Usalpharma: a cloud-based architecture to support quality assurance training processes in health area using virtual worlds.

This paper discusses how cloud-based architectures can extend and enhance the functionality of the training environments based on virtual worlds and how, from this cloud perspective, we can provide support to analysis of training processes in the area of health, specifically in the field of training processes in quality assurance for pharmaceutical laboratories, presenting a tool for data retrieval and analysis that allows facing the knowledge discovery in the happenings inside the virtual worlds.

Development of a Mucoadhesive Vehicle Based on Lyophilized Liposomes for Drug Delivery through the Sublingual Mucosa.

A pharmaceutical vehicle based on lyophilized liposomes is proposed for the buccal administration of drugs aimed at systemic delivery through the sublingual mucosa. Liposomes made of egg phosphatidylcholine and cholesterol (7/3 molar ratio) were prepared and lyophilized in the presence of different additive mixtures with mucoadhesive and taste-masking properties. Palatability was assayed on healthy volunteers. The lyophilization cycle was optimized, and the lyophilized product was compressed to obtain round and capsule-shaped tables that were evaluated in healthy volunteers. Tablets were also assayed regarding weight and thickness uniformities, swelling index and liposome release. The results proved that lyophilized liposomes in unidirectional round tablets have palatability, small size, comfortability and buccal retention adequate for sublingual administration. In contact with water fluids, the tablets swelled, and rehydrated liposomes were released at a slower rate than permeation efficiency determined using a biomimetic membrane. Permeability efficiency values of 0.72 ± 0.34 µg/cm2/min and 4.18 ± 0.95 µg/cm2/min were obtained for the liposomes with and without additives, respectively. Altogether, the results point to the vehicle proposed as a liposomal formulation suitable for systemic drug delivery through the sublingual mucosa.

Lyoprotective Effects of Mannitol and Lactose Compared to Sucrose and Trehalose: Sildenafil Citrate Liposomes as a Case Study.

The lyoprotective effects of mannitol and lactose have been evaluated in the production of sildenafil citrate liposomes. Liposomes were prepared by mixing the components under ultrasonic agitation, followed by a transmembrane pH gradient for remote drug loading. Mannitol and lactose, as compared to sucrose and trehalose, were used as the stabilizing agents, and different freeze-drying cycles were assayed. The remaining moisture and the thermal characteristics of the lyophilized samples were analyzed. Size, entrapment efficiency, biocompatibility, and cell internalization of original and rehydrated liposomes were compared. The type of additive did not affect the biocompatibility or cell internalization, but did influence other liposome attributes, including the thermal characteristics and the remaining moisture of the lyophilized samples. A cut-off of 5% (w/w) remaining moisture was an indicator of primary drying completion-information useful for scaling up and transfer from laboratory to large-scale production. Lactose increased the glass transition temperature to over 70 °C, producing lyoprotective effects similar to those obtained with sucrose. Based on these results, formulations containing liposomes lyophilized with lactose meet the FDA's requirements and can be used as a biocompatible and biodegradable vehicle for the pulmonary delivery of therapeutic doses of sildenafil citrate.

Recent advances in colon drug delivery systems.

As a result of its ability to target certain drugs and/or peptides to the colonic region for the treatment of several diseases while avoiding systemic absorption and potential side effects, colon drug delivery has become a field of research of growing interest. Developing new pharmaceutical formulations capable of reaching the colon requires a broad knowledge of natural and synthetic/semisynthetic polymers. Chitosan, polyethylene-oxide, hydroxypropyl methylcellulose, pectin, natural gums, alginates and polymethacrylates have shown promise when applied in the development of colon drug delivery systems, which range from classic formulation strategies such as tablets and capsules to more sophisticated approaches like nanosystems and integrated osmotic-like formulations. This work aims to bring together knowledge regarding the materials and processes used in the development of such pharmaceutical formulations, as well as to highlight recent advances in the field.

Enteric coating of oral solid dosage forms as a tool to improve drug bioavailability.

Enteric coating is a common procedure in the development of oral pharmaceutical dosage forms. The main advantage of enteric coating is that it protects the drug from acidic pH and enzymatic degradation in the stomach while protecting it from the undesirable effects of some drugs. There is certain controversy regarding the real influence of enteric coating on the bioavailability of many drugs. Various scientific articles have demonstrated an improvement in the extent of bioavailability of some drugs when enteric coating is used. In recent years, there have been many studies examining different formulation strategies for monolithic and multiparticulate systems, including different pharmaceutical oral dosage forms and delivery systems based on the combined use of enteric coating and other methods that improve the bioavailability of drugs administered orally. However, the real bioavailability, serum levels and therapeutic effect of these drugs may be influenced by gastrointestinal pH values, gastrointestinal environment, inter-individual or intra-individual variability in gastric emptying and gastrointestinal transit time, interpatient variability associated with the type of polymer used for enteric coating or other formulation variables. It deserves special attention to know the real influence of enteric coating on the bioavailability of new oral dosage forms.

Optimization of release kinetics from sustained-release formulations using model-independent pharmacokinetic simulation.

In the present work, a single model-independent approach was developed to optimize the release kinetics of drugs from sustained-release formulations, using stavudine (d4T) as a model drug. This approach is based on the pharmacokinetic simulation of drug plasma levels through a semiparametric approach of the input function and on convolution with an empirical polyexponential unit impulse response function. Input functions were evaluated using different zero-order and first-order release constants. Optimum drug release to obtain a specific pharmacokinetic profile was approached using target model-independent pharmacokinetic parameters such as C(max)(SS), C(min)(SS), t(max)(SS), and peak-trough fluctuations. A Monte Carlo simulation was performed to estimate the fractional attainment of d4T plasma concentrations over therapeutic d4T levels. Zero-order (K(0) = 4 mg/h) and first-order (K(1) = 0.05 h(-1)) release constants were optimal for the formulation of sustained-release d4T tablets, plasma concentrations within the therapeutic range being achieved.

Critical factors in the release of drugs from sustained release hydrophilic matrices.

Hydrophilic matrix systems are one of the most interesting drug delivery systems, and they are currently some of the most widely used to control the release rate of drugs. There are too much factors involved in drug release from hydrophilic matrix systems. The most important factors to be taken into account when developing a formulation based on hydrophilic matrices are the percentage, solubility and drug particle size; the type of polymer, the percentage incorporated, its degree of viscosity and the polymer particle size. Also important are the drug/polymer ratio and the amount of water entering the matrix. Other factors have been shown to be involved in the release of drugs, such as the percentage and mixtures of polymers and the dimensions of the matrix. The compression force is important among the formulation factors to the extent that it determines the amount of air trapped in the matrix. Knowledge of these factors involved in the release of the drugs is crucial for the optimal development of formulations based on hydrophilic systems.