Phenol Release from Petrolatum Ointments

J. D. Segers, J. L. Zatz and V. P. Shah, "In Vitro Release of Phenol from Ointment Formulations", Pharm. Tech., 21 (1), 70-81 (1997)

Abstract:

These studies were directed to development of practical, reliable methods for characterizing drug release from petrolatum ointments. The apparatus was a modification of the standard USP dissolution apparatus. Release slopes and diffusion coefficients were the same whether a membrane was present or not, confirming that the membrane did not limit transport. Standard deviations were lower with a membrane present. The method detected changes in drug concentration, formulation and manufacturing procedure. Table 1 shows the effect of cooling rate and mixing speed on the diffusion coefficient of phenol. All of the ointments had the same composition in this experiment.

Table 1. Effect of manufacturing method on phenol release from petrolatum ointments.

Manufacture Mean Diffusion Coefficient (cm2/h x 10000)

Slow cool, slow mix 2.53

Slow cool, fast mix 2.93

Fast cool, slow mix 3.89

Fast cool, fast mix 4.73

Table 1. Effect of manufacturing method on phenol release from petrolatum ointments.
Manufacture	Mean Diffusion Coefficient (cm2/h x 10000)
Slow cool, slow mix	2.53
Slow cool, fast mix	2.93
Fast cool, slow mix	3.89
Fast cool, fast mix	4.73

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