An Investigation for Skin Tissue Regeneration Enhancement/Augmentation by Curcumin-Loaded Self-Emulsifying Drug Delivery System (SEDDS)

Diabetes, one of the global metabolic disorders, is often associated with delayed wound healing due to the elevated level of free radicals at the wound site, which hampers skin regeneration. This study aimed at developing a curcumin-loaded self-emulsifying drug delivery system (SEDDS) for diabetic wound healing and skin tissue regeneration. For this purpose, various curcumin-loaded SEDDS formulations were prepared and optimized. Then, the SEDDS formulations were characterized by the emulsion droplet size, surface charge, drug content/entrapment efficiency, drug release, and stability. In vitro, the formulations were assessed for the cellular uptake, cytotoxicity, cell migration, and inhibition of the intracellular ROS production in the NIH3T3 fibroblasts. In vivo, the formulations' wound healing and skin regeneration potential were evaluated on the induced diabetic rats. The results indicated that, after being dispersed in the aqueous medium, the optimized SEDDS formulation was readily emulsified and formed a homogenous dispersion with a droplet size of 37.29 ± 3.47 nm, surface charge of -20.75 ± 0.07 mV, and PDI value of less than 0.3. The drug content in the optimized formulation was found to be 70.51% ± 2.31%, with an encapsulation efficiency of 87.36% ± 0.61%. The SEDDS showed a delayed drug release pattern compared to the pure drug solution, and the drug release rate followed the Fickian diffusion kinetically. In the cell culture, the formulations showed lower cytotoxicity, higher cellular uptake, and increased ROS production inhibition, and promoted the cell migration in the scratch assay compared to the pure drug. The in vivo data indicated that the curcumin-loaded SEDDS-treated diabetic rats had significantly faster-wound healing and re-epithelialization compared with the untreated and pure drug-treated groups. Our findings in this work suggest that the curcumin-loaded SEDDS might have great potential in facilitating diabetic wound healing and skin tissue regeneration.

Alprazolam and lorazepam single and multiple-dose effects on psychomotor skills and sleep

The effects of alprazolam 0.5 mg and lorazepam 2 mg on cognitive and psychomotor skills were assessed in twelve normal volunteer subjects in a randomised, double-blind, crossover design. Single and multiple dose effects were monitored using a battery of tests comprising critical flicker fusion threshold (CFFT), choice reaction time (CRT), simulated car tracking, and subjective ratings of perceived sedation (LARS) and of sleep behaviour (LSEQ). Compared with placebo baseline scores, treatment with lorazepam 2 mg (both single and multiple doses) resulted in a widespread impairment of CRT, tracking accuracy, and CFFT. Single doses of alprazolam 0.5 mg reduced CFFT with respect to the placebo baseline. Single and multiple dose treatment with both drugs resulted in subjective reports of sedation, a reduction of sleep onset latency, and improved sleep quality. Only lorazepam 2 mg significantly disrupted the integrity of behaviour on waking from sleep. These results suggest important pharmacodynamic differences between the two drugs in the doses used.

Psychopharmacological effects of vinpocetine in normal healthy volunteers

Twelve healthy female volunteers received pre-treatments with vinpocetine 10, 20, 40 mg and placebo (t.d.s.) for two days according to a randomised, double-blind crossover design. On the third day of treatment and 1 h following morning dosage, subjects completed a battery of psychological tests including Critical Flicker Fusion (CFF), Choice Reaction Time (CRT), Subjective Ratings of Drug Effects (LARS) and a Sternberg Memory Scanning Test. No statistically significant changes from placebo were observed on CFF, CRT or subjective ratings of drug effects. However, memory as assessed using the Sternberg technique was found to be significantly improved following treatment with vinpocetine 40 mg when compared to placebo and results suggested a localised effect of the drug on the serial comparison stage of the reaction process.

Effects of zopiclone and benzodiazepine hypnotics on search in short-term memory

The effects of zopiclone 7.5 mg in comparison to flunitrazepam 1 mg, triazolam 0.25 mg and lormetazepam 1 mg on stages of information processing in a memory-scanning task were investigated in 10 normal volunteers using a double-blind placebo-controlled cross-over design. Overall reaction times for the test were significantly increased 1 h following treatment with zopiclone, flunitrazepam and triazolam and in the morning following nighttime medication with flunitrazepam. The effects of zopiclone, flunitrazepam and triazolam were found to be located in the serial comparison and response-selection organization stages of the reaction process although both flunitrazepam and triazolam caused additional impairment of stimulus encoding.

The effects of benzodiazepines on short-term memory and information processing

The effects of flunitrazepam 1 mg, triazolam 0.25 mg, lormetazepam 1 mg and placebo on stages of information processing in a Sternberg memory scanning task were investigated in ten normal volunteers. Overall reaction times for the task were increased 1 h following treatment with triazolam and both 1 h and 10 h following treatment with flunitrazepam. Response latencies were not appreciably altered by lormetazepam or placebo. The effects of flunitrazepam and triazolam were found to be localised in the stimulus encoding and serial comparison stages of the reaction process and not in response-selection organisation.

The effects of zimeldine and amitriptyline on car driving and psychomotor performance

The development of an objective measure of car driving performance, brake reaction time (BRT), is described, and the effects of amitriptyline and zimeldine on this measure are compared in a placebo-controlled, acute, single dose, volunteer study. The effects of treatment on laboratory tests of critical flicker fusion (CFF) threshold, choice reaction time (CRT) and tracking accuracy and on self-assessments of sedation are also examined. At 2 hours post-treatment, amitriptyline produced a significant increase in brake reaction time when compared to both placebo and zimeldine. At 4 hours post-treatment, a significant reduction in "tracking accuracy" and a significant increase in CRT was observed after treatment with amitriptyline, while no such effects were seen with zimeldine. Measures of CFF threshold and self-ratings of sedation also revealed that amitriptyline produced a significant degree of sedation at 4 hours when compared to zimeldine and placebo. In contrast, zimeldine produced elevated CFF threshold, but did not affect self-ratings of sedation.

The effects of lormetazepam on aspects of sleep and early morning performance

Lormetazepam in a dose range 0.5-2.0 mg was given on a repeated dose regimen to a group of 12 healthy female volunteers in a double blind crossover design with each subject acting as her own control and receiving all 3 drug treatment conditions. There were no consistent or persistent effects noticed with 0.5 mg lormetazepam on tests of psychomotor function, performance and analogue rating scales for sleep and early morning behaviour. Lormetazepam 1 mg produced no significant effects on objective (CFF) or subjective measures (ARS) of sedation the morning following either acute or repeated dosing and had no effects on subjective ratings of sleep and early morning behaviour. Digit symbol substitution was impaired following acute doses of lormetazepam 1 mg. Evidence of a significant residual sedative effect was found on CFF and ARS ratings only after acute dosing with lormetazepam 2 mg. These sedative sequelae were not found after repeated doses of lormetazepam 2 mg although DSST scores were impaired. Lormetazepam 2 mg significantly improved sleep induction and sleep quality scores without impairing the ease of waking and the integrity of early morning behaviour. Lormetazepam 1 mg shows no residual sedative effect as measured by CFF and ARS, the morning following either acute or repeated doses.

The effects of midazolam in conjunction with alcohol on iconic memory and free-recall

The effects of midazolam 15 mg and alcohol 0.5 g/kg on short-term storage in the visual system (iconic memory) and free recall of a word list were investigated in 8 normal volunteers. Acute doses of midazolam, alcohol and midazolam in combination with alcohol were all found to decrease iconic memory whereas only midazolam and midazolam + alcohol impaired immediate recall. Anterograde amnesia was observed following treatment with midazolam and midazolam in conjunction with alcohol. The results suggest a potentiation of the effects of midazolam, on aspects of human memory by the co-administration of small doses of alcohol.