HPMC

This study aimed to develop hydrophilic matrix based controlled release  gastroretentive drug delivery system of Lamivudine floating matrix tablets, which after oral administration are designed to prolong the gastric residence time, increase the drug bioavailability and diminish the side effects of irritating drugs. FTIR studies revealed that there is no interaction between the drug and polymers used for the formulation. Among all the formulations F21 containing HPMC K100M, Carbopol 934P, Polyox WSR 303 and sodium bicarbonate, as gas generating agent was selected as optimized formulation based on physico chemical properties, floating lag time (34 sec) and total floating time (>24 h). From in vitro dissolution studies, the optimized formulation F21 showed drug release of 99.36±5.36%, whereas 92.36±5.02% of the drug was released from the marketed product within 24h. From in vivo bioavailability studies, after oral administration of floating tablet containing 100 mg Lamivudine, the Cmax, Tmax, and AUC0–∞ of optimized gastroretentive formulation were found to be 32.11±3.16 µg/mL, 8.00±1.26 h and 225±28.14 µg*h/ml, respectively. Cmax and AUC values of optimized formulation were found to be significantly higher than of marketed product, where longer gastric residence time is an important condition for prolonged or controlled drug release and also for improved bioavailability. Hence, gastro retention can be a promising approach to enhance bioavaiilability of Lamivudine with narrow absorption window in upper GIT.

The present study was aimed to develop and optimize extended release (ER) matrix tablets of Lamivudine trilayer tablets to achieve zero-order drug release for prolonged period of time. Lamivudine tablets were prepared by direct compression and consist of middle active layer with different grades of HPMC, MCC and PVP K30, upper and lower layers were prepared with Carnauba wax, Xanthan gum, EC and MCC. The tablets were also evaluated for physicochemical characteristics and release kinetics. The physicochemical characteristics of the prepared tablets were satisfactory. The developed drug delivery systems showed prolonged drug release rates over a period of 24 h. The release profile of the optimized formulation (HF23) was described by the Zero-order and Higuchi model. The results indicate that the approach used could lead to a successful development of extended release formulation of short biological half-life drug. These results also demonstrated the suitability of three-layered tablet formulation of Lamivudine to provide controlled release for prolonged period of time and improved linearity for Lamivudine in comparison to marketed product in the effective management of AIDS with patient compliance.

ABSTRACT: Floating microspheres of Tolcapone was prepared by ionotropic gelation method with an aim of increasing the gastric residence time and for controlled release using different polymers like HPMC K4M and HPMC K15M as rate retarding agent in concept to optimize the formulation. The FTIR studies indicated no significant interaction observed between drug and excipients. The F12 formulation showed the excellent flow properties. % yield, % entrapment efficiency and swelling index of optimized formulation was found to be 98.45%, 98.02% and 98.50%, respectively. The %buoyancy was excellent with approximately 98.42% of the microspheres floating upto 24h. The Cumulative % drug released from F12 microspheres was found to be 98.26±5.05% with in 12h and compared with the marketed product 91.25±5.00%. The optimized formulation F12 best fitted into zero order and Higuchi kinetics indicating diffusion controlled drug release pattern. SEM studies showed spherical shape and revealed the presence of pores on the floating microspheres surface which was responsible for floating ability. From stability studies optimized microspheres were stable at for 6 months. The F12 formulation showed the better results with HPMC K15M compared with HPMC K4M as rate retarding polymer. These results indicated that the Tolcapone loaded microspheres could potentially be exploited as a delivery system with controlled drug release in the effective management of Parkinson’s disease. Keywords: Floating microspheres, Tolcapone, HPMC, %buoyancy, Release order kinetics.  

Present work aimed at preparing quick onset of action of Granisetron HCl which is beneficial in emesis, aiding in the enhancement of bioavailability and is very convenient for administration without the problem of swallowing and using water. The films were prepared by using different grades of HPMC E3, E6 and E15, maltodextrin DE6 and other polymers by solvent casting method. They were evaluated for physical characteristics such as thickness, uniformity of weight, folding endurance, drug content, surface pH, percentage elongation and tensile strength and results were found to be satisfactory. The formulations were subjected to disintegration and in-vitro drug release test. The in vitro disintegration time of the optimized formulation F9 was 9 sec and drug release was found to be very fast i.e. 97.8% of within 8 min when compared with innovator product i.e 70.8%. In vivo studies confirmed that their potential as an innovative dosage form to improve the bioavailability and considered to be potentially useful for the treatment of emesis where quick onset of action is desirable. DSC and FTIR data revealed that no interactions takes place between the drug and polymers used in the optimized formulation. From the above results, it can be a good alternative to conventional Granisetron Hydrochloride tablets in the treatment of emesis. In vitro and in vivo evaluation of the films confirmed their potential as an innovative dosage form to improve delivery and quick onset of action of Granisetron Hydrochloride.

The aim of the present work was to develop and optimize gastroretentive floating system of Gemifloxacin mesylate using HPMC polymers, Gelucire 50/13 and Polyox WSR 301 to improve oral bioavailability of Gemifloxacin mesylate floating tablets by increasing gastric residence time. The tablets were prepared by direct compression method. The effect of polymers concentration and viscosity grades of HPMC on drug release profile was evaluated. The result of in vitro dissolution study showed that the drug release profile could be sustained by increasing the concentration of HPMC and Polyox WSR 301. The optimized formulation (F12) containing HPMC K100M, Gelucire 50/13 and Polyox WSR301 showed 99.12% drug release at the end of 12h. The optimized formulations (F12) containing showed desired buoyancy (floating lag time of about 35 seconds and total floating time of >12h). Optimized formulation (F12) followed diffusion controlled zero order kinetics and non-fickian transport of the drug. FTIR studies revealed the absence of any chemical interaction between drug and polymers used.

The purpose of the research was to prepare and evaluate Roxatidine acetate HCl floating microspheres by ionotropic gelation method. Fourteen formulations were prepared, among all the formulations F13 was selected as optimized formulation based on the micromeretic and evaluation parameters including drug release studies. In the in vitro release study of formulation, F13 showed 95.65% drug release after 12 h in a controlled manner, which is desired for disease like peptic ulcer. In vitro release profiles from optimized formulation F13 were applied on various kinetic models. The best fit with the highest correlation coefficient was observed in zero order and Higuchi model, indicating diffusion controlled principle. The innovator Rotane 150 mg conventional tablet showed the drug release of 96.45% within 1 h. FT-IR and DSC analyses confirmed the absence of drug-polymer interaction. The results obtained from evaluation and performance study of different types of Roxatidine microspheres showed that system may be useful to achieve a controlled drug release profile, reduce the dose of drug, dosing frequency and improve patient compliance when compared with marketed product. Key words: Roxatidine, buoyancy, HPMC, gum olibanum, microspheres.

The aim of the present study was to develop sustained release formulation of Isoniazide to maintain constant therapeutic levels of the drug for over 12 hrs. Various polymers such as Guar gum,HPMCK100 M,PEG 6000 AND Carbopol 934 p were employed as polymers. Isoniazide dose was fixed as 100 mg. Total weight of the tablet was considered as 400 mg. Polymers were used in the concentration of 100, 150 and 200 mg concentration. All the formulations were passed various physicochemical evaluation parameters and they were found to be within limits. Whereas from the dissolution studies it was evident that the formulation (F6) showed better and desired drug release pattern i.e.,96.10 % in 12 hours. It followed zero order release kinetics mechanism.

The aim of the present study was to develop sustained release formulation of Verapamil Hydrochloride to maintain constant therapeutic levels of the drug for over 12 hrs. Various grades of HPMC polymers, Guar gum and Xanthan gum were employed as polymers. Verapamil Hydrochloride dose was fixed as 120 mg. Total weight of the tablet was considered as 400 mg. Polymers were used in the concentration of 60, 120 and 180 mg concentration. All the formulations were passed various physicochemical evaluation parameters and they were found to be within limits. Whereas from the dissolution studies it was evident that the formulation (F6) showed better and desired drug release pattern i.e., 96.10 % in  12 hours containing Guar gum polymer in the concentration of 180mg . It followed zero order release kinetics. For the optimized formulation alcohol effect has been studied by using various concentrations of alcohol in dissolution medium. As the concentration of alcohol increases the sustained action of polymer was decreased. Hence it was concluded that alcohol has significant effect on drug release pattern.

The aim of the present study is to prepare Tinidazole microspheres by using different polymers. Microspheres were prepared by solvent evaporation method by using various polymers. Formulation is optimized on the basis of acceptable microspheres properties and in-vitro release. In order to obtain best optimized product, 6 different formulations were developed. Different polymers like Eudragit S100, HPMC 6000 and HPC 1000 were taken as variables. Particle size analysis, Shape and Surface Morphology, Flow properties, Degree of swelling, Drug entrapment efficacy, Invitro drug release study were studied as response variables. The different physical properties showed best comparable results with drug. But higher percentage of drug release was observed when the formulation contained Eudragit S 1000 in 1:1 ratio(f3) compared to other formulations. The formulation contained Eudragit was selected as optimized product.

The objective of present study was to prepare and evaluate Zaltoprofen (ZLT) enteric coated oral mucoadhesive sustained release (SR) tablet in order to improve its GI residence time and improve its bioavailability by using natural biopolymers like xanthan gum and semisynthetic polymer HPMC for its safe use in rheumatoid arthritis, osteoarthritis, ankylosing spondylitis condition. The sustained release polymers, hydroxypropyl methylcellulose (HPMC) of different viscosities and xanthan gum evaluated in different proportions as a major matrix material. Drug-polymer compatibility studies by FTIR and DSC gave confirmation about their purity and showed no interaction physically between drug and selected polymers. ZLT matrix tablets were prepared by wet granulation.  The effect of polymer concentration on the drug release profile and in-vitro bioadhesion of the matrix tablets was studied. A 32 full factorial design was utilized in the optimizing the levels of HPMC and Xanthan gum. Concentration of HPMC K4M and the concentration of xanthan gum per tablet were used as the independent variables.  The dependent variables were the bioadhesive strength, percent drug dissolved at 2, 6 and 10 hours. The data obtained were fit to a model and polynomial equations were generated. Response surface graph was generated based on these equations. Formulation composition with desired release characteristics and bioadhesive strength were found to be predictive using this model. The optimized factorial batch was further given the coating of Opadry® enteric (94 series) polymer in order to avoid GI disturbances. The Z-22 tablets were kept for stability study at 40°C ±2°C and 75% ± 5% RH for a period of 6 months according to ICH guidelines. The formulation was found to be stable after 6 months of study. The pharmacokinetic parameters Cmax, Tmax, Mean Residence Time (MRT) and Area under Curve (AUC) of developed SR tablet were found to be improved with significant difference (p