Delapril/Manidipine

Dissolution method for delapril and manidipine combination tablets based on an absorption profile of manidipine

The present study describes the development and validation of a dissolution method for delapril (DEL) and manidipine (MAN) combination tablets, using a simulated absorption profile based on in vivo data for MAN. The suitable in vitro dissolution profile for this formulation was obtained using 900 mL of citrate buffer pH 3.2 at 37 °C±0.5 °C as dissolution medium and USP apparatus 2 (paddle) at 75 rpm. All samples were analyzed by a liquid chromatography (LC) method. Under these conditions, a significant linear relationship between the absorbed (calculated by deconvolution approach) and dissolved fractions of MAN was obtained (R=0.997) and an in vivo-in vitro (IVIV) correlation for this particular formulation containing MAN can be established. Validation parameters for dissolution methodology such as the specificity, linearity, accuracy and precision were also evaluated according to the international guidelines, giving results within the acceptable range. Therefore, the proposed dissolution conditions can be applied for the simultaneous release analysis of DEL and MAN from the solid dosage form, contributing to the improvement of the quality control of pharmaceutics and minimizing the number of bioavailability studies.

Combination delapril/manidipine as antihypertensive therapy in high-risk patients

The majority of patients with hypertension, and in particular high-risk patients or those with diabetes mellitus or renal dysfunction, are likely to require combination therapy with at least two antihypertensive agents (from different classes) to achieve their blood pressure (BP) target. The delapril/manidipine fixed-dose combination consists of two antihypertensive agents with different, yet complementary, mechanisms of action. Delapril/manidipine has demonstrated short- and long-term antihypertensive efficacy in a number of clinical studies in patients with hypertension with an inadequate response to monotherapy. Comparative studies have demonstrated that delapril/manidipine is as effective as enalapril/hydrochlorothiazide (HCTZ) in patients with hypertension with an inadequate response to monotherapy, and as effective as irbesartan/HCTZ, losartan/HCTZ, olmesartan medoxomil/HCTZ, ramipril/HCTZ and valsartan/HCTZ in reducing BP in patients with hypertension and diabetes, or in obese patients with hypertension. Therapy with delapril/manidipine also appears to exert beneficial effects that extend beyond a reduction in BP, including nephroprotective activity and an improvement in fibrinolytic balance, supporting its value as a treatment option in these patient populations at high or very high cardiovascular risk because of the presence of organ damage, diabetes or renal disease.

Delapril and manidipine measurements by liquid chromatography-tandem mass spectrometry in a pharmaceutical formulation

A simple, specific, fast and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous analysis of delapril (DEL) and manidipine (MAN) from their combination formulation was developed and validated using fesoterodine as the internal standard (IS). The LC-MS/MS method was carried out on a Luna C8 column (50 × 3.0 mm i.d., 3 µm) with a mobile phase consisting of methanol and 10 mmol L(-1) ammonium acetate (90 : 0, v/v), run at a flow rate of 0.25 mL min(-1). The mass spectrometry method was performed employing positive electrospray ionization operating in multiple reaction monitoring mode, monitoring the transitions of m/z 453.1 → 234.1 for DEL, m/z 611.1 → 167.0 for MAN and m/z 412.2 → 223.0 for IS. The total analysis time was 3 min and the method was linear in the concentration range of 6-1080 ng mL(-1) and 2-360 ng mL(-1) for DEL and MAN, respectively. Parameters investigated for the method validation, such as the specificity, linearity, precision, accuracy and robustness, gave results within the acceptable range. Moreover, the proposed method was successfully applied for the simultaneous determination of DEL and MAN and the results were compared to validated liquid chromatography and capillary electrophoresis methods showing non-significant differences (P = 0.9).

Fixed-dose manidipine/delapril versus losartan/hydrochlorothiazide in hypertensive patients with type 2 diabetes and microalbuminuria

INTRODUCTION

Patients with diabetes complicated by hypertension and microalbuminuria have elevated cardiovascular risk, and controlling blood pressure in these patients is an urgent clinical priority. The present study aimed to examine the effects of a fixed-dose combination of antihypertensives on blood pressure and microalbuminuria.

METHODS

Patients with type 2 diabetes, mild-to-moderate hypertension (diastolic blood pressure 85-105 mmHg, systolic blood pressure <160 mmHg, and 24-hour mean systolic blood pressure >130 mmHg), and microalbuminuria were randomized to 1 year of doubleblind treatment with fixed-dose manidipine/delapril (n=54) or losartan/hydrochlorothiazide (HCTZ) (n=56).

RESULTS

Blood pressure was significantly reduced at 1 year in both groups (-22.2/-14.6 mmHg and -19.5/-14.3 mmHg, for systolic and diastolic blood pressure respectively, P<0.001 for each), with no significant between-group difference. Reductions in microalbuminuria occurred in both groups, with mean changes at 1 year of -3.9 mg/mmol creatinine (95% CI -5.3, -2.5) for manidipine/delapril (P<0.001 vs. baseline) and -2.7 mg/mmol creatinine (95% CI -4.0, -1.3) for losartan/HCTZ (P<0.001 vs. baseline and P=0.199 between groups). Glycemia over the 1-year study was largely unaffected; the blood glucose concentration was reduced from baseline with manidipine/delapril, although not statistically significant (mean change -0.2 mmol/L, P=0.064). Both treatments were well tolerated, with discontinuation for adverse events for one (1.9%) patient in the manidipine/delapril group and two (3.6%) in the losartan/HCTZ group.

CONCLUSIONS

A fixed-dose manidipine/delapril combination represents a useful addition to the treatment options available to control hypertension complicated by diabetes and microalbuminuria.