N-dimethylformamide, oleic acid), apart from propylene glycol. Penetration enhancers had a plasticizer-like effect that decreased the peel strength and shear strength of HMPSA. A combination of 1% oleic acid and 4% menthol had the highest in vitro penetration rate and was selected for patch preparation. The patch formulation was optimized by replacing some of the plasticizer by penetration enhancers to achieve good adhesion and effective transdermal flux. The final patch showed a high efficiency, with a relative bioavailability of 1,494%. This suggests that HMPSA may be a promising material for drug-delivery patches.

Sucrose esters as natural surfactants in drug delivery systems--a mini-review

Sucrose esters (SEs) are widely used in the food and cosmetic industries and there has recently been great interest in their applicability in different pharmaceutical fields. They are natural and biodegradable excipients with well-known emulsifying and solubilizing behavior. Currently the most common pharmaceutical applications of SEs are for the enhancement of drug dissolution and drug absorption/permeation, and in controlled-release systems. Although the number of articles on SEs is continuously increasing, they have not yet been widely used in the pharmaceutical industry. The aim of this review is to discuss and summarize some of the findings and applications of SEs in different areas of drug delivery. The article highlights the main properties of SEs and focuses on their use in pharmaceutical technology and on their regulatory and toxicological status.

Status of surfactants as penetration enhancers in transdermal drug delivery

Surfactants are found in many existing therapeutic, cosmetic, and agro-chemical preparations. In recent years, surfactants have been employed to enhance the permeation rates of several drugs via transdermal route. The application of transdermal route to a wider range of drugs is limited due to significant barrier to penetration across the skin which is associated with the outermost stratum corneum layer. Surfactants have effects on the permeability characteristics of several biological membranes including skin. They have the potential to solubilize lipids within the stratum corneum. The penetration of the surfactant molecule into the lipid lamellae of the stratum corneum is strongly dependent on the partitioning behavior and solubility of surfactant. Surfactants ranging from hydrophobic agents such as oleic acid to hydrophilic sodium lauryl sulfate have been tested as permeation enhancer to improve drug delivery. This article reviews the status of surfactants as permeation enhancer in transdermal drug delivery of various drugs.

Effect of menthol on the penetration of tobacco carcinogens and nicotine across porcine oral mucosa ex vivo

INTRODUCTION

Menthol is a flavored tobacco additive claimed to mask the bitter taste and reduce the harshness of cigarette smoke. (Azzi, C., Zhang, J., Purdon, C. H., Chapman, J. M., Nitcheva, D., Hebert, J. R., et al., 2006, Permeation and reservoir function of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo[a]pyrene (B[a]P) across porcine esophageal tissue in the presence of ethanol and menthol. Carcinogenesis, 27, 137-145). have shown that menthol increased the flux of tobacco carcinogens (TC) across porcine esophagus. As oral mucosa is exposed to both smoke and smokeless tobacco in tobacco users, the objective of this study was to determine whether menthol influenced the penetration of the TC nitrosonornicotine (NNN) across porcine buccal (BM) and floor of mouth (FM) mucosa.

METHODS

Porcine BM and FM were collected at slaughter, mounted in perfusion chambers (n = 7/group), and exposed to tritiated NNN ((3)H-NNN; Amersham, activity 1 muCi/ml) and tritiated nicotine ((3)H-nicotine; Sigma) in 3% nicotine/phosphate-buffered saline (0.01 M, pH 7.4) containing 0.01% unlabeled NNN (National Cancer Institute Chemical Carcinogen Repository) +/- 0.08% menthol for 0.5, 1, 2, or 12 hr. K(p) values (cm/min) were determined and statistically analyzed (analysis of variance, Tukey's, p < .05).

RESULTS

FM and BM permeability to both (3)H-NNN and (3)H-nicotine was significantly increased (p < .05) with addition of menthol over that of nicotine alone regardless of exposure times. Even short 30-min menthol exposure significantly increased the flux of both compounds, and this was maintained throughout the experiment.

DISCUSSION

Menthol enhances penetration of NNN and nicotine through FM and BM in vitro, even after short exposure. This may reflect loading of a superficial epithelial reservoir (Squier, C. A., Kremer, M. J., Bruskin, A., Rose, A., & Haley, J. D., 1999. Oral mucosal permeability and stability of transforming growth factor beta-3 in vitro. Pharmaceutical Research, 16, 1557-1563.), thus delivering menthol and enhancing flux for several hours. Practical implications are for a potentially increased oral exposure to carcinogens among users of menthol-flavored cigarettes and chewing tobacco.