How different are epidemiology and treatment of cancer persistent pain (PP) and breakthrough pain (BTP) in elderly patients (pts)? Results of a French prospective survey

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Background: Efforts have been made in the recent years to improve pain care in cancer pts, especially for elderly ones Methods: We conducted a national survey in France in order to evaluate the actual situation. Data were collected from 100 cancer centers and analyzed using SAS software. Only adult pts treated for cancer pain, with their treatment initiated less than 8 days before study, were considered. Comparisons were made considering pts under and over 70 years old Results: Epidemiology: 793 pts were included, 565 being under 70 years old (mean 54), 228 over 70 years old (mean 76). There were more men in the elder group (67% vs 54%, this being explained by some differences in tumor type (more prostate cancer). Proportion of metastatic pts was not different (78 vs 79%) but metastatic sites were not the same, especially bone mets (70 vs 55%). Fewer pts were currently treated with chemo or radiotherapy in the elder group. Median WHO performance status was worse in elderly pts (3 vs 2). Characteristics of pain: Of note, characteristics of PP and BTP (pain location, nociceptive or neuropathic pain, intensity for PP and BTP, number of BTP episodes) were not different between the 2 groups. Pain treatment: Almost all the pts received opioids in both groups for PP and BTP, while elder pts were treated less frequently with specific drugs for neuropathic pain (antidepressant and anti-epileptic), and psychological support was less likely offered to them (36 vs 48%) Conclusions: Characteristics of PP and BTP in cancer pts are not influenced by pts age. Progresses have been made as elder pts receive opioids as often as younger ones, but improvements are still needed concerning the treatment of neuropathic pain and psychological support in elderly pts.

No significant financial relationships to disclose.

Progesterone freeze-dried systems in sublingual dosage form

Various polymer matrices were tested to enhance progesterone bioavailability as part of an emergency therapy. Among the different polymers used, i.e. poly(N-vinylpyrrolidone) (PVP), poly(ethylene oxide) (PEO), Dextran T70 and partially saponified poly(methyl glyoxylate) (PMGz), the latter gives the fastest solubilization rate. The best results were obtained with the lyophilized dosage form instead of a simple mixture of the drug within the polymer matrix. A nearly instantaneous solubilization was observed with PMGz copolymers bearing 10-40% of carboxylic groups and containing up to 20% of the drug. The instantaneous solubilization of the PMGz matrix is due to the hydrophilic moieties, and the presence of hydrophobic zones in PMGz promotes good affinity with the drug and optimal dispersion into the matrix.

Stability assessment of ketoconazole in aqueous formulations

Ketoconazole is an imidazole antifungal agent. It has a wide antifungal spectrum and possesses some antibacterial activity. In inappropriate formulations, especially in aqueous media, ketoconazole molecules may be unsteady. The stability of ketoconazole in aqueous media was assessed as a function of pH, antioxidant and ketoconazole concentrations. It was found that ketoconazole was least stable at pH 1 among the pH values studied (pH 1-9). Since the major degradation pathway was specific acid catalysis, based upon the transition-state theory, the entropy (DeltaS) of the activation was calculated and found to be negative indicating that the activated complex was more constrained than the individual species. The free energy of activation (DeltaG) was estimated to be 30 kcal mol(-1). The viscosity of the formulation was found to be more stable at high pH because carbopol is stable at basic pH and protected ketoconazole. It appears that the amount of ketoconazole in the formulation has a low influence on the degradation mechanisms. The increase of the butylated hydroxytoluene antioxidant levels from 0.05 to 0.4%, adversely affected the stability of ketoconazole. In conclusion, the expected shelf life of the final ketoconazole formulation (pH 7, 0.1% butylated hydroxytoluene) was 15 months.

Rheological behavior of drug suspensions in Gelucire mixtures and proxyphylline release from matrix hard gelatin capsules

Mixtures of Gelucires 50/02 and 50/13 showing different hydrophilic-lipophilic balances (HLB) and of proxyphylline were used to prepare suspensions at a concentration of 25% and to manufacture extended release hard gelatin capsules by cooling. The rheological behaviors of Gelucire mixtures with and without drug were determined by adjustment of the rheograms to the Ostwald power-law and by statistical assessment of the flow index. Pure Gelucire mixtures were very slightly shear thickening whereas proxyphylline suspensions had a thixotropic shear thinning behavior. These rheological behaviors can be explained by the chemical composition and by the ratio of the two Gelucires used. Extended release of proxyphylline was obtained with all these mixtures. Drug release increased with Gelucire mixture HLB owing to higher erosion. A viscosity-release relationship was found and allowed, with these two Gelucires of extreme HLB and viscosities, to define the formulations which will give an optimal drug release, by the determination of their suspension viscosity. Modeling of dissolution kinetics has generally shown the predominance of surface erosion of the plugs relative to drug diffusion inside the matrix. This was confirmed by the better linearization of percentage released, according to Hixson-Crowell as compared with Higuchi.

Rheology of polyol behenates and drug release from matrix monolithic capsules

Three polyol behenates with similar melting points (MP) and different hydrophilic-lipophilic balances (HLB) were studied (MP/HLB: 70/02, 63/05 and 57/13). After melting at MP+30 degrees C, the rheological behaviour of behenates was determined by adjustment of the rheograms to the Ostwald power-law and by statistical assessment of the flow index. Behenates showed slight shear thickening. This shear thickening increased when HLB of behenates decreased. This behaviour accounted for a reorganization of the particles under the shear, which became easier when the proportion of the polyethylene glycol chains in the wax decreased. Proxyphylline was used to prepare suspensions at a concentration of 25% in the melted behenates, and to manufacture monolithic capsules by cooling. The suspensions had a shear-thinning behaviour with or without thixotropy. Colloidal particles and aggregates formed in these suspensions directly influenced the rheological properties, as observation of solidified suspensions by scanning electron microscopy confirmed. Extended release of proxyphylline was obtained with the three waxes. Behenates 63/05 and 70/02 gave inert matrices and released drug very slowly. Hydrodispersible behenate 57/13 swelled and made up a kind of hydrophilic matrix that released proxyphylline more quickly, due to slight erosion. In the three cases, the release mechanism was basically diffusional in nature.

Increase of uterine motility and simultaneous decrease of progesterone concentrations in the rat after bilateral ovariectomy at mid-pregnancy

Comparison of uterine activities recorded during the control period to those obtained during the two recording periods after ovariectomy (0-30 min and 30-60 min) showed an increase of the amplitude of uterine contractions (P less than 0.005) and a decrease of the interval between two successive uterine contractions (P less than 0.005) and the delay of electrical activities (P less than 0.005). Progesterone treatment (50 mg/kg i.m.) of ovariectomized rats prevented the abrupt fall in plasma progesterone concentrations, measured by RIA, which in turn inhibited the increase of uterine mechanical and electrical activities. A close relation between the increase of myometrial activity and the decrease of progesterone concentrations after ovariectomy is suggested. The activation of the myometrium would be principally induced by the fall of progesterone or by the variation of the oestrogen/progesterone ratio; these changes in sexual steroid hormones would augment the uterine sensitivity to physiological stimuli or modify the activity of other factors involved in the regulation of the myometrium.