Determination of residual acetone and acetone related impurities in drug product intermediates prepared as Spray Dried Dispersions (SDD) using gas chromatography with headspace autosampling (GCHS)

Spray dried solid dispersion of repaglinide using hypromellose acetate succinate: in vitro and in vivo characterization

OBJECTIVE

This research study attempted to develop spray-dried solid dispersion, to enhance the solubility of repaglinide, an antidiabetic drug.

SIGNIFICANCE

Aqueous solubility plays a major role in drug delivery because any chemical entity has to be in a dissolved state at the site of absorption, in order to get absorbed. Solid dispersion (SD) is one of the widely used techniques to enhance solubility and hence dissolution rate of poorly soluble drugs.

METHODS

Repagnilide, in hypromellose acetate succinate (HPMCAS) solution, was dried by spray drying to obtain spray-dried solid dispersion (SDSD). Plackett-Burman and Box-Behnken designs were used for screening formulation as well as process parameters, and optimization respectively. DSC, XRD, SEM were carried out to confirm the preparation of solid dispersion. SDSD was evaluated for in vitro dissolution, flow properties, Percentage yield and in vivo oral glucose tolerance test.

RESULT

Spray dried solid dispersion comprising (w/w) drug:polymer ratio of 1:3.82, 2.56% of aerosil and inlet temperature of 90 °C, corresponded to the best formulation obtained in this work. It showed t ₈₅% of less than 15 min and a significant reduction in blood glucose level in rats as compared to pure drug and marketed formulation.

CONCLUSION

Thus, it can be concluded that spray-dried solid dispersion prepared using HPMCAS is a useful technique for solubility and dissolution enhancement of repaglinide.

Recent strategies in spray drying for the enhanced bioavailability of poorly water-soluble drugs

Poorly water-soluble drugs are a significant and ongoing issue for the pharmaceutical industry. An overview of recent developments for the preparation of spray-dried delivery systems is presented. Examples include amorphous solid dispersions, spray dried dispersions, microparticles, nanoparticles, surfactant systems and self-emulsifying drug delivery systems. Several aspects of formulation are considered, such as pre-screening, choosing excipient(s), the effect of polymer structure on performance, formulation optimisation, ternary dispersions, fixed-dose combinations, solvent selection and component miscibility. Process optimisation techniques including nozzle selection are discussed. Comparisons are drawn with other preparation techniques such as hot melt extrusion, freeze drying, milling, electro spinning and film casting. Novel analytical and dissolution techniques for the characterization of amorphous solid dispersions are included. Progress in understanding of amorphous supersaturation or recrystallisation from solution gathered from mechanistic studies is discussed. Aspects of powder flow and compression are considered in a section on downstream processing. Overall, spray drying has a bright future due to its versatility, efficiency and the driving force of poorly soluble drugs.

Determination of Residual Solvents in Linezolid by Static Headspace GC

A headspace gas chromatographic method was developed for the determination of residual solvents in linezolid active substances. The solvents include petroleum ether (60-90°C), acetone, tetrahydrofuran, ethyl acetate, methanol, dichloromethane (DCM) and pyridine. The method showed the possibility to detect the tested solvents with a linear determination correlation coefficient (r) greater than 0.9995 except for petroleum ether (0.9980). The limits of detection ranged between 0.12 μg/mL (petroleum ether) and 3.56 μg/mL (DCM), and the limits of quantity ranged between 0.41 μg/mL (petroleum ether) and 11.86 μg/mL (DCM). The method achieved good accuracy (recoveries ranging from 92.8 to 102.5%) and precision for both run-to-run and day-to-day assay (relative standard deviation ranging from 0.4 to 1.3%) for all seven solvents concerned, which were applied in the quality control of three batches of linezolid successfully.