ABSTRACT
Objective: Using ultrafine hydroxypropyl cellulose (HPC) powders as coating material to prepare moisture barrier coating film for Compound Danshen Tablets by an innovative electrostatic powder coating technology. The effects of coating prescription and process parameters on coating efficiency and coating film properties were investigated, so as to provide new ideas for moistureproof coating of moisture sensitive traditional Chinese medicine such as Compound Danshen Tablets. Methods: Free films were prepared by applying an electrostatic deposition process, and the effects of liquid plasticizer on the mechanical properties and the water vapor permeability were investigated. And the Compound Danshen Tablets were dry coated with ultrafine powders by the electrostatic coating technology. The effects of coating formulations and processing conditions on the moisture sorption behavior of the barrier film coated tablets were studied. Results: The coating efficiency could be manipulated by adjusting the charging voltage of the electrostatic spray gun and the amount of the liquid plasticizer. Compared with static curing process, dynamic curing process was capable to produce a satisfactory film with an enhanced moisture barrier function for the herbal medicines. The best coating process parameters were plasticizer spraying time 3 min and titanium dioxide addition ratio 1%. The minimum hygroscopicity was achieved when the coating level was increased to 6.7%. Conclusion: The moisture-protective effect by using a novel electrostatic coating technology with ultrafine powders was efficiently achieved, suggesting that it was a promising alternative for the protection for the moisture sensitive drugs.
ABSTRACT
A series of blend microspheres were developed from gelatin and hydroxypropyl cellulose (HPC) by emulsion crosslinking method employing glutaraldehyde (GA) as a crosslinker. Valganociclovir hydrochloride (VHCL), an anti HIV drug, was loaded in to these microspheres via insitu method. These microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), to confirm the formation of crosslinking and absence of chemical interactions between drug, polymer and crosslinking agent. Further the microspheres were characterized by scanning electron microscopy to study the surface morphology of the microspheres and observed that the microspheres have smooth surface with spherical structure and no phase separation. The microspheres with the average particle sizes ranging from 614.5μm to 693.4μm were obtained. X-ray diffraction (X-RD) studies were performed to understand the crystalline nature of drug and its uniform distribution into blend microspheres. An in vitro release study was performed in phosphate buffer solution (pH-7.4) at 370C. The release rates were fitted to an emperical equation to understand the diffusion parameters, which indicate non-Fickian or anomalous trend release of VHCL. Further the results indicated that the release of drug was found for more than 12 h.
ABSTRACT
Verapamil Hydrochloride is a calcium channel blocking anti-anginal agent. Extensive first pass metabolism, low bioavailability (~20%) and short biological half life (4.8 hrs) altogether makes it an ideal candidate for transdermal drug delivery. The objectives of this study were to develop matrix-type transdermal patches of verapamil hydrochloride (VPL) with combinations of hydroxypropyl methyl cellulose (HPMC) and hydroxy propyl cellulose (HPC) as matrix polymers and to investigate the influence of oleic acid (OA) on in vitro permeation of VPL through rat skin. The permeation studies were performed using Franz-type diffusion cells and full-thickness excised abdominal rat skin. The effect of the polymers on the drug release, percentage moisture loss, percentage moisture absorption, folding endurance, and thickness, were investigated.. In vitro release studies showed zero-order release of the drug from all the patches, and the mechanism of release was diffusion mediated. Data was analysed using different release kinetic models. In vitro release profiles showed that from optimized combination the release of the drug was sustained and it extended over a period of 24 hr VPM 006 emerged as the most satisfactory formulation as far as its technological properties were concerned.