Parenteral administration of pharmaceutical products is one of the most popular methods used to produce quick onset of action and also 100% bioavailability. Main problem occurs with the parenteral drug delivery is lack of convenience, affordability, accuracy, sterility, safety etc. Such drawbacks with this delivery system makes it less preferable. Hence, all the disadvantages of these systems can be easily overcome by use of prefilled syringes. The objective of this review article is to provide information regarding prefilled syringes; it's method of preparation, direction to use, advantages, its future scope, and development.

Introduction: A pulsatile drug delivery system is characterized by a lag time that is an interval of no drug release followed by rapid drug release. The purpose of this work was to develop hollow calcium alginate beads for floating pulsatile release of valsartan intended for chronopharmacotherapy. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. Materials and Methods: To overcome the limitations of various approaches for imparting buoyancy, hollow/porous beads were prepared by simple process of acid-base reaction during ionotropic crosslinking by low viscosity sodium alginate and calcium chloride as a crosslinking agent. In this study, investigation of the functionality of the sodium alginate to predict lag time and drug release was statistically analyzed using the response surface methodology (RSM). RSM was employed for designing of the experiment, generation of mathematical models and optimization study. The chosen independent variables, i.e. sodium alginate and potassium bicarbonate were optimized with a 3 ² full factorial design. Floating time and cumulative percentage drug release in 6 h were selected as responses. Results: Results revealed that both the independent variables are significant factors affecting drug release profile. A second-order polynomial equation fitted to the data was used to predict the responses in the optimal region. The optimized formulation prepared according to computer-determined levels provided a release profile, which was close to the predicted values. The floating beads obtained were porous (21-28% porosity), hollow with bulk density <1 and had Ft ₇₀ of 2-11 h. The floating beads provided expected two-phase release pattern with initial lag time during floating in acidic medium followed by rapid pulse release in phosphate buffer. Conclusion: The proposed mathematical model is found to be robust and accurate for optimization of time-lagged formulations for programmable pulsatile release of valsartan.

Introduction: The purpose of the present study was to screen excipients such as amino acids and non-aqueous solvents for their stabilizing effect on catalase, a model protein, for lyophilization. The present study also includes optimization of lyophilization cycle for catalase formulations, which is essential from the commercial point of view, since lyophilization is an extremely costly process. Materials and Methods: Activity of catalase was determined using catalase activity assay. Differential scanning calorimetry was used to determine eutectic melting temperature of the frozen catalase solution, which is essential for the optimization of lyophilization cycle. Results: When catalase was lyophilized without excipients, it was found that about 65-78% of the initial activity of catalase was lost during the lyophilization process in a concentration dependent manner. The maximum stability of catalase during lyophilization was observed at pH 7.0. Amino acids like alanine, glycine, lysine, serine and 4-hydroxy proline showed strong stabilizing effect on catalase during lyophilization by protecting catalase activity above 95%, whereas valine and cysteine hydrochloride showed destabilizing effect on catalase. Non-aqueous solvents such as dimethyl formamide, dimethyl sulphoxide, polyethylene glycol (PEG) 200, PEG 400, PEG 600 and ethylene glycol also showed destabilizing effect on catalase during lyophilization. Conclusions: In order to prevent loss of catalase activity during lyophilization of catalase, use of amino acids like alanine, glycine, lysine, serine and 4-hydroxy proline in optimum concentration is highly advisable.

Background and Aim: Momordica charantia Linn. is traditionally used as a medicine for diabetes. The present investigation was aimed to formulate and evaluate transdermal patchesof Momordica charantia Linn. Materials and Methods: The transdermal films containing the herbal drug component fractionated fromethanolicextract of M. charantia fruits were prepared by using hydroxy propyl methyl cellulose as a polymer.The films were evaluated for folding endurance, thickness, weight variation, drug contents and in vitro diffusion studies and in vivo parameterslike acute and sub-acute antihyperglycemic activity in diabetic rats, biochemicalstudies, skin irritation in rats and stability studies. Result and discussion: The weightof transdermal patches of M. charantia (2 cm ² ; 10 mg/patch) and was found to be 0.03 gm.Thickness of patches of M. charantia (2 cm ² ; 10 mg/patch) was found to be satisfactory. The percentage release of active constituents from transdermal patches of M.charantia (2 cm ² ; 10 mg/patch) was found to be 47.59% in 10% hydroalcoholic phosphate buffer pH 7.4 at the end of 6 h.The transdermal route exhibited negligible skin irritation and in vivo results revealed that the patches successfully decrease the blood glucose level. Conclusion: From the results, we concluded that the well-known herbal drug M. charantia Linn. have been found to be effective for diabetes through modern pharmaceutical formulation techniques.

Background: Hypertension shows circadian rhythm that there is a rise in pressure from the time of waking or before (about 4 to 8 a.m.), in most people. Conventional drug delivery system of captopril is inappropriate for the delivery of drug, as they cannot be administered just before the symptoms are worsened, because during this time the patients are asleep, bedtime dosing of captopril will not provide a therapeutic plasma drug concentration at the early hours of morning because of poor pharmacokinetic profile and shorter half-life of 1.9 hours. Thus, this study attempts to design and evaluate a chronomodulated pulsatile drug delivery system of captopril which was aimed to release the drug after a lag time of 6 hours. Materials and Methods: Present delivery system was prepared by rupturable coating method. The core containing captopril as a bioactive compound were prepared by direct compression method and then coated sequentially with an inner swelling layer containing hydrocolloid HPMC E5 and an outer rupturable layer consisted of Eudragit RL/RS (1 : 1). Total 12 formulations with different levels of inner swelling layer and outer polymeric layer were prepared and subjected to various processing and formulative parameters like the effect of core composition, level of swelling layer, and rupturable coating on lag time was investigated. In vitro drug release and rupture tests were performed using United States Pharmacopoeia paddle method at 50 rpm in 0.1N HCl and phosphate buffer of pH 6.8. Results: The results showed that as the amount of inner swelling layer increases, the lag time decreases and as the Eudragit coating level increases, the lag time increases and percent water uptake of time-dependent pulsatile release system decreases. The presence of an osmotic agent and effervescent agent helped in shortening of lag time. Conclusion: The system was found to be satisfactory in terms of release of the drug after the lag time of 6 hours.

The effect of DC iontophoresis using low (0.2 mA/cm ² ) and high current density (0.5 mA/cm ² ) on transdermal permeation of methotrexate loaded into polyacrylamide hydrogel patch was investigated. Flux of 20.57±1.02 μg/cm ² /h and 36.8±2.21 μg/cm ² /h was achieved with low and high current density DC iontophoresis, respectively. Attenuated total reflectance-Fourier Transform infrared (ATR-FTIR) spectra and microscopic studies of the treated skin samples supported the permeation results. A greater decrease in the peak height of asymmetric, symmetric C-H stretching vibration and ester peak was noticed with 0.5 mA/cm ² current density as compared to 0.2 mA/cm ² current density samples. Furthermore, an increase in the ratio of amide I and amide II bands from 2.6 to 11 with increase in current density was noticed, thus indicating that hydration levels are associated with iontophoresis and play an important role in increasing the drug permeation. Scanning electron microscopy revealed increase in pore size of the hair follicles. Light microscopy studies of the skin samples treated with low current density DC iontophoresis demonstrated epidermal thinning and focal disruptions, spongiosis and appendageal dilatations. With higher current density, disruption of epidermis in almost half of the sectioned area, loss of appendages and fractured collagen in the dermis was noticed. Moreover, the reversibility studies conducted in vivo on mice revealed that the recovery process had started within 24 h and is complete in 48 h for lower current density treated animals. However, the histological changes associated with 0.5 mA/cm ² current density were not reversible in 48 h and edema, appendageal dilatations along with focal disruption of epidermis persisted. Hence our study suggests that high density current is not well-tolerated by the skin.

Aim and Background: Domperidone is a dopamine antagonist with antiemetic properties having a plasma half life of 7-9 h with 15% oral bioavailability. In the present work transdermal patches of domperidone were prepared with the objective to improve its therapeutic efficacy, patient compliance and to reduce the frequency of dosing and side effects, as well as to avoid its extensive first pass metabolism of the drug. Materials and Methods: The patches were prepared using ethyl cellulose (EC): Poly vinyl pyrrolidone (PVP), poly vinyl alcohol (PVA): Poly vinyl pyrrolidone (PVP) and hydroxypropylmethylcellulose (HPMC): Sodium (carboxy methyl cellulose) CMC as polymers in combination. The physicochemical parameters like thickness, drug content, weight variation, moisture absorption and drug permeation studies were evaluated for the prepared patches. No significant difference in thickness, average weight and in the drug content among the patches. Results: It was observed that from hydrophilic polymers the drug release was found to be faster compared to (F5 and F6 & F3 and F4) combination of hydrophilic and lipophilic polymers used in the study. Patches containing HPMC and Sodium CMC (F5 and F6) showed faster release as the patches showed maximum percentage amount moisture absorption. The in vitro release data was treated with kinetic equations and it followed Higuchi's diffusion mechanism. The in vivo bioavailability study was performed in rats and observed that, drug reached to the peak in approximately 60 min (16%) after oral route of administration. However, approximately same amount of drug was found in the serum from transdermal formulation in 6 h and further increase in the amount of drug in the serum, indicated that the drug 5 bioavailability could be better and hence the hepatic metabolism can be avoided, as it is evident from the data. Further, the decrease in the amount of drug present in the serum 45 min after oral administration also indicated that major amount of drug might have got metabolized and the bioavailability is reduced. However, the transdermal patch released further amount of drug (33%) at the end of 24 h. Conclusion: The present study can be concluded that transdermal patch can extend the release of drug for many hours with better bioavailability and also can avoid the first pass effect.

Introduction: Present investigation describes an influence of ratio of Gelucire 43/01(hydrophobic) to hydroxypropyl methylcellulose K4M (HPMC K4M) (hydrophilic) and different fillers on release of famotidine from gastro-retentive tablets using 3 ² full factorial design. Ratio of Gelucire 43/01 to HPMC K4M (X ₁ ) and the type of filler (X ₂ ) were selected as independent variables while buoyancy lag time (BLT), drug release at 1h (Q ₁ ), 6h (Q ₆ ), and the 12h (Q ₁₂ ) were selected as dependent variables. Materials and Methods: Gastro-retentive tablets of famotidine were prepared by a solvent free melt granulation technique using Gelucire 43/01 as a hydrophobic meltable binder. HPMC K4M and sodium bicarbonate were used as matrixing agent and gas-generating agent, respectively. Prepared tablets were evaluated for in vitro dissolution, in vitro buoyancy, friability, hardness, drug content and weight variation. Dissolution data were fitted to various models to ascertain kinetics of drug release. The data were analyzed using regression analysis and analysis of variance. Results: All formulations (F ₁ -F ₉ ) showed floating within 3min and had total floating time of more than 12h. It was observed that a type of filler and the ratio of Gelucire 43/01 to HPMC K4M had significant influence on buoyancy lag time (P = 0.037) and Q ₆ (P = 0.011), respectively without significant influence on Q ₁ and Q _12. Conclusion: Formulation F ₅ was selected as an optimum formulation as it showed more similarity in dissolution profile with theoretical profile (Similarity factor, f ₂ = 83.01). The dissolution of batch F ₅ can be described by zero order kinetics (r ² = 0.9914) with anomalous (non-Fickian) diffusion as a release mechanism (n = 0.559). The difference observed in in vitro release profile after temperature sensitivity study at 40°C for 1 month was insignificant.