Dissolution enhancement of chlorzoxazone using cogrinding technique.

PURPOSE: The aim of the present work was to improve rate of dissolution and processing parameters of BCS class II drug, chlorzoxazone using cogrinding technique in the presence of different excipients as a carrier. MATERIALS AND METHODS: The drug was coground with various carriers like polyethylene glycol (PEG 4000), hydroxypropyl methylcellulose (HPMC) E50LV, polyvinylpyrrolidone (PVP)K30, Kaolin and Neusilin US2 using ball mill, where only PEG 4000 improved dissolution rate of drug by bringing amorphization in 1:3 ratio. The coground mixture after 3 and 6 h was evaluated for various analytical, physicochemical and mechanical parameters. RESULTS: The analysis showed conversion of Chlorzoxazone from its crystalline to amorphization form upon grinding with PEG 4000. Coground mixture as well as its directly compressed tablet showed 2.5-fold increment in the dissolution rate compared with pure drug. Directly compressible tablets prepared from pure drug required a large quantity of microcrystalline cellulose (MCC) during compression. The coground mixture and formulation was found stable in nature even after storage (40°C/75% relative humidity). CONCLUSIONS: Cogrinding can be successfully utilized to improve the rate of dissolution of poorly water soluble drugs and hence bioavailability.

Preparation and evaluation of agglomerated crystals by crystallo-co-agglomeration: an integrated approach of principal component analysis and Box-Behnken experimental design.

Poor mechanical properties of crystalline drug particles require wet granulation technique for tablet production which is uneconomical, laborious, and tedious. The present investigation was aimed to improve flow and mechanical properties of racecadotril (RCD), a poorly water soluble antidiarrheal agent, by a crystallo-co-agglomeration (CCA) technique. The influence of various excipients and processing conditions on formation of directly compressible agglomerates of RCD was evaluated. Principal component analysis and Box-Behnken experimental design was implemented to optimize the agglomerates with good micromeritics and mechanical properties. The overall yield of the process was 88-98% with size of agglomerates between 351 and 1214 µm. Further, higher rotational speed reduced the size of agglomerates and disturbed sphericity. The optimized batch of agglomerates exhibited excellent flowability and crushing strength. The optimized batch of RCD agglomerates was characterized by fourier transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffractometry and gas chromatography which illustrated absence of drug-excipient interaction with minimal entrapment of residual solvent. Hence, it may be concluded that both excipients and processing conditions played a vital role to prepare spherical crystal agglomerates of RCD by CCA and it can be adopted as an excellent alternative to wet granulation.

Influence of polymers/excipients on development of agglomerated crystals of secnidazole by crystallo-co-agglomeration technique to improve processability.

BACKGROUND: Direct tabletting is a need of Pharmaceutical industries. Poor mechanical properties of drug particles require wet granulation which is uneconomical, laborious, and tedious. OBJECTIVE: Objective of this work was to study influence of various polymers/excipients on formation of directly compressible Crystallo-co-agglomerates (CCA) of water soluble drug Secnidazole (hydroxy-2-propyl)-1-methyl-2-nitro-5-imidazole), an antimicrobial agent. METHOD: Acetone-petroleum ether system was used to develop CCA of drug in the presence of polymers/excipients. Clarity of the supernatant was considered an endpoint for completion of agglomeration. The prepared CCA were subjected for topographic, micromeritic, mechanical, compressional, and drug release properties. RESULTS: The process yielded ~92 to 98% wt/wt CCA containing secnidazole with the diameter between 0.2 and 0.7 mm. CCA showed excellent flow, packability, compatibility, and crushing strength. Heckel plot showed lower σ(0) and higher tensile strength with lower elastic recovery (0.55-1.28%) of CCA. Dissolution profile of CCA was improved. Differential scanning calorimetry , fourier transform infra-red, and x-ray diffractometry results showed absence of drug-excipient interaction. DISCUSSION: Matrix beads were generated with uniform dispersion of crystallized drug. Excellent flow, packability, and compactability were due to sphericity of agglomerates. Higher crushing strength of CCA was an indication of good handling qualities. Lower σ(0), higher tensile strength, and lower elastic recovery indicated excellent compressibility of agglomerates. Improvement in dissolution profile was due to porous nature of CCA. CONCLUSION: Excipients and polymers can play a key role to prepare CCA, an excellent alternative to wet granulation process to prepare particles for direct compression.