Comparison of cyclosporin A pharmacokinetics of a new microemulsion formulation and standard oral preparation in patients with psoriasis

Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis

BACKGROUND

Psoriasis is an immune-mediated disease with either skin or joints manifestations, or both, and it has a major impact on quality of life. Although there is currently no cure for psoriasis, various treatment strategies allow sustained control of disease signs and symptoms. The relative benefit of these treatments remains unclear due to the limited number of trials comparing them directly head-to-head, which is why we chose to conduct a network meta-analysis.

OBJECTIVES

To compare the efficacy and safety of non-biological systemic agents, small molecules, and biologics for people with moderate-to-severe psoriasis using a network meta-analysis, and to provide a ranking of these treatments according to their efficacy and safety.

SEARCH METHODS

For this update of the living systematic review, we updated our searches of the following databases monthly to October 2021: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of systemic treatments in adults over 18 years with moderate-to-severe plaque psoriasis, at any stage of treatment, compared to placebo or another active agent. The primary outcomes were: proportion of participants who achieved clear or almost clear skin, that is, at least Psoriasis Area and Severity Index (PASI) 90; proportion of participants with serious adverse events (SAEs) at induction phase (8 to 24 weeks after randomisation).

DATA COLLECTION AND ANALYSIS

We conducted duplicate study selection, data extraction, risk of bias assessment and analyses. We synthesised data using pairwise and network meta-analysis (NMA) to compare treatments and rank them according to effectiveness (PASI 90 score) and acceptability (inverse of SAEs). We assessed the certainty of NMA evidence for the two primary outcomes and all comparisons using CINeMA, as very low, low, moderate, or high. We contacted study authors when data were unclear or missing. We used the surface under the cumulative ranking curve (SUCRA) to infer treatment hierarchy, from 0% (worst for effectiveness or safety) to 100% (best for effectiveness or safety).

MAIN RESULTS

This update includes an additional 19 studies, taking the total number of included studies to 167, and randomised participants to 58,912, 67.2% men, mainly recruited from hospitals. Average age was 44.5 years, mean PASI score at baseline was 20.4 (range: 9.5 to 39). Most studies were placebo-controlled (57%). We assessed a total of 20 treatments. Most (140) trials were multicentric (two to 231 centres). One-third of the studies (57/167) had high risk of bias; 23 unclear risk, and most (87) low risk. Most studies (127/167) declared funding by a pharmaceutical company, and 24 studies did not report a funding source. Network meta-analysis at class level showed that all interventions (non-biological systemic agents, small molecules, and biological treatments) showed a higher proportion of patients reaching PASI 90 than placebo. Anti-IL17 treatment showed a higher proportion of patients reaching PASI 90 compared to all the interventions, except anti-IL23. Biologic treatments anti-IL17, anti-IL12/23, anti-IL23 and anti-TNF alpha showed a higher proportion of patients reaching PASI 90 than the non-biological systemic agents. For reaching PASI 90, the most effective drugs when compared to placebo were (SUCRA rank order, all high-certainty evidence): infliximab (risk ratio (RR) 50.19, 95% CI 20.92 to 120.45), bimekizumab (RR 30.27, 95% CI 25.45 to 36.01), ixekizumab (RR 30.19, 95% CI 25.38 to 35.93), risankizumab (RR 28.75, 95% CI 24.03 to 34.39). Clinical effectiveness of these drugs was similar when compared against each other. Bimekizumab, ixekizumab and risankizumab showed a higher proportion of patients reaching PASI 90 than other anti-IL17 drugs (secukinumab and brodalumab) and guselkumab. Infliximab, anti-IL17 drugs (bimekizumab, ixekizumab, secukinumab and brodalumab) and anti-IL23 drugs (risankizumab and guselkumab) except tildrakizumab showed a higher proportion of patients reaching PASI 90 than ustekinumab and three anti-TNF alpha agents (adalimumab, certolizumab and etanercept). Ustekinumab was superior to certolizumab; adalimumab and ustekinumab were superior to etanercept. No significant difference was shown between apremilast and two non-biological drugs: ciclosporin and methotrexate. We found no significant difference between any of the interventions and the placebo for the risk of SAEs. The risk of SAEs was significantly lower for participants on methotrexate compared with most of the interventions. Nevertheless, the SAE analyses were based on a very low number of events with low- to moderate-certainty for all the comparisons (except methotrexate versus placebo, which was high-certainty). The findings therefore have to be viewed with caution. For other efficacy outcomes (PASI 75 and Physician Global Assessment (PGA) 0/1), the results were similar to the results for PASI 90. Information on quality of life was often poorly reported and was absent for several of the interventions.

AUTHORS' CONCLUSIONS

Our review shows that, compared to placebo, the biologics infliximab, bimekizumab, ixekizumab, and risankizumab were the most effective treatments for achieving PASI 90 in people with moderate-to-severe psoriasis on the basis of high-certainty evidence. This NMA evidence is limited to induction therapy (outcomes measured from 8 to 24 weeks after randomisation), and is not sufficient for evaluating longer-term outcomes in this chronic disease. Moreover, we found low numbers of studies for some of the interventions, and the young age (mean 44.5 years) and high level of disease severity (PASI 20.4 at baseline) may not be typical of patients seen in daily clinical practice. We found no significant difference in the assessed interventions and placebo in terms of SAEs, and the safety evidence for most interventions was low to moderate quality. More randomised trials directly comparing active agents are needed, and these should include systematic subgroup analyses (sex, age, ethnicity, comorbidities, psoriatic arthritis). To provide long-term information on the safety of treatments included in this review, an evaluation of non-randomised studies and postmarketing reports from regulatory agencies is needed. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis

BACKGROUND

Psoriasis is an immune-mediated disease for which some people have a genetic predisposition. The condition manifests in inflammatory effects on either the skin or joints, or both, and it has a major impact on quality of life. Although there is currently no cure for psoriasis, various treatment strategies allow sustained control of disease signs and symptoms. Several randomised controlled trials (RCTs) have compared the efficacy of the different systemic treatments in psoriasis against placebo. However, the relative benefit of these treatments remains unclear due to the limited number of trials comparing them directly head-to-head, which is why we chose to conduct a network meta-analysis.

OBJECTIVES

To compare the efficacy and safety of non-biological systemic agents, small molecules, and biologics for people with moderate-to-severe psoriasis using a network meta-analysis, and to provide a ranking of these treatments according to their efficacy and safety.

SEARCH METHODS

For this living systematic review we updated our searches of the following databases monthly to September 2020: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase. We searched two trials registers to the same date. We checked the reference lists of included studies and relevant systematic reviews for further references to eligible RCTs.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of systemic treatments in adults (over 18 years of age) with moderate-to-severe plaque psoriasis or psoriatic arthritis whose skin had been clinically diagnosed with moderate-to-severe psoriasis, at any stage of treatment, in comparison to placebo or another active agent. The primary outcomes of this review were: the proportion of participants who achieved clear or almost clear skin, that is, at least Psoriasis Area and Severity Index (PASI) 90 at induction phase (from 8 to 24 weeks after the randomisation), and the proportion of participants with serious adverse events (SAEs) at induction phase. We did not evaluate differences in specific adverse events.

DATA COLLECTION AND ANALYSIS

Several groups of two review authors independently undertook study selection, data extraction, 'Risk of bias' assessment, and analyses. We synthesised the data using pair-wise and network meta-analysis (NMA) to compare the treatments of interest and rank them according to their effectiveness (as measured by the PASI 90 score) and acceptability (the inverse of serious adverse events). We assessed the certainty of the body of evidence from the NMA for the two primary outcomes and all comparisons, according to CINeMA, as either very low, low, moderate, or high. We contacted study authors when data were unclear or missing. We used the surface under the cumulative ranking curve (SUCRA) to infer on treatment hierarchy: 0% (treatment is the worst for effectiveness or safety) to 100% (treatment is the best for effectiveness or safety).

MAIN RESULTS

We included 158 studies (18 new studies for the update) in our review (57,831 randomised participants, 67.2% men, mainly recruited from hospitals). The overall average age was 45 years; the overall mean PASI score at baseline was 20 (range: 9.5 to 39). Most of these studies were placebo-controlled (58%), 30% were head-to-head studies, and 11% were multi-armed studies with both an active comparator and a placebo. We have assessed a total of 20 treatments. In all, 133 trials were multicentric (two to 231 centres). All but two of the outcomes included in this review were limited to the induction phase (assessment from 8 to 24 weeks after randomisation). We assessed many studies (53/158) as being at high risk of bias; 25 were at an unclear risk, and 80 at low risk. Most studies (123/158) declared funding by a pharmaceutical company, and 22 studies did not report their source of funding. Network meta-analysis at class level showed that all of the interventions (non-biological systemic agents, small molecules, and biological treatments) were significantly more effective than placebo in reaching PASI 90. At class level, in reaching PASI 90, the biologic treatments anti-IL17, anti-IL12/23, anti-IL23, and anti-TNF alpha were significantly more effective than the small molecules and the non-biological systemic agents. At drug level, infliximab, ixekizumab, secukinumab, brodalumab, risankizumab and guselkumab were significantly more effective in reaching PASI 90 than ustekinumab and three anti-TNF alpha agents: adalimumab, certolizumab, and etanercept. Ustekinumab and adalimumab were significantly more effective in reaching PASI 90 than etanercept; ustekinumab was more effective than certolizumab, and the clinical effectiveness of ustekinumab and adalimumab was similar. There was no significant difference between tofacitinib or apremilast and three non-biological drugs: fumaric acid esters (FAEs), ciclosporin and methotrexate. Network meta-analysis also showed that infliximab, ixekizumab, risankizumab, bimekizumab, secukinumab, guselkumab, and brodalumab outperformed other drugs when compared to placebo in reaching PASI 90. The clinical effectiveness of these drugs was similar, except for ixekizumab which had a better chance of reaching PASI 90 compared with secukinumab, guselkumab and brodalumab. The clinical effectiveness of these seven drugs was: infliximab (versus placebo): risk ratio (RR) 50.29, 95% confidence interval (CI) 20.96 to 120.67, SUCRA = 93.6; high-certainty evidence; ixekizumab (versus placebo): RR 32.48, 95% CI 27.13 to 38.87; SUCRA = 90.5; high-certainty evidence; risankizumab (versus placebo): RR 28.76, 95% CI 23.96 to 34.54; SUCRA = 84.6; high-certainty evidence; bimekizumab (versus placebo): RR 58.64, 95% CI 3.72 to 923.86; SUCRA = 81.4; high-certainty evidence; secukinumab (versus placebo): RR 25.79, 95% CI 21.61 to 30.78; SUCRA = 76.2; high-certainty evidence; guselkumab (versus placebo): RR 25.52, 95% CI 21.25 to 30.64; SUCRA = 75; high-certainty evidence; and brodalumab (versus placebo): RR 23.55, 95% CI 19.48 to 28.48; SUCRA = 68.4; moderate-certainty evidence. Conservative interpretation is warranted for the results for bimekizumab (as well as mirikizumab, tyrosine kinase 2 inhibitor, acitretin, ciclosporin, fumaric acid esters, and methotrexate), as these drugs, in the NMA, have been evaluated in few trials. We found no significant difference between any of the interventions and the placebo for the risk of SAEs. Nevertheless, the SAE analyses were based on a very low number of events with low to moderate certainty for all the comparisons. Thus, the results have to be viewed with caution and we cannot be sure of the ranking. For other efficacy outcomes (PASI 75 and Physician Global Assessment (PGA) 0/1) the results were similar to the results for PASI 90. Information on quality of life was often poorly reported and was absent for several of the interventions.

AUTHORS' CONCLUSIONS

Our review shows that compared to placebo, the biologics infliximab, ixekizumab, risankizumab, bimekizumab, secukinumab, guselkumab and brodalumab were the most effective treatments for achieving PASI 90 in people with moderate-to-severe psoriasis on the basis of moderate- to high-certainty evidence. This NMA evidence is limited to induction therapy (outcomes were measured from 8 to 24 weeks after randomisation) and is not sufficient for evaluation of longer-term outcomes in this chronic disease. Moreover, we found low numbers of studies for some of the interventions, and the young age (mean age of 45 years) and high level of disease severity (PASI 20 at baseline) may not be typical of patients seen in daily clinical practice. Another major concern is that short-term trials provide scanty and sometimes poorly-reported safety data and thus do not provide useful evidence to create a reliable risk profile of treatments. We found no significant difference in the assessed interventions and placebo in terms of SAEs, and the evidence for all the interventions was of low to moderate quality. In order to provide long-term information on the safety of the treatments included in this review, it will also be necessary to evaluate non-randomised studies and postmarketing reports released from regulatory agencies. In terms of future research, randomised trials directly comparing active agents are necessary once high-quality evidence of benefit against placebo is established, including head-to-head trials amongst and between non-biological systemic agents and small molecules, and between biological agents (anti-IL17 versus anti-IL23, anti-IL23 versus anti-IL12/23, anti-TNF alpha versus anti-IL12/23). Future trials should also undertake systematic subgroup analyses (e.g. assessing biological-naïve participants, baseline psoriasis severity, presence of psoriatic arthritis, etc.). Finally, outcome measure harmonisation is needed in psoriasis trials, and researchers should look at the medium- and long-term benefit and safety of the interventions and the comparative safety of different agents. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis

BACKGROUND

Psoriasis is an immune-mediated disease for which some people have a genetic predisposition. The condition manifests in inflammatory effects on either the skin or joints, or both, and it has a major impact on quality of life. Although there is currently no cure for psoriasis, various treatment strategies allow sustained control of disease signs and symptoms. Several randomised controlled trials (RCTs) have compared the efficacy of the different systemic treatments in psoriasis against placebo. However, the relative benefit of these treatments remains unclear due to the limited number of trials comparing them directly head-to-head, which is why we chose to conduct a network meta-analysis. This is the baseline update of a Cochrane Review first published in 2017, in preparation for this Cochrane Review becoming a living systematic review.

OBJECTIVES

To compare the efficacy and safety of conventional systemic agents, small molecules, and biologics for people with moderate-to-severe psoriasis, and to provide a ranking of these treatments according to their efficacy and safety.

SEARCH METHODS

We updated our research using the following databases to January 2019: the Cochrane Skin Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS and the conference proceedings of a number of dermatology meetings. We also searched five trials registers and the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) reports (until June 2019). We checked the reference lists of included and excluded studies for further references to relevant RCTs.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of systemic treatments in adults (over 18 years of age) with moderate-to-severe plaque psoriasis or psoriatic arthritis whose skin had been clinically diagnosed with moderate-to-severe psoriasis, at any stage of treatment, in comparison to placebo or another active agent. The primary outcomes of this review were: the proportion of participants who achieved clear or almost clear skin, that is, at least Psoriasis Area and Severity Index (PASI) 90 at induction phase (from 8 to 24 weeks after the randomisation), and the proportion of participants with serious adverse effects (SAEs) at induction phase. We did not evaluate differences in specific adverse effects.

DATA COLLECTION AND ANALYSIS

Several groups of two review authors independently undertook study selection, data extraction, 'Risk of bias' assessment, and analyses. We synthesised the data using pair-wise and network meta-analysis (NMA) to compare the treatments of interest and rank them according to their effectiveness (as measured by the PASI 90 score) and acceptability (the inverse of serious adverse effects). We assessed the certainty of the body of evidence from the NMA for the two primary outcomes, according to GRADE, as either very low, low, moderate, or high. We contacted study authors when data were unclear or missing.

MAIN RESULTS

We included 140 studies (31 new studies for the update) in our review (51,749 randomised participants, 68% men, mainly recruited from hospitals). The overall average age was 45 years; the overall mean PASI score at baseline was 20 (range: 9.5 to 39). Most of these studies were placebo-controlled (59%), 30% were head-to-head studies, and 11% were multi-armed studies with both an active comparator and a placebo. We have assessed a total of 19 treatments. In all, 117 trials were multicentric (two to 231 centres). All but two of the outcomes included in this review were limited to the induction phase (assessment from 8 to 24 weeks after randomisation). We assessed many studies (57/140) as being at high risk of bias; 42 were at an unclear risk, and 41 at low risk. Most studies (107/140) declared funding by a pharmaceutical company, and 22 studies did not report the source of funding. Network meta-analysis at class level showed that all of the interventions (conventional systemic agents, small molecules, and biological treatments) were significantly more effective than placebo in terms of reaching PASI 90. At class level, in terms of reaching PASI 90, the biologic treatments anti-IL17, anti-IL12/23, anti-IL23, and anti-TNF alpha were significantly more effective than the small molecules and the conventional systemic agents. At drug level, in terms of reaching PASI 90, infliximab, all of the anti-IL17 drugs (ixekizumab, secukinumab, bimekizumab and brodalumab) and the anti-IL23 drugs (risankizumab and guselkumab, but not tildrakizumab) were significantly more effective in reaching PASI 90 than ustekinumab and 3 anti-TNF alpha agents: adalimumab, certolizumab and etanercept. Adalimumab and ustekinumab were significantly more effective in reaching PASI 90 than certolizumab and etanercept. There was no significant difference between tofacitinib or apremilast and between two conventional drugs: ciclosporin and methotrexate. Network meta-analysis also showed that infliximab, ixekizumab, risankizumab, bimekizumab, guselkumab, secukinumab and brodalumab outperformed other drugs when compared to placebo in reaching PASI 90. The clinical effectiveness for these seven drugs was similar: infliximab (versus placebo): risk ratio (RR) 29.52, 95% confidence interval (CI) 19.94 to 43.70, Surface Under the Cumulative Ranking (SUCRA) = 88.5; moderate-certainty evidence; ixekizumab (versus placebo): RR 28.12, 95% CI 23.17 to 34.12, SUCRA = 88.3, moderate-certainty evidence; risankizumab (versus placebo): RR 27.67, 95% CI 22.86 to 33.49, SUCRA = 87.5, high-certainty evidence; bimekizumab (versus placebo): RR 58.64, 95% CI 3.72 to 923.86, SUCRA = 83.5, low-certainty evidence; guselkumab (versus placebo): RR 25.84, 95% CI 20.90 to 31.95; SUCRA = 81; moderate-certainty evidence; secukinumab (versus placebo): RR 23.97, 95% CI 20.03 to 28.70, SUCRA = 75.4; high-certainty evidence; and brodalumab (versus placebo): RR 21.96, 95% CI 18.17 to 26.53, SUCRA = 68.7; moderate-certainty evidence. Conservative interpretation is warranted for the results for bimekizumab (as well as tyrosine kinase 2 inhibitor, acitretin, ciclosporin, fumaric acid esters, and methotrexate), as these drugs, in the NMA, have been evaluated in few trials. We found no significant difference between any of the interventions and the placebo for the risk of SAEs. Nevertheless, the SAE analyses were based on a very low number of events with low to very low certainty for just under half of the treatment estimates in total, and moderate for the others. Thus, the results have to be viewed with caution and we cannot be sure of the ranking. For other efficacy outcomes (PASI 75 and Physician Global Assessment (PGA) 0/1) the results were very similar to the results for PASI 90. Information on quality of life was often poorly reported and was absent for several of the interventions.

AUTHORS' CONCLUSIONS

Our review shows that compared to placebo, the biologics infliximab, ixekizumab, risankizumab, bimekizumab, guselkumab, secukinumab and brodalumab were the best choices for achieving PASI 90 in people with moderate-to-severe psoriasis on the basis of moderate- to high-certainty evidence (low-certainty evidence for bimekizumab). This NMA evidence is limited to induction therapy (outcomes were measured from 8 to 24 weeks after randomisation) and is not sufficient for evaluation of longer-term outcomes in this chronic disease. Moreover, we found low numbers of studies for some of the interventions, and the young age (mean age of 45 years) and high level of disease severity (PASI 20 at baseline) may not be typical of patients seen in daily clinical practice. Another major concern is that short-term trials provide scanty and sometimes poorly-reported safety data and thus do not provide useful evidence to create a reliable risk profile of treatments. Indeed, we found no significant difference in the assessed interventions and placebo in terms of SAEs, but the evidence for all the interventions was of very low to moderate quality. In order to provide long-term information on the safety of the treatments included in this review, it will also be necessary to evaluate non-randomised studies and postmarketing reports released from regulatory agencies. In terms of future research, randomised trials comparing directly active agents are necessary once high-quality evidence of benefit against placebo is established, including head-to-head trials amongst and between conventional systemic and small molecules, and between biological agents (anti-IL17 versus anti-IL23, anti-IL23 versus anti-IL12/23, anti-TNF alpha versus anti-IL12/23). Future trials should also undertake systematic subgroup analyses (e.g. assessing biological-naïve participants, baseline psoriasis severity, presence of psoriatic arthritis, etc.). Finally, outcome measure harmonisation is needed in psoriasis trials, and researchers should look at the medium- and long-term benefit and safety of the interventions and the comparative safety of different agents. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Molecular basis of the counteraction by calcium channel blockers of cyclosporine nephrotoxicity

Nephrotoxicity is a serious side effect for the immunosuppressant drug cyclosporine A(CSA). In this study, we tested the hypothesis that administration of calcium channel blockers such as verapamil or nifedipine ameliorates renal CSA-induced renal dysfunction. Furthermore, our study investigates the roles of inflammatory, oxidative, and fibrotic pathways in CSA-induced renal dysfunction. Six groups of male rats ( n = 6/group) were used and received one of the following treatments for seven consecutive days: vehicle (Cremophor EL ip), CSA (25 mg·kg^-1·day^-1 ip), verapamil (2 mg·kg^-1·day^-1 ip), nifedipine (3 mg·kg^-1·day^-1 ip), CSA in the presence or absence of either verapamil, or nifedipine. Biochemical and histomorphometric analyses showed that rats treated with CSA exhibited clear signs of nephrotoxicity that included 1) proteinuria and elevations in serum creatinine and blood urea nitrogen, 2) mesangial expansion, 3) increases in glomerular and tubular type IV collagen expression, and 4) increases in the glomerulosclerosis and tubulointerstitial fibrosis indices. Although the single administration of nifedipine or verapamil had no significant effect on renal pathology, or its biochemical and physiological function, the concurrent use of either calcium channel blockers significantly and equipotently ameliorated the biochemical, morphological, and functional derangements caused by CSA. More importantly, we report that the oxidative (reactive oxygen species production, NADPH-oxidase activity, and dual oxidase 1/2 levels), fibrotic (transforming growth factor-β1 expression), and inflammatory (NF-κB expression) manifestations of renal toxicity induced by CSA were significantly reversed upon administration of nifedipine or verapamil. Together, these results highlight the efficacy of calcium channel-blocking agents in attenuating CSA-induced nephrotoxicity and predisposing biochemical and molecular machineries.

Comparison of clinical effects, trough and peak levels between branded and generic formulation of Cyclosporine in stable psoriatic patients

BACKGROUND

Cyclosporine A (CyA) is a drug for moderate-to-severe psoriasis. Recently, a generic formulation has been approved as bioequivalent to the branded one. The guidelines for the bioequivalence for critical-dose drugs with a narrow therapeutic range, such as CyA, are questionable. Therefore, it is important to assess the clinical outcome and the pharmacokinetics of different formulations in various patient groups. The current literature lacks of this information in dermatology. The primary objective of this prospective study is to investigate the clinical equivalence (in terms of maintenance of clinical effect) between the generic formulation of CyA and its branded one in patients with psoriasis. A secondary objective is to analyze their trough (C<inf>0</inf>) and peak levels (C<inf>2</inf>).

METHODS

Twenty patients with stable psoriasis under treatment with the branded CyA were monitored in terms of clinical efficacy (psoriasis area severity index, PASI), safety (laboratory values), and their pharmacokinetics utilizing trough (C<inf>0</inf>) and peak plasma concentration (C<inf>2</inf>). The same patients were subsequently shifted to the generic formulation for comparison.

RESULTS

In our sample the efficacy of the two formulations was equal in most cases (P=0.863). A non-significant difference between the C<inf>0</inf> and C<inf>2</inf> of the branded CyA compared to the generic one emerged (respectively P=0.738 and P=0.695).

CONCLUSIONS

The branded and the generic formulations of CyA seem to be not only bioequivalent, but also comparable in terms of clinical efficacy in patients with psoriasis. However, larger samples are required to confirm these findings.

Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis

BACKGROUND

Psoriasis is an immune-mediated disease for which some people have a genetic predisposition. The condition manifests in inflammatory effects on either the skin or joints, or both, and it has a major impact on quality of life. Although there is currently no cure for psoriasis, various treatment strategies allow sustained control of disease signs and symptoms. Several randomised controlled trials (RCTs) have compared the efficacy of the different systemic treatments in psoriasis against placebo. However, the relative benefit of these treatments remains unclear due to the limited number of trials comparing them directly head to head, which is why we chose to conduct a network meta-analysis.

OBJECTIVES

To compare the efficacy and safety of conventional systemic agents (acitretin, ciclosporin, fumaric acid esters, methotrexate), small molecules (apremilast, tofacitinib, ponesimod), anti-TNF alpha (etanercept, infliximab, adalimumab, certolizumab), anti-IL12/23 (ustekinumab), anti-IL17 (secukinumab, ixekizumab, brodalumab), anti-IL23 (guselkumab, tildrakizumab), and other biologics (alefacept, itolizumab) for patients with moderate to severe psoriasis and to provide a ranking of these treatments according to their efficacy and safety.

SEARCH METHODS

We searched the following databases to December 2016: the Cochrane Skin Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and LILACS. We also searched five trials registers and the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) reports. We checked the reference lists of included and excluded studies for further references to relevant RCTs. We searched the trial results databases of a number of pharmaceutical companies and handsearched the conference proceedings of a number of dermatology meetings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of systemic and biological treatments in adults (over 18 years of age) with moderate to severe plaque psoriasis or psoriatic arthritis whose skin had been clinically diagnosed with moderate to severe psoriasis, at any stage of treatment, in comparison to placebo or another active agent.

DATA COLLECTION AND ANALYSIS

Three groups of two review authors independently undertook study selection, data extraction, 'Risk of bias' assessment, and analyses. We synthesised the data using pair-wise and network meta-analysis (NMA) to compare the treatments of interest and rank them according to their effectiveness (as measured by the Psoriasis Area and Severity Index score (PASI) 90) and acceptability (the inverse of serious adverse effects). We assessed the certainty of the body of evidence from the NMA for the two primary outcomes, according to GRADE; we evaluated evidence as either very low, low, moderate, or high. We contacted study authors when data were unclear or missing.

MAIN RESULTS

We included 109 studies in our review (39,882 randomised participants, 68% men, all recruited from a hospital). The overall average age was 44 years; the overall mean PASI score at baseline was 20 (range: 9.5 to 39). Most of these studies were placebo controlled (67%), 23% were head-to-head studies, and 10% were multi-armed studies with both an active comparator and placebo. We have assessed all treatments listed in the objectives (19 in total). In all, 86 trials were multicentric trials (two to 231 centres). All of the trials included in this review were limited to the induction phase (assessment at less than 24 weeks after randomisation); in fact, all trials included in the network meta-analysis were measured between 12 and 16 weeks after randomisation. We assessed the majority of studies (48/109) as being at high risk of bias; 38 were assessed as at an unclear risk, and 23, low risk.Network meta-analysis at class level showed that all of the interventions (conventional systemic agents, small molecules, and biological treatments) were significantly more effective than placebo in terms of reaching PASI 90.In terms of reaching PASI 90, the biologic treatments anti-IL17, anti-IL12/23, anti-IL23, and anti-TNF alpha were significantly more effective than the small molecules and the conventional systemic agents. Small molecules were associated with a higher chance of reaching PASI 90 compared to conventional systemic agents.At drug level, in terms of reaching PASI 90, all of the anti-IL17 agents and guselkumab (an anti-IL23 drug) were significantly more effective than the anti-TNF alpha agents infliximab, adalimumab, and etanercept, but not certolizumab. Ustekinumab was superior to etanercept. No clear difference was shown between infliximab, adalimumab, and etanercept. Only one trial assessed the efficacy of infliximab in this network; thus, these results have to be interpreted with caution. Tofacitinib was significantly superior to methotrexate, and no clear difference was shown between any of the other small molecules versus conventional treatments.Network meta-analysis also showed that ixekizumab, secukinumab, brodalumab, guselkumab, certolizumab, and ustekinumab outperformed other drugs when compared to placebo in terms of reaching PASI 90: the most effective drug was ixekizumab (risk ratio (RR) 32.45, 95% confidence interval (CI) 23.61 to 44.60; Surface Under the Cumulative Ranking (SUCRA) = 94.3; high-certainty evidence), followed by secukinumab (RR 26.55, 95% CI 20.32 to 34.69; SUCRA = 86.5; high-certainty evidence), brodalumab (RR 25.45, 95% CI 18.74 to 34.57; SUCRA = 84.3; moderate-certainty evidence), guselkumab (RR 21.03, 95% CI 14.56 to 30.38; SUCRA = 77; moderate-certainty evidence), certolizumab (RR 24.58, 95% CI 3.46 to 174.73; SUCRA = 75.7; moderate-certainty evidence), and ustekinumab (RR 19.91, 95% CI 15.11 to 26.23; SUCRA = 72.6; high-certainty evidence).We found no significant difference between all of the interventions and the placebo regarding the risk of serious adverse effects (SAEs): the relative ranking strongly suggested that methotrexate was associated with the best safety profile regarding all of the SAEs (RR 0.23, 95% CI 0.05 to 0.99; SUCRA = 90.7; moderate-certainty evidence), followed by ciclosporin (RR 0.23, 95% CI 0.01 to 5.10; SUCRA = 78.2; very low-certainty evidence), certolizumab (RR 0.49, 95% CI 0.10 to 2.36; SUCRA = 70.9; moderate-certainty evidence), infliximab (RR 0.56, 95% CI 0.10 to 3.00; SUCRA = 64.4; very low-certainty evidence), alefacept (RR 0.72, 95% CI 0.34 to 1.55; SUCRA = 62.6; low-certainty evidence), and fumaric acid esters (RR 0.77, 95% CI 0.30 to 1.99; SUCRA = 57.7; very low-certainty evidence). Major adverse cardiac events, serious infections, or malignancies were reported in both the placebo and intervention groups. Nevertheless, the SAEs analyses were based on a very low number of events with low to very low certainty for just over half of the treatment estimates in total, moderate for the others. Thus, the results have to be considered with caution.Considering both efficacy (PASI 90 outcome) and acceptability (SAEs outcome), highly effective treatments also had more SAEs compared to the other treatments, and ustekinumab, infliximab, and certolizumab appeared to have the better trade-off between efficacy and acceptability.Regarding the other efficacy outcomes, PASI 75 and Physician Global Assessment (PGA) 0/1, the results were very similar to the results for PASI 90.Information on quality of life was often poorly reported and was absent for a third of the interventions.

AUTHORS' CONCLUSIONS

Our review shows that compared to placebo, the biologics ixekizumab, secukinumab, brodalumab, guselkumab, certolizumab, and ustekinumab are the best choices for achieving PASI 90 in people with moderate to severe psoriasis on the basis of moderate- to high-certainty evidence. At class level, the biologic treatments anti-IL17, anti-IL12/23, anti-IL23, and anti-TNF alpha were significantly more effective than the small molecules and the conventional systemic agents, too. This NMA evidence is limited to induction therapy (outcomes were measured between 12 to 16 weeks after randomisation) and is not sufficiently relevant for a chronic disease. Moreover, low numbers of studies were found for some of the interventions, and the young age (mean age of 44 years) and high level of disease severity (PASI 20 at baseline) may not be typical of patients seen in daily clinical practice.Another major concern is that short-term trials provide scanty and sometimes poorly reported safety data and thus do not provide useful evidence to create a reliable risk profile of treatments. Indeed, we found no significant difference in the assessed interventions and placebo in terms of SAEs. Methotrexate appeared to have the best safety profile, but as the evidence was of very low to moderate quality, we cannot be sure of the ranking. In order to provide long-term information on the safety of the treatments included in this review, it will be necessary to evaluate non-randomised studies and postmarketing reports released from regulatory agencies as well.In terms of future research, randomised trials comparing directly active agents are necessary once high-quality evidence of benefit against placebo is established, including head-to-head trials amongst and between conventional systemic and small molecules, and between biological agents (anti-IL17 versus anti-IL23, anti-IL23 versus anti-IL12/23, anti-TNF alpha versus anti-IL12/23). Future trials should also undertake systematic subgroup analyses (e.g. assessing biological-naïve patients, baseline psoriasis severity, presence of psoriatic arthritis, etc.). Finally, outcome measure harmonisation is needed in psoriasis trials, and researchers should look at the medium- and long-term benefit and safety of the interventions and the comparative safety of different agents.

Single-dose and steady state pharmacokinetics of CSA and two main primary metabolites, AM1 and AM4n in patients with rheumatic/autoimmune diseases

BACKGROUND

Cyclosporine A (CsA) is an immunomodulatory agent used in standard immunosuppressive regimens in solid organ transplantations as well as in the treatment of autoimmune diseases such as rheumatoid arthritis (RA), systemic lupus and psoriasis. Its immunosuppressive activity is primarily due to parent drug. However, following oral administration, absorption is incomplete and varies between individuals. Further, there is a dearth of pharmacokinetic data for CsA in autoimmune patients compared to transplant recipients.

AIM

The goal of this study was to investigate the single-dose and steady state pharmacokinetics of CsA and two main primary metabolites, AM1 and AM4N, in patients with rheumatic/autoimmune diseases.

METHODS

Thirty-eight subjects, average age (years± SD) 46.8 (±11.6) years with rheumatoid arthritis, systemic lupus erythematosus, psoriatic arthritis, ankylosing spondylitis and undifferentiated SpA were included in an observational open study. The single dose pharmacokinetics (area under the concentration-time curve of CsA and its metabolites (AUC) and other PK parameters) were determined over a 24 h period following oral administration of 1.3 mg/kg oral CsA. Two CsA formulations-Neoral and the Czech generic substitute Consupren®, were used. Pharmacokinetic analysis was performed on all 38 patients after administration of a single dose of CsA (1.34 mg/ kg/day). In 12 patients only, a second series of blood samples was taken to calculate monitored PK parameters under steady state conditions.

RESULTS

Pharmacokinetic assessment showed AUC(0-24) 3009.66 ± 1449.78 ng/ml.h and C(max) 827.84 ± 425.84 after administration of a single dose of CSA, AUC(0-24) 3698.50 ± 2147 ng/ml.h and C(max) 741 ± 493 ng/ml after repeated dose. The proportion of the AM1 metabolite (AUC(0-24)) after a single dose of CsA corresponded to 40% of the parent compound and to approximately 35% of the parent compound in steady state conditions. The proportion of AM4N metabolite was low in both conditions and represented only 3 and 4.5% after a single dose and at steady state, respectively.

CONCLUSION

The pharmacokinetic data (AUC(CsA), C(max)) for the whole 24 h interval were similar to the published findings, mainly under steady state conditions. The AM1 (AUC(0-24)) after a single dose of CsA and in steady state conditions represented about 40% of the parent drug. The ratio of AM4N metabolite was low in both conditions.

The use of ciclosporin in psoriasis

Ciclosporin is a cyclic undecapeptide discovered in the 1970s to possess a potent inhibitory action on T lymphocytes. The subsequent discovery, in 1979, that it was remarkably effective in treatment of psoriasis transformed thinking about the nature of the disease, which subsequently became generally recognized as autoimmune in nature. Ciclosporin remains one of the most effective and rapidly acting treatments currently available for psoriasis. Virtually all the diverse manifestations of this disease can respond. The main side effects are nephrotoxicity and hypertension. There is considerable variation between individuals in susceptibility to these so careful monitoring is required. Ciclosporin should be used in single or intermittent short courses for all except the most severe cases as this is safer than continuous treatment. The rate of improvement depends very much on the dose, which ranges from 2 to 5.0 mg/kg/day. Ciclosporin can be combined with any topical treatment and a useful dose-sparing effect can be achieved in this way if patients are compliant. In severe cases ciclosporin is often used in combination with other systemic antipsoriatic drugs in order to spare the dose of each agent and reduce toxicity. Concurrent or intercurrent use of ultraviolet therapy is discouraged due to the increased risk of non-melanoma skin cancer. This article reviews the mode of action, pharmacokinetics, indications, contraindications, side effects, dosage regimens, pretreatment screening and monitoring, drug interactions, and use of treatment combinations with ciclosporin in the management of psoriasis.

Improvement in intestinal coenzyme q10 absorption by food intake

Coenzyme Q10 (CoQ10) is widely consumed as a food supplement because of its recognition as an important nutrient in supporting human health. Absorption of compounds from the gastrointestinal tract is one of the important determinants of oral bioavailability. However, the absorption of dietary CoQ10 is slow and limited due to its hydrophobicity and large molecular weight. The absorption of orally applied compounds can be enhanced by interactions with food or food components. Thus, we investigated the effect of food intake on the absorption of CoQ10 after oral supplementation. In this study, we demonstrated that food intake enhanced the intestinal absorption of CoQ10. In order to improve intestinal absorption of CoQ10 after oral supplementation, we developed an emulsion formulation. Intestinal absorption of CoQ10 after administration of the emulsion formulation was also enhanced by food intake. Moreover, the peak concentration and the extent of absorption after administration of the emulsion formulation were greater than those after administration of a suspension formulation. It is possible that administration of CoQ10 in an emulsion formulation enhances the pharmacological effects of CoQ10.

Isothermal Crystallization of Imwitor 742 from Supercooled Liquid State

PURPOSE

Crystallization behavior of Imwitor 742 was investigated for use as a liquid-filled capsule carrier.

MATERIALS AND METHODS

The crystallization behavior of Imwitor 742 was assessed using DSC, X-ray diffraction, and microscopy. The physical stability of Imwitor 742 under refrigerated and ambient conditions was estimated by isothermal crystallization studies using DSC. The effect of hard capsule shells and additives on crystallization kinetics was also examined.

RESULTS

When Imwitor 742 was cooled in the DSC measurement, the form alpha appeared at -20 degrees C. When this form was heated from -40 degrees C, melt-crystallization into the form beta + beta' was initiated at -30 degrees C, followed by successive melting. Isothermal crystallization studies at temperatures higher than -14 degrees C yielded the form beta + beta'. The crystallization behavior was explained in terms of the Avrami model fitting by assuming 2-dimensional crystal growth. Kinetic analysis suggested that the liquid state of Imwitor 742 was maintained for 46 h and 40 months at 5 and 25 degrees C, respectively, although the deviation in induction time was expected to be large at these temperatures. Addition of hard capsule shells promoted the crystallization behavior, while addition of drug or water prolonged the induction time.

CONCLUSION

The supercooled liquid state of Imwitor 742 was quite stable. However, additives to retard crystallization should be used, because the deviation in the induction time was very large. Hard capsule shells enhanced the crystallization of Imwitor 742, possibly by acting as nuclei for crystal growth.

The novel formulation design of self-emulsifying drug delivery systems (SEDDS) type O/W microemulsion I: enhancing effects on oral bioavailability of poorly water soluble compounds in rats and beagle dogs

We examined the design of the versatile novel self-emulsifying drug delivery systems (SEDDS) type O/W microemulsion formulation which enhances the oral bioavailability by raising the solubility of poorly water soluble compounds. Namely, seven kinds of poorly water soluble compounds such as disopyramide, ibuprofen, ketoprofen, tolbutamide, and other new compounds, as the model compounds were used to compare the plasma concentration profile of the compound following single oral administration of each compound to rats and beagle dogs as a solution, an oily solution, a suspension (or a powder), an O/W microemulsion, and a SEDDS type O/W microemulsion. And the enhancing effect of the SEDDS type O/W microemulsion on the gastrointestinal absorption of these compounds was evaluated. In the components of the SEDDS type O/W microemulsion, medium chain fatty acid triglyceride (MCT), diglyceryl monooleate (DGMO-C), polyoxyethylene hydrogenated castor oil 40 (HCO-40), and ethanol were used as an oil, a lipophilic surfactant, a hydrophilic surfactant, and a solubilizer, at the mixture ratio of 25/5/45/25 (w/w%), respectively. Thereby, to six kinds of the model compounds except disopyramide, the solubility was from 340 to 98,000 times that in water, and the AUCs in plasma concentration of the compound were equivalent to that of solution or O/W microemulsion administration, or was increased by 1.5 to 78 times that of suspension administration. Accordingly, this novel SEDDS type O/W microemulsion is the versatile, useful formulation which enhances the oral bioavailability by raising the solubility of poorly water soluble compounds.

The novel formulation design of self-emulsifying drug delivery systems (SEDDS) type O/W microemulsion III: the permeation mechanism of a poorly water soluble drug entrapped O/W microemulsion in rat isolated intestinal membrane by the Ussing chamber method

We used ibuprofen as a poorly water soluble model drug, to examine the influence of bile salts and mucin layers on the permeability of that entrapped in an O/W microemulsion, in a rat isolated intestinal membrane by the Ussing chamber method. Under the presence of 3 kinds of the primary bile salts such a sodium taurocholate, etc., or a secondary bile salt such a sodium taurochenodeoxycholate at 0.01 mmol/L concentration, a significant difference was not demonstrated in the permeation clearance of the ibuprofen entrapped O/W microemulsion, as compared with the case without the bile salts. Thus, the bile salts did not have a remarkable influence on the permeability of the drug entrapped in the O/W microemulsion, and it was verified that this O/W microemulsion was hardly influenced by the flow of the bile secretion. On the other hand, when N-acetyl-L-cysteine (NAC) with the removal ability of a mucin layer was combined with the ibuprofen entrapped O/W microemulsion at the concentration of 3 and 10 mmol/L, it was shown that the permeation clearance of free ibuprofen did not decrease, but that of ibuprofen entrapped in the O/W microemulsion decreased with the increase of the NAC concentration. Therefore, it is confirmed that the mucin layer participates in the permeability of the drug entrapped in the O/W microemulsion. From these results, the mechanism in which the drug entrapped in the O/W microemulsion is released in a mucin layer, without passing through the route of the mixed micelle formation by bile, thereafter the drug permeates an intestinal membrane, is supposed.

Basic immunosuppressive drugs outside solid organ transplantation

Immunosuppressive drugs are the backbone of solid organ transplantation. The introduction of new immunosuppressive drugs led to improved patient and organ survival rates. Nowadays, acute rejection can be reduced to a minimum. Individualization and avoidance of drug-related adverse effects became a new goal to achieve. The potency of immunosuppressive drugs makes them attractive for use in various autoimmune diseases; therefore, the experience on immunosuppressive drugs outside the field of organ transplantation is analysed in this review.

The novel formulation design of O/W microemulsion for improving the gastrointestinal absorption of poorly water soluble compounds

The design of the novel O/W microemulsion formulation, which enhances the oral bioavailability by raising the solubility of poorly water soluble compounds was examined. Using medium chain fatty acid triglyceride (MCT), diglyceryl monooleate (DGMO-C), polyoxyethylene hydrogenated castor oil 40 (HCO-40), ethanol and PBS (pH 6.8) as an oil phase, a lipophilic surfactant, a hydrophilic surfactant, a solubilizer and an aqueous phase, at the mixture ratio of 5%/1%/9%/5%/80% (w/w), respectively, the O/W microemulsion with an average particle diameter of 20 nm or less was prepared. Moreover, for nine kinds of poorly water soluble compounds, such as Ibuprofen, Ketoprofen, Tamoxifen, Testosterone, Tolbutamide and other new compounds, the solubility to water was increased from 60 to 20,000 times by this O/W microemulsion formulation. The AUCs in plasma concentration of Ibuprofen and a new compound, ER-1039, following single oral administration of these compounds as the O/W microemulsion to fasted rats were equivalent to that of solution administration or increased by nine and two times that of suspension administration, respectively. Accordingly, this novel O/W microemulsion is a useful formulation, which enhances the oral bioavailability by raising the solubility of poorly water soluble compounds.

The Use of Systemic Immune Moderators in Dermatology: An Update

In addition to corticosteroids, dermatologists have access to an array of immunomodulatory therapies. Azathioprine, cyclophosphamide, methotrexate, cyclosporine, and mycophenolate mofetil are the systemic immunosuppressive agents most commonly used by dermatologists. In addition, new developments in biotechnology have spurred the development of immunobiologic agents that are able to target the immunologic process of many inflammatory disorders at specific points along the inflammatory cascade. Alefacept, efalizumab, etanercept, and infliximab are the immunobiologic agents that are currently the most well known and most commonly used by dermatologists. This article reviews the pharmacology, mechanism of action, side effects, and clinical applications of these therapies.

The Novel Formulation Design of Self-emulsifying Drug Delivery Systems (SEDDS) Type O/W Microemulsion II: Stable Gastrointestinal Absorption of a Poorly Water Soluble New Compound, ER-1258 in Bile-fistula Rats

The stabilization effect of the novel self-emulsifying drug delivery systems (SEDDS) type O/W microemulsion on the gastrointestinal absorption of a poorly water soluble new compound, ER-1258 was examined by bile-fistula model rats. In the components of this formulation, medium chain fatty acid triglyceride (MCT), diglyceryl monooleate (DGMO-C), polyoxyethylene hydrogenated castor oil 40 (HCO-40) and ethanol were used as an oil, a lipophilic surfactant, a hydrophilic surfactant and a solubilizer at the mixture ratio of 25/5/45/25 w/w%, respectively. The ratios of AUC in the non-treated rats to that in the bile-fistula rats were 5.1, 12.1 and 3.0 for the suspension, the oily solution and the SEDDS type O/W microemulsion, respectively. The risk from which the difference between individuals of the compound absorption amounts resulting from the flow of the bile secretion serves as the maximum was high in order of oily solution>suspension>SEDDS type O/W microemulsion. Therefore, it was verified that the SEDDS type O/W microemulsion was able to reduce this risk, compared with the other formulations. When short chain fatty acid triglyceride (Triacetin) was used as an oil, the similar effect was demonstrated in the formulation composed of sorbitan sesquioleate (SO-15) as a lipophilic surfactant and polyoxyethylene hydrogenated castor oil 60 (HCO-60) or polyoxyethylene 20 sorbitan monooleate (TO-10M) as a hydrophilic surfactant.

Therapeutic drug monitoring of cyclosporine

The introduction of cyclosporine into clinical practice improved transplant outcome. However, the use of cyclosporine is not without problems. A narrow therapeutic index (the drug causes irreversible kidney damage when given in too high a dose) coupled with variable absorption and unpredictable pharmacokinetics has resulted in the need to measure cyclosporine blood concentrations to enable the dose of the drug to be individualised to the patient. When this is done correctly therapeutic efficacy can be maximised while toxicity is kept to a minimum. The evolution of cyclosporine dose optimisation started with the adjustment of empirical fixed doses by clinical "judgement;" progressed to therapeutic drug monitoring of trough, predose, C0 concentration with non specific assays that measured parent drug and metabolite; then on to "specific" cyclosporine C0 measurements; through area under curve monitoring using full profile measurements and limited sampling scheme procedures; and finally ending up with absorption profiling that targets AUC in the first 4 hours or the 2 hour blood cyclosporine concentration, C2. At the same time the formulation of cyclosporine has changed from Sandimmune to Neoral and now generic forms of the latter are available. The evidence base supporting C2 monitoring continues to grow and the technique will need to be customised as new combination therapies emerge. Therapeutic drug monitoring of cyclosporine may also need to be tailored to avoid the potential negative impact of switching patients to generic forms of the drug.

Microemulsion formulation for enhanced absorption of poorly soluble drugs. I. Prescription design

Microemulsion formulations, which can be used to improve the bioavailability of poorly soluble drugs, were designed using only pharmaceutical excipients. Several types of oils and surfactants were tested and it was found that propyleneglycol monoalkyl ester and glycerol monoalkyl ester were solubilized easily in an aqueous medium by various types of surfactants. Although propyleneglycol dialkyl ester was difficult to be solubilized, the solubility was significantly enhanced by mixing it with glycerol monoalkyl ester at the ratio of 1:1. The most suitable surfactants for preparing microemulsion formulations were HCO-40, HCO-60, Tween 80, BL-9EX and Pluronic P84. The use of additional surfactants such as sodium dodecyl sulfate or sodium deoxycholate significantly improved the solubilization capacity of the oils, although formulations free of these surfactants were also available. These microemulsion formulations can be administered as a form of water-in-oil microemulsion or surfactant-oil mixture, and are expected to convert to oil-in-water microemulsion in the small intestine.

Microemulsion formulation for enhanced absorption of poorly soluble drugs. II. In vivo study

Oral administration study of microemulsion formulations, which are known to improve the bioavailability of poorly soluble drugs, was performed using rats. Nitrendipine was used as a poorly soluble model drug, and its absorption was enhanced significantly by employing the microemulsion formulations compared to a suspension or an oil solution. The effect of the fed state on the oral absorption of nitrendipine became insignificant with the microemulsion formulations, although it affected the absorption from the suspension formulation significantly. The absorption behavior also varied with the type of surfactant. The absorption from Tween 80-based formulation was very rapid, while HCO-60-based formulation showed prolonged plasma concentration profile. However, the absorption from BL-9EX (polyoxyethylene alkyl ether)-based formulation was hardly observed. Damage to the gastrointestinal mucosa, which seems to be a serious problem of surfactant-based formulations, also differed with the type of surfactant employed. HCO-60 and Tween 80-based formulations were mild to the organs, while BL-9EX-based formulation caused serious damage. The behavior and absorption mechanism of the microemulsion formulations are discussed.

Microemulsion-based media as novel drug delivery systems

Microemulsions are clear, stable, isotropic mixtures of oil, water and surfactant, frequently in combination with a cosurfactant. These systems are currently of interest to the pharmaceutical scientist because of their considerable potential to act as drug delivery vehicles by incorporating a wide range of drug molecules. In order to appreciate the potential of microemulsions as delivery vehicles, this review gives an overview of the formation and phase behaviour and characterization of microemulsions. The use of microemulsions and closely related microemulsion-based systems as drug delivery vehicles is reviewed, with particular emphasis being placed on recent developments and future directions.

Recommendations for bioequivalence testing of cyclosporine generics revisited

The immunosuppressant cyclosporine is generally considered a critical-dose drug. The validity of standard criteria to establish bioequivalence between cyclosporine formulations has recently been challenged. Recommendations included establishment of individual bioequivalence rather than average bioequivalence, establishment of bioequivalence in transplant patients and in subgroups known to be poor absorbers, as well as long-term efficacy and safety studies in transplant patients. However, at the moment individual bioequivalence is a theoretical concept, the practical benefits of which have not statistically been proven. The proposed patient pharmacodynamic studies can be expected to require an unrealistically high number of subjects to achieve sufficient statistical power. It is well established that the common practice of blood-concentration-guided dosing of cyclosporine efficiently compensates for interindividual and intraindividual variability and allows for safely switching cyclosporine formulations as bioinequivalent as Sandimmune and Neoral. Recent studies comparing the generic cyclosporine formulation SangCya with Neoral, including individual bioequivalence, bioequivalence in transplant patients, and long-term safety after switching from Sandimmune to SangCya, confirmed that it was valid to conclude bioequivalence of both cyclosporine formulations based on standard average bioequivalence criteria. Present FDA guidelines for approving bioequivalence can be considered adequate and sufficient for generic cyclosporine formulations.

Advances in psoriasis therapy

New uses of older drugs, new combinations of treatments, and new phototherapeutic modalities are enabling clinicians to offer patients safer and more effective treatments. New vehicles for topical delivery of older treatments have created more cosmetically elegant preparations that are better accepted by patients. This article discusses new developments in topical therapy, phototherapy, oral therapy, and injectable therapy for psoriasis.

Halofantrine metabolism in microsomes in man: major role of CYP 3A4 and CYP 3A5

We have clarified the contribution of the different enzymes involved in the N-debutylation of halofantrine in liver microsomes in man. The effect of ketoconazole and cytochrome P450 (CYP) 3A substrates on halofantrine metabolism has also been studied. The antimalarial drug halofantrine is metabolized into one major metabolite, N-debutylhalofantrine. In microsomes from nine livers from man, N-debutylation of halofantrine was highly variable with apparent Michaelis-Menten constant V(max) and K(m) values of 215+/-172 pmol min(-1) mg(-1) and 48+/-26 micromol L(-1), respectively, (mean+/-standard deviation). Formation of N-debutylhalofantrine was cytochrome P450 (CYP)-mediated. Studies using selective inhibitors of individual CYPs revealed the role of CYP 3As in the formation of N-debutylhalofantrine. alpha-Naphthoflavone, a CYP 3A activator, increased metabolite formation. In microsomes from 12 livers from man the rate of N-debutylation of halofantrine correlated strongly with CYP 3A4 relative levels (P = 0.002) and less strongly, but significantly, with CYP 2C8 levels (P = 0.025). To characterize CYP-mediated metabolism of halofantrine further, incubations were performed with yeast microsomes expressing specific CYP 3A4, CYP 3A5, CYP 2D6, CYP 2C8 and CYP 2C19 from man. The rate of formation of N-debutylhalofantrine was six- and twelvefold with CYP 3A4 than with CYP 3A5 and CYP 2C8, respectively. CYP 2D6 and CYP 2C19 did not mediate the N-debutylation of halofantrine, but, because in-vivo CYP 2C8 is present at lower concentrations than CYP 3A in the liver in man, the involvement of CYP 3As would be predominant. Diltiazem, erythromycin, nifedipine and cyclosporin (CYP 3A substrates) inhibited halofantrine metabolism. Similarly, ketoconazole inhibited, non-competitively, formation of N-debutylhalofantrine with an inhibition constant, K(i), of 0.05 microM. The theoretical percentage inhibition of halofantrine metabolism in-vivo by ketoconazole was estimated to be 99%. These results indicate that both CYP 3A4 and CYP 3A5 metabolize halofantrine, with major involvement of CYP 3A4. In-vivo, the other CYPs have a minor role only. Moreover, strong inhibition, and consequently increased halofantrine cardiotoxicity, might occur with the association of ketoconazole or other CYP 3A4 substrates.

Immunosuppressive agents in dermatology. An update

Azathioprine, cyclophosphamide, methotrexate, and cyclosporine are the immunosuppressive agents most commonly used by dermatologists. Azathioprine has a relatively good safety profile and is therefore often preferred for the treatment of chronic eczematous dermatitides and bullous disorders. Awareness of the role of genetic polymorphisms in its metabolism can increase the efficacy and safety of this drug. Cyclophosphamide is an antimetabolite that has a more rapid onset of immunosuppressive effect than azathioprine, but has significant short-term and long-term toxicity. It is of use in fulminant, life-threatening cutaneous disease. Methotrexate is an antimetabolite that has significant anti-inflammatory activity. Despite its hepatotoxicity, its role in inflammatory dermatoses is broadening. Likewise, the role of cyclosporine is being expanded. This drug has potent T-cell inhibitory effects secondary to interference with intracellular signal transduction. Given the evidence for cumulative renal toxicity, it currently has a role in the short-term treatment of refractory psoriasis and atopic dermatitis, as well as in select inflammatory dermatoses. Familiarity with disease-specific clinical efficacy, side-effect profile, and dosage allows the successful and judicious use of these drugs in dermatologic disorders.