Optimization of Self-Microemulsifying Drug Delivery Systems (SMEDDS) Using a D-Optimal Design and the Desirability Function

D-optimal design and the desirability function were applied to optimize a self-microemulsifying drug delivery system (SMEDDS). The optimized key parameters were the following: 1) particle size of the dispersed emulsion, 2) solubility of the drug in the vehicle, and 3) the vehicle compatibility with the hard gelatin capsule. Three formulation variables, PEG200, a surfactant mixture, and an oil mixture, were included in the experimental design. The results of the mathematical analysis of the data demonstrated significant interactions among the formulation variables, and the desirability function was demonstrated to be a powerful tool to predict the optimal formulation for the explored system.

Intestinal lymphatic transport of halofantrine in rats assessed using a chylomicron flow blocking approach: the influence of polysorbate 60 and 80

The aim of the study was to examine the effects of polysorbate 60 and 80 on intestinal lymphatic transport of a poorly water-soluble compound, halofantrine, using a chylomicron flow blocking approach in rats. Male Sprague-Dawley rats were pretreated intraperitoneally with 3.0 mg/kg cycloheximide or saline. One hour later, rats were dosed with 6.7 mg/kg halofantrine in 0.4 or 1.0 g/kg polysorbate 60 or 80, 0.33 g/kg soybean oil or 0.33 g/kg soybean oil+1.0 g/kg polysorbate 80 by gavage, and plasma samples were collected. The fraction of halofantrine transported to the lymphatic system was determined as the difference between the bioavailability in saline-pretreated rats and cycloheximide-pretreated rats. No significant differences in halofantrine transport to the systemic blood and in the deduced lymphatic transport were observed between the two polysorbates, at the tested dosages. The lymphatic transport of halofantrine was the same whether dosing with polysorbate 60, polysorbate 80 or soybean oil; accordingly both surfactants can be used as lymphotropic carriers. Furthermore, there was a good correlation between the halofantrine transport to blood and lymphatics in the chylomicron flow blocking model and published results from the mesenteric lymph-cannulated model.

Development of simulated intestinal fluids containing nutrients as transport media in the Caco-2 cell culture model: Assessment of cell viability, monolayer integrity and transport of a poorly aqueous soluble drug and a substrate of efflux mechanisms

The purpose of this study was to identify simulated intestinal fluids (SIFs) containing nutrients compatible with the Caco-2 cell culture model and to examine the impact of the identified medium on the transport of a poorly aqueous soluble model compound, estradiol, and a substrate of efflux mechanisms, etoposide. Monolayer integrity was evaluated by transepithelial electrical resistance and cellular viability by release of lactate dehydrogenase to the apical compartment and cellular protein content. It was shown that the viability of Caco-2 cells was enhanced by use of the CO(2) independent nutritional medium, Leibovitz's L-15 compared to Hanks' balanced salt solution. SIF containing 5mM sodium taurocholate and 1.25 mM phosphatidylcholine or lysophosphatidylcholine in Leibovitz's L-15 induced less release of lactate dehydrogenase than the traditional transport medium, HBSS. Addition of lipolysis products, 0.5mM oleic acid and 0.25 mM monoolein, did only cause increase in lactate dehydrogenase in 3 of 12 comparisons. The presence of SIFs in the apical compartment was shown to decrease flux of estradiol due to incorporation of estradiol in micelles and hence a decreased fraction of free estradiol. Further, a concentration dependent increase in the apparent permeability of etoposide was observed from apical to basolateral compartment, which indicated that components in the SIFs affects efflux mechanisms.

Complexation of tauro- and glyco-conjugated bile salts with three neutral β-CDs studied by ACE

Complexation of the bile salts (BS) taurocholate, tauro-beta-muricholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate, and glycochenodeoxycholate common in rat, dog, and man with natural beta-CD and the chemically modified beta-CDs 2-hydroxypropyl-beta-CD and 2-O-methyl-beta-CD was studied using mobility shift ACE. The CDs were selected due to their frequent use in preformulation and drug formulation as oral excipients for the solubilization of drug substances with low aqueous solubility. ACE was demonstrated to be a feasible and efficient technique for investigation of the interactions between BS and beta-CDs. All the investigated BS possessed affinity for the three CDs with stability constants ranging from 2x10(3) to 4x10(5) M(-) (1). The requirements and assumptions related to the use of ACE for estimating high affinity stability constants were discussed. The extent and pattern of hydroxylation significantly influenced the affinity of the glyco- and tauro-conjugated BS toward the beta-CDs (chenodeoxycholates >> deoxycholates > cholates) whereas the nature of the beta-CD derivatization and BS conjugation played a minor role only. The results indicate that displacement of drug substances from beta-CD inclusion complexes is likely to occur in the small intestine where BS are present potentially influencing drug bioavailability.

Expression of ZNF652, a novel zinc finger protein, in vulvar carcinomas and its relation to prognosis

AIMS

To determine the levels of expression of ZNF652 and its relevance to prognosis in vulvar squamous cell carcinomas.

METHODS

22 cases of vulvar intraepithelial neoplasia (VIN) and tumours from 217 patients with vulvar squamous cell carcinomas were investigated for expression of ZNF652 using immunostaining methods. The effect of ZNF652 ectopic expression was determined in the vulvar carcinoma cell line SW954 by western and cell-based assays.

RESULTS

High levels of ZNF652 nuclear expression were observed in 5 (100%) of VIN I, 6 (75%) of VIN II and 109 (50.2%) of the vulvar carcinomas, whereas low levels were seen in 2 (25%) VIN II, 9 (100%) of VIN III and 108 (49.8%) of the vulvar carcinomas. High levels of ZNF652 expression in the vulvar carcinomas were significantly correlated to high expression of EphA2. However, when correcting for multiple testing this correlation was lost. No association was identified between ZNF652 expression and p16, p21, p27, p53, cyclin A, D1, D3, E, EphrinA-1 and human papillomavirus. Variations in levels of ZNF652 were not related to prognosis. Low levels of ZNF652 protein were identified in the vulvar carcinoma cell line SW954. Furthermore, SW954 cells ectopically expressing ZNF652 showed reduced cell proliferation and the ability to form colonies on plastic.

CONCLUSIONS

ZNF652 protein expression is reduced in 25% of VIN II, 100% of VIN III and approximately 50% of the cases of vulvar squamous cell carcinoma, and may be an early event in the pathogenesis of vulvar squamous cell carcinoma. Variations in the levels of ZNF652 were not related to patient's prognosis.

Expression of EphA2 and EphrinA-1 in vulvar carcinomas and its relation to prognosis

AIMS

To examine the expression of EphA2 and EphrinA-1 in vulvar squamous cell carcinomas and investigate their prognostic relevance.

METHODS

Tumours from 224 patients with vulvar squamous cell carcinomas were investigated for expression of EphA2 and EphrinA-1 using single and double immunostaining methods.

RESULTS

High expression (strong/moderate staining intensity) of EphA2 and EphrinA-1 was observed in 114 (51%) and 126 (56%) vulvar carcinomas, respectively. In the three cases tested using the double immunostaining method, colocalisation of EphA2 and EphrinA-1 proteins was identified in the same neoplastic cells. High EphA2 expression was significantly correlated to high expression of EphrinA-1 (p<0.01) and cyclin A (p<0.01), large tumour size (p = 0.03), deep invasion (p<0.01) and higher FIGO stage (p = 0.05). A correlation between high EphrinA-1 expression and high levels of cyclin A (p<0.01) and p21 (p<0.01), deep invasion (p<0.01) and higher FIGO stage (p = 0.01) was also seen. In univariate analysis, high expression of EphrinA-1 was associated with poor survival (p = 0.03). However, in the multivariate analysis neither EphrinA-1 nor EphA2 were significantly correlated to survival.

CONCLUSIONS

EphA2 and EphrinA-1 were overexpressed in 51% and 56% of the vulvar squamous cell carcinomas, respectively, and high levels of EphA2 and EphrinA-1 proteins were associated with deep tumour invasion and high FIGO stage. However, EphA2 and EphrinA-1 were not independently associated with clinical outcome in vulvar carcinomas.

Molecular markers for lymph node involvement in locally advanced cervical carcinomas

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Background: Lymph node involvement is the first indication of cervical cancer spread and a strong prognostic factor. The aims of the present study were to identify genes associated with lymph node involvement. Methods: The nodal status and tumor volume were determined from MR images in 48 patients with FIGO stage 2a to 4a at the time of diagnosis. cDNA microarray technique was used to identify genes that differed in expression between node positive and negative tumors. Biopsies enriched for carcinoma tissue were co-hybridized with a common reference sample in a dye-swap design. Quantitative real time PCR (qRT PCR) and immunohistochemistry were used to validate microarray results and determine protein expression of selected genes. Results: Pathologic lymph nodes were seen in 29 patients and normal nodes in 19. We identified 16 genes with higher and 15 with lower expression in node positive tumors as compared to the negative ones. QRT PCR data of 4 genes were consistent with these findings. CKS2, MRPS23, MRPL11, LSM3 and PDK2 were upregulated in node positive tumors suggesting high proliferation activity and oxygen consumption. MSN, KLF3 and TBX3 were downregulated. CKS2, MRPS23, MRPL11, PDK2, LSM3, TBX3, KLF3 and MSN were significantly related to progression free survival in univariate analysis. Protein expression, determined for CKS2 and MSN, was significantly correlated to survival, consistent with these results. In multivariate analysis including only gene variables, MRPL11, PDK2 and TBX3 were significant. Including also clinical and MRI variables, tumor volume, KLF3 and TBX3 were significant. NEK1, CSTA, ANX4 and DDOST were upregulated indicating activated DNA damage repair (NEK1) and resistance to apoptosis (CSTA, ANX4, DDOST). NTN4 and HYAL1, which are involved in cell-matrix interactions, were downregulated, suggesting mechanisms for increased cell migration and invasive growth. Conclusions: Our findings are consistent with known phenotypic characteristics of node positive cervical tumors, such as hypoxia and high lactate content. They point to molecular mechanisms for development of hypoxia, deregulation of glucose metabolism, activation of survival strategies and interactions between carcinoma cells and tumor stroma that may promote metastasis formation.

No significant financial relationships to disclose.

Effect of different surfactants in biorelevant medium on the secretion of a lipophilic compound in lipoproteins using Caco-2 cell culture

The impact of a pharmaceutical relevant metabolizable, ionic surfactant or two synthetic, nonionic surfactants on the absorption and lipoprotein incorporation of a lipophilic drug, retinol, was studied in the Caco-2 cell culture. Filter-grown monolayers of Caco-2 cells were incubated for 20 h with (3)H-retinol and (14)C-oleic acid and with increasing concentrations of lyso-phosphatidylcholine (lyso-PC), Cremophor RH40, or Tween 80. The concentration of (3)H-retinol and (14)C-lipid was measured in the apical, intracellular, and basolateral compartments. The basolateral medium was ultracentrifugated into different lipoprotein classes and their (3)H-retinol and (14)C-lipid concentrations were determined. The cells incubated with lyso-PC and Tween 80 increased the incorporation of (3)H-retinol and (14)C-lipid into chylomicrons and very low density lipoproteins (VLDL). The explored surfactants impacted the incorporation of (3)H-retinol and (14)C-lipid in chylomicrons and VLDL in a concentration-dependent manner. As these surfactants interfere with the intestinal lipoprotein secretion, inclusion of high concentrations of the surfactants in lipid-based formulations of poorly aqueous soluble drugs might impact the degree of intestinal lymphatic transport of the drug after oral administration.

Markers of apoptosis in stage IB squamous cervical carcinoma

AIMS

To examine the prognostic relevance of the expression of the Bcl-2, Bcl-xL, and Bax proteins in stage IB squamous cervical carcinoma (SCC).

METHODS

In total, 220 patients who underwent radical hysterectomy and bilateral lymphadenectomy at the Norwegian Radium Hospital for stage IB SCC between 1987 and 1993 were studied. Immunohistochemistry using monoclonal antibodies against Bcl-2, Bcl-xL, and Bax was used to examine protein expression. Ten patients who underwent hysterectomy for uterine prolapse served as controls.

RESULTS

Cytoplasmic expression of Bcl-2, Bcl-xL, and Bax was low (< 5% positive cells) in 159 of 220 (73%), 193 of 220 (87%), and 39 of 220 (18%) tumours, respectively, and high (> or = 5% positive cells) in 61 of 220 (27%), 27 of 220 (13%), and 181 of 220 (82%) tumours, respectively. In univariate analysis, all classic clinicopathological parameters but none of the investigated proteins were associated with prognosis. In multivariate analysis, only deep stromal invasion was independently related to survival.

CONCLUSION

Bcl-2, Bcl-xL, and Bax were not independently associated with prognosis in stage IB SCC.

Influence of the Type of Surfactant and the Degree of Dispersion on the Lymphatic Transport of Halofantrine in Conscious Rats

PURPOSE

To compare the lymphatic transport and the portal absorption of halofantrine (Hf) when administered in (i) a triacylglycerol (TG) solution, (ii) an o/w-emulsion that contains a metabolizable surfactant, and (iii) an o/w-emulsion that contains a synthetic surfactant.

METHODS

Lymph cannulated rats were orally dosed with Hf in a TG solution or in o/w-emulsions dispersed by lecithin or Cremophor RH40. Lymph was continuously collected, and blood was sampled periodically in the course of 30 h. Hf in the lymph and blood and TG and phosphatidyl choline (PC) in the lymph were analyzed.

RESULTS

A significantly (p < 0.05) higher level of Hf was found in the intestinal lymph when dosed in one of the emulsions (22.8+/-2.8% and 20.2+/-2.5%) compared to in the TG solution (7.9+/-1.1%). No difference in the lymphatic transport of Hf was observed between the two emulsions. The portal absorption of Hf was similar for the three vehicles.

CONCLUSIONS

The emulsified vehicles favor an increased lymphatic transport of Hf. The portal transport of Hf was not significantly different for the three vehicles. This indicates that a different degree of dispersion of the TG vehicle can change the route of transportation of Hf.

TP53 mutations in early-stage ovarian carcinoma, relation to long-term survival

We conducted the present study to evaluate the frequency and prognostic importance on long-term survival of TP53 mutations and TP53 protein accumulation in a cohort of 178 patients with early-stage ovarian carcinomas. TP53 mutations scored as aberrant temporal temperature gradient gel electrophoresis pattern from all exons were observed in 39.9% of the tumours. Full screening of exons 5–8, followed by sequencing, was successful in 135 cases, and 48 mutations altering the protein were detected in 39 cases (28.9%). TP53 mutations were slightly less common in the Federation of Gynecologists and Obstetricians stage IA than in IB/IC (P=0.05). No significant correlations with histological type, grade of differentiation, DNA ploidy status or age at diagnosis were found. TP53 protein accumulation analysed by immunohistochemistry was found in 32.6% of all tumours, and was a poor predictor of TP53 mutations with 56.4% sensitivity, 77.1% specificity, 50% positive predictive value and 81.3% negative predictive value. Neither TP53 mutations nor TP53 protein accumulation influenced the prognosis significantly in this group of patients.

Successful in silico predicting of intestinal lymphatic transfer

The possibility of developing a quantitative relationship between molecular structure and lymphatic transfer of lipophilic compounds co-administered with a long-chain triglyceride vehicle was examined. Molecular descriptors were calculated using the computer program VolSurf, and lymphatic transfer data were derived from the literature. A significant structure-property relationship was established using partial least squares, projection to latent structures statistics (PLS). R(2)X was 0.77, R(2)Y was 0.83 and the prediction power of Q(2) was 0.73 in the two-component PLS model. A number of descriptors contributed to the prediction leading to a complex model, but the prediction power was improved with the PLS model when compared to the frequently used method by relating logP values (LogKow) with lymphatic transfer.

Comparison of two intervention programmes in young female players in European handball - with and without ankle disc

INTRODUCTION

The prevention of injuries in all sports calls for a structured plan. The plan consists, as earlier described, of four steps. We have previously presented studies incorporating all four steps. The studies have shown that it is possible to prevent most injuries in young female players in European handball by applying a training programme combining the use of an ankle disc with functional strength training. In the previous studies we were not able to discriminate whether the preventive effect was due to the functional strength training or the training with the ankle disc. The aim of this study was to compare a programme with ankle disc and functional strength training with a programme with functional strength training only.

METHODS

Twenty handball teams were asked to participate, and 16 of 20 handball teams agreed to participate. The teams were cluster randomised to either the programme with or without an ankle disc.

RESULTS

The group using the programme without the ankle disc had a significantly higher number of traumatic injuries (16 vs. 6). The incidences of traumatic injuries in the ankle disc group were 2.4 (95% CI 0.7; 6.2) injuries per 1000 h of match and 0.2 (95% CI 0.02; 0.7) injuries per 1000 h of practice. In the group without ankle disc the incidences were 6.9 (95% CI 3.3; 12.7) injuries per 1000 h of match and 0.6 (95% CI 0.2; 1.3) injuries per 1000 h of practice. A significantly higher multivariate odds ratio (4.8) was found in the group not using the ankle disc. In addition the group using the ankle disc had significantly fewer moderate and major injuries.

CONCLUSION

By adding ankle disc training to a training programme with functional strength training, it is possible to reduce the number of injuries significantly, especially the number of moderate and major injuries.

Examination of oral absorption and lymphatic transport of halofantrine in a triple-cannulated canine model after administration in self-microemulsifying drug delivery systems (SMEDDS) containing structured triglycerides

The potential for lipidic self-microemulsifying drug delivery systems (SMEDDS) containing triglycerides with a defined structure, where the different fatty acids on the glycerol backbone exhibit different metabolic fate, to improve the lymphatic transport and the portal absorption of a poorly water-soluble drug, halofantrine, were investigated in fasted lymph cannulated canines. Two different structured triglycerides were incorporated into the SMEDDS; 1,3-dioctanoyl-2-linoleyl-sn-glycerol (C8:0-C18:2-C8:0) (MLM) and 1,3-dilinoyl-2-octanoyl-sn-glycerol (C18:2-C8:0-C18:2) (LML). A previously optimised SMEDDS formulation for halofantrine, comprising of triglyceride, Cremophor EL, Maisine 35-1 and ethanol was selected for bioavailability assessment. The extent of lymphatic transport via the thoracic duct was 17.9% of the dose for the animals dosed with the MLM SMEDDS and 27.4% for LML. Also the plasma availability was affected by the triglyceride incorporated into the multi-component delivery system and availabilities of 56.9% (MLM) and 37.2% (LML) were found. These data indicate that the pharmaceutical scientist can use the structure of the lipid to affect the relative contribution of the two absorption pathways. The MLM formulation produced a total bioavailability of 74.9%, which is higher than the total absorption previously observed after post-prandial administration. This could indicate the utility of disperse lipid-base formulations based on structured triglycerides for the oral delivery of halofantrine, and potentially other lipophilic drugs.

Deregulation of D-type cyclins in uterine cancers. Cyclin D1/D3 is differentially expressed in cervical cancer

BACKGROUND

We have previously found cyclin D1 to be overexpressed in 45% of corpus cancers, but in only 3% of cervical cancers. To see whether and how D-type cyclins contribute to the neoplastic phenotype in uterine cancers, aberrant expression and association between cyclins D1 and D3 proteins were studied.

MATERIALS AND METHODS

Expression of cyclin D3 was investigated by immunohistochemistry in 51 patients with primary cancer of the corpus and 73 cases of primary cervical carcinomas. Amplification of the cyclin D1 and D3 genes was investigated by fluorescence in situ hybridisation (FISH).

RESULTS

We found high/moderate levels of cyclin D3 in 53.5% of cervical cancers and 55% of corpus cancers. High/moderate expression of cyclin D1 and D3 was associated in the corpus cancers, but not in cervical cancers. The accumulation of cyclin D3 but not D1 protein could, in some cases, be explained by increased gene dosage since extra copies of chromosome 6 were found.

CONCLUSION

This study demonstrates that in cervical cancers cyclin D3 may compensate for low levels of cyclin D1, whereas in corpus cancers both isoforms may contribute to the neoplastic phenotype.

Association between histology grade, expression of HsMCM2, and cyclin A in human invasive breast carcinomas

AIM

Increased proliferation of tumour cells has prognostic value in human invasive breast carcinomas (IBCs), and high histology grade and cyclin A expression, which may reflect high proliferation rate, are associated with poor prognosis. Expression of HsMCM2 is related to cell proliferation. This study evaluates the correlation between the expression of cyclins A, D1, D3, and E, Ki-67, proliferating cell nuclear antigen (PCNA), histology grade, and HsMCM2 expression, in addition to the independent prognostic value of HsMCM2 expression in human IBCs.

METHODS

Immunohistochemistry to evaluate HsMCM2, Ki-67, and PCNA expression in tumours from 147 patients with IBC.

RESULTS

Nuclear staining for HsMCM2 was seen in 10-30% of the tumour cells in 30 samples, in 30-70% in 40 samples, in > 70% in 44 samples, and in < 10% in 33 samples. One way ANOVA showed a significant association between expression of HsMCM2 and cyclin A, D3, E, histology grade, and Ki-67. A borderline correlation was seen between HsMCM2 and PCNA. In multivariate analysis, the only association was with cyclin A, in addition to a borderline association with histology grade. In a Cox regression hazards model, expression of HsMCM2 was associated with poor patient survival, although it lost its independent prognostic value when cyclin A expression was included. Ki-67 and PCNA expression were not associated with patient survival.

CONCLUSION

Cyclin A expression is independently associated with HsMCM2 expression, histology grade, and Ki-67. HsMCM2 expression is associated with poor patient survival, although it loses prognostic value when adjusted for cyclin A.

Structured triglyceride vehicles for oral delivery of halofantrine: examination of intestinal lymphatic transport and bioavailability in conscious rats

PURPOSE

To compare the influence of triglyceride vehicle intramolecular structure on the intestinal lymphatic transport and systemic absorption of halofantrine in conscious rats.

METHODS

Conscious, lymph cannulated and nonlymph cannulated rats were dosed orally with three structurally different triglycerides; sunflower oil, and two structured triglycerides containing different proportion and position of medium-(M) and long-chain (L) fatty acids on the glycerol backbone. The two structured triglycerides were abbreviated MLM and LML to reflect the structural position on the glycerol. The concentration of halofantrine in blood and lymph samples was analyzed by HPLC.

RESULTS

Both the lymphatic transport and the total absorption of halofantrine were enhanced by the use the MLM triglyceride. The estimated total absorption of halofantrine in the lymph cannulated animals was higher than in the nonlymph cannulated animals, and this was most pronounced for the animals dosed with the structured triglycerides.

CONCLUSIONS

Using MLM as vehicle increases the portal absorption of halofantrine and results in similar lymphatic transport levels when compared to sunflower oil. Total absorption when assessed as absorption in the blood plus lymphatic transport for halofantrine after administration in the MLM triglyceride was higher than after administration in sunflower oil.