Crisp extruded snack food like products were produced from a range of cereal products using a short barrel, single screw snack food extruder. The retention of B group vitamins during extrusion processing was compared for the different cereal grains and under different extrusion conditions. This work showed that short barrel extruders used for snack food production retain between 44% and 62% of the B group vitamins. This is considerably higher than the 20% retention for maize reported previously for long barrel extruders. The stability of the vitamins was similar, with riboflavin and niacin having the highest stability. Pyridoxine was stable in maize, but less so in oats and the maize+pea ingredients. Thiamin was the least stable during extrusion. It is concluded that short term high-temperature cooking of extruded snacks allows the retention of higher levels of heat labile B vitamins than the longer time and lower temperature cooking methods used in modern snack food extruders.

A method was developed for determination of salicylic acid in anti-acne pharmaceutical preparations involving separation on a preadsorbent high performance thin layer chromatography (HPTLC) silica gel plate with fluorescent phosphor, detection by fluorescence quenching, and quantification by densitometric scanning. Salicylic acid was directly detected and quantified on the plate at levels as low as 1 mu g, and no interference was encountered from other ingredients in the medication formulations.The method was applied to the analysis of a commercial gel preparation with a label value of 2.0% salicylic acid, and an average value of 99.2% of theoretical was obtained (n=16). Accuracy was validated by analysis of a 10% benzoyl peroxide anti-acne gel spiked with 2% salicylic acid, and recovery averaged 100.0% (n=10). The coefficients of variation for the analyses were 3.9 and 5.6%, respectively. Advantages of the new HPTLC method are discussed.

A method was developed for determination of elemental sulfur in sulfur topical pharmaceutical preparations involving separation on a preadsorbent HPTLC silica gel plate with fluorescent phosphor, detection by fluorescence quenching, and quantification by densitometric scanning. Sulfur was directly detected and quantified on the plate at levels as low as 800 ng, and no interference was encountered from other ingredients in the medication formulations. The method was applied to the analysis of commercial liquid and cream preparations having respective label values of 5% and 8% sulfur, and recoveries averaged 99.3 and 99.5%. An unknown cream medication was assayed using the method and the accuracy of the result was validated by standard addition. All analyses were carried out with 5 or 6 replicates to evaluate precision, and coefficients of variation ranged from 2-4%.