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Ophthalmic delivery of dexamethasone can control inflammation and also some forms of uveitis. But it is effective therapeutically over a short period of time and frequent instillation is required. hydroxypropyl methylcellulose matrix films containing dexamethasone were prepared by casting method in presence and absence of particulate kaolin for extending ophthalmic drug delivery. Fourier-transform infrared spectroscopy confirmed the complexation of dexamethasone and kaolin in the film via formation of hydrogen bond and the observed shouldering at 1032 cm-1 increased with corresponding higher amount of kaolin binding. Differential scanning calorimetry thermogram resulted in almost complete amorphization of dexamethasone in the film. X-ray diffractogram demonstrated almost disappearance of kaolinite diffraction and the reduced order of dexamethasone crystal lattice in all the film formulations. Submicrons, tubular and nano-fibrous morphology of the kaolin and drug particles were seen in the scanning electron microscope images of the film. Relatively extended diffusion controlled drug release and ophthalmic permeation behavior were observed with the increase of kaolin loading in the film. Stable complex facilitated the sustained ophthalmic delivery of dexamethasone and prolonged anti-inflammatory activity. Molecular docking study also revealed the complex formation of dexamethasone with kaolin and hydroxypropyl methyl cellulose to understand the fitting and stable configuration of drug-carrier interaction. Kaolin-based hydroxypropyl methyl cellulose hydrogel film containing dexamethasone as a model drug can enhance the corneal residence time for anti-inflammation for an extended period of time. [ABSTRACT FROM AUTHOR]

Hydration behavior of hydrogel-based polymeric film possesses great importance in mucosal drug delivery. Modified Lag phase sigmoid model was used for the investigation of hydration of the film. Kaolin incorporated HPMC K100LVCR (HL) and K100M (HH) films containing dexamethasone as a model drug have been prepared for studying swelling kinetics. Swelling of HL and HH films was decreased with the gradual increase of kaolin content and HH of higher viscosity has shown higher value than HL matrix. Kaolin also inhibited the film erosion process. Mathematically modified lag phase sigmoid model demonstrated similarity of the predicted swelling content with the observed value. High R2 and small RMSE value confirmed the successful fitting of the modified lag phase sigmoid model to the experimental data of swelling content. τ value similar to the observed one was obtained. This modified model could be reliable enough for estimating hydration process in food grains, food packaging films etc. [ABSTRACT FROM AUTHOR]

In this investigation, the effect of kaolin on hydration kinetics and swelling behavior of hydroxypropyl methylcellulose ocular film was studied. Gradual reduction in the extent of and rate of swelling of the film was noticed with increasing the content of kaolin. Peppas model revealed that the diffusion coefficient was increased in the presence of kaolin and also increased for the film of higher viscosity polymeric film. Peppas model suggested that the polymeric film followed the diffusion-controlled swelling mechanism. The Peleg rate constant was increased from 1.69 to 44.39 h/g indicating the initial water adsorption rate in the decreasing order while Peleg capacity constant did not vary significantly in the presence and absence of kaolin indicating lack of remarkable change of water adsorption capacity. The presence of kaolin in the film could maintain a safe corneal hydration level. [ABSTRACT FROM AUTHOR]

Purpose: Kaolin can adhere to the mucosa and protect it by absorbing toxins, bacteria, and viruses. Ocular delivery and anti-inflammatory activity of dexamethasone hydrogel system could be advantageous after kaolin incorporation. Methods: Hydroxypropyl methylcellulose (HPMC) films of dexamethasone have been prepared without and with kaolin by solvent casting method. Differential scanning calorimetry (DSC), X-ray diffractometry (XRD), and scanning electron microscopy (SEM) were utilized for evaluating thermal property, crystallinity, and morphology of the film preparations respectively. In vitro drug release and corneal permeation ex vivo were carried out in phosphate buffer saline of pH 7.4 (PBS) at 34 ± 0.5°C for 6 h. Anti inflammatory effect of the prepared film was evaluated using carrageenan induced rabbit eye. Results: Disappearance of melting endotherm in the DSC thermogram is the indication of almost complete amorphization of drug in all the films. High-intensity reflections with characteristic peaks of pure drug crystal have resulted extensively reduced ordering of the crystal lattice in the X-ray pattern of all the films. Photomicrographs revealed that the plate-shaped geometry of the drug crystal has almost been lost in absence and presence of the nano-kaolin particles in the films. Kaolin incorporation controlled the drug release up to 6 h. Ocular permeation was diffusion controlled and extended for 6 h or more without exhibiting significant “Burst effect”. Adsorption of drug onto the surface of nano-kaolin prolonged the permeation due to cation exchange and hydrogen bonding. Signs of inflammation of the carrageenan induced rabbit eye have been disappeared almost completely after 2 h of film application. Conclusions: Local controlled delivery sustained anti-inflammatory activity of dexamethasone has been achieved using kaolin incorporated HPMC film. [ABSTRACT FROM AUTHOR]

Analysis of the binding interactions of ibuprofen and silicified-microcrystalline cellulose (SMCC) has been undertaken. Co-processing of ibuprofen with SMCC was carried out by solid state ball milling, and aqueous state equilibration followed by freeze drying to investigate the effect of silicified-microcrystalline cellulose on ligand. Molecular docking study revealed that ibuprofen formed complex through hydrogen bond with microcrystalline cellulose (MCC) and silicon dioxide (SiO2); the binding energy between MCC and SiO2, and ibuprofen and SMCC were found as -1.11 and -1.73 kcal/mol respectively. The hydrogen bond lengths were varying from 2.028 to 2.056 Å. Interaction of Si atom of SMCC molecule with Pi-Orbital of ibuprofen has shown the bond length of 4.263 Å. Significant improvement in dissolution of ibuprofen has been observed as a result of interaction. Binary and ternary interactions revealed more stabilizing interactions with ibuprofen and SMCC compared to SMCC formation. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Amlodipine mucoadhesive film improved ocular permeation in presence of cyclodextrins. • SBCD improved permeation to the highest extent compared to other films. • Amlodipine-SBCD film could be effectively utilized for anti-inflammatory activity. • Binary and ternary molecular docking studies were performed to explain interactions. Abstract Mucoadhesive type ocular film has been prepared for studying the anti-inflammatory potential of amlodipine (AML) on carrageenan-induced rabbit model and the effect of sulphobutyl-ether-beta-cyclodextrin on corneal permeation was tested. Hydroxypropyl methylcellulose (HPMC) ocular film was prepared after complexation of amlodipine with β-cyclodextrin, (BCD), hydroxypropyl β-cyclodextrin (HPCD), and sulfobutylether β-cyclodextrin (SBCD). The film without cyclodextrin showed a maximum swelling, and erosion to the highest extent. Both drug release and permeation were highly diffusion controlled and highest improvement was observed with SBCD due to increased dissolution, compared to other formulations with or without cyclodextrin. Highest binding energy and highest extent of amorphization were noticed in the SBCD film formulation. Improved amlodipine release in-vitro and ocular permeation were found by the HPMC film formulation after complexation of the drug with cyclodextrins wherein SBCD exhibited both to the highest extent. Binary and ternary systems molecular docking studies confirmed the lowest energy of binding between amlodipine and BCD compared to HBCD and SBCD. Signs of acute inflammation were mitigated within 2 h of film application in the cul-de-sac. Presence of sulphobutyl-ether β-cyclodextrin in the amlodipine-HPMC film can improve ocular permeation significantly and could be utilized as mucoadhesive type formulation for anti-inflammatory activity. [ABSTRACT FROM AUTHOR]