Formulation M5 (12.5% w/w menthol), prepared using Apifil, showed the highest in vitro permeability of BRB, hence this formulation was selected for skin-irritation and anti-inflammatory studies.
The skin-irritation test of Formulation M5 resulted in a score of less than 2 (see Table IV). Compounds that have scores
of 2 or less are considered to be nonirritants (21). Hence, both types of topical cream formulations may be categorized as
Table IV: Skin irritation scores following topical berberine-hydrochloride cream application.
The results of anti-inflammatory activity studies after topical application are reported in Table V. For the control formulation,
the paw volume increases arithmetically with time. Formulation M5 and the standard diclofenac gel formulation showed better
reduction in paw-volume measurement than did the control formulation. Statistical analysis showed that the edema inhibition
of Formulation M5 and the standard diclofenac gel formulation were much better than that of the control group (P < 0.05).
However, there was no statistical difference between the anti-inflammatory effects of formulation M5 or the standard diclofenac
gel (P >0.05).
Table V: Anti-inflammatory activity of different topical gel formulations of berberine hydrochloride.
Topical applications have a great potential as an effective and safe way to administer BRB for local antimicrobial and anti-inflamatory
effects. An antimicrobial study of a prepared cream formulation of BRB indicated good antibacterial activity against S. aureus and antifungal effect against C. albicans. An in vitro permeation study using rat epidermal membranes and anti-inflammatroy studies by the carrageenan-induced rat-paw edema method
showed that menthol enhanced the transdermal absorption of BRB formulations based on aqueous cream BP. The topical-cream formulations
of BRB developed in this study have great utility and are a viable option for the effective and controlled management of inflammation
and skin infections caused by S. aureus and C. albicans.
Nikunjana A. Patel* is an assistant professor in the department of pharmacognosy, Natvar J. Patel is a principal, Rakesh P. Patel is an associate professor, and Rakesh K. Patel is a professor, all at S.K. Patel College of Pharmaceutical Education and Research, Ganpat University, Kherva, 382711 Mehsana,
Gujarat, India, fax +91 2762 286082, firstname.lastname@example.org
*To whom all correspondence should be addressed.
Submitted: Feb. 20, 2009. Accepted: Mar. 23, 2009.