Quantification of theophylline or paracetamol in milk matrices by high-performance liquid chromatography / 药物分析学报

A simple, accurate and sensitive high-performance liquid chromatography (HPLC) method was developed, validated and applied to the determination of either theophylline or paracetamol in milk-based samples. The method allowed drug quantification in fresh and powdered milk with a relatively short run time of analysis and it was also successfully applied to the quantification of the drugs in solid dosage forms intended for pediatric use. Moreover, the main significant advantages over other published works are the simplicity of the sample preparation, reduced assay time and sample loss. The method meets the International Conference on Harmonization guideline for analytical methods validation regarding specificity,linearity,accuracy,precision, specificity and robustness as required by health authorities and applied by industry while designing and marketing new drug products.The technique encompasses the separation of the analytes with a reverse phase C18column under isocratic conditions and UV detection at 272 nm and 243 nm,respectively,for theophylline and paracetamol. The lower limit of quantification for both drugs was determined as 0.2μg/mL and the between-batch accuracy was 99.7%.This HPLC method allows quantification of theophylline and paracetamol in milk matrices and it can be applied in the design,development and production of milk-based pediatric dosage forms.

An ultrastructural study of spermiogenesis in three species of Physalaemus (Anura, Leptodactylidae)

Ultrastructural aspects of spermiogenesis and testicular spermatozoa of three anuran amphibians, Physalaemus biligonigerus, P. fuscomaculatus and P. gracilis, were investigated by electron microscopy. The nuclei, middle pieces and tails of the three species were similar. In all cases, the nuclei were elongated and the acrosome consisted of a cone-shaped cap. The connecting pieces located in the flagellum implantation zone had transverse striations. The tails had a 9 + 2 axial filament pattern, a juxtaxonemal fiber and an undulating membrane. In contrast to other Leptodactylidae spermatozoa, no axial rod were observed in these Physalaemus species

Cytochemical localization of phosphatases in the germ- and Sertoli cells of Odontophrynus cultripes (Amphibia, Anura, Leptodactylidae)

Ultrastructural cytochemical techniques were used for the localization of phosphatases in spermatid and spermatozoon, as well as in Sertoli cells of Odontophrynus cultripes (Amphibia, Anura, Leptodactylidae). Acid phosphatase was found in the acrosome. Thiamine pyrophosphatase was observed in the Golgi cisternae and in the tail spermatozoon surface. Glucose-6-phosphatase was located in the membrane complex of the acrosomal region. Already, in the Sertoli cells acid phosphatase was located in the lysosomes and glucose-6-phosphatase was observed in association with the endoplasmic reticulum and Golgi complex. These observations support the idea that various phosphatases may play some role in spermatid differentiation and in the interactions germ cells--Sertoli cells during spermiogenesis process