Hybrid polymeric matrices for oral modified release of Desvenlafaxine succinate tablets

Purpose: Desvenlafaxine succinate (DSV) is a water soluble anti-depressant drug, which is rapidly absorbed after oral administration exaggerating its side effects. The current work aimed to prepare controllable release DSV matrix to reduce DSV side effects related to its initial burst. Methods: Fifteen DSV matrix formulations were prepared using different polymers, polymer/drug ratios and matrix excipients and characterized using Differential Scanning Calorimetry (DSC), infrared (IR) spectroscopy, water uptake and in vitro DSV release. The release kinetics were calculated to determine the drug release mechanism. Ex-vivo DSV absorption via rat intestinal mucosal cells and the calculation of the apparent permeability coefficient (P_app) were performed using everted sac technique. Results: Maltodextrin was the best matrix excipient (F7 and F10) showing acceptable decrease in the initial burst compared to the innovator. The addition of negatively charged polymers sodium carboxy methyl cellulose (SCMC) or sodium alginate resulted in an interaction that was proved by DSC and IR findings. This interaction slowed DSV release. F10 showed an excellent absorption of more than 80% of DSV after 4 h and the highest similarity factor with the innovator (84.7). Conclusion: A controllable release pattern of DSV was achieved using Methocel, Maltodextrin and SCMC. The obtained results could be used as a platform to control the release of cationic water soluble drugs that suffer from side effects associated with their initial burst after oral administration.

Lyophilization monophase solution technique for improvement of the physicochemical properties of an anticancer drug, flutamide

Flutamide (FLT), an anticancer drug for prostatic carcinoma, has poor aqueous solubility and low oral bioavailability. This study describes the ability of beta-cyclodextrin (betaCD) and hydroxypropyl-beta-cyclodextrin (HPbetaCD) to form complexes with flutamide with enhanced solubility and dissolution rate in vitro. FLT-CD lyophilized dispersions (LDs) were prepared via lyophilization monophase solution technique using tertiary butyl alcohol (TBA) as a cosolvent. FLT showed an A(L)-type phase solubility diagram consistent with a linear increase in drug solubility as a function of CD concentration. Gas chromatography indicated that the LDs contain 0.02-0.03% w/w residual TBA. Based on the data from differential scanning calorimetry (DSC) and X-ray diffractometry (XRD), FLT was fully amorphous in 1:5 FLT-HPbetaCD LD as indicated by complete disappearance of FLT endothermic and diffraction peaks. The Fourier transform infrared (FTIR) spectra indicated that a FLT-CD interaction took place in the lyophilized complex. The particle sizes of 1:1 FLT-betaCD and FLT-HPbetaCD LDs were 0.92 and 0.82microm, with a high surface area (484.55 and 705.68m(2)/g) and porosity (769.46 and 1020.99e(-3)ml/g), respectively. The dissolution rate of FLT from its CD complexes was enhanced significantly. After 30min in 0.1N HCl, about 73% and 86% of FLT were dissolved from 1:5 FLT-betaCD and FLT-HPbetaCD LDs, respectively, compared to only 13.45% of pure drug. No endothermic peak corresponding to FLT melting was detected in 1:5 FLT-HPbetaCD LD after storage at 20 degrees C and 45% relative humidity for 90days thus indicating the stability of this binary system. These data suggest that cyclodextrins might be useful adjuncts in preparation of immediate-release formulations of FLT.

High-dose percutaneous ethanol injection therapy of liver tumors. Patient acceptance and complications

PURPOSE

To study the safety of high-dose ethanol injections in liver tumors and their acceptability as out-patient procedures under local anesthesia.

MATERIAL AND METHODS

Twenty-nine patients received 20-95 ml of 95% ethanol by 62 percutaneous injections under local anesthesia. Pain was assessed by a visual analogue scale from 1 to 10 for 33 of the sessions. Side effects, complications, post-treatment requirement of parenteral analgesics, and hospital stay (discharge the same day or later) were recorded. The sessions were compared to 80 injections of <20 ml of ethanol in 18 patients.

RESULTS

High-dose injections with an average volume of 39 ml gave a mean pain score of 5.1, with a weak relationship between pain and volume. Other side effects and complications were unrelated to the ethanol dose. They comprised 1 syncopation, 1 occasion of hypoventilation requiring antidote to opiates, 12 short episodes of nausea or vomiting without need for i.v. fluids, 2 instances of sepsis, and 1 abscess that was drained percutaneously. Thirty-nine of the 62 sessions were performed in day care. Ethanol was given in high doses without apparent complications after or shortly before liver resections (3 patients in each group), and on 4 occasions in 2 HIV carriers. Low-dose injections resulted in a mean pain score of 4.7 with the same requirement of i.v. analgesics as high doses, fewer instances of nausea and no infectious complications.

CONCLUSION

High-dose ethanol injections in patients with liver malignancy had no mortality and a reasonable complication rate. They could be given without general anesthesia, often in day care.

Potent effect of recombinant growth hormone on bone mineral density and body composition in adults with panhypopituitarism

Six patients (21-50 years) with growth hormone deficiency and panhypopituitarism were given recombinant growth hormone, somatotropin, 0.04-0.1 U.kg.body wt-1.day-1, for 12 months. All patients reported improved well-being with increased working capacity. Bone mineral density, as measured by single photon absorptiometry at two sites on the forearm, showed increased values in 5/6 patients after 12 months when measured at the most distal site (predominantly trabecular bone) and in 4/6 at the more proximal site (predominantly cortical bone). Five patients continued therapy for an additional year and after 18 months a significant increase in bone mineral density was seen at both the distal and proximal sites. The mean annual increase in bone mineral density was 12.0 +/- 0.6 (SEM)% and 3.8 +/- 1.3% at the distal and proximal sites, respectively. In a growth hormone deficient control group without growth hormone therapy, the corresponding values were -2.4 +/- 0.6% and -1.9 +/- 0.4%, respectively. Lean body mass, estimated anthropometrically, increased significantly after 12 months and total body potassium, measured by whole body counting technique, increased in 4/6 patients. During growth hormone treatment, the IGF-1 values were above the mean values for age and 50% of the values were above the mean +2 SD. B-glucose, P-insulin, serum IGF-2, procollagen-III peptide and phosphate increased and urea, creatinine and IGF-binding protein-1 decreased during treatment. The beneficial effects of growth hormone substitution, especially on bone mineral density, indicate that growth hormone substitution should be considered in all patients with hypopituitarism and growth hormone deficiency, irrespective of age.