Formulation of lyotropic liquid crystal containing mulberry stem extract: influences of formulation ingredients on the formation and the nanostructure.

OBJECTIVE: This study focused on the formulation of lamellar lyotropic liquid crystal (LLC) loaded with mulberry stem extract (MSE). METHODS: The LLC formulation tested used two oils: n-dodecane or tridecyl salicylate, a co-solvent (propylene glycol) and a single (PEG-7 glyceryl cocoate) or mixed surfactant system. The mixed surfactant was PEG-7 glyceryl cocoate/PEG-40 hydrogenated castor oil/glyceryl monooleate. The LLC formation and phase behaviour were observed by polarized optical microscopy (POM) before and after MSE loading. Nanostructure determinations on these formulations following MSE loading used small angle X-ray scattering (SAXS) at 25-40°C. RESULTS: Lamellar LLCs are formed more easily with n-dodecane than tridecyl salicylate. Propylene glycol, in the aqueous phase (1 : 1), failed to form LLC due to suboptimal critical packing parameter (CPP) value. A single or mixed surfactant system also influenced the formation of lamellar LLC according to the chemical structure of both oils and especially the surfactants used. The four lamellar LLC formulations selected for MSE loading were PEG-7 glyceryl cocoate/tridecyl salicylate/water; mixed surfactant/tridecyl salicylate/water; PEG-7 glyceryl cocoate/n-dodecane/water and mixed surfactant/n-dodecane/water, named F1, F2, F3 and F4, respectively. MSE in F1 and F3 did not affect the lamellar structure, while MSE in F2 and F4 enlarged the lamellar structure. The SAXS data confirmed that the LLC formulations obtained were lamellar and the structure persisted with MSE. CONCLUSION: These lamellar formulations should find widespread application for MSE and perhaps other similar herbal cosmetics.

Average bioequivalence of clarithromycin immediate released tablet formulations in healthy male volunteers.

The objective of this study was to assess average bioequivalence of two immediate released tablet formulations of 500-mg clarithromycin tablets in 24 healthy Thai male volunteers. In a randomized, single dose, fasting state, two-period, crossover study design with a 1-week washout period, each subject received a 500-mg clarithromycin tablet. Plasma samples were collected over a 24-hour period after oral administration and were analyzed by using a validated method using high performance liquid chromatography with electrochemical detection. Pharmacokinetic parameters were determined by using noncompartmental analysis. The time to reach the maximal concentration (tmax, h), the peak concentration (Cmax, ng/mL), and the area under the curve (AUC0-infinity, ng x h/mL) of the Reference and Test formulations were 2.0 +/- 0.8 vs. 2.2 +/- 0.9, 2793 +/- 1338 vs. 2642 +/- 1344, and 17912 +/- 7360 vs. 17660 +/- 7992, respectively. Relative bioavailability was 0.99. The 90% confidence interval of Cmax and AUC0-infinity were 82.6-112.1% and 84.7-112.0%. Bioequivalence between the Test and Reference formulation can be concluded.

Formulation and development of a patch containing tamarind fruit extract by using the blended chitosan-starch as a rate-controlling matrix.

A cosmetic patch containing tamarind fruit extract was formulated and developed by blending two types of natural polymers: chitosan with molecular weight of 100 000 and starch such as corn, potato or tapioca starch. The physicochemical characteristics, i.e. flexibility, colour, transparency, integrity, gloss, water sorption and bioadhesion property and the stability of the patch without tamarind content were investigated. Stability test was performed by keeping the prepared patches at 4 degrees C, at room temperature or at 45 degrees C for 2 weeks. The results showed that the formulations composed of chitosan:corn starch ratio of 4.5 : 0.5 (CC(4.5 : 0.5)) and chitosan:tapioca starch ratios of 4.5 : 0.5 (CT(4.5 : 0.5)) and 4.0 : 1.0 (CT(4 : 1)) provide patches with favourable physical characteristics, high water sorption, good bioadhesion ability and good stability. After the lyophilized tamarind extract in an amount corresponding to 5% of tartaric acid was incorporated into the formulations of CC(4.5 : 0.5), CT(4.5 : 0.5) and CT(4 : 1), the ability of the patches to adhere to skin was improved. However, after keeping the test patches at room temperature or at 45 degrees C for 6 weeks, their colours were intensified while their flexibilities and skin adhesion properties decreased. A 12-h in vitro permeation was investigated by studying the cumulative amount of tartaric acid permeated through the Silastic membrane (Dow-Coming, Midland, MI, USA). The CC(4.5 : 0.5) patch tended to give the highest amount of tartaric acid released. The release pattern of all the blended polymeric matrices was exhibited in two distinct phases: the rapid phase, where the flux averaged 3.61 microg min(-1) mm(-2); and the slow phase, where the flux averaged 1.89 microg min(-1) mm(-2).

Freeze-drying of tert-butyl alcohol/water cosolvent systems: effects of formulation and process variables on residual solvents.

The objective of this study was to identify significant formulation and processing variables affecting levels of tert-butyl alcohol (TBA) and isopropyl alcohol (IPA) in freeze-dried solids prepared from TBA/water cosolvent systems. The variables examined were the physical state of the solute (crystalline vs amorphous), initial TBA concentration, freezing rate, cake thickness, and the temperature and duration of secondary drying. Sucrose and glycine were used as models for noncrystallizing and crystallizing solutes, respectively. The TBA concentration above which eutectic crystallization takes place was determined by differential scanning calorimetry. Model formulations were subjected to extremes of freezing rate by either dipping in liquid nitrogen or by slowly freezing on the shelf of a freeze-dryer. Dynamics of solvent loss during secondary drying was determined by withdrawing samples as a function of time at different shelf temperatures using a thief system. On the basis of these studies, the most important determinant of residual TBA level is the physical state of the solute. Freeze-dried glycine contained very low levels of residual TBA (0.01-0.03%) regardless of freezing rate or initial TBA concentration. For freeze-dried sucrose, residual TBA levels were approximately 2 orders of magnitude higher and were significantly affected by initial TBA concentration and freezing rate. For the sucrose/TBA/water system, relatively low residual TBA levels were obtained when the initial TBA level was above the threshold concentration for eutectic crystallization of TBA, whereas samples freeze-dried from solutions containing TBA concentrations below this threshold contained significantly higher levels of TBA. Residual IPA levels increased continuously with initial concentration of TBA in the sucrose/TBA/water system. Formulations of sucrose/TBA/water which were frozen rapidly contained residual TBA levels which were approximately twice those measured in the same formulation after slow freezing and drying under the same conditions. For the sucrose/TBA/water system, the temperature and time of secondary drying had only minimal influence on residual TBA in the freeze-dried solid. At low initial TBA concentrations (2%), residual TBA increases with increased cake thickness, perhaps because of the influence of depth of fill on effective freezing rate.

Sphingobacterium multivorum septicemia: a case report.

A 47-year-old man presented with a history of fever, chills and weight loss for 3 months. He had been treated for diabetes mellitus during the past 3 years. He developed high fever with abnormal liver function tests. Both Widal and Weil-Felix reactions were negative with normal roentgenogram of the chest. His anti-HIV tests were positive. The cultures from the blood and sputum yielded pure Sphingobacterium multivorum sensitive to sulfamethoxazole-trimethoprim, chloramphenicol, tetracycline, cefotaxime, ceftazidine and ceftriaxone. On the next day, the patient developed signs and symptoms of meningitis with the CSF containing chronic and acute inflammatory cells but revealed no growth on culture. The patient was treated with a combination of ceftriazone and trimethoprim-sulfamethoxazole but he died on the 6th day after admission. This patient was the fifth reported case infected with S.multivorum. It illustrates that this potentially pathogenic organism can cause septicemia in an immunodeficient patient.

Serum transcobalamin II level in glucose-6-phosphate dehydrogenase deficient subjects with typhoid fever.

Transcobalamin II (TCII) is the vitamin B12 binding protein which is responsible for delivery of this vitamin to the tissues. High values for serum TCII have been reported in many clinical conditions. This paper describes the elevated serum TCII levels in three G-6-PD deficient patients with typhoid fever. They had severe hemolysis with hemoglobinuria associated with slight liver dysfunctions but without obvious increased serum creatinine and BUN concentrations. A remarkable increase in serum TCII level was observed during active hemolysis and decreased to the normal level within 2-3 days after hemolysis ceased. The mechanism of increased serum TCII during hemolysis is probably due to hemoglobinuria secondary to excessive hemolysis. As Hb is known to be efficiently reabsorbed by the proximal tubule cells and can competitively inhibit the tubular uptake of TCII-B12. It is possible that excess Hb interferes with TCII uptake and degradation at renal tubular cells. Therefore, the circulating TCII survival is prolonged resulting in the elevated TCII level. Furthermore, lysosomal degradation of newly synthesized TCII is a normal process that regulates the TCII secretion. Therefore, a reduced lysosome-mediated uptake of TCII-B12 by renal tubular cell may stimulate the TCII secretion as has been shown experimentally in vitro.

Serum transcobalamin II levels in patients with acute and chronic renal failure.

Serum TCII levels were determined in 57 patients with acute and chronic renal failure. They were divided into 3 groups, group I was malarial patients with acute renal failure, group II and III were patients with acute renal failure and chronic renal failure from other underlying causes, respectively. All patients in group I had serum TCII over 2000 pg/ml while these values were within the normal limits in the other 2 groups. These findings indicated that elevated serum TCII occurred only in malarial patients with acute renal failure. The clearance and urinary excretion of TCII in malarial patients were found to be lower and increased to the normal levels after recovery from azotemia, indicating that the failure of excretion of TCII by the kidneys may be responsible for elevated serum TCII levels. The pathophysiological changes in the kidneys in malarial patients may reduce the amount of filtered TCII-B12 through the glomeruli and decrease TCII-B12 uptake by the renal tubules resulting in the decreased TCII degradation by tubular cells. Therefore, the intravascular TCII survival is prolonged with elevated serum TCII levels in these patients.

Serum transcobalamin II levels in patients with malaria infection.

Serum transcobalamin II (TCII) levels were determined in 56 patients with P. falciparum malaria infection. They were divided into 3 groups: severe (malarial parasite > 5% or patients with cerebral malaria or renal insufficiency), moderate (1-5% infection without complications) and mild (1% infection). Elevated serum TCII values were found only in patients with severe malaria infection. These values correlated directly with parasitemia, blood urea nitrogen and creatinine, but were not correlated with alkaline phosphatase. As 17 patients with azotemia had elevated serum TCII levels while other 3 patients with normal BUN and creatinine concentrations had serum TCII levels within the normal limits. These findings indicated that malarial patients with renal insufficiency had increased serum TCII. A possible mechanism is the reduced TCII-B12 that filtered through the glomeruli due to the reduced renal blood flow with the decreased its uptake by proximal tubular cells resulting in the decreased degradation of TCII by the tubular lysosomal enzymes. Determination of serum TCII level may be used as an indicator of renal function in malarial patients with renal insufficiency.

Persistently elevated serum transcobalamin II in a patient with cerebral malaria and typhus infections.

A 25-year-old man presented with a history of fever, chills and vomiting for three days. The parasite count was 207 ring-forms of P. falciparum per 1000 red cells. He developed hemoglobinuria and excreted hemoglobin in the urine 0.20-0.30 g/dl for 14 days during admission. Many blood transfusions were administered for correcting anemia. Although the malarial parasites disappeared one week after anti-malarial therapy, however, the fever and hemoglobinuria persisted. The Weil-Felix reaction OXK was positive with a titre of 1:40 on admission and increased to 1:160 on the second week. Chloramphenical and prednisolone were given for treatment of typhus fever and all symptoms subsided. Serum TCII levels were found to be increased and persisted high during the hemoglobinuria. The clearance of TCII was lower and increased relatively slowly to the normal level on day 30. On the other hand, TCII excretion in the urine was found to be increased during hemoglobinuria. These findings indicate that the catabolism and clearance of TCII in this patients is impaired with increased TCII excretion in the urine in parallel to the hemoglobinuria. Serum TCII level is, therefore, increased and persistently high in a patient with malaria and typhus fever infections with hemoglobinuria.

Abnormally elevated serum transcobalamin II levels in patients with cerebral malaria.

Transcobalamin II (TCII) levels have been reported to be elevated in patients with many clinical conditions including proliferative reticuloendothelial system. As reactive macrophage hyperplasia frequently occurs in patients with malaria, the objective of the present study was to determine TCII in patients with Plasmodium falciparum with cerebral symptoms. The studies were performed on 14 cerebral malaria patients as well as 60 normal subjects. The mean values of serum vitamin B12 and TCII levels were significantly higher in the patient group and 6 and 7 patients had serum vitamin B12 and TCII levels higher than the normal values. There was direct relationship between serum TCII levels and BUN or creatinine levels. These findings indicated that raised serum TCII level occurred only in patients with renal insufficiency. A decreased glomerular fiLtration rate reduced the amount of vitamin B12 and TCII-B12 that filtered through the glomeruli resulting in the reduced proximal tubular cells uptake and its degradation of TCII. This reduced lysosomal enzyme activity, therefore, prolongs the intravascular TCII survival and increased secretion of TCII into the circulation. Therefore, serum TCII levels were elevated in these cerebral malaria patients.

Increased circulating levels of transcobalamin II in malarial patients with renal involvement.

Vitamin B12 and its binding proteins were measured in the serum and urine of four patients with Plasmodium falciparum who had renal insufficiency. The results showed that these patients had elevated serum transcobalamin II (TCII) levels which decreased to the normal level after recovery from azotaemia. There were direct relationships between serum TCII levels and blood urea-nitrogen or creatinine concentrations. The clearance and urinary excretion of vitamin B12 and TCII were significantly lower in the patients' group than in normal subjects. All these findings indicated that elevated serum TCII could occur in P. falciparum patients with renal insufficiency. This is probably caused by a reduction in renal plasma flow and glomerular filtration rate (GFR), secondary to a low or ineffective blood volume. The reduced GFR, in turn, reduces the TCII-B12 that filters through the glomeruli, resulting in decreased TCII-B12 uptake by the renal tubules, and thus slows down the TCII degradation by lysosomal enzymes. The decreased TCII catabolism therefore prolongs the TCII survival in the circulation and probably stimulates TCII synthesis and secretion in a feedback mechanism.

Optic neuropathy in a patient with vitamin B12 deficiency: a case report.

A 19-year-old man presented with blurring of vision for 2 weeks. He also complained of anorexia with weight loss during the past 4 months. Eight years ago, his small bowel from midportion of the jejunum, ileum, ascending colon and transverse colon were resected because of gangrene. He gave no history of exposure to tobacco, alcohol or other toxins. The bone marrow aspiration showed hypocellular with panhypoplasia. Serum vitamin B12 level was low while serum and red cell folate were within normal limits. His visual acuity was 5/200 in both eyes with centrocecal scotomas in both eyes. Other neurologic and ophthalmic examinations were found to be normal. The patient was given intramuscular injections of 1,000 micrograms of cyanocobalamin. Four months later, his visual acuity improved, serum vitamin B12 level and the bone marrow returned to be normal. This is a frank case of optic neuropathy in a patient with vitamin B12 deficiency due to a massive small bowel resection.

Vitamin B12 deficiency: report of a childhood case.

An 11-year-old boy who presented with anemia, premature grey hair, hyperpigmented skin, paresthesia, recurrent aphthous ulcers and epistaxis was eventually proved to be a case of vitamin B12 deficiency. Due to the paucity of this deficiency, the diagnosis may easily be delayed and overlooked resulting in unfavorable consequences. Therapeutic response to vitamin B12 was dramatic in this reported case.

The source and content of vitamin B12 in the tempehs.

Vitamin B12 contents were determined on 10 commercial tempeh samples purchased from various markets in Jakarta, Indonesia. A relatively high vitamin B12 content was found, i.e., 19 ng/g (ranges from 1.8 to 41.4 ng/g). As soybeans contain no vitamin B12, the amount of vitamin in the tempeh must therefore be derived from the other sources during the fermentation process. The tempeh prepared in the laboratory by inoculation of the commercial starter into the sterile soybean contained a much higher amount of vitamin B12, 127 ng/g (ranges from 122 to 136 ng/g). Pure mold and a single species of bacteria were isolated from the starter and commercial tempehs. Pure mold did not produce vitamin B12 in the sterile broth, soybean and medium used for vitamin B12 production. Only the isolated bacteria, identified as K. pneumoniae, could produce vitamin B12 in those substrates. The presence of mold did not significantly enhance or inhibit the vitamin B12 production by K. pneumoniae. It was, therefore, concluded that K. pneumoniae, the bacteria contaminated during the process of tempeh production, was responsible for the vitamin B12 production.

Iron excretion in thalassemia children treated with deferoxamin methansulfonat: intravenous drip compared to the subcutaneous routes.

The iron excretion in the three beta-Thal/Hb E patients were determined comparing the effect of DF given by subcutaneous push, subcutaneous drip and intravenous drip. The subcutaneous drip or intravenous drip increased urine iron excretion by 5.6-11.2 times whereas the subcutaneous push, 3.5-5.3 times only. It is recommended that for countries where the infusion machine is very expensive the DF should be given by intravenous drip or the modified, simple and inexpensive equipment for subcutaneous drip.

Superoxide dismutase and catalase activities of cultured erythrocytes infected with Plasmodium falciparum.

It has already shown that catalase activity is significantly decreased in red cells of patients with P. falciparum. The mechanism suggested was by this enzyme inactivation through increased H2O2 generated during malarial infection. The present study was performed to verify this hypothesis. Catalase activities of red cells with high or low parasitemia in patients with P. falciparum were found to be lower than those of normal red cells. However, P. falciparum-infected red cells cultured for one week showed similar SOD and catalase levels to normal red cells. There was also no significant difference in the catalase levels between the parasitized and non-parasitized red cells. The difference in catalase activity of infected red cells before and after culture could be explained in terms of the activation of mononuclear cells and macrophages in vivo. During the sojourn of the parasitized red cells in close proximity to the macrophages of the spleen, they might trigger oxidative bursts resulting in increased H2O2. In order to protect themselves from oxidant damage, the catalase in the infected red cells could be inactivated by H2O2 resulting in the reduction of this enzyme.