RÉSUMÉ
This work aimed at formulating a trilaminate dressing loaded with tranexamic acid. It consisted of a layer of 3 % sodium hyaluronate to initiate hemostasis. It was followed by a mixed porous layer of 5 % polyvinyl alcohol and 2 % kappa-carrageenan. This layer acted as a drug reservoir that controlled its release. The third layer was 5 % ethyl cellulose backing layer for unidirectional release of tranexamic acid towards the wound. The 3 layers were physically crosslinked by hydrogen bonding as confirmed by Infrared spectroscopy. Swelling and release studies were performed, and results proposed that increasing number of layers decreased swelling properties and sustained release of tranexamic acid for 8 h. In vitro blood coagulation study was performed using human blood and showed that the dressing significantly decreased coagulation time by 70.5 % compared to the negative control. In vivo hemostatic activity was evaluated using tail amputation model in Wistar rats. Statistical analysis showed the dressing could stop bleeding in a punctured artery of the rat tail faster than the negative control by 59 %. Cranial bone defect model in New Zealand rabbits was performed to check for bone hemostasis and showed significant decrease in the hemostatic time by 80 % compared to the control.
Sujet(s)
Bandages , Carragénane , Hémorragie , Acide hyaluronique , Poly(alcool vinylique) , Rat Wistar , Acide tranéxamique , Animaux , Lapins , Hémorragie/traitement médicamenteux , Hémorragie/prévention et contrôle , Poly(alcool vinylique)/composition chimique , Acide tranéxamique/composition chimique , Acide tranéxamique/administration et posologie , Acide hyaluronique/composition chimique , Humains , Cellulose/analogues et dérivés , Cellulose/composition chimique , Mâle , Modèles animaux de maladie humaine , Rats , Libération de médicament , Coagulation sanguine/effets des médicaments et des substances chimiques , Antifibrinolytiques/composition chimique , Antifibrinolytiques/administration et posologie , Antifibrinolytiques/pharmacologie , Hémostatiques/composition chimique , Hémostatiques/pharmacologie , Hémostatiques/administration et posologie , Préparations à action retardéeRÉSUMÉ
A well-made chitosan-PVP block copolymer platform was equipped with highly ordered and uniform nano-channels. This highly adhesive block copolymer platform was designed to ensure the efficient co-delivery of two synergistic-acting hypoglycemic drugs. Linagliptin oral bioavailability is 30% due to poor permeability and intestinal degradation. Its pharmacokinetics shows a non-linear profile. Empagliflozin exhibited decreased permeability and decreased solubility in aqueous media between pH 1 and 7.5. Cubosomes were functionalized as a good microdomain to guest and improve the physicochemical characteristics of drug molecules with decreased permeability and solubility. Cubosomes loaded with linagliptin (linagliptin cubosomes (LCs)) and empagliflozin (empagliflozin cubosomes ECs) were separately prepared using the top-down method and optimized by applying 23 factorial design. Optimized cubosomal systems LCs (F3) and ECs (F4) were incorporated into a chitosan-PVP gel to obtain dual cubosome-loaded platforms (LECF) optimized through 22 factorial design. The permeation study from the optimized LECF (C1) ensured enhanced empagliflozin permeation alongside continued efflux for linagliptin, resolving potential risks due to its non-linear plasma profile. The in-vivo study revealed that AUC(0-∞) of linagliptin and empagliflozin was enhanced by 2- and threefold, respectively. Therefore, the chitosan-PVP block copolymer platform buccal application for the co-delivery of linagliptin and empagliflozin could contribute to enhanced clinical effectiveness in treating diabetes.
Sujet(s)
Composés benzhydryliques , Chitosane , Diabète de type 2 , Glucosides , Humains , Linagliptine/pharmacocinétique , Linagliptine/usage thérapeutique , Diabète de type 2/traitement médicamenteux , Chitosane/usage thérapeutique , HypoglycémiantsRÉSUMÉ
Wound control in patients on anticoagulants is challenging and often leads to poor hemostasis. They have a higher tendency to develop alveolar osteitis after tooth extraction. The application of a hemostatic dressing that has a high absorbing capacity and is loaded with an antifibrinolytic drug could help in controlling the bleeding. Alginate/nano-hydroxyapatite (SA/Nano-HA) composite aerogels loaded with tranexamic acid (TXA) were prepared. Nano-HA served as a reinforcing material for the alginate matrix and a source of calcium ions that helps in blood clotting. It influenced the porosity and the water uptake capacity. TXA release from SA/Nano-HA aerogels showed a biphasic profile for up to 4 h. Blood coagulation studies were performed on human whole blood. The TXA-loaded aerogel significantly reduced the clotting time by 69% compared to the control (p < 0.0001). Recalcification time was significantly reduced by 80% (p < 0.0001). Scanning electron microscopy analysis revealed the porous nature of the aerogels and the ability of the optimum aerogel to activate and adhere platelets to its porous surface. The cell migration assay showed that there was a delay in wound healing caused by the TXA aerogel compared to the control sample after treating human fibroblasts. Results suggest that the developed aerogel is a promising dressing that will help in hemostasis after tooth extraction.
RÉSUMÉ
Nanosponges are porous solid nanoparticles composed of hyper-cross-linked polymers that serve as specific micro-domains designed for the co-encapsulation of two drugs with different chemical structures. Our goal was to engineer a novel assembly of multilayer nanosponges (MLNS) based on a layer-by-layer approach. This MLNS was engineered to incorporate two drugs (linagliptin and empagliflozin) in a new drug delivery route. Linagliptin has a low oral bioavailability due to intestinal degradation and low permeability. Its pharmacokinetics shows a non-linear profile which leads to a disproportionate increase in its effectiveness with increasing the dose frequency. Empagliflozin has a low permeability and is very slightly soluble in aqueous media between pH 1-7.5. MLNS could improve their bioavailability along with resolving possible risks due to the non-linear pharmacokinetics of linagliptin and maximizing its dose efficiency. 23 factorial design was used to optimize the novel systems. MLNS (F4) was chosen as the optimal system with an average diameter of 40 nm and the highest entrapment efficiency which accounts for 92.93 % ± 2.27 and 100.94 % ± 0.55 for linagliptin and empagliflozin respectively. Förster resonance energy transfer confirmed the formation of a multilayer structure in MLNS. The optimized system was incorporated within chitosan mucoadhesive buccal films which were optimized through 22factorial design. The permeation study from optimized MLNS-film (B4) ensured an improved empagliflozin permeation along with a controlled efflux for linagliptin, resolving possible risks due to the nonlinear plasma profile. The in-vivo study of MLNS-film (B4) revealed that AUC(0-∞)of linagliptin and empagliflozin was enhanced by two-fold and ten-fold, respectively. Therefore, the nano-buccal formulation for the co-delivered hypoglycemic drugs could contribute to improved clinical efficacy in the treatment of diabetes.
Sujet(s)
Maladies cardiovasculaires , Chitosane , Diabète de type 2 , Inhibiteurs de la dipeptidyl-peptidase IV , Composés benzhydryliques/usage thérapeutique , Maladies cardiovasculaires/traitement médicamenteux , Chitosane/usage thérapeutique , Diabète de type 2/induit chimiquement , Diabète de type 2/traitement médicamenteux , Glucosides , Humains , Hypoglycémiants , Linagliptine/effets indésirables , Linagliptine/usage thérapeutique , Préparations pharmaceutiquesRÉSUMÉ
Thiamine hydrochloride (TH) was thought to exert a good insect repellent activity. The purpose of this work was to develop a formulation that releases TH in sustained regimen on human skin. Long lasting protection against mosquito bites was achieved. Pullulan acetate (PA) was used to prepare TH nanospheres. Optimal system was incorporated in Pluronic® hydrogel. Formulae were tested for in-vitro release and ex-vivo permeation. Complete protection time (CPT) was done adopting Kaplan-Meier survival function for the synthetic repellent (DEET), TH solution and nanospheres in hydrogel. Release profile of TH solution, nanospheres and nanosphere-loaded hydrogel (DG) demonstrated an added effect of DG, where t 1/2 was 11.2 ± 1.4 h. SEM for DG showed homogenous dispersion of nanospheres inside the matrix of the gel. Ex-vivo permeation showed only 0.761 ± 0.04% of TH in hydrogel permeated the skin after 12 h, while 44.98 ± 3.2% permeated when TH solution was applied. Clinical study revealed a significant difference in CPT between TH solution with either DEET or (DG) (p<0.05), and no significant difference between DEET and DG with CPT 400 ± 31 and 360 ± 18 min, respectively (P > 0.05). The high efficacy of TH-loaded hydrogel rendered it a successful alternative for DEET, offering long protection against mosquito bites.
Sujet(s)
Insectifuges , N,N-Diéthyl-méta-toluamide , Humains , Peau , ThiamineRÉSUMÉ
OBJECTIVE: The present work focuses on improving zaleplon (ZAP) performance through nanosizing its insoluble particles which were then delivered intranasally in powder form. SIGNIFICANCE: Since nanopowders have an exceptional ability to cross cell membrane, their absorption is facilitated in the solid form. Hence, delivering insoluble ZAP nanocrystals (NC) through intranasal route improves its bioavailability due to both nanosization and the escape of hepatic metabolism. METHODS: Nanocrystals were prepared by anti-solvent precipitation followed by probe sonication in presence of Soluplus®, Poloxamer-188 (0.25%), sodium lauryl sulfate (0.5%), and mannitol. Physicochemical evaluation of the prepared NC was done by DSC and XRPD. TGA was performed for stability detection. Ex vivo permeation study through isolated cattle nasal mucosal membrane, in addition to an in vivo bioavailability study was performed for assessment of the prepared NC. RESULTS: Nanosization to 200 nm contributed to the enhancement in dissolution â¼100% within 30 min and reduced half-life to 1.63 min. Confirmation of adsorption of polymers over NC' surface was elucidated. TGA confirmed their thermal stability. Ex vivo permeation study showed a 2.7 enhancement ratio in favor of the prepared NC. Both the extent and rate of NC absorption through nasal mucosa of rabbits were significantly higher (p Ë .05) than in case of oral tablets. The relative bioavailability of NC was increased 3.14 times as compared to the Sleep aid® tablets. CONCLUSION: The intranasal delivery of nanoscale ZAP powder proved to be a successful alternative to oral formulations that suffer poor absorption and limited bioavailability.
Sujet(s)
Acétamides/pharmacologie , Nanoparticules , Pyrimidines/pharmacologie , Acétamides/composition chimique , Administration par voie orale , Animaux , Biodisponibilité , Taille de particule , Poudres , Pyrimidines/composition chimique , Lapins , SolubilitéRÉSUMÉ
A target of best dissolution improvement of poorly soluble drugs is a necessity for the success of formulation in industry. The present work describes the preparation, optimization, and evaluation of a new spherical agglomeration technique for glimepiride as a model of poorly soluble drugs. It involved the emulsification of a drug solution containing a dispersed carrier that tailors the crystal habit of the drug to a perfect spherical geometry, in a poor solvent containing a hydrophilic polymer which imparts sphericity and strength to the formed agglomerates. The FTIR peaks of optimized product did not show any sign of chemical interaction between the drug and adsorbed carrier. The DSC and X ray diffractogram showed a peak characteristic of spherical agglomerates with much less intensity than that of glimepiride. The dissolution t1/2 of the drug slightly decreased from 381 min to 334 min in plain agglomerates. Introducing polymers in the aqueous phase of emulsion led to an improvement in the dissolution, reflected in t1/2 ranging from 118 to 231 min. Agglomerates prepared with Starlac/PVP demonstrated the most optimum physicochemical characteristics being spherical, with the best flowability and packability parameters. The t1/2 was as short as 19 min. The new carrier/polymer system offered a synergistic combination that highly contributed in dissolution enhancement of glimepiride. The spheronization and amorphisation offered by the new technique could account for such improvement.
RÉSUMÉ
Thiamine hydrochloride has been suggested as a natural, safe yet effective alternative for chemical insect repellents. However, there is a demand for a reassessment of the minimum required dose that is sufficient to perform a topical repellency on the human skin. Therefore, the purpose of the current work is to establish a dose-response curve from which the effective dose (ED) is calculated. A series of increasing concentrations of thiamine hydrochloride were applied to the forearm of adult volunteers, the number of bites was counted and the percent repellency calculated accordingly. Data of percent repellency were converted to probit values which were plotted against log doses. A linear relation was obtained from the dose-response curve with an r2 = 0.958. Statistical validation of the equation was tested through linear regression analysis, where the slope and intercept were found significant from zero. No significant difference was shown between observed and expected responses (p > 0.05). ED 50 and 99.9% were computed from the linear equation and found to be 4.57 and 344 mg, respectively. This finding can be supported by future works in which a proper formulation of thiamine hydrochloride in the respective doses would be presented. One can get prolonged safe protection against insect bites.
Sujet(s)
Culicidae , Morsures et piqûres d'insectes/prévention et contrôle , Insectifuges/pharmacologie , Thiamine/pharmacologie , Adulte , Animaux , Humains , PeauRÉSUMÉ
Mosapride belongs to class IV in Biopharmaceutics Classification System and is used in the treatment of reflux esophagitis. It exhibits poor bioavailability due to limited permeability, solubility and extensive first-pass metabolism. In this study, intranasal mosapride-loaded cross-linked xyloglucan Pluronic micelles (MOS-XPMs) was formulated and optimized to improve the low solubility & bioavailability of MOS. The solid dispersion technique using 23 full factorial design was applied. (MOS-XPMs) (F4) had the highest desirability value (0.952) and, therefore, it was selected as an optimal system. Xyloglucan cross-linked in the shell of Pluronic micelles offered improved stability and mucoadhesiveness to MOS-XPMs. 1H NMR spectra ensured the cross-linking of xyloglucan with Pluronic micelle shell and micelle stabilization. A Pharmacodynamic study revealed that MOS-XPMs showed 1.5-fold increase in duodenal and cecal motility compared to MOS suspension and 1.7-fold increase compared to the oral marketed product. The new MOS-XPMs were shown to be successful at improving the therapeutic efficacy of mosapride.
RÉSUMÉ
Repeated dose medication usually maximizes adverse effects, while sustained release systems did not offer a fast onset of action. Etodolac was formulated to enable pulsatile and sustained drug release, which was chronologically more suitable as an anti-inflammatory drug. Eudragit® RSPO, Eudragit® RLPO, and HPMC K15M were added in the sustained release layer and tried in different ratios. Croscarmellose sodium or sodium starch glycolate were used as superdisintegrants for the fast release layer offering the loading dose for rapid onset of drug action. Bilayer tablets were successively coated with Opadry®II, HPMC K4M and E5 (1:40), and Surelease®. All formulations complied with the Pharmacopeial standards for post-compression parameters. In-vitro release profile illustrated a lag-time of 4â¯h followed by a rapid loading dose release for 2â¯h. A prolonged steady state release with a t1/2 of 11â¯h lastly occurred. The coated bilayer tablet showed pulsatile and sustained release effects in rats. The licking time and swelling degree were tested and results demonstrated significant difference (Pâ¯<â¯0.05) between the sustained anti-inflammatory action of formulation C1 compared to other groups. Therefore the new chronological design could provide a consistent drug release over 24â¯h with good protection against associated symptoms of gastric release.
RÉSUMÉ
Atopic bronchial asthma is chronic respiratory diseases of high frequency and high morbidity and mortality especially in patients refractory to the ordinary medical management. This study aimed to investigate the association between Serpin family B Member 2 (SERPINB2) gene expression and bronchial asthma severity. A total of 127 adult patients with asthma were enrolled in this study. Allergic respiratory symptoms were assessed and patients were classified according to Global Initiative for Asthma (GINA) criteria. The patients were subjected to skin prick test (SPT) by commonly encountered aeroallergens and pulmonary function tests. Sputum samples were subjected to RNA extraction and real time PCR amplification (q PCR) of SERPINB2 mRNA. The relative gene expression was determined by fold change (2-??Ct) after calculation of delta-delta Ct (Cycle threshold of patients- Cycle threshold of healthy control). Assessment of the q PCR results was done by Receiver operating characteristic curve (ROC). Patients with severe bronchial asthma constituted 44% of asthma patients and mild asthma 22% of asthmatics. SPT revealed that 23 % of the patients were mono-sensitized and 77 % were poly-sensitized. The mites and pollens were the most frequently sensitizing allergens detected by SPT (53%, and 47%, respectively. SERPINB2 gene expression in asthma group that discriminated them from healthy control was > 0.01. The highest increase of expression was found ( > 1.92 fold) severe asthma compared to the mild group. A negative correlation was found between SERPINB2 expression and pulmonary function tests FEV1/FVC % and FEV1% (r?=?-0.921 and -0.805, P < 0.001), respectively. While significant positive correlation was found between SERPINB2 expression and total IgE levels (r?=?0.932 and P-value < 0.001), and SPT results (r?=?0.923 and P-value < 0.001). In conclusion, the expression level of SERPINB2 gene significantly correlated with the severity of bronchial asthma.
Sujet(s)
Asthme/génétique , Cellules épithéliales/métabolisme , Serpines/génétique , Adulte , Humains , Immunoglobuline E/sang , Réaction de polymérisation en chaine en temps réelRÉSUMÉ
Purpose: Triple solid dispersion adsorbates (TSDads) and spherical agglomerates (SA) present new techniques that extensively enhance dissolution of poorly soluble drugs. The aim of the present study is to hasten the onset of hypoglycemic effect of glimepiride through enhancing its rate of release from tablet formulation prepared from either technique. Methods: Drug release from TSDads or SA tablets with different added excipients was explored. Scanning electron microscopy (SEM) and effect of compression on dissolution were illustrated. Pharmacodynamic evaluation was performed on optimized tablets. Results: TSDads & SA tablets with Cross Povidone showed least disintegration times of 1.48 and 0.5 min. respectively. Kinetics of drug release recorded least half-lives (54.13 and 59.83min for both techniques respectively). Cross section in tablets displayed an organized interconnected matrix under SEM, accounting for the rapid access of dissolution media to the tablet core. Components of tablets filled into capsules showed a similar release profile to that of tablets after compression as indicated by similarity factor. The onset time of maximum reduction in blood glucose in male albino rabbits was hastened to 2h instead of 3h for commercial tablets. Conclusion: After optimization of tablet excipients that interacted differently with respect to their effect on drug release, we could conclude that both amorphisation and spheronization were equally successful in promoting in vitro dissolution enhancement as well as providing a more rapid onset time for drug action in vivo.
RÉSUMÉ
Specific immunotherapy (SIT) is one of the important lines for the treatment of food allergy. Efficacy tests for clinical response to SIT are limited and subjective. In this study, we aimed to evaluate the validity of food specific Ig E levels as a biomarker of clinical improvement in children with food allergy treated with oral immunotherapy (OIT). We analysed 184 children with food allergy, 143 had undergone 2 years of food OIT and 41 were on allergen restricted diet and considered as control. All patients were subjected to Double-Blind Placebo-Controlled Food Challenge test (DBPCFC), allergic symptom score calculation, and serum food specific Ig E level before and after oral immunotherapy for treated patients and after 2 year of allergen restricted diet for the control group. Receiver Ooperating Ccharacteristic Ccurves (ROCs) analysis was done to determine the cut off, areas under the curve, sensitivity, and specificity were calculated for the specific Ig E test. According to the result of DBPCFC and result of food specific Ig E test, milk Milk allergy was the most frequently food allergy as it was encountered in 76 children out of 184 children (41.3%) , followed by egg and fish allergy in 64(34.7%), and 44 (23.7%) cases, respectively. Oral desensitization was successful in 91 %, 82%, and 67% of patients with milk, Egg, and fish allergy, respectively. The OIT group showed a statistically significant greater reduction in symptom scores compared to the control group (P < 0.001). Also, there was a significant decrease in food specific Ig E level in responders for all types of food allergy tested (P Ë0.001), and . In responders group, there was significant correlation between the specific IgE level and symptom scores (r = 0.5, P = 0.03). Food specific Ig E levels cut off levels were < 0.8, < 2.05, and < 23 IU/ml allowed detection of effective OIT for milk, egg, and fish allergy, respectively. It is concluded that serum specific Ig E is correlated correlates with the clinical response to OIT and offers an advantage over double blind challenge test which is a risky and time consuming process.
Sujet(s)
Allergènes , Hypersensibilité alimentaire/thérapie , Immunoglobuline E/sang , Immunothérapie , Administration par voie orale , Animaux , Marqueurs biologiques/sang , Enfant , Méthode en double aveugle , Oeufs , Hypersensibilité alimentaire/sang , Humains , Lait , Produits de la merRÉSUMÉ
This is a prospective interventional comparative study which aimed to investigate correlation between tear film allergen specific IgE levels and the skin prick test in diagnosing different types of allergic conjunctivitis. One hundred twenty patients with allergic conjunctivitis were included in this study and were classified into 4 groups based on the type of allergic conjunctivitis. Patients were subjected to skin prick test (SPT). Micro capillary method was used to collect tear samples for the quantitative assessment of specific IgE by Immune blot assay. The most common allergens were mixed mould, mixed pollen, and mixed mite. The results of tear film specific IgE in detection of allergens were evaluated against the SPT. The Receiving Operating Characteristic Curve (ROCs) revealed that tear film allergen-specific IgE specificity was 100% and sensitivity was 75%-100% to the three common allergens in the 4 studied groups. The correlation between tear's specific IgE and skin prick test was statistically significant for pollen, mite, and mould allergens in patient with SAK (r = 0.821, P Ë 0.001 for pollen, r = 0.964, P Ë 0.001 for mite, and r= 0.811, P Ë 0.02 for mould ), PAC (r = 0.851, P Ë 0.001 for pollen, r = 0.826, P Ë 0.001 for mite, and r= 0.861, P Ë 0.001 for mould) and VKC (r = 0.802, P Ë 0.001 for pollen, r = 0.894, P Ë 0.001 for mite, and r= 0.861, P Ë 0.061 for mould). In patient with AKC, the correlation was statistically significant for only mite allergen (r = 1, P Ë 0.001). We concluded that Tear film specific IgE test can be considered as a good alternative to skin prick test in diagnosis of the causative allergens in allergic conjunctivitis.
Sujet(s)
Allergènes/immunologie , Conjonctivite allergique/diagnostic , Immunoglobuline E/analyse , Larmes/composition chimique , Conjonctivite allergique/immunologie , Humains , Études prospectives , Tests cutanésRÉSUMÉ
OBJECTIVES: This study aimed to compare polymerase chain reaction (PCR) and IgM detection using enzyme linked immune-sorbent assay (ELISA) in diagnosis of congenital cytomegalovirus (CMV) infection. METHODS: This study was conducted from May 2009 to December 2010. Urine and blood samples were collected from 94 neonates with suspected congenital CMV infection. Serum and part of urine samples were stored at -20°C freezer, until the serologic and PCR tests were achieved. A 94 fresh urine samples were processed for cell culture. Nineteen (20.2%) out of 94 urine samples were proven positive for CMV infection by viral culture. For comparing PCR and IgM ELISA we used tissue culture technique as a reference, the 19 positive samples on culture (CMV group) and 20 negative samples (control group) were included in the comparison. Some characteristics of CMV and control groups were compared including sex, age, birth weight, gestational age < 37 and small for gestational age. Clinical and laboratory abnormalities were also compared in both groups. RESULTS: This study showed that the sensitivity and specificity of PCR in relation to viral culture were 100% and 100% respectively, there was excellent agreement between both tests (Kappa coefficient was 1 and P=0.000). On the other hand, the sensitivity of IgM CMV ELISA in relation to viral culture was 63.2% and the specificity was 85%. There was good agreement between both tests (Kappa coefficient was 0.48 and P=0.002). By comparing CMV and control groups, there were high statistically significant differences between both groups as regard the birth weight, gestational age < 37 and small for gestational age items (P= 0.00, 0.03 and 0.01 respectively). There were statistically insignificant differences as regarding the clinical and laboratory abnormalities detected for neonates of both groups. In this study jaundice (63%) and hepato-splenomegaly (42%) were the most common clinical signs in both groups. CONCLUSIONS: PCR is more sensitive and specific technique for detection of congenital CMV infection than CMV IgM ELISA. Being more cost effective, less cumbersome and less time consuming in relation to viral culture, PCR may be used in detection of congenital CMV infection.
RÉSUMÉ
This report describes zero-order approximation for metoclopramide hydrochloride sublingual tablet formulation. Effects of type and concentration of excipients on release were investigated. Study revealed that highest rate of dissolution was attained with crosspovidone and decreased in the order crosspovidone > sodium starch glycolate > ac-di-sol. All formulations demonstrated flush release, except the one containing 10% crosspovidone where a lag time of 0.5 min. was depicted. Increasing the concentration of crosspovidone from 5 to 10% gave the same half-life, whereas kinetics of release changed to zero order. Differential scanning colorimetry and infrared spectroscopy did not reveal any sign of physical or chemical interaction between drug and crosspovidone. In order to study the alignment of polymeric network inside tablet matrix, scanning electron microscopy was performed on the tablet and its cross-section. Matrix with 10% crosspovidone showed higher density of interconnections extending to the interior of core enabling fast and constant release. Hence physicochemical characteristics of crosspovidone could be tailored by varying its concentration, in a way that provided a porous matrix with tight arrangement of polymeric chains, resembling to an assemblage of cylinders with constant apertures, from which zero-order release was approached.
Sujet(s)
Métoclopramide/composition chimique , Administration par voie sublinguale , Chimie pharmaceutique/méthodes , Excipients/composition chimique , Période , Cinétique , Povidone/composition chimique , Solubilité , Amidon/analogues et dérivés , Amidon/composition chimique , Comprimés/composition chimiqueRÉSUMÉ
Octyl-p-methoxycinnamate (OMC) is a sun-blocking agent that absorbs ultraviolet (UV) radiation in UVB range. However, when exposed to sunlight, OMC is converted into a less UV-absorbent form, which reduces its effectiveness. The aim of this study was to stabilize the oil by microencapsulation and to convert it into a free-flowing powder form. In addition, the study aimed to develop a suitable high-performance liquid chromatography method to detect the oil in the presence of its degradation product. OMC was microencapsulated by the congealable disperse-phase encapsulation using carnauba wax (cw) and beeswax (bw) at different wax-to-drug ratios (2:1 and 4:1). The photostability of the oil was investigated by exposing the microspheres to UV radiation. After 180 min of exposure, the photoprotective abilities of all the tested formulae were similar and reached about 82%. However, physicochemical assessment showed superiority of cw microspheres over their bw analogues.
Sujet(s)
Cinnamates/composition chimique , Processus photochimiques/effets des radiations , Produits antisolaires/composition chimique , Rayons ultraviolets , Capsules , Stabilité de médicament , Facteurs temps , Cires/composition chimiqueRÉSUMÉ
We investigated 120 patients suspected clinically to have pulmonary aspergillosis with different clinical manifestations "aspergilloma (Subgroup A), allergic bronchopulmonary aspergillosis (Subgroup B) and invasive pulmonary aspergillosis (Subgroup C)" and correlated between their clinical and laboratory findings and endogenous specific aflatoxin production. They were subjected to isolation of Aspergillus strains, measurement of serum total IgE and specific Aspergillus IgG by ELISA and identification of aflatoxin producing Aspergillus strains using fluorescence analysis of spectroline. Aspergillus was isolated from 45 patients (37.5%). Subgroup A had a negative statistically non-significant correlation between clinical and laboratory findings as regard total IgE and for Aspergillus IgG (only haemoptysis &weight loss had significant correlation with aspergillus IgG). Subgroup B & Subgroup C had positive, statistically significant correlation &negative statistically non significant correlation respectively as regard all clinical findings and both total IgE & serum IgG. This study also showed that 6 Aspergillus strains out of 45(13.3%) produced endogenous aflatoxin. It is concluded that a significant correlation that exists between clinical and serological findings in allergic pulmonary aspergillosis. Aflatoxins may be produced in vivo by strains of Aspergillus and may result in manifestations similar to those caused by ingestion of aflatoxin in food.