Rajesh K. Parikh

Preparation and Assessment of Novel Coprocessed Superdisintegrant Consisting of Crospovidone and Sodium Starch Glycolate: A Technical Note

Summary and ConclusionCoprocessed superdisintegrant consisting of crospovidone and SSG exhibited good flow and compression characteristics. Cefixime trihydrate and ibuprofen tablets containing coprocessed superdisintegrant exhibited quick disintegration and improved drug dissolution.

Improving the tablet characteristics and dissolution profile of ibuprofen by using a novel coprocessed superdisintegrant: a technical note.

Summary and ConclusionThe coprocessed superdisintegrant proved to be superior to the physical blend in terms of flow due to size enlargement. Furthermore, the coprocessed superdisintegrant displayed superiority in terms of crushing strength, disintegration time, and drug dissolution. The advantages of the proposed method are easy adaptability in industry and the possibility of bypassing the existing patents in the ereas of quick disintegration and dissolution.

Application of Simplex Lattice Design and Desirability Function for the Formulation Development of Mouth Dissolving Film of Salbutamol Sulphate

The aim of the present investigation was to prepare and optimize the formulation of mouth dissolving film of salbutamol sulphate by applying experimental design technique. The films were prepared using hydroxypropyl methylcellulose, polyvinyl pyrrolidone and polyvinyl alcohol by solvent evaporation technique. Simplex lattice design and desirability function were adopted for the preparation of film possessing desirable and optimized characteristics. Tensile strength, elastic modulus, percentage strain, load at yield, and percentage drug release were selected as dependent variables. Regression equations and contour plots were used to relate the dependent and independent variables. The concept of similarity factor S(d) was used to prove similarity of dissolution between distilled water and simulated saliva (pH = 6.8). The polymers greatly influenced the mechanical properties and % drug release from the film. From the computed value of desirability function, it was determined that the film containing hydroxypropyl methylcellulose and polyvinyl alcohol was the best batch. The experimental design serves to be a useful tool for the formulation development of mouth dissolving film.

Development of directly compressible metformin hydrochloride by the spray-drying technique

Development of directly compressible metformin hydrochloride by the spray-drying technique Metformin hydrochloride exhibits poor compressibility during compaction, often resulting in weak and unacceptable tablets with a high tendency to cap. The purpose of this study was to develop directly compressible metformin hydrochloride by the spray-drying technique in the presence of polymer. Metformin hydrochloride was dissolved in solutions containing a polymer, namely polyvinylpyrrolidone (PVP K30), in various concentrations ranging from 0-3% (m/V). These solutions were employed for spray-drying. Spray-dried drug was evaluated for yield, flow property and compressibility profile. Metformin hydrochloride spray-dried in the presence of 2% PVP K30 showed an excellent flow property and compressibility profile. From the calculated Heckels parameter (Py = 2.086), it was demonstrated that the treated drug showed better particle arrangement in the initial compression stage. Kawakita analysis revealed better packability of the treated drug compared to the untreated drug. Differential scanning calorimetry and Fourier transform infrared spectroscopy experiments showed that the spray-dried drug did not undergo any chemical modifications. Tablets made from the spray-dried drug (90%, m/m) were evaluated for crushing strength, friability and disintegration time and the results were found satisfactory. Razvoj metformin hidroklorida za izravnu kompresiju metodom sušenja raspršivanjem Metformin hidroklorid se teško komprimira zbog čega nastaju slabe tablete neodgovarajuć e kvalitete s velikom tendencijom kalanja. Cilj ovog rada je prirediti metformin hidroklorid za izravnu kompresiju metodom sušenja raspršivanjem u prisutnosti polimera. Metformin hidroklorid je otopljen uz dodatak različitih količina (0-3% m/V) polivinilpirolidona (PVP K30). Dobivene otopine sušene su raspršivanjem, a tako pripravljenom metformin hidrokloridu određivano je iskorištenje, tečnost i kompresibilnost. Metformin hidroklorid pripravljen u prisutnosti 2% PVP K30 ima izvrsnu tečnost i kompresibilnost. Izračunati Heckelovi parametri (Py = 2,086) pokazuju da tako obrađeni metformin hidroklorid tvori veće čestice na početku kompresije. Analiza po Kawakiti ukazuje na to da se obrađeni lijek bolje preša od neobrađenog. Diferencijalna pretražna kalorimetrija (DSC) i Fourierova transformirana infracrvena spektroskopija (FTIR) pokazuju da sušenje raspršivanjem nije uzrokovalo nikakve kemijske promjene. Iz obrađenog metformina izrađene su tablete (90% m/m) sa zadovoljavajućom lomljivošću, drobivošću i vremenom dezintegracije.

Microparticles of rifampicin: comparison of pulmonary route with oral route for drug uptake by alveolar macrophages, phagocytosis activity and toxicity study in albino rats

Abstract Context: Tuberculosis (TB) is a chronic infectious disease with increasing incidence of drug resistance. Oral treatment for TB and multidrug resistance (MDR)-TB can have serious side effects. The causative agent of TB, Mycobacterium tuberculosis, resides in alveolar macrophages (AM). Pulmonary administration of anti-TB drugs can help in delivery of high concentration to AM. The ability of AM to phagocytose can also be utilized to generate mycobactericidal nitric oxide (NO) to improve efficacy of anti-TB drugs. Objective: To compare the uptake of rifampicin (RIF) by AM post oral and pulmonary administration of RIF microparticles (RM) and to compare hepatotoxicity and phagocytosis activity. Materials and Methods: RM were produced by spray drying process. RM were administered to rats through oral as well as intratracheal route. The uptake of RIF by AM and liver was measured. NO was measured in bronchoalveolar lavage (BAL) fluid. SGOT and SGPT levels were measured in serum. Results: Significantly higher (p < 0.05) concentration of RIF was found in AM post intratracheal administration. NO production was also significantly higher but less than toxic level. SGOT and SGPT levels as well as uptake of RIF by liver were indicative of no hepatotoxicity post intratracheal administration. Discussion: Phagocytosis of RM post intratracheal administration leads to significantly higher drug level in AM as well as production of significantly higher levels of NO. Conclusion: The administration of RM as dry powder inhalation (DPI) formulation may reduce treatment time of TB and chances of drug resistance TB.

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 σ0 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.

Formulation development of smart gel periodontal drug delivery system for local delivery of chemotherapeutic agents with application of experimental design

Smart gel periodontal drug delivery systems (SGPDDS) containing gellan gum (0.1–0.8% w/v), lutrol F127 (14, 16, and 18% w/v), and ornidazole (1% w/v) were designed for the treatment of periodontal diseases. Each formulation was characterized in terms of in vitro gelling capacity, viscosity, rheology, content uniformity, in vitro drug release, and syringeability. In vitro gelation time and the nature of the gel formed in simulated saliva for prepared formulations showed polymeric concentration dependency. Drug release data from all formulations was fitted to different kinetic models and the Korsemeyer-Peppas model was the best fit model. Drug release was significantly decreased as the concentration of each polymer component was increased. Increasing the concentration of each polymeric component significantly increased viscosity, syringeability, and time for 50%, 70%, and 90% drug release. In conclusion, the formulations described offer a wide range of physical and drug release characteristics. The formulation containing 0.8% w/v of gellan gum and 16% w/v of lutrol F127 exhibited superior physical characteristics.

Inhaled microparticles of antitubercular antibiotic for in vitro and in vivo alveolar macrophage targeting and activation of phagocytosis

Tuberculosis (TB) is a chronic infectious disease with increasing incidence of drug resistance. Oral treatment for TB and multidrug resistance-TB can have serious side effects. The causative agent of TB, Mycobacterium tuberculosis, resides in alveolar macrophages (AMs). Pulmonary administration of antitubercular (anti-TB) antibiotic can help in delivery of high concentration to AM. The ability of AM to phagocytose can also be utilized to generate mycobactericidal nitric oxide (NO) to improve efficacy of anti-TB antibiotics. The objective in this investigation was made to prepare isoniazid microparticles (IM) and polymeric microparticles of isoniazid (INH-PM) using poly-ε-caprolactone as polymer and to evaluate in vitro through cell culture techniques and in vivo through pulmonary administration of IM and INH-PM for uptake of isoniazid by AM. The hepatotoxicity was determined through serum glutamate oxaloacetate transferase (SGOT) and serum glutamate pyruvate transferase (SGPT) levels and histological examination. The results depicted that the significantly higher (P<0.05) concentration of isoniazid was found in AM with INH-PM in vitro and in vivo. NO production was also significantly higher but less than toxic level. SGOT and SGPT levels, uptake of INH by liver and histological examination were indicative of no hepatotoxicity with INH-PM and IM. Phagocytosis of IM and INH-PM leads to significantly higher drug level in AM as well as production of significantly higher levels of NO without compromising the viability of cells. The administration of IM and INH-PM as dry powder inhalation formulation may reduce the treatment time of TB and chances of drug-resistant TB.

Design of a Potential Colonic Drug Delivery System of Mesalamine

The aim of the present investigation was to develop a site-specific colonic drug delivery system, built on the principles of the combination of pH and time sensitivity. Press-coated mesalamine tablets with a coat of HPMC E-15 were over-coated with Eudragit® S100. The in vitro drug release study was conducted using sequential dissolution technique at pH 1.2, 6.0, 7.2 and 6.4 mimicking different regions of gastrointestinal tract. The optimized batch (F2) showed less than 6% of drug release before reaching colonic pH 6.4 and complete drug release was obtained thereafter within 2 hr. A short-term dissolution stability study demonstrated statistical insignificant difference in drug release.

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.