DEVELOPMENT AND EVALUATION OF DROTOVERINE TASTE MASKED TABLETS WITH IMPROVED DISSOLUTION EFFICIENCY USING SOLID DISPERSION TECHNIQUE
The purpose of this research is to mask the bitter taste of the drug, Drotoverine using solid dispersion technique. The taste-masked drug is formulated in to a conventional tablet by direct compression method for ease of administration. Taste masking was done by solid dispersion using polymer such as urea and mannitol by melting/fusion method Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were performed to identify the physicochemical interaction between drug and carrier, hence its effect on dissolution. Conventional taste masked tablets were evaluated for weight variation, disintegration time, hardness and friability. In vitro drug release studies were performed for conventional tablets of drotoverine. Bitterness score was evaluated on volunteers. FTIR spectroscopy and SEM showed no interaction between drug and carriers. Conventional tablets prepared using solid dispersion, showed faster disintegration and complete bitter taste masking of drotoverine. In addition the prepared tablets exhibited better dissolution profile. Taste evaluation of taste masked tablets in human volunteers rated tasteless with a score of 0. Thus, results conclusively demonstrated successful masking of taste and oral disintegration of the formulated tablets in the oral cavity with improved dissolution.
Design and evaluation of taste masked Drotaverine HCl orodispersible tablets using polymethacrylate polymers
The objective of this present study was to mask the in ensely bitter taste of drotaverine hydrochlorid e and to formulate orodispersible tablet. Taste masking w as done by complexing drotaverine HCl with polymethacrylate polymers (Eudragit E100 and Eudrag it RD100) by solvent evaporation technique. The drug: polymer ratio was (1:10) with drug content 40 mg. The granules of two optimized drug-polymer complexes (DPCs) were tested for packing and flow p roperties. These granules were compressed into tablets and evaluated for hardness, friability, dru g content, wetting, in vitro disintegration time an d in vitro taste in simulated salivary fluid (SSF) of pH 6.2. Their dissolution profiles (i.e. F 1 and F2) were compared with commercial formulation (MKT). The opt imized formulations were further characterized with Fourier-Transform Infrared Spectroscopy (FTIR) to investigate any interactions between the drug and the added excipients. The granules of the optim ized DPCs were free flowing with angle of repose <28. The DPCs tablets (i.e. F1 and F2) had hardness an d friability values of ≥ 4kg/cm and <0.9% respectively. These tablets disintegrated rapidly (<75sec) with a wetting time of ≤22sec. It also showed rapid drug release in stimulated gastric fluid (SGF ) compared with marketed formulation. For instance, the maximum release of drotaverine hydrochloride in F1, F2 and MKT were achieved in 30, 15 and 90mins respectively. Taste evaluation of the DPCs t able s (F1 and F2) in human volunteers revealed considerable taste masking with the degree of bitte rness below threshold value. There were also no drug/excipient interactions. This study shows the s uitability of polymethacrylate polymers (Eudragit E 100 and Eudragit RD100) in masking the bitter taste of or dispersible tablets of drotaverine HCl.
Wood Microbiology: Decay and Its Prevention
Introductory text on the principles of decay and discoloration processes in wood, with emphasis on the major fungal damages which may develop during the growth, storage, and use of wood. The characteristics, detection, effects, and control of microbial attacks are stressed. Provides a synthesis of the current literature on wood microbiology, a rapidly expanding field of study. (Abstractor's note: This is an important resource for conservation researchers studying the decay of wood in art and architecture.) The following is a list of chapter headings: 1) Introduction to wood microbiology; 2) Wood deterioration agents; 3) Characteristics and classification of fungi and bacteria; 4) Factors affecting the growth and survival of fungi in wood (fungal ecology); 5) Fungal metabolism in relation to wood decay; 6) The decay setting: some structural, chemical, and moisture features of wood in relation to decay development; 7) General features, recognition, and anatomical aspects of wood decay; 8) Chemical changes in wood caused by decay fungi; 9) Ultrastructural features of wood decay; 10) Changes caused by decay fungi in the strength and physical properties of wood; 11) Colonization and microbial interactions in wood decay; 12) Decays originating in the stems of living trees; 13) Biodeterioration of stored wood and its control; 14) Wood stains and discolorations; 15) Decay problems associated with some major uses of wood products; 16) Detection of internal decay; 17) Paint mildew and related degradative problems; 18) Natural decay resistance (wood durability); 19) Chemical protection of wood (wood preservation); and 20) Some trends in wood microbiology research and a new emphasis (biotechnology). -- AATA