Acetaminophen (paracetamol) is available in a wide range of oral formulations designed to meet the needs of the population across the age-spectrum, but for people with impaired swallowing, i.e. dysphagia, both solid and liquid medications can be difficult to swallow without modification. The effect of a commercial polysaccharide thickener, designed to be added to fluids to promote safe swallowing by dysphagic patients, on rheology and acetaminophen dissolution was tested using crushed immediate-release tablets in water, effervescent tablets in water, elixir and suspension. The inclusion of the thickener, comprised of xanthan gum and maltodextrin, had a considerable impact on dissolution; acetaminophen release from modified medications reached 12–50% in 30?min, which did not reflect the pharmacopeia specification for immediate release preparations. Flow curves reflect the high zero-shear viscosity and the apparent yield stress of the thickened products. The weak gel nature, in combination with high G' values compared to G'' (viscoelasticity) and high apparent yield stress, impact drug release. The restriction on drug release from these formulations is not influenced by the theoretical state of the drug (dissolved or dispersed), and the approach typically used in clinical practice (mixing crushed tablets into pre-prepared thickened fluid) cannot be improved by altering the order of incorporation or mixing method. 相似文献
Context: Most of the active pharmaceutical ingredients (APIs) suffer from a drawback of poor aqueous solubility. In addition to the same, some APIs show poor tabletting behavior creating problems in formulation development. Crystal engineering can be an efficient tool in rectification of such problems associated with the APIs. Thus present work deals with crystallization of ibuprofen (a model drug) onto the surface of dicalcium phosphate (DCP) particles using different techniques.
Objective: The objective of the present work was to prepare ibuprofen-loaded DCP particles and further to analyze them for compressibility and dissolution behavior.
Materials and methods: Various crystallization techniques such as solvent evaporation (SE), melt crystallization (MC), melt sonocrystallization (MSC), antisolvent crystallization (AC), and antisolvent sonocrystallization (ASC) were screened for the preparation of ibuprofen-loaded DCP. Products obtained from different techniques were analyzed for physicochemical, micromeritic and compression properties.
Results and discussion: ASC technique was found to be suitable for preparing directly compressible ibuprofen-loaded DCP particles. The change in the crystal habit (needle to plate shape) of ibuprofen and its crystallization in miniscular form onto the surface of DCP particles showed significant improvement in the dissolution rate and compression properties of ibuprofen due to an increase in specific surface area when compared with ibuprofen crystallized by other techniques. Additionally, the tablets prepared from ASC powder did not require binder since ibuprofen acted as melt binder during compression.
Conclusion: Directly compressible ibuprofen-loaded DCP particles can serve as an alternative for conventional ibuprofen tablets prepared by wet granulation technique. 相似文献
In this paper we design and implement the pseudo session initiation protocol (p-SIP) server embedded in each mobile node to provide the ad-hoc voice over Internet protocol (VoIP) services. The implemented p-SIP server, being compatible with common VoIP user agents, integrates the standard SIP protocol with SIP presence to handle SIP signaling and discovery mechanism in the ad-hoc VoIP networks. The ad-hoc VoIP signaling and voice traffic performances are analyzed using E-model R rating value for up to six hops in the implemented test-bed. We also conduct the interference experiments to imitate the practical ad-hoc VoIP environment. The analyzed results demonstrate the realization of ad-hoc VoIP services by using p-SIP server. 相似文献
As the first broad reform of the EU data protection legislation is being achieved, and notwithstanding EU institutions’ confident discourse, scepticism remains about the reform’s ability to safeguard the fundamental right to data protection in the face of evolving data processing techniques underlying so-called big data. Yet, one might wonder whether the cause for this difficulty should be ascribed mainly to technological progresses that the law finds it hard to deal with or rather to the policy choices embedded in the legal reform itself. Indeed, a new data protection enforcement model is being adopted, which relies heavily on risk assessment and management by the data controllers themselves. Likewise, data protection authorities see their supervisory role significantly weakened. These developments and the underlying rationality are discussed. Given the limitations of the risk-based approach as currently devised, we suggest that it be reappraised in consideration of risk regulatory experiences in other domains. 相似文献