ABSTRACT
Meloxicam [MLX] is a poorly water-soluble non steroidal anti-inflammatory drug [NSAID]. The main objective of the present work was to enhance the dissolution of MLX and thus its bioavailability by the aid of additives. The novelty of this work rises from the utilization of spray drying technology to produce micro particulates solid dispersion systems containing MLX in the presence of small amount of additives. Differential scanning calorimetry [DSC], Fourier transform infrared spectroscopy [FT-IR], and Scan Electron Microscope [SEM] were used for studying the physico-chemical and morphological properties of MLX samples. The dissolution of MLX samples was investigated in two different pH media. The morphology of MLX solid dispersion micro-particles was spherical in shape according to SEM. FT-IR profiles indicated that a complex was formed between MLX and the additives. DSC patterns of the MLX micro-particles suggested a reduction in the crystallinity of MLX and probability of presence of an interaction between MLX and the additives. The rate of dissolution of the spray-dried MLX enhanced as compared with the unprocessed MLX in both acidic and neutral media. It was found that 100% of the added MLX released within 5 min in phosphate buffer dissolution medium [pH 7.4] compared to that of the unprocessed MLX [15% in 60 min]. Such increase rate in the dissolution of the spray dried MLX could be attributed to the increase in wettability of MLX particles and the hydrophilic nature of the additives. The anti-inflammatory effect of the spray dried MLX was explored using formalin induced rat paw edema model. The spray-dried samples showed an increase in the anti-inflammatory activity of MLX as compared to the unprocessed MLX. This work reveals that the spray drying technique is suitable for preparation of micro-particles with improved dissolution and anti-inflammatory effect of MLX
Subject(s)
Thiazines , Drug Liberation , Anti-Inflammatory Agents , Thiazines/administration & dosageABSTRACT
Althrough a period of time extending from January to December 2001, fifty-one patients [32 males and 19 females] and of ages ranged from 2 months to 70 years were selectively included in our study for the clinical suspicion of posterior fossa space occupying lesions [SOL]. All patients submitted to full clinical assessment that was followed by a dual sitting radiologic work-up including CT scanning [using a Toshiba CT machine] and multiplanar MR imaging [using a Gyroscan MR machine] where comparison of the obtained CT and MR findings was performed depending on the proof obtained from final operative and histopathologic reports to assess the well-established role of the former [CT] to that of superadded latter procedure [MR] in the light of our experience in this respect. According to the histopathologic results, it was noted that cerebellar astrocytomas were the most frequent [18] ones representing 35.8% followed by 12 medulloblastomas [23.6%], 8 brain-stem gliomas [15.7%], 3 meningiomas [5.7%], 3 acoustic neuromas, 3 hemangioblastomas [5.7%], 2 ependymomas [3.9%] and 2 choroid plexus papillomas [CPPs] [3.9%]. It was noted that MR imaging has notably improved the tumour detectability regarding its borders and relation to the surrounding tissues that were sometimes improperly assessed on CT images due to petrous bones imaging artifacts and regarding its ability to detect the CSF seedlings of a tumour that was seen only on contrast-enhanced MR images in six of our patients due to its highest inherent resolution and soft tissue discrimination ability and to the unlimited multiplanar imaging capabilities, although detection of calcification is still a unique advantage of CT over MR imaging in this respect. In our study, the compared overall accuracy of MR to CT was 99.32% to 98.42% respectively. We concluded that when both procedures are available for usage, MR should be that of choice