ABSTRACT
Microcapsules of vitamin A palmitate were prepared by gelatin-acacia complex coacervation. The effects of colloid mixing ratio, core-to-wall ratio, hardening agent, concentration of core solution, and drying method on the coacervation process and the properties of the microcapsules were investigated. The microcapsules of vitamin A palmitate were prepared using different weight ratios of gelatin and acacia, that is, 2:3, 1:1, and 3:2 under controlled conditions. The other factors studied were 1:1, 1:2, and 1:3 core-to-wall ratios; 30, 60, and 120 min of hardening time; 2, 5, and 10 ml of formaldehyde per 280 g of coacervation system as a hardening agent; and 30%, 40%, and 50% w/w vitamin A palmitate in corn oil as a core material. The drying methods used were air drying, hot air at 40 degrees C, and freeze-drying. The results showed that spherical microcapsules were obtainedfor all conditions except for 30 min of hardening time, which did not result in microcapsules. The optimum conditions for free-flowing microcapsules with a high percentage of entrapped drug were 1:1 gelatin-to-acacia ratio and 1:2 core-to-wall ratio when hardening with 2 ml formaldehyde for 60 min and using 40% w/w vitamin A palmitate in corn oil as the core concentration. In addition, drying the microcapsules by freeze-drying provided microcapsules with excellent appearance.
Subject(s)
Antioxidants/chemistry , Vitamin A/analogs & derivatives , Vitamin A/chemistry , Acacia , Antioxidants/administration & dosage , Antioxidants/analysis , Capsules , Desiccation , Diterpenes , Drug Compounding , Excipients , Formaldehyde , Gelatin , Microscopy, Electron, Scanning , Particle Size , Retinyl Esters , Spectrophotometry, Ultraviolet , Vitamin A/administration & dosage , Vitamin A/analysisABSTRACT
This study explored the application of chitosan-alginate (CA) and chitosan-pectin (CP) complex films as drug release regulator for the preparation of multiunit controlled-release diclofenac sodium capsules. Pellets containing drug and microcrystalline cellulose, in a ratio of 3:5, were prepared in a fluidized rotary granulator. The pellets were coated with CA, CP, sodium alginate, pectin, and chitosan solutions. The pellets, equivalent to 75 mg drug, were filled into capsules. After 2 h of dissolution test in acidic medium, the amount of the drug released from any preparation was negligible. The pellets were further subject to pH 6.8 phosphate buffer More than 80% drug release at 12 h was observed with the uncoated pellets and those coated with sodium alginate, pectin or chitosan. Both 1% CA and 3% CP coated pellets exhibited drug release profiles similar to that of Voltaren SR75. It was found that approximately 60% and 85% of the drug were released at 12 and 24 h, respectively. Both Differential thermal analysis (DTA) and Fourier transform infrared spectroscopy (FTIR) analyses revealed complex formation between chitosan and these anionic polymers. It could be concluded that CA and CP complex film could be easily applied to diclofenac sodium pellets to control the release of the drug.
Subject(s)
Alginates/chemistry , Chitin/chemistry , Delayed-Action Preparations/chemistry , Diclofenac/chemistry , Pectins/chemistry , Alginates/ultrastructure , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Antidiarrheals/chemistry , Biocompatible Materials/chemistry , Capsules , Chemistry, Pharmaceutical , Chitin/analogs & derivatives , Chitin/ultrastructure , Chitosan , Glucuronic Acid , Hexuronic Acids , Microscopy, Electron, Scanning , Pectins/ultrastructure , Spectroscopy, Fourier Transform InfraredABSTRACT
Phenylpropanolamine hydrochloride (PPA) pellets were prepared in a fluidized-bed rotary granulator. Microcrystalline cellulose and distilled water were used as pelletization enhancer and binder, respectively. The pellets were coated with methacrylate ester copolymer (Eudragit RS 100) solution containing a 1:1 ratio mixture of triethyl citrate and castor oil as plasticizers. The addition of approximately 30% microcrystalline cellulose and 2% croscarmellose sodium to the 50% coated pellets produced fast disintegrating tablets. Dissolution profiles of both pellets and their respective matrix tablets were comparable and conformed to the USP dissolution requirement for PPA extended-release capsules.