The objective of this study was to study and to analyze caffeine release from gel and
emulgel prepared from carbopol. The properties of the preparations were determined (e.g.
visual inspection, pH test, spreadability and in vitro release). The mech
anisms of caffeine
release were analyzed according to zero and first orders, and to Higuchi and Korsmeyer-
Peppas models. Results were analyzed statistically using student t-test.
The gels were transparent while emulgels were creamy, white and smooth. pH values
were suitable for dermal application and spreadability was not changed in both cases. On
the other hand, accumulated released amount of caffeine was decreased from emulgel in
comparison with the gel. The release pattern was in accordance with Higuchi equation and
n value referred that the diffusion was the main mechanism of release from the gel while
the relaxation and the erosion contributed importantly in the release of suspended caffeine
from emulgel.
The objective of this study was to prepare acceptable carbopol gels and to evaluate
the factors influencing the spreadability and release properties of a model hydrophilic
compound (caffeine). Results were analyzed statistically using student t-tes
t. The gels
were transparent at 1 and at 2% caffeine (with alcohol). Spreadability was decreased when
carbopol was increased and when caffeine quantity was changed (except at 2% carbopol).
Spreadability was affected statistically with change of cosolvent. Released caffeine
quantity (%) was increased with decreasing of carbopol quantity and increasing of caffeine
quantity introduced in the formula. Total caffeine quantity (%) was decreased with alcohol
presence. Caffeine release followed Higuchi pattern, e.g. diffusion was the principal
mechanism of caffeine release from these formulas.
