Lidocaine Transdermal Patch: Pharmacokinetic Modeling and In Vitro-In Vivo Correlation (IVIVC)

The present study aims to develop the correlation between in vitro and in vivo skin permeation of lidocaine in its transdermal patch. In order to minimize the run-to-run variability during in vitro skin permeation studies, release normalized cumulative percent (%Ct n) was calculated. A suitable polynomial mathematical model was used to establish a correlation between time and %Ct n. Percent in vivo absorbed was calculated by using numerical deconvolution (NDC) and non-compartmental analysis (NCA) methods. Pharmacokinetic (PK) parameters such as AUC last and C max were predicted with the established in vitro-in vivo correlation (IVIVC) models. The minimum prediction errors in NDC method for C max were found to be -30.9 and -25.4% for studies I (in vivo study in human volunteers with one batch of Lidoderm patch; internal validation) and II (in vivo study in human volunteers with another batch of Lidoderm patch; external validation), respectively, whereas minimum prediction errors in NCA method were relatively low (3.9 and 0.03% for studies I and II, respectively) compared to those in NDC method. The prediction errors for AUC last were found to be less than 2% for both methods and studies. The established method in this study could be a potential approach for predicting the bioavailability and/or bioequivalence for transdermal drug delivery systems.

Curcumin half analog modulates interleukin-6 and tumor necrosis factor-alpha in inflammatory bowel disease

BACKGROUND

The present study was aimed at examining the effect of dehydrozingerone (DHZ), half analogue of curcumin which is the active constituent of turmeric (Curcuma longa) in the di-nitrochlorobenzene (DNCB) induced model for inflammatory bowel disease (IBD).

MATERIALS AND METHODS

Male Wistar rats (200-220 g) were divided into four groups (n = 6). Chemical induction of IBD was done by sensitizing with 300 µL of 20 g/L of DNCB (in acetone) onto the nape of rats for 14 days followed by intra-colonic instillation of 250 µL of DNCB (0.1% DNCB in 50% alcohol) solution on day 15. Rats in Group 1 (normal control) and Group 2 (DNCB control) were treated with vehicle. Rats in Group 3 were treated with DHZ (100 mg/kg, p.o.; 8 days) and Group 4 animals were treated with sulfasalazine (SS) (100 mg/kg, p.o.; 8 days). On 24(th) day, the rats were killed, colon removed and the macroscopic, biochemical, and histopathological evaluations were performed.

RESULTS

The levels of myeloperoxidase, thiobarbituric acid reactive substrate, and nitrite increased significantly (P < 0.05) in the DNCB group whereas reduced significantly in the DHZ and SS treated groups. Serum nitrite levels were found to be insignificant between the different groups. Interleukin-6, tumor necrosis factor-alpha level was significantly high in the DNCB group.

CONCLUSION

These findings show that DHZ can be a promising molecule for the treatment of IBD.

Modulatory effects of sesamol in dinitrochlorobenzene-induced inflammatory bowel disorder in albino rats

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of gastrointestinal tract of immune, genetic and environmental origin. In the present study, we examined the effect of sesamol (SES), the main anti-oxidative constituent of Sesamum indicum (sesame seed) Linn. in the dinitrochlorobenzene (DNCB)-induced model for IBD in rats.

METHODS

The groups were divided into normal control, DNCB control, SES and sulfasalazine (SS). On day 24, the rats were killed, colon removed and the macroscopic, biochemical and histopathological evaluations were performed.

RESULTS

The levels of MPO, TBARS and nitrite increased significantly (p < 0.05) in the DNCB group, whereas reduced significantly in the SES, SS treated groups. Serum nitrite levels were found to be insignificant between the different groups. IL-6 and TNF-α levels were significantly high in the DNCB group.

CONCLUSIONS

We conclude the mucosal protective effect of SES on colon due to its potent antioxidant actions. Further investigation is required in a chronic model of different rodent strain for its role involved in the cytokine pathway.